Abstracts with Programs - Geological Society of America
Transcription
Abstracts with Programs - Geological Society of America
2010 Abstracts with Programs • Rocky Mountain Section Meeting 2010 Abstracts with Programs • Volume 42, Number 3 Rocky Mountain Section Meeting April 2010 62nd Annual Meeting of the Rocky Mountain Section, GSA Rushmore Plaza Civic Center Rapid City, South Dakota, USA 21–23 April 2010 www.geosociety.org/sectdiv/rockymtn/2010mtg/ • ISSN 0016-7592 Table of Contents Abstracts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1, 39 Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22, 23 Schedule of Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Program of Technical Sessions Wednesday, 21 April . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Thursday, 22 April . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Friday, 23 April . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Index of Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 NOTICE In the interest of public information, The Geological Society of America provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. The opinions (views) expressed in this publication and/or by speakers and exhibitors at these sessions are their own and do not reflect official positions of The Geological Society of America. GSA Abstracts with Programs, Vol. 42, No. 3; ISSN 0016-7592—Coden: GAAPBC is published by the Geological Society of America, Inc., with offices at 3300 Penrose Place, Boulder, Colorado 80301 USA. Five issues published in 2010: February (1), March (2), May (1), and October. Copyright © 2010, the Geological Society of America, Inc. (GSA). All rights reserved. Copyright not claimed on content prepared wholly by U.S. Government employees within the scope of their employment. 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Abstracts Volume 42, No. 3 Abstracts to be presented at the meeting of the Rocky Mountain Section of the Geological Society of America and associated societies. Rapid City, South Dakota 21–23 April 2010 Note indexing system Numbers (2-4, 15-4) indicate session and order of presentation within that session. Further information concerning the presented papers on which these abstracts are based should be obtained by contacting the authors of the abstracts. vector in a set of imbricated, SW-directed thrusts. The veins occur in both the margin of the stock and in strata of the contact aureole on the NE limb of the Deep Creek anticline, and sub-parallel axial-plane cleavage. The intrusion accentuated the anticline and the magma was confined to the adjacent syncline, which was thermally softened and thinned under the load of the stock. Mineral assemblages in the veins and in the altered wallrocks indicate that the host rocks had cooled to about 300 C when the hydrothermal ore fluids were injected and deposited the gold. Evidently, late-stage hydrothermal fluids had accumulated in the interior of the Garnet stock, and, upon reaching a critical fluid pressure, had hydro-fractured the crystallized margin of the stock and the contact aureole, and then filled the fractures with gold-bearing quartz veins. The veins therefore comprise parts of the kinematic assemblage of the Lewis and Clark line shear zone, a conclusion that should enhance exploration and development of gold deposits in the district. SESSION NO. 1, 10:20 AM Wednesday, 21 April 2010 Economic Geology Rushmore Plaza Civic Center, Rushmore G 1-1 10:20 AM Felsman, Jason M. [171704] GEOLOGY, HYDROTHERMAL ALTERATION, AND GOLD MINERALIZATION IN THE VICINITY OF TAYLOR RIDGE AND CARBON HILL, BEAR LODGE MOUNTAINS, CROOK COUNTY, WYOMING FELSMAN, Jason M., Geological Sciences, University of Idaho, 7407 Hwy 79 S, Pine Bluff, AR 71603, jason.felsman@vandals.uidaho.edu Gold mineralization and associated hydrothermal alteration in the Bear Lodge Mountains, Crook County, Wyoming, have not been examined previously in detail. The Bear Lodge Mountains are a domal uplift, which is the northernmost extension of the Black Hills of South Dakota and Wyoming. The dome is cored by Eocene alkaline igneous rocks and carbonatite dikes, containing Precambrian granite xenoliths and surrounded by Phanerozoic sedimentary rocks. The Bear Lodge Dome is host to fluorite, gold-tellurium, rare-earth, thorium, and copper mineralization. Field mapping and detailed petrographic study utilizing the cathodoluminescence technique, scanning electron microscopy, electron microprobe analysis, laser ablation mass spectrometry, X-ray diffraction, radiometric and magnetic surveys, and geochemical analysis of the area around Taylor Ridge and Carbon Hill reveal gold-tellurium mineralization, which is related to structurally controlled, incipient and massive potassic fenitization. Potassic fenitization is manifest as potassium-feldspar + pyrite ± biotite alteration. Hydrothermal potassium-feldspar with Fe3+-activated red cathodoluminescence precipitated in veins and replaced Ti4+-activated blue-luminescent potassium-feldspar and Mn2+-activated green-luminescent plagioclase feldspar; and F and Sm to Lu-enriched apatite replaced and overgrew LREE-enriched igneous apatite. Lithologic contacts, breccia pipes, and faults are preferentially Au-Te-mineralized due to increased permeability that channels hydrothermal fluid flow. The study area is enriched in rare-earth elements and base metals, representing a transition from low-temperature mineralization typical of the Bear Lodge Dome and alkaline epithermal gold deposits in general, to relatively high-temperature epithermal mineralization, indicating that there may be porphyry-style mineralization at depth. Some gold deposited during episodes of potassic fenitization was remobilized during subsequent clay alteration, oxidation, and silicification. 1-2 10:40 AM Sears, James 11:00 AM Harp, Michael T. [171885] DEVELOPING A USEFUL SET OF PROXY ELEMENTS FOR TARGETING GOLD DEPOSITS IN THE BLACK HILLS, SOUTH DAKOTA HARP, Michael T., Geology and Environmental Science, University of Akron, Akron, OH 44325-4101, mth3@zips.uakron.edu and FRIBERG, LaVerne M., Geology and Environmental Science, The University of Akron, Department of Geology and Environmental Science, The University of Akron, Akron, OH 44325-4101 X-Ray Fluorescence (XRF), petrography, and Energy-Dispersive X-ray Spectrometry (EDAX) have been used to determine the element concentration in samples and the distribution within minerals for 222 metamorphic rocks from the Black Hills, S.D. The spatial distribution of proxy element concentrations in the whole rock are compared to sample location and known gold deposit in the Black Hills. XRF data of 222 rock chips from whole rock samples was collected using a portable XRF unit to determine major, minor and trace element abundances. Statistical analyses of the XRF data indicates a moderate to strong correlation between gold and the elements (proxy) Mn (19 to 16116 ppm), S (1283 to 79452 ppm), As (n.d. to 132ppm), Pb (n.d. to 318 ppm), Cl (625 to 31277ppm), Ba (n.d. to 1101 ppm) in. Samples containing visible gold have higher concentrations of the proxy elements. The integration of this data with Arc GIS is being used to test for the spatial relationship of the chosen proxy elements to known gold deposits in the Precambrian core of the Black Hills. Samples (22) were chosen for detailed petrographic analyses based on higher (greater than 18 ppm) gold concentrations previously determined through XRF analysis. EDAX raster scans are being completed on these samples in order to determine concentration variations of the chosen proxy elements within the individual mineral grains. Preliminary analyses indicates that sample proximity to known gold deposits in the Black Hills can be correlate with increases in minor and trace proxy element concentrations in the mineral phases. High concentrations of the proxy elements Mn (200 to 1500 ppm), S (3400 to 14800 ppm), As (15 to 132 ppm), Ba (180 to 780 ppm), Pb ( 14 to 170 ppm), Cl (4800 to 29200) at rims and along fractures in the silicate and sulfide minerals are believed to be related to the associated gold bearing fluids which passed through the rocks. [171751] GOLD-BEARING VEINS IN THE GARNET MINING DISTRICT, GRANITE COUNTY, MONTANA: SYN-TECTONIC MINERALIZATION ALONG THE LEWIS AND CLARK LINE SHEAR ZONE SEARS, James, Dept. of Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812-1296, james.sears@umontana.edu Five known gold-bearing vein systems in the Garnet mining district of the central-western Montana Rockies follow the fringe of the Late Cretaceous Garnet stock, a satellite pluton of the Boulder batholith. The syn-tectonic Garnet stock intruded the Lewis and Clark line transpressional shear zone at a depth of 6 km. The stock provided gold-bearing hydrothermal fluids, and the Lewis and Clark line provided structural control for emplacement of the stock and deposition of hydrothermal veins. The stock has a cross-section rather like a cocktail glass; a narrow feeder dike in Proterozoic rocks flares upward and outward in the Lower Paleozoic section. A composite down-plunge projection indicates that the veins filled dilational steps perpendicular to the slip 1-3 1-4 11:20 AM Lufkin, John L. [171783] ORIGIN OF ORE TEXTURES: PORPHYRY COPPER DEPOSITS LUFKIN, John L., 995 Moss Street, Golden, CO 80401, lufk3@comcast.net and CANTORIN, Maritza, University of San Marcos, Lima, Peru By last count, there are more than 100 porphyry copper deposits in North America, but there is scant information on textures of ore minerals in this type of deposit, or in the other types of porphyry deposits as well. In this study, 76 polished thin sections were examined in reflected light from 8 porphyry copper deposits in Montana, Utah, Arizona, and New Mexico. In the giant Bingham Canyon deposit, Utah, primary copper sulfides of chalcopyrite and bornite responsible for the copper ore grade of 0.75%, are disseminated throughout the host quartz monzonite. In the primary ore, these textures are dominated by lattice intergrowths of chalcopyrite-bornite in the upper part of the deposit. They are also modified by small patches of chalcocite and covel- 2010 GSA Rocky Mountain Section Meeting 1 SESSION NO. 1 lite, and many are mantled by rims of chalcopyrite. In the deep parts of the deposit that are currently being mined, lattice intergrowths of bornite-chalcocite are most common. Intergrowths such as these have long been interpreted as the result of exsolution processes, and were first studied by George Schwartz in the 1930s. A much less common intergrowth texture in porphyry deposits, known as “chalcopyrite disease” (Barton, 1970; Eldridge, Barton, and Ohmoto, 1983; Craig and Vaughan, 1981) is also observed in some skarns and at the Continental mine in the Butte deposit, Montana. It is still uncertain whether the disseminated chalcopyrite in sphalerite is due to processes of replacement, exsolution, or penecontemporaneous growth. In the Arizona porphyry deposits, including those at Morenci, Ray, and Copper Cites, samples were collected mostly from the oxide and supergene enrichment zones. Ore textures in these samples are also classified as intergrowths, but consist mostly of replacements of pyrite and less commonly of chalcopyrite. In the replacement process, the secondary covellite and chalcocite commonly form rim replacements of the pyrite, which penetrate the grains along permeable fractures, or the cleavage planes of chalcopyrite (eg., Morenci). The same is true for the porphyry deposit at Santa Rita, New Mexico, where well developed veins of pure supergene chalcocite, as much as 0.6 cm wide, are observed. 1-5 11:40 AM Samimi, Hadi [171694] INVESTIGATING AND MODELING FLUID AND RESERVOIR ROCK HETEROGENEITIES OF AN OIL SANDS RESERVOIR, A CASE STUDY FROM WESTERN CANADIAN SEDIMENTARY BASIN SAMIMI, Hadi1, PATRUYO, David1, LARTER, Stephen R.1, SPENCER, Ronald J.1, GATES, Ian2, HUBBARD, Stephen M.1, and MARCANO, Norka1, (1) Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada, HSamimi@ucalgary.ca, (2) Chemical and Petroleum (Schulich School of Engineering), University of Calgary, 2500, University Dr., NW, Calgary, AB T2N 1N4, Canada Oil Sands of Northern Alberta is the largest unconventional resources in North America, but it is usually highly heterogeneous reservoir, making it very challenging to produce from. The McMurry formation of lower Cretaceous age in Western Canadian Sedimentary Basin is characterized by highly heterogeneous strata that have been attributed to fluvial, estuarine and/or deltaic depositional settings. It is mainly composed of siliciclastics; interbedded Sandstone, Siltstone units, breccia at channel lag and shale-mud lamination/layering to form Inclined Heterolithic Stratification. Understanding the reservoir heterogeneities (from both rock and fluid point of view) is paramount for a successful development and production strategy. We have tried to take a multi-disciplinary geology and engineering approach in order to integrate seismic, well log, core and organic geochemistry data to be able to create realistic, geologically sound, high resolution 3D reservoir model reflecting depositional, sedimentological and geochemical interpretations for the middle McMurry formation of Long Lake project located in Canada’s Athabasca oil sands deposits. Such a model improves reservoir simulation results and helps to develop better production designs with higher recovery factors form the oil sands. A point bar model that evolved through lateral channel migration is created from seismic time slices to build reservoir architecture. Facies model is obtained by use of core log data and sedimentary structures (physical and biogenic) present. A fluid model to address bitumen heterogeneity and define compartmentalization of reservoir elements is created through molecular geochemistry analysis of core extracted bitumen and viscosity measurements. It helps to understand reservoir continuity and is important to the efficient placement of injector and producer well pairs during thermal process production design. Permeably and porosity values calculated and populated from grain size distribution, core and log data. Geo-model is created in Petrel software, up-scaled and imported for thermal simulation of a SAGD process in CMG simulator. Different well geo-tailoring patterns were simulated to determine optimized production configuration with the fluid and reservoir rock heterogeneities considered into the model. SESSION NO. 2, 8:00 AM Wednesday, 21 April 2010 Paleontology 8:00 AM Hasiotis, Stephen T. [171866] ENIGMATIC, LARGE- AND MEGA-DIAMETER BURROWS IN THE LOWER PERMIAN CEDAR MESA SANDSTONE, COMB RIDGE AND MOQUI DUGWAY, SOUTHEASTERN UTAH HASIOTIS, Stephen T., Department of Geology, University of Kansas, 1475 Jayhawk Blvd, 120 Lindley Hall, Lawrence, KS 66045, hasiotis@ku.edu and RASMUSSEN, Donald L., Plateau Exploration Inc, 1450 Kay Street, Longmont, CO 80501 Preliminary fieldwork in the lower part of the Cedar Mesa Sandstone has found enigmatic largeand mega-diameter, subhorizontal burrows in the southern part of Comb Ridge and the Valley of the Gods. Large-diameter burrows in the southern part of Comb Ridge occur in interbedded sandstone, siltstone, mudstone, and gypsum beds, but prominently found in pedogenically modified clastic interbeds. Overall, the architectural morphology of the burrows is simple. Burrows are subhorizontal and at ~10–15 degrees from horizontal. The longest exposed burrow is nearly 50 cm. Burrow shape is elliptical and ~5–15 cm in diameter and ~2.5–5 cm in height, with the majority larger in diameter, rather than smaller. The surficial morphology preserved on the burrow walls is mostly smooth, however, the best-preserved burrows contain nearly 1-cm-diameter knobby surfaces, and scratch marks that are longitudinal to the burrow wall, as well curvilinear as C-shaped scalloped marks. Mega-diameter burrows discovered to date in outcrops above the Valley of the Gods vary from simple to moderately complex in architectural morphology, as simple branched networks rather than three-dimensional boxwork. The longest exposed burrow is nearly 150 cm. Burrows are strongly subhorizontal and at ~5–10 degrees from horizontal, with a short, J-shaped entrance. Burrow shape is strongly elliptical. Burrow diameter ranges from ~25–50 cm in diameter and ~5–10 cm in height; these dimensions likely indicate that the original diameter was also strongly elliptical. The surficial morphology preserved on the burrow walls varies from smooth to finely knobby and hummocky surfaces. Both sizes of burrows are interpreted to have been constructed by vertebrates of different sizes and likely from different families or orders. Squamate reptiles likely constructed the large-diameter burrows, whereas the mega-diameter burrows where likely excavated by very large reptiles or possibly by large labyrinthodont amphibians. 2 2010 GSA Abstracts with Programs 8:20 AM Pagnac, Darrin [171742] THE EARLIEST PROBOSCIDEAN IN SOUTH DAKOTA FROM THE MIDDLE MIOCENE (BARSTOVIAN) FORT RANDALL FORMATION PAGNAC, Darrin, Museum of Geology, South Dakota School of Mines and Technology, 501 E Saint Joseph Street, Rapid City, SD 57701, darrin.pagnac@sdsmt.edu The “Proboscidean Datum” (the earliest appearance of the group) for the Great Plains has been calibrated between 14.2-14.0 Ma. Proboscideans (gomphotheres, mastodons, and elephants) are common constituents of Great Plains paleofaunas by the late Barstovian NALMA (15.012.5 Ma). Late Barstovian proboscidean remains are most commonly found in the Valentine Formation of Nebraska, but have also been reported from the Madison Valley beds of Montana, Barstovian paleofaunas from central Wyoming, and most notably from correlative assemblages from the Pawnee Creek Formation in northeastern Colorado. Previously, the earliest occurrences of Proboscidea from South Dakota were from the Wolf Creek and Mission assemblages of early Clarendonian age. The earliest record of proboscideans in South Dakota is now recorded from the Fort Randall Formation. The Fort Randall Formation consists of several hundred feet of fluvial channel sands and overbank silts and clays intermittently exposed in southern South Dakota and into Nebraska. The Fort Randall Formation unconformably overlies the Cretaceous marine shales of the Pierre Group, and is overlain by the Valentine Formation. The highly resistant Bijou Quartzite commonly caps exposures of Fort Randall Formation serving as a useful marker bed. The Fort Randall Formation contains a diverse and well-documented late Barstovian fossil mammal assemblage, including extensive records of insectivores and rodents. SDSM 78602, a large fragment of tooth enamel from a gomphotheriid proboscidean molar, was recovered from McConnell/Trenholm Site (V2006-1), approximately 1.5 miles from the Fort Randall Fm. type section. The fragment represents a portion of the characteristic “trefoil” molar cusp (diagnostic of the family) and lateral portion of the tooth crown. While the specimen is not of exceptional quality, its recovery from the Fort Randall Formation extends the record of Proboscidea in South Dakota to the latest Barstovian. 2-3 8:40 AM Martin, James E. [171663] A NEW PALEONTOLOGICAL REPOSITORY AT THE MUSEUM OF GEOLOGY, SOUTH DAKOTA SCHOOL OF MINES AND TECHNOLOGY MARTIN, James E., Museum of Geology, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, James.Martin@sdsmt.edu Since 1899, the Museum of Geology at the SD School of Mines and Technology has engaged in the collection, preservation, conservation, and study of fossil and mineral resources. The current repository has operated from the Old Gymnasium and houses approximately 300,000 vertebrate fossil specimens and their associated contextual archived information; approximately 500,000 specimens of all varieties are preserved in the repository. As the result of overcrowding in approximately 9000 ft2, the Museum staff has worked for over 20 years in the pursuit of a facility to adequately house these non-renewable resources, as well as to provide space for education, research, and various laboratory functions. Through funding from the State of South Dakota and various private donors, the eight million dollar facility is finally a reality and will open in May, 2010. The new repository contains 33,000 ft2, including a geological-paleontological library, archival/ curation center, type specimen storage, study rooms, and dedicated storage for vertebrate and invertebrate paleontological specimens, fossil plants, Recent vertebrate skeletons, and minerals from around the world. Supporting laboratories include those for preparation, casting/replication, chemistry, and conservation. Multiple benefits of the new repository revolve around education, research, and public service. Many students and researchers are attracted to the paleontology/ geology program at the School of Mines because of its uniqueness and location in the midst of the great western fossil beds. The repository functions as a library of fossil resources and is an integral portion of the undergraduate and graduate programs in paleontology. The current collections are world renowned, having been meticulously collected with precise geographic and stratigraphic data. Therefore, numerous researchers and students from around the world utilize the collections to understand the history of life on this planet. The new repository provides adequate space and equipment to undertake paleontological and geological studies, space to house and access current specimens and contextual data, and space to conserve and preserve future specimens collected from the Northern Great Plains and elsewhere. 2-4 Rushmore Plaza Civic Center, Rushmore G 2-1 2-2 9:00 AM Mahan, Shannon A. [171707] THE ANGUS MAMMOTH CONTROVERSY: RESOLVED? MAHAN, Shannon A., U.S. Geological Survey, Box 25046 Federal Center, Denver, CO 80225, smahan@usgs.gov, HOLEN, Steven, Curator of Archeology, Denver Museum of Nature and Science, Denver, CO 80205, and MAY, David W., Department of Geography, University of Northern Iowa, 205 Innovative Teaching and Technology Center, Cedar Falls, IA 50614 The discovery of the Angus Mammoth in south-central Nebraska in 1931 was an important event in the history of North America archaeology because Figgins (1931) interpreted this find to be the first well-documented association of a fluted artifact with a mammoth in North America. However, a controversy soon emerged based on a geological interpretation of the deposits that made them much too old for a mammoth-human association to be valid. The major uncertainty is actually related to the problem of estimating the age of the mammoth bones, since they do not contain the necessary collagen for radiocarbon dating. The controversy remained during the eighty years that followed the site discovery, and the Angus Mammoth Site (25NO101) was relegated to a little-known footnote in American archaeology. However, recent luminescence dating results on sediment the bones were buried in clearly indicate that the remains are significantly older than the Holocene, at around 56,200-75,300 years old. We have determined that the matrix above the mammoth is more than 45,000 years too old for the mammoth/fluted point association to be valid. Research over the last thirty years, including archival research, oral interviews, test excavations, geomorphic studies and several attempts to acquire OSL dates on the site has finally resolved the controversy...we think. Our presentation will show the results of stratigraphic correlation and intense archival research, the luminescence ages, and our best guess on how the fluted point ended up next to the mammoth. SESSION NO. 3 2-5 9:20 AM Bunds, Michael P. [171883] USING LICHENOMETRY TO ASSESS LONG TERM GLOF AND LANDSLIDE FREQUENCY IN THE NEPAL HIMALAYA BUNDS, Michael P.1, EMERMAN, Steven H.1, BHATTARAI, Tara N.2, ANDERSON, Ryan B.1, ADHIKARI, Narayan2, KARKI, Kabita2, and PALMER, Mallory A.1, (1) Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, bundsmi@ uvu.edu, (2) Department of Geology, Tri-Chandra Multiple Campus, Tribhuvan University, Ghantaghar, Kathmandu, Nepal Glacial lake outburst floods (GLOFs) and landslides are major hazards in and downstream from glaciated areas in the Nepal Himalaya and many other mountainous areas, and it is possible that global warming will increase GLOF frequency. However, in the Nepal Himalaya, little is known of the frequency of GLOFs prior to 50 years ago, making it difficult to assess the long term hazard they pose. In light of this, the objectives of our study are to develop the first lichen apparent growth curve for the region and use lichenometry to date pre-historic GLOF events as well as major landslides in the area. The first stage of the study was carried out in May 2009 near Kyanjin Gompa in Langtang Valley, Nepal, with the purpose of developing a lichen apparent growth curve for Rhizocarpon geographicum for the area. R. geographicum is commonly used for lichenometry in alpine areas because it is easily identified, long-lived and slow-growing. The lichen apparent growth curve empirically relates lichen diameter to age and allows for dating the time of surface exposure of rocks. To develop the apparent growth curve, diameters of R. geographicum lichen were measured on boulders at two sites that local people recalled having been covered by ice blocks from Khyimjung Glacier until 1959 and 1982. Lichen diameters were also measured on boulders downslope from Kyanjin Gompa on two debris flows that had been previously dated at 1611 ± 135 and 1474 ± 163 using 10Be. The apparent growth curve that best fits the data is y = 51.11(1 – exp(-0.0458x)) + 0.1620x, where y is maximum lichen diameter (mm) and x is time (years). Application of the apparent growth curve to lichen diameters measured on boulders deposited by a landslide that dammed the Langtang River above Kyanjin Gompa dates the landslide to 1683, and lichen diameters on boulders deposited by a large landslide that occurred along the Langtang River above Langtang Village yield an age of 1904, and lichen diameters on the end moraine of Khyimjung Glacier date its most recent advance to 1966. In addition, lichen diameters on ancient mani walls (Buddhist sacred walls) suggest that the walls are cleaned of lichen every 10-20 years on average. Future work will include improving the calibration of our apparent growth curve, broadening the geographic application of the apparent growth curve and dating GLOF deposits. 2-6 9:40 AM Hasiotis, Stephen T. [171851] BIOTA AS A MAJOR SOIL-FORMING FACTOR AND ECOSYSTEM ENGINEERS THROUGH RECENT EARTH HISTORY BASED ON CONTINENTAL TRACE FOSSILS—SOIL BIOTA AS GEOENGINEERS HASIOTIS, Stephen T., Department of Geology, University of Kansas, 1475 Jayhawk Blvd, 120 Lindley Hall, Lawrence, KS 66045, hasiotis@ku.edu and HALFEN, Alan F., Geography, University of Kansas, 1475 Jayhawk Blvd, 213 Lindley Hall, Lawrence, KS 66045 The role of above- and belowground biota as a soil-forming factor, with the exception of plants, has been overlooked and underestimated despite the work of Darwin on worms and vegetable mould, and later studies by Schaller, Thorp, Hole, and Johnson on the work of animals, soilmixing rates, and biomantles. Only recently is bioturbation by animals as a major soil-forming factor being recognized through pedogenic and geologic studies of soils and paleosols, respectively. Also recently recognized is the work of a variety of animals as allogenic or autogenic ecosystem engineers that directly or indirectly modulate the availability of resources to other species via physical state changes in abiotic or biotic materials through their own physical structures (autogenic) and by transforming materials from one state to another (allogenic). Earthworms, termites, ants, crayfish, a variety of soil bugs and beetles, and a variety of small but abundant burrowing mammals are ecosystem engineers as their burrowing activity (1) changes the physical, chemical, and biological properties of sediment; (2) improves drainage, gas exchange, and oxygenation of soils, and (3) increases microbial activity and decomposition rates. The study of continental trace fossils (neoichnology and paleoichnology) and of paleosols has provided abundant evidence and data that demonstrates the significance of bioturbation in the formation of modern soils, but also in paleosols as early as the Devonian. Traces in mid to late Paleozoic paleosols show synchronicity in their formation. An abundance of trace fossils interpreted as nests and burrows of termites, ants, crayfishs, soil bugs, beetles, and tetrapods (mammals and therapsids) are found in a variety of imperfectly drained to well-drained, immature to mature paleosols. Ichnopedologic fabrics in paleosols produced by representatives of these animals demonstrate that their behaviors have changed little since the early to mid Mesozoic. As these organisms and their activity are paramount today in maintaining ecosystem health through the detritivore nutrient cycling system, sediment mixing, and the creation and destruction of soil features, they should be referred to as geoengineers because they have shaped the evolution of terrestrial ecosystems and continental landscapes since the Mesozoic. SESSION NO. 3, 8:00 AM Wednesday, 21 April 2010 T1. Geoscience and Engineering at the Deep Underground Science and Engineering Lab (DUSEL) in Lead, South Dakota Rushmore Plaza Civic Center, Alpine Room 3-1 8:00 AM Rempe, Norbert T. [171536] GEOLOGIC WASTE REPOSITORIES, UNDERGROUND SCIENCE LABORATORIES, AND RADIOACTIVITY: A PARADIGM SHIFT REMPE, Norbert T., 1403 N Country Club Cir, Carlsbad, NM 88220-4115, rempent@yahoo.com Shielding provided by overburden against cosmogenic background attracts highly sensitive experiments to mined underground spaces that are also suitable to permanently isolate radioactive waste. These disparate functions focus attention on natural nuclear processes and radioactivity as geologic factors and agents. Life evolved among the ruins of cosmic fusion reactors; humans thrive in radioactive environments; without the natural fusion reactor closest to Earth, a.k.a. Sol, much of life we know is not possible; and earliest known fission reactors reached critical mass billions of years before Fermi. Natural geologic environments have isolated dangerous -including radioactive- materials for much of Earth’s history. The teaching of facts, data, and real comparative risks at the interfaces between geology and all things nuclear and radioactive must prevail over the more comfortable recourse to regulatory (rarely principally science-based) standards and legal compliance in science curricula. 3-2 8:20 AM Roggenthen, W.M. [171950] DEVELOPMENT OF THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY (DUSEL) ROGGENTHEN, W.M., Dept. of Geology and Geol. Eng, SD School of Mines and Tech, 501 E. St. Joseph Street, Rapid City, SD 57701, wroggen@silver.sdsmt.edu Announcement of the impending closure of the Homestake Gold Mine in Lead, SD, in 2000 led to the consideration of repurposing the site into a scientific laboratory. The mine had been the location of an underground neutrino laboratory for over 35 years, and the opportunity to convert the mine to a facility dedicated to science was particularly appealing. This event marked the beginning of the initiative to establish a Deep Underground Science and Engineering Laboratory (DUSEL). Preservation and improvement of the site through resources provided by governmental and private funding has resulted in refurbishment of the shafts, pumping of the water from the underground, and preparation of space for an Early Implementation Program involving a number of physics, geoscience, and geomicrobiology investigations. Preparation for the main phase of laboratory development is currently in the preliminary design phase. This phase involves the conduct of geotechnical investigations for the laboratory rooms and the large excavations. These rooms and large cavities will host the physics experiments requiring protection from cosmic radiation. Interference from this source would cause unacceptable background in the detectors searching for neutrino reactions and dark matter. The design phase involves preparation of plans for outfitting of the laboratories, upgrading of the shafts, and planning the excavation design. This work will lead to the construction of a multi-disciplinary laboratory that will operate in excess of 30 years. 3-3 8:40 AM Weinig, Walter [171984] CIVIL ENGINEERING AND MINING PROJECTS—RECONCILIATION OF DESIGN PHILOSOPHIES POPIELAK, Roman S.1, WEINIG, Walter1, and VARDIMAN, David M.2, (1) Golder Associates Inc, 44 Union Boulevard, Suite 300, Lakewood, CO 80228, Walter_Weinig@golder.com, (2) DUSEL, Victor, CO 80860 The conduct of scientific experiments at DUSEL will require excavation of large openings at a considerable depth below the surface. The laboratory-module excavations will have footprint dimensions about 66 x 328 feet (20 meters [m] x 100 m) and the excavation of the large cavity to host the water Cherenkov neutrino detector will have a diameter greater than 180 feet (55 m) and height of approximately 240 feet (80 m), including the crown of the excavation. Construction of such openings in a high-rock-stress environment, at a depth of 4,850 feet (1,478 m), requires combined experience in design and construction of large civil engineering underground facilities and deep mines. Experience in civil engineering is fundamental to secure a high level of stability of large caverns and minimal disturbance to rock due to the blasting. Experience in mining is indispensible when it comes to excavations at considerable depths where a high-rock-stress field dominates the behavior of the rock mass. Combination of the mining and civil engineering experiences requires reconciliation of differences in their respective approaches to design and construction. The first aspect differentiating mining and civil engineering projects is the issue of “design life” or “stand-up time.” In mines, the object is to get the underground excavations to stand up just long enough for the ore to be extracted: in underground civil engineering projects, the underground excavations must be stable, without any rockfalls, for at least the life if the project, which may be a hundred years or more.An important difference is also the concept of maintenance. In mines, there is a tolerance for rockfalls (within the limits of mine safety) as there are mining equipment and personnel on hand who can easily stabilize any area of the mine. In civil engineering projects, there is little or no tolerance for rockfalls when the project is in service due to the safety hazard, conduct of scientific experiments and, especially because there is no mining equipment on hand to undertake stabilization work. Reconciliation of these differing design philosophies is of particular importance for DUSEL’s project, which involves construction of the large excavations applying civil engineering standards in a deep mining environment. 3-4 9:00 AM Terry, Michael [171953] 3-D GEOLOGIC MODEL OF THE LARGE CAVITY AREA AT THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY, HOMESTAKE MINE, SOUTH DAKOTA TERRY, Michael, Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, michael.terry@sdsmt.edu and LISENBEE, Alvis L., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701 Preparation of a geologic model for the Large Cavity area on the 4850 Level of Homestake mine has progressed in two phases. The initial 3-D VULCAN model utilized incomplete drift maps (4100 and 4850 levels) and 376 m of exploration drill core prepared by Homestake mine geologists across several years before mine closure. In the second half of 2009, mapping of 1,394 m of drifts and logging of 1,363 m of drill core by several consulting groups have markedly increased understanding of geology of the 4850 Level and allowed a progression of geologic understanding there. The area of the proposed Large Cavities lies west of the Vent Drift within the Yates member amphibolite. This area is along the axial portion of the large SSE-plunging, Precambrian-aged Lead anticline, as defined by foliation within the amphibolite and the trend of the upper amphibolite contact. A swarm of Tertiary rhyolite dikes (15% to 40% of the rock mass) crosses the Yates member-Poorman Formation contact. Along the drifts, the attitude of individual dikes, and of the 900 foot-wide swarm, changes from sub-vertical dips and a NNW strike in phyllite of the Poorman to northerly strikes and generally eastward dips, sub-parallel to the well developed fabric, within the amphibolite. The margins of the dikes are distinctly flow banded and annealed with the country rock. Recognition of this change in strike of the dike swarm required revision of the original geologic model which predicted a continuous, NNW strike. The currently defined locations of the 55 m-diameter Cavities lie within the zone of combined rhyolite dikes and amphibolite. Minor faults and calcite-filled veins are abundant within the amphibolite member, but are annealed. Abundant systematic joint sets are also present. 2010 GSA Rocky Mountain Section Meeting 3 SESSION NO. 3 3-5 9:20 AM Stetler, Larry [171709] HYDROLOGIC, CLIMATIC, AND GROUND MOTION STUDIES AT HOMESTAKE DUSEL STETLER, Larry1, DAVIS, Arden D.1, SALVE, Rohit2, VOLK, James3, and VANBEEK, Jason1, (1) Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701-3901, larry.stetler@ sdsmt.edu, (2) Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, (3) Accelerator Physics, Fermi National Laboratory, Batavia, IL 60510 Earth science-related research at Homestake DUSEL has been occurring along several avenues since 2008 by SDSMT faculty, students, and research partners. This group has focused on hydrology, meteorology, and slow ground motion. Part of the motivation for these experiments has been to establish an early baseline dataset of physical parameters to benefit planned future research. Hydrologic work has been directed toward measurement of water reduction at the facility and fracture flow testing that has been performed on the 4850-ft level. Meteorology stations have been established on the 1250, 2000, 2600, and 4850-ft levels with one surface station. Ground motion has been recorded on the 2000-ft level where two types of tiltmeters have been installed. Early results have indicated water information critical to future facility construction and utilization, the climatic sensitivity of the underground spaces to human disturbances, and the detection of earth tides and secondary motions associated with blasting on the 4850-ft level. Each of these systems will expanded as the facility grows to provide viable data for the foreseeable future. These data are open to public access through established websites at SDSMT with links from the Sanford Underground Laboratory. 3-6 9:40 AM Jones, Tessa L. [171659] FROM BASIC PHYSICS TO COMPLEX HYDROGEOLOGY: A UNIQUE APPROACH FOR DERIVING HYDRAULIC CONDUCTIVITY IN AN UNDERGROUND LAB JONES, Tessa L., Geologic Engineering, South Dakota School of Mines and Technology, 501 East St. Joseph St, Rapid City, SD 57701, tessaj@gmail.com, VAN BEEK, Jason K., Geological Engineering, South Dakota School of Mines and Technology, 501 East St. Joseph St, Rapid City, SD 57701, WANG, Joe S., Earth Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 95720, and DAVIS, Arden D., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701 The Sanford Underground Laboratory is the interim facility for the future federally funded Deep Underground Science and Engineering Lab (DUSEL). The lab is situated in Precambrian metasedimentary and metavolcanic rocks intersected by Tertiary dike swarms. The Homestake mine was closed in 2001 and the pump system keeping the mine dry was turned off in 2003. By 2008 the water level had risen 3470 ft in the 8000-ft deep mine. Reactivation of the pump system in 2008 has led to a reduction in water level of more than 500 ft. Investigation of previously flooded areas has revealed that iron dissolved in the water oxidized as the mine flooded, staining the submerged rocks; however, isolated air pockets have been identified by long stretches of unstained areas along the top of tunnels and other openings. A new approach is being tested to determine rock permeability through analysis of air pocket properties in several rock formations and multiple depths. Combining the ideal gas law, Darcy’s equation, and field measurements, a model has been created to determine the mass of air forced from the air pocket into the rock matrix over a period of time. Hydraulic conductivity values will be derived, based on the volume of gas lost into the rock. 3-7 10:20 AM Muxen, Andrew B. [171691] AUTONOMOUS UNDERWATER VEHICLES AND THEIR APPLICATION TO UNDERGROUND MAPPING AND EXPLORATION MUXEN, Andrew B., Mechanical Engineering, South Dakota School of Mines and Technology, 501 E Staint Joseph St, Rapid City, SD 57701, muxenmi@hotmail.com, TOLLE, Charles R., Electrical and Computer Engineering, South Dakota School of Mines and Technology, 501 E Saint Joseph St, Rapid City, SD 57701, and MCGOUGH, Jeffery, Mathematics and Computer Science Department, South Dakota School Of Mines and Technology, 501 E Saint Joseph St, Rapid City, SD 57701 A new research program in autonomous underwater vehicles (AUV) has begun at the South Dakota School of Mines and Technology (SDSMT). The project has formed under the cross departmental robotics intelligent autonomous systems (RIAS) program at SDSMT. The team is made up of primarily undergraduate students with a growing number of graduate students. The current AUV is intended for scientific exploration and underwater work under extreme conditions. With a design pressure rating of 1500 psi (10,300 kPa), this submersible will be capable of depths of over 1000 meters beneath sea level. This pressure rating will be achieved by using crushable design techniques, e.g. instead of building a pressure vessel to protect the electrical component compartments, their compartments will be filled with mineral oil. The AUV will be capable of speeds of 1 m/s and five degrees of freedom. An array of mapping sensors will be utilized, including sonar, Inertial measurement unit, and a visual light camera. This unit is being constructed for an operation time of three hours. It will operate between 20 and 200 degrees F. The AUV is designed to incorporate many sensors including a water sampling system, visual, ultra-violet, and inferred imaging systems, temperature and pressure sampling, and potential for mineral or biological collection system. This AUV is being build specifically for use in DUESL but could be configured for other applications. The AUVs initial mission will be to map the flooded regions of DUSEL. This paper will explore the progress made so far by the team. 3-8 10:40 AM Sonnenthal, Eric [172055] A COUPLED THERMAL-HYDROLOGICAL-MECHANICAL-CHEMICAL-BIOLOGICAL EXPERIMENTAL FACILITY AT DUSEL HOMESTAKE SONNENTHAL, Eric1, ELSWORTH, Derek2, FREIFELD, Barry1, LOWELL, Robert3, MAHER, Kate4, MAILLOUX, Brian J.5, and UZUNLAR, Nuri6, (1) Div Earth Sciences, Lawrence Berkeley National Lab, MS 90-1116, Berkeley, CA 94720-0001, elsonnenthal@lbl.gov, (2) Department of Energy and Mineral Engineering, Penn State, 231 Hosler Building, University Park, PA 16802-5000, (3) Department of Geosciences, Virginia Tech, 4044 Derring Hall, Blacksburg, VA 24061-0420, (4) Dept. of Geological and Environmental Science, Stanford University, Green Earth Sciences 253, 367 Panama St, Stanford, CA 94305, (5) Department of Environmental Sciences, Barnard College, 76 Claremont Ave, New York, NY 10027, (6) South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701 Most natural and engineered earth system processes involve strong coupling of hydrological, thermal, mechanical, chemical, and sometimes biological processes in rocks that are heterogeneous at a wide range of spatial scales. Fluids - primarily water, but also CO2, hydrocarbons and volcanic gases - exert a pervasive influence on processes in the Earth’s crust where their transport is moderated by flow through fractured heated rock under stress. A preliminary design has been formulated for a large-scale subsurface experimental facility at the 4850 foot level 4 2010 GSA Abstracts with Programs depth of the Homestake Mine to investigate coupled Thermal-Hydrological-Mechanical-ChemicalBiological (THMCB) processes in fractured rock at depth. The experiment will be part of the proposed Deep Underground Science and Engineering Laboratory (DUSEL) in the Homestake Mine, South Dakota. Geochemical, isotopic, microbiological, mechanical and transport experiments and numerical modeling are being used to guide the experimental design and to evaluate the anticipated time and spatial scales of the coupled THMCB processes. In particular, the experimental facility will probe the nonlinear feedbacks between processes that can dynamically modify physical and chemical properties – those that have taken place and those that will take place, as analogs of natural and engineered processes. Initial conditions and history are only known roughly at best, and the boundary conditions have likely varied over time as well. Processes such as multicomponent chemical and thermal diffusion, multiphase flow, advection, and thermal expansion/contraction, are taking place simultaneously in rocks that are structurally and chemically complex—heterogeneous assemblages of mineral grains, pores, and fractures—and visually opaque. The only way to fully understand such processes is to carry out well-controlled experiments at a range of scales (grain/pore-scale to decimeter-scale) that can be interrogated and modeled. The THMCB experimental facility is also intended to be a unique laboratory for testing hypotheses regarding effects of heat and chemical reactions on microbial communities. We describe an array of investigations that may be completed in such a facility related to the evolution of natural and engineered processes. 3-9 11:00 AM Tuffour, Peprah [171788] MINERAL CHEMISTRY OF CHLORITE, HOMESTAKE GOLD DEPOSIT, NORTHERN BLACK HILLS, SOUTH DAKOTA: IMPLICATIONS FOR GOLD DEPOSITION IN IRON-FORMATIONHOSTED GOLD DEPOSITS TUFFOUR, Peprah, Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701-3901, peprah.tuffour@mines.sdsmt.edu, PATERSON, Colin J., Department of Geology and Geological Engineering, South Dakota School of Mines &Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995, and TERRY, Michael P., Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701 The Homestake gold mine, in the northern Black Hills, South Dakota produced about 40 million ounces of gold from ten ore ledges or plunging fold structures from 1976 -2001. Several generations of chlorites (both hydrothermal and metamorphic) occur throughout the Homestake deposit. Type I and Type II chlorites are interpreted to be the product of prograde metamorphism. Type III chlorite is found in all ore bodies and believed to be hydrothermal, directly linked to flow of gold-bearing fluids. The chlorite is abundant (from 5 to >30 volume percent) in ore bodies and decreases in abundance outside the ore settings. Chlorite, siderite, and ankerite in three hundred and eleven (311) samples of selvages have been analyzed for Au, Al, Fe, Mg, Mn, K, Na, Si and Ca. Chlorite compositions vary with proximity to ore and centroids of ore ledges, notably showing increases in Mn and Mg, and decreases in Fe and Si. Other elements do not show any systematic variations in and around ore zones. These and other elemental variations are examined to elucidate the influence of fluid-rock interaction and chlorite chemistry on gold precipitation. 3-10 11:20 AM Ellingson, William [171784] CONTROLS ON PREFERRED LOCALIZATION OF GOLD ORE IN SYNCLINES WITHIN THE HOMESTAKE MINE, LEAD, SOUTH DAKOTA, USA ELLINGSON, William, Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, william.ellingson@ mines.sdsmt.edu, PATERSON, Colin J., Department of Geology and Geological Engineering, South Dakota School of Mines &Technology, 501 E Saint Joseph St, Rapid City, SD 577013995, and TERRY, Michael P., Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701 The Homestake iron-formation-hosted deposit produced more than 40 million ounces of gold between 1876 and 2001, and is regarded as a giant. The controls on this deposit are still in question. The Proterozoic host sequence is tightly to isoclinally folded in a structure that generally plunges southeasterly. Several hypotheses have been proposed over the years that gold deposition was structurally controlled. Mineralization is spatially associated with quartz veins and shear zones, but the relationship of ore bodies to the fold structures is intriguing. In-mine exploration focused on synclines, and almost all of the gold ore was mined from the synclinal hinges (oddnumbered ledges) of the Homestake Formation; the anticlinal hinges (even-numbered ledges) were rarely mined, and by implication were less favored for ore deposition. This study focuses on the structural characteristics of ledges 6 through 9, including the volume percent of quartz veining, variability of thickness of the Homestake Formation, fold geometry, and gold grade distribution. To accomplish this, 200 scale and 50 scale maps were used to compare and contrast the differences between the synclinal and anticlinal ledges. Drill logs were used to determine variation of thicknesses of the Homestake Formation. 3-11 11:40 AM Hamer, Rayburn C. [171768] HYDROTHERMAL ALTERATION AND GOLD DEPOSITION IN THE HOMESTAKE IRONFORMATION-HOSTED GOLD DEPOSIT, LEAD, SOUTH DAKOTA HAMER, Rayburn C. and PATERSON, Colin J., Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, Rayburn.Hamer@mines.sdsmt.edu The Homestake deposit located in Lead, South Dakota was one of the largest gold deposits, having produced over 40 million ounces of gold from 1876 to 2001. The deposit is hosted in the Proterozoic-aged Homestake Formation which is an iron formation consisting of either ironcarbonate or iron-silicate metasedimentary rocks. The unit is characterized by siderite in the greenschist facies and grunerite in the lower amphibolite facies, with minor chlorite, quartz, and graphite. The ore is located in and adjacent to quartz veins, and typically consists of arsenopyrite, pyrrhotite and native gold contained in a matrix of quartz±chlorite±biotite±garnet. Alteration is related to retrograde metamorphism and a post-metamorphic hydrothermal event, the latter coincident with gold deposition. Dominant alteration minerals mostly in halos adjacent to quartz veins are chlorite, carbonate (siderite and ankerite) and sericite. The chlorite grains in random to parallel orientation are believed to be directly related to the gold-bearing fluids. Sericite alteration occupies bleached zones consisting of sericite, siderite, carbonate, quartz and plagioclase. The objective of this study is to determine the extent of fluid-wall rock interaction in the Homestake Formation and to constrain the possible controls of ore deposition, specifically the influence of fluid-mineral reactions on gold deposition. Four different quartz veins from 3 drill holes were chosen and samples were taken at intervals away from the vein into unaltered country rock. Using petrography and geochemistry, the alteration assemblages will be distinguished from unaltered country rock assemblages. The different assemblages will elucidate changes in fluid chemistry that could have led to gold precipitation. SESSION NO. 5 SESSION NO. 4, 10:20 AM Wednesday, 21 April 2010 T4. Geologic Hazards of the Rocky Mountains and Great Plains Rushmore Plaza Civic Center, Ponderosa Room 4-1 10:20 AM Stetler, Larry [171900] LANDUSE MODELING IN THE BLACK HILLS FOR RESPONSIBLE DEVELOPMENT STETLER, Larry, Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701-3901, larry.stetler@sdsmt.edu Rapid development in many portions of the Black Hills and surrounding areas has highlighted the need for increased awareness of potential geological and environmental impacts. The need exists to understand and protect surface water, groundwater, and soil resources, as well as to reduce or eliminate risks from slope hazard, subsidence, and flooding. A recent study in Pennington County culminated in a model generating development risk maps. The approach utilized digital maps of geology, topography, soils, soil and rock slope stability, hydrology, aquifer susceptibility and vulnerability, subsidence and solution, and existing roads and development in a Geographic Information System. Many of these input layers were developed through separate and comprehensive thesis or dissertation projects, including the geologic mapping, aquifer susceptibility and vulnerability, hydrology, and slope stability. The GIS model merged them together to produce development rick maps that showed low, moderate, or high development risks. Each category was able to be explored to determine which of the input layers was most responsible for a certain risk rating. Thus, planners and developer are potentially able to determine risk hazards and provide remediation methods prior to development. This tool is being expanded to include additional geologic units and areas to include much of the development regions with the Black Hills area. 4-2 10:40 AM Anderson, Fred J. [171714] LANDSLIDES IN NORTH DAKOTA: AN OVERVIEW OF THE LANDSLIDE INVENTORY MAPPING PROGRAM AT THE NORTH DAKOTA GEOLOGICAL SURVEY ANDERSON, Fred J., North Dakota Geological Survey, 600 East Boulevard Avenue, Bismarck, ND 58505, fjanderson@nd.gov Landslides occur in natural and anthropogenic settings in North Dakota and are most commonly found within major river valleys and on engineered slopes along major transportation corridors. A focused, observational landslide inventory mapping program, ongoing since 2000, has mapped over 8,856 individual landslides over a mapping area of 36,000 km2 (8.9 x 106 acres). Landslides are dominantly found in two settings, controlled by the surface geology of the Great Plains in western and southwestern North Dakota and along major river valleys of the Missouri, Sheyenne, James, Souris, and Red Rivers. Mapped landslides are typically large slump failures occurring in Early Cenozoic strata of the Fort Union Group in western and southwestern North Dakota, and within Late Cretaceous shales of the Pierre Formation in eastern North Dakota. Localized riverbank slumping within cutbank meanders in Pleistocene glaciolacustrine sediments of the Sherack and Brenna Formations, occur in the Red River Valley. Slope failures found along ND HWY 22 in western North Dakota, on Riverview Drive in Valley City, and along the Red River near Drayton, are recent examples of this recurring geologic hazard. 4-3 11:00 AM Pellowski, Christopher J. [171835] THE HERMOSA FLOOD OF AUGUST 17, 2007: EXTENT, EFFECTS, AND COMPARISON TO FEMA FLOOD INSURANCE RATE MAP PELLOWSKI, Christopher J., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, christopher.pellowski@ mines.sdsmt.edu and LISENBEE, Alvis L., Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995 In late afternoon on August 17, 2007, a strong storm cell stalled over the eastern edge of the Black Hills, centered four miles west of Hermosa. In about four hours, four to 12 inches of rain fell in ~23 square miles of Battle Creek drainage basin and four to ten inches fell in ~11 square miles along Grace Coolidge Creek. By 9 p.m. flood depths reached 16 ft along Battle Creek canyon west of Hermosa, 17 ft at the railroad bridge south of town, and six to 14 feet east of the village. The FEMA FLOOD INSURANCE RATE MAP shows two categories for the flood plain: Zone A (100 yr flood): Zone B (100-500 yr flood). Along Grace Coolidge Creek, the flood occupied a portion of Zone A (terrace I: 4-6 ft above normal flow): Along Battle Creek, it covered all of Zone A and part of Zone B (the middle terrace {II: 11-12 ft} and portions of the upper terrace {III. 17-29 ft} in areas immediately downstream of abrupt meander bends). Flooding produced extensive damage to structures, but no loss of life, in predicted flooding areas shown on the FEMA map. Field-based mapping of bent grass and twigs, trapped debris, scoured surfaces, floated objects, e.g., cars, horses, etc. show that the earliest and latest flows paralleled the stream bed on terrace I, but not on II and III. Rupture of a railroad embankment and release of a 10-foot depth of water produced pressure sufficient to float and move houses up to one mile. 4-4 11:20 AM Epstein, Jack [170302] EVAPORITE KARST IN THE BLACK HILLS, SOUTH DAKOTA AND WYOMING EPSTEIN, Jack, US Geological Survey, MS926A, 12201 Sunrise Valley Drive, Reston, VA 20192, jepstein@usgs.gov Dissolution of gypsum and anhydrite in four stratigraphic units of Pennsylvania to Jurassic age in the Black Hills, South Dakota and Wyoming, has resulted in development of karstic collapse and has affected formational hydrologic characteristics. Subsidence has caused damage to houses and sewage retention sites. Substratal anhydrite dissolution in the Minnelusa Formation has produced breccia pipes and pinnacles, a regional collapse breccia, sinkholes, and extensive disruption of bedding. Anhydrite removal probably dates back to the early Tertiary when the Black Hills was uplifted. Evidence of recent collapse includes fresh scarps surrounding shallow depressions, steep-sided sinkholes more than 60 feet deep, and sediment disruption resulting in contamination of water wells and springs. Proof of sinkhole development to at least 26,000 years ago includes the Vore Buffalo Jump, near Sundance, WY, and the Mammoth Site in Hot Springs, SD. Several collapse sinkholes in the Spearfish Formation west of Spearfish, SD, which contain springs that support fish hatcheries and are used for local agricultural water supply, probably originated by dis- solution 500 feet below the surface in the Minnelusa Formation. As the anhydrite dissolution front in the subsurface Minnelusa moves down dip and radially away from the center of the Black Hills uplift, present resurgent springs will dry up and new ones will form as the erosion of the Black Hills progresses. Abandoned sinkholes and breccia pipes, preserved in cross section on canyon walls, attest to the former position of the dissolution front. Collapse features extend as much as 1,000 feet upward into post-Minnelusa rocks, as into the Minnekahta Limestone, for example. The Spearfish Formation, mostly comprising red shale and siltstone, is generally considered to be a confining layer. However, in the lower part of the Spearfish solution openings along gypsum beds and secondary fracture porosity have developed due to considerable expansion during the hydration of anhydrite to gypsum. This part of the Spearfish yields water to wells and springs making it a respectable aquifer. Processes involved in the formation of gypsum karst should be considered in land use planning in this increasingly developed part of the northern Black Hills, especially in the I-90 urban corridor. 4-5 11:40 AM Goodman, Brian S. [170770] ERIONITE, A NATURALLY OCCURRING FIBROUS MINERAL HAZARD IN THE TRI-STATE AREA OF NORTH DAKOTA, SOUTH DAKOTA, AND MONTANA GOODMAN, Brian S., Montana Department of Transportation Environmental Services, 2701 Prospect Avenue, Helena, MT 59620, bgoodman@mt.gov and PIERSON, M. Patrick, U.S. Forest Service, Custer National Forest, 1310 Main Street, Billings, MT 59105 Erionite, a naturally occurring fibrous zeolite mineral, was previously identified in the Killdeer Mountains of North Dakota and in several areas of the western U.S. associated with low temperature diagenesis of tertiary volcanics by alkaline groundwater. Recent sampling and analysis has expanded the detection of erionite south across the Tri-State region of North Dakota, Montana, and South Dakota associated with butte capping outcrops and eroded sediments derived from the Late Oligocene-Miocene Arikaree Formation as mapped in Montana and the Arikaree, Brule, and Chadron Formations as mapped in South Dakota. Disturbance of the erionite-bearing outcrop and sediments has occurred in some locales through fire suppression actions, aggregate mining, road construction, timber harvesting, recreational uses, agricultural and ranching activities. Malignant mesothelioma disease clusters associated with erionite exposure have been recognized in Turkey since the late 1970s and recently in Mexico. Disease clusters have not been identified in the U.S. and the mineral remains largely unregulated here; however, animal studies indicate that some forms of erionite have the potential to be more carcinogenic than asbestiform minerals. Data collection and analysis efforts are underway at the state and federal level to identify the extent of naturally occurring erionite-bearing geologic materials and evaluate the exposure and potential human health hazard resulting from past management activities. Data from these studies should be incorporated into land use management decision-making and overall environmental management. SESSION NO. 5, 8:00 AM Wednesday, 21 April 2010 T8. GIS and Remote Sensing Applications in the Geosciences Rushmore Plaza Civic Center, Ponderosa Room 5-1 8:00 AM Esker, Donald Anton [171756] THE MAMMOTH SITE OF HOT SPRINGS SD, THE MAPPING OF A LONG TERM EXCAVATION SITE AGENBROAD, Larry, ESKER, Donald Anton, and WILKINS, W.J., Mammoth Site of Hot Springs, South Dakota, 1800 Highway 18 Bypass, Hot Springs, SD 57747, done@mammothsite.org Discovered in 1974, the Mammoth Site of Hot Springs, South Dakota is a Late Pleistocene faunal trap that claimed the lives of at least 58 Columbian and Wooly mammoths, and preserved their remains along with those of 83 other plant and animal taxa. Careful mapping of this site over the last 36 years has provided researchers with a wealth of information curation of specimens and scientific study. Initially, the Mammoth Site used string-grid mapping and hand-drawn cartography. The maps were very accurate and the best to be had at the time, but did not take advantage of emerging technologies. Early efforts to computerize the mapping process used AutoCAD, early GIS software, and a Nikon laser transit. However, the software was not well suited to specimen mapping and the Nikon transit proved difficult to use in the bonebed. The system automated the catalog but proved to be less accurate and less detailed than the original string-grid system. In 2007, The Mammoth Site embarked on a complete re-map of the bonebed using the latest technology. The site upgraded to ESRI ArcGIS 9 mapping software, supported by a Trimble 5200 robotic transit and a crane-based camera (CraneCam). The remap project was completed in 2009, and the new map now shows the precise locations of over 1,100 bones and hundreds of fragments and geological features to within a few millimeters. The new map also contains 28 fields of ancillary data for each specimen including species, orientation, quality of preservation, associations with other specimens, and the names and thoughts of the excavators. The Mammoth Site is taking the mapping project in two new directions. The first is a project to add legacy data to the ArcGIS 9 map, where, using previously existing anchor points, data from the hand-drawn maps will be incorporated into the current electronic map. The second will give the maps another dimension. Using photographs from the CraneCam and special software, a preliminary three dimensional point cloud has already been generated that compares favorably with LIDAR-style 3-D maps. 5-2 8:20 AM Matthews, Neffra A. [171837] USING GIS TO TRACK FOSSIL FOOTPRINTS: TAKE It OUTSIDE AT THE JURASSIC MOCCASIN MOUNTAIN TRACKSITE, UTAH MATTHEWS, Neffra A.1, CHRISTENSEN, Tom2, TITUS, Alan L.3, NOBLE, Tommy A.1, and BREITHAUPT, Brent H.4, (1) National Operations Center, USDOI-Bureau of Land Managment, Denver, CO 80225, neffra_matthews@blm.gov, (2) DOI, BLM - Kanab Field Office, 318 N. 100 E, Kanab, UT 84741, (3) Grand Staircase–Escalante National Monument, Bureau of Land Management, Kanab, UT 84741-3244, (4) Wyoming State Office, Bureau of Land Management, Cheyenne, WY 82003 The Moccasin Mountain Tracksite (reported in the fall of 2007) is located in Southern Utah on land managed by the Bureau of Land Management’s Kanab Field Office. Here in a 1,000 m2 slickrock 2010 GSA Rocky Mountain Section Meeting 5 SESSION NO. 5 area of the Navajo Formation (age ~185 ma) multiple track levels are revealed. This spectacular vertebrate paleontological resource lies in a very popular off-highway vehicle (OHV) area. The Moccasin Mountain Tracksite (MMT) provides an ideal opportunity for the successful synergy of management, science, technology, interpretation, and recreation. OHV activity has impacted the track surface at the MMT necessitating the closure of the track-bearing area to vehicular traffic to protect this significant paleontological resource. Scientifically, the site contains a high ichnodiversity and density, with important preservational features. At least six different track types have been observed, including tridactyl (Grallator and Eubrontes) and tetradactyl forms (Batrachopus and Otozoum). Tracks occur on dune foreset beds, interdune-bounding, and truncation surfaces, and are preserved as underprints and molds, in convex hyporelief, and more rarely in concave epirelief. The morphology varies from distinct preservation of anatomical features, such as pads and claw impressions, to areas of undifferentiated dinoturbation. In 2008, close-range photogrammetric documentation of the site was conducted using both ground-based and low-altitude aerial imagery. Digital terrain data and ortho-imagery, at a variety of scales, are integrated into a unified real-world coordinate system for display and analysis in a Geographic Information System. The proximity of the site to recreational destinations in Southern Utah and its unique scientific value make it ideally suited for a BLM “Take It Outside” program. This Program encourages children and their families to spend more time outdoors on the public lands; to improve children’s overall health; and to promote stewardship of the public lands. The integrated imagery forms the basis for a brochure for K- 12 students, and adults, to use as a self-guided tour of the site. This brochure will be an effective tool for interpreting this unique site to the public and increasing awareness and concern for such natural treasures. 5-6 9:40 AM Murray, Kyle Edward [171965] COMPUTING GeoVolumes FOR GROUNDWATER SYSTEMS USING GIS MURRAY, Kyle Edward, Geological Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, kyle.murray@utsa.edu and LE, Tuan, Civil and Environmental Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 Recent developments in GIS have allowed for representation of three-dimensional features using vector-based objects called multipatches. These objects can be stored in a relational geodatabase along with other features of a groundwater system. Because the geometry of subsurface geologic units may take on a variety of patterns, the methods for computing multipatches may differ depending on the extent and geometry of overlying or underlying geologic units. In this study we develop geoprocessing models that are suitable for computing multipatch features under various geometric configurations. The models are applied to the groundwater system in the Piceance Creek Basin of western Colorado. Multipatches are computed for shale-oil rich and lean zones in the Green River Formation, in addition to aquifers and aquitards in the overlying and underlying formations. Because volumetric statistics are not explicitly stored with the multipatch features, parallel geoprocessing models are developed for estimating retort volumes and groundwater volumes. The geoprocessing models presented in this study are designed to be easily implemented when representing and quantifying three-dimensional features, and can be applied to other groundwater systems using an industry standard GIS. SESSION NO. 6, 8:00 AM 5-3 8:40 AM Marini, Brandon L. [171856] LOCALITY DATABASE FOR MUSEUM OF GEOLOGY PALEONTOLOGICAL COLLECTIONS MARINI, Brandon L.1, RYCZEK, Daniel1, LINN, Thomas1, LEROY, Janine1, and PRICE, Maribeth2, (1) Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E Saint Joseph St, Rapid City, SD 57701, brandon.marini@ mines.sdsmt.edu, (2) Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701 The Museum of Geology at the South Dakota School of Mines and Technology houses an estimated 300,000 specimens. The locality information for these collections runs the gamut from township-range notations in field notebooks and index cards to precisely positioned UTM coordinates in a spreadsheet. A single, searchable locality database accessible to research staff and visiting scientists is sorely needed, but has never been developed. Students are designing a locality database for the Museum, implemented as a geodatabase within a Geographic Information System (GIS). The combination of a potentially large spatial extent covering multiple states with the need for highly precise locations presents an exceptional design challenge, as does the sensitive nature of the information being archived. The students will design a pilot database for a smaller area encompassing several counties while designing for a much larger area for eventual implementation. Because much of the locality data were collected before the advent of GPS, base layers needed to correctly locate a specimen based on sometimes scanty information will be included, such as township/range, hydrology, towns, roads, and digital orthophotoquads. The students will test the database using a small selection of localities in a restricted location but covering a time span of many years, in preparation for a major effort to implement the entire database. 5-4 9:00 AM Webb, David A. [171894] ADAPTING PROVEN LIDAR TECHNOLOGY TO COST EFFECTIVE SOLUTIONS FOR 1-FOOT CONTOURS WITH THE FLI-MAP FX WEBB, David A., Regional Sales Manager, Fugro Horizons, Inc, 3600 Jet Drive, Rapid City, SD 57703, dave.webb@fugrohorizons.com FLI-MAP Fx - The use of LiDAR in support of surface water hydrology studies has become a common practice in recent years with published guidelines such as FEMA that recognize this technology. The Cache la Poudre River is a tributary of the South Platte River with its headwaters in the Colorado Front Range. The study area is located in the foothills upstream to the rivers’ emergence north of the city of Fort Collins. With numerous bends, steep-walled canyons and high topographic relief, the area presents a challenge to cost effective LiDAR data acquisition that meets accuracy standards for a 1-foot contour interval. Using the technological developments of the FLI-MAP system and its advantages with respect to corridor mapping along with lower associated operating costs of a fixed-wing platform led to the synthesis of the FLI-MAP Fx system. By simultaneously collecting imagery and LiDAR data at three different angles, a high relief surface can be accurately covered with fewer flight lines and also achieve a greater probability of vegetation penetration. While the TALON system is not a replacement for traditional FLI-MAP corridor mapping nor for large area projects where higher altitude sensors are best suited, this study does indicate that an integrated system designed for medium altitude and a point density sufficient for 1-foot contours can meet the requirements for hydrological and other uses at a lower cost than what could be achieved otherwise. 5-5 9:20 AM Minnick, Matthew [171846] GIS AND WEB BASED WATER RESOURCES MANAGEMENT FOR OIL SHALE DEVELOPMENT IN THE WESTERN UNITED STATES, STAGE I MINNICK, Matthew and ZHOU, Wendy, Geology and Geological Engineering, Colorado School of Mines, 1516 Illinois Street, Golden, CO 80401, mminnick@mines.edu Development of oil shale resources in the western United States will require significant quantities of water for surface or in-situ retorting, reclamation, and associated economic growth. The Department of Energy (DOE) estimates the use of 105 to 315 million gallons (2.5 to 7.5 million barrels) of water per day for an oil shale industry producing 2.5 million barrels of oil a day. It is estimated that an additional 58 million gallons (1.4 million barrels) of water per day will also be needed to support the population growth and industry infrastructure. This three year project funded by the DOE focuses on the development of the oil shale bearing Green River Formation in the Piceance Basin of western Colorado. A Geographic Information Systems (GIS) based regional water resource infrastructure, and web-based data warehouse for storing, managing, analyzing, visualizing, and disseminating Piceance Basin oil shale data are being developed to address both water quantity and quality issues. The first stage of this project presented here focuses on data acquisition and storage in the form of the ESRI ArcHydro surface and groundwater data models to support the state of art ArcGIS Server Enterprise application and analytical modeling of the hydrologic systems. The ArcHydro database schema provides the structure for the coupling of both surface water and groundwater observational data along with output from numerical modeling to support dynamic analytical models to address water availability. This robust spatial relational model combined with customized data and analytical toolsets accessed via the web will provide the DOE with a dynamic water resource assessment and management tool that can be applied to other oil shale basins. 6 2010 GSA Abstracts with Programs Wednesday, 21 April 2010 Engineering Geology and Geophysics (Posters) Rushmore Plaza Civic Center, Rushmore H 6-1 BTH 1 Tuffour, Peprah [171733] LANDSLIDE HAZARD ZONATION MAPS FOR RAPID CITY, SOUTH DAKOTA TUFFOUR, Peprah and STETLER, Larry, Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701-3901, peprah.tuffour@mines.sdsmt.edu Rapid City is located on the eastern flank of the Black Hills in Paleozoic and Mesozoic stratigraphy including limestone, shale, and sandstone units dipping approximately 12° to the east. Swelling clay, gypsum, friable sandstone, and structural fabric add to a high natural instability. Rapid development in this hilly region makes landslide awareness a critical concern for landowners. Landslides have occurred in Rapid City since the earliest development in the 1880s. Most have occurred due to development in inappropriate areas, unstable areas without mitigation, and areas of swelling soils or having dissolution potential. Lack of reliable information has been the largest contributing factor to slope instabilities. We provide a first attempt at developing a usable tool for development and planning that consists of three thematic maps; geology, landuse, and slope. Ranks assigned to each layer were based on its potential to cause, or influence, landslide activity and ranged between 5 (high) to 1 (low). Ranked maps were overlain using a weighted overlay to produce a landslide hazard zonation map. The resulting map contains five zones; very high, high, moderate, low, and very low. About 15% of the region had very high susceptibility (slopes >550) and high susceptible areas occurred in isolated patches. Both areas represent favorable development properties. These products may provide information for developers to conduct risk assessment during development. 6-2 BTH 2 Ward, Dustin [171934] RELATIVE INFLUENCE OF QUARTZ MICROSTRUCTURE ON CRUSTAL SEISMIC ANISOTROPY WARD, Dustin, Geological Sciences, University of Colorado at Boulder, 2200 Colorado Avenue, Boulder, CO 80309, dustin.ward@colorado.edu and MAHAN, Kevin, Dept Geol. Sciences, University of Colorado, Boulder, CO 80309 Deformation induced crystallographic preferred orientation (CPO) of anisotropic minerals is an important constraint on seismic anisotropy of the middle and lower crust. Understanding the mineralogical and deformational influence on seismic anisotropy may offer the potential to better interpret deep crustal structure. Experiments show the highest degree of seismic anisotropy in samples containing significant amounts of foliated mica, however, the contribution of other common crustal minerals is poorly understood. As quartz is one of the most common crustal minerals, and its contribution to seismic anisotropy is poorly constrained, I am investigating a suite of mylonitic micaceous quartzites to examine the influence of quartz microstructures on seismic anisotropy. Electron backscatter diffraction (EBSD) techniques can characterize not only the phases present in a sample, but also their complete 3-dimensional crystallographic orientations. This method provides a statistically robust dataset on which textural analysis is easily performed and from which seismic properties can be calculated. Using this method, the following hypotheses are being tested: 1) a quartz CPO, in the presence of aligned mica, will constructively interfere with bulk rock seismic anisotropy therefore increasing the overall magnitude of anisotropy and influencing the anisotropic orientation and 2) a quartz CPO, in the presence of aligned mica, will destructively interfere with bulk rock seismic anisotropy therefore decreasing the overall magnitude of anisotropy and altering the anisotropic orientation. Preliminary results from rocks in central Colorado and southern Wyoming suggest that a quartz CPO decreases the overall anisotropy compared to that solely due to mica and that the orientation of seismic anisotropy is affected by the presence of a quartz CPO. This supports our latter hypothesis and may have important implications when interpreting mid-crustal deformation via seismic data, although further investigation is required. Future research plans include the analysis of samples deformed at various metamorphic conditions in an effort to place constraints on the effect of quartz deformation mechanisms on seismic anisotropy. SESSION NO. 8 6-3 BTH 3 Schneider, John M. [171960] TWO-DIMENSIONAL SEISMIC REFLECTION EVALUATION OF THE I&W BRINE CAVERN CARLSBAD, NEW MEXICO SCHNEIDER, John M., Geology and Geological Engineering, South Dakota School of Mines & Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, john.schneider@ mines.sdsmt.edu and GOODMAN, William M., Engineering Department Senior Staff Geologist, RESPEC, Oviedo, 32766 In 2008, the collapse of two solution-mined brine caverns in the Permian Salado Formation near Carlsbad, New Mexico, initiated public and regional governmental concern about the stability of similar wells in the area. The New Mexico Oil Conservation Division conducted an investigation focusing on brine extraction wells with comparable geologic conditions and dimensions of the collapsed wells, and concluded that the operations and geologic setting of the I&W, Inc well site, located at the intersection of U.S. Highway 285 and 62 within the city limits in Carlsbad shared similarities to sites where caverns failed. High-resolution P-waves two-dimensional seismic reflection data assisted in defining the lateral extent of solution-mined cavern at the I&W site. Cavern effects include downwarping and loss of amplitude of reflectors interpreted to represent upper Salado and overlying Rustler Formation strata. The snap shot of subsurface conditions provided by the seismic reflection data is being augmented with routine surface subsidence measure measurements. SESSION NO. 7, 8:00 AM Wednesday, 21 April 2010 Paleontology (Posters) Rushmore Plaza Civic Center, Rushmore H 7-1 BTH 4 Rowe, Becci J. [171724] MIOCENE FLORA OF THE ALVORD CREEK FORMATION, OREGON; INTERPRETATION OF ANCIENT CLIMATE ROWE, Becci J., Department of Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, Becci.Rowe@sdsmt.edu, GABEL, Mark L., Herbarium, Black Hills State Univeristy, Spearfish, SD 57799, and SHELTON, Sally Y., Museum of Geology, South Dakota School of Mines & Technology, Rapid City, SD 57701 The Alvord Creek Formation is located in the southeastern corner of Oregon, in the Steens Mountains. The Alvord Creek beds (light colored tuffs and tuffaceous shales with interbedded andesite flows and basaltic intrusives) are overlain by and interbedded with the Pike Creek Volcanic Series (rhyolite/dacite) flows. The proximity, duration, and intensity of a low shield cone affected the thickness of the ash layers. The Alvord Creek fossil plant localities are in siliceous, tuffaceous shales and are approximately 21.3 Ma. An unconformity exits between these siliceous volcanic formations and the overlying Steens Basalts. Miocene angiosperm plants collected from Alvord Creek are compared with extant plants using leaf morphology. Preliminary field identification indicates cherry (Prunus), hornbeam (Carpinus), juniper (Juniperus), maple (Acer), rose family (Rosaceae), sumac (Rhus) and willow (Salix) are present. Previous work enumerated 26 species in the Alvord Creek paleoflora. Plant physiognomy and habitat requirements of the nearest extant relatives will be used as proxies for temperature and moisture conditions to interpret Miocene climate. 7-2 BTH 5 Wahl, William R. [171744] THE REDESCRIPTION AND EXCAVATION OF WILBUR KNIGHT’S 1895 MEGALNEUSAURUS REX SITE WAHL, William R., Paleontology, BigHorn Basin Foundation, 110 Carter Ranch RD, Thermopolis, WY 82443, wwahl2@aol.com Examination of the collection site of the large Jurassic pliosaur Megalneusaurus rex has revealed new fossil material as well as both tools and artifacts from the 1895 excavation. The rediscovery of Wilbur Knight’s original site was made possible by the use of his letters describing the two articulated hind-paddles and his geological description of the area. This information has been used to verify that Megalneusaurus rex was collected from the upper Redwater Shale Member of the Sundance Formation and that the original excavation was incomplete. Newly collected fossil material has included another articulated flipper, portions of vertebrae and large amounts of gut contents. Scattered piles of bone and spoil mounds indicating past disturbance has allowed for some speculation as to the outline and parameters of the original excavation. A broken knife blade and a button were recovered from the site. A nail was recovered above the uncollected flipper bones suggesting the site was marked for potential return to the excavation in 1895. Remains of a metal ‘Hercules Blasting Powder’ canister and an intact whiskey bottle were also collected from near the site. It is hoped that a more extensive investigation of the intact spoil piles will reveal more artifacts and information. The rediscovery of the site is significant in that little is known about this largest member of the Sundance marine reptile fauna. 7-3 BTH 6 Racay, Christopher A. [171865] A LONG MORTICHNIALTRACKWAY OF MESOLIMULUS WALCHI FROM THE TITHONIAN STAGE OF THE UPPER JURASSIC SOLNHOFEN LITHOGRAPHIC LIMESTONE NEAR WINTERSHOF, GERMANY LOMAX, Dean R., 10 Earlesmere Ave, Doncaster, DN4 OQE, United Kingdom, skalidis7@ hotmail.com and RACAY, Christopher A., Wyoming Dinosaur Center, 110 Carter Ranch Rd, Thermopolis, WY 82443, cracay@wyodino.org A complete, 9.7 meter long mortichnial trackway (WDC CSG-233) was discovered in a plattenkalk quarry near Wintershof, Bavaria; Germany and it may be the longest reported trackway described to date. It was collected from the Lower Tithonian of the Upper Jurassic Solnhofen Limestone. The trackway is represented by footprints, telson drag impressions along with a completely preserved Mesolimulus walchi at the end of its trackway. The telson drag impressions are fairly long and consistent at the beginning of the trackway, however, about the last 1/3rd of the track the telson drag impressions get shorter and more erratic, suggesting that the horseshoe crab was trying to swim up and get out of the lagoon. The bottom of the lagoon was hypersaline, making it hard for any organism to survive. There is no sign of footprints leading away from the specimen indicating that the horseshoe crab is not a molt. The cause of death of M. walchi is unknown, however, it may have been washed into the lagoon and struggled to get out of the toxic environment. No predatory marks have been found to suggest that it may have been dropped by a predator. SESSION NO. 8, 8:00 AM Wednesday, 21 April 2010 T1. Geoscience and Engineering at the Deep Underground Science and Engineering Lab (DUSEL) in Lead, South Dakota (Posters) Rushmore Plaza Civic Center, Rushmore H 8-1 BTH 7 Peters, Catherine A. [170804] MONITORING FLUID CONCENTRATION AND PHASE CHANGES IN FLOW EXPERIMENTS AT THE PROPOSED DUSEL CO2 FACILITY DOBSON, Patrick F.1, PETERS, Catherine A.2, RAMAKRISHNAN, T.S.3, STABINSKI, Eric3, LIANG, Kenneth3, VERMA, Sandeep3, OLDENBURG, Curtis M.1, FREIFELD, Barry M.1, and WANG, Joseph S.1, (1) Earth Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, pfdobson@lbl.gov, (2) Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, cap@princeton.edu, (3) Schlumberger-Doll Research Center, 1 Hampshire Street, Cambridge, MA 02139 DUSEL CO2 is a proposed experimental facility at DUSEL for studying CO2 migration and trapping mechanisms associated with geologic sequestration of CO2. The proposed facility consists of three sand-filled long column pressure vessels with a length of ~500 m and a diameter of ~1 m supported within a 3 m-diameter raised bore shaft. Each vessel will have an inner fluid-filled tube with a diameter of ~25 cm designed to house an array of detectors to monitor fluids within the sand-filled annulus during the flow experiments. External heaters will be used to control the temperature and compressors will be used to adjust the pressure gradient. One of the proposed experiments consists of the evaluation of fluid flow processes and associated residual gas trapping and dissolution during the upward rise of a buoyant CO2 slug in a sand-filled column saturated with brine under hydrostatic pressure and “natural” geothermal gradient conditions spanning the range from supercritical to gaseous conditions for CO2. Critical to the experimental facility is the monitoring of fluid conditions at high resolution within the vessels. The tube in the center of each vessel will serve as a proxy well to accommodate a variety of existing down-hole technologies to monitor flow column conditions. A combinable nuclear magnetic resonance tool will be used to discriminate between water and CO2-filled pores; similar measurements will be conducted using a reservoir saturation tool. Sonic (1-20 kHz) and ultrasonic (100s of kHz) tools will also be used to image fluids, using differences in acoustic impedance to distinguish liquid from gas phases. These measurements will be used to construct a vertical saturation profile, and to determine how it changes over time as the CO2 plume moves upwards. Distributed temperature and pressure sensors will also be deployed outside of the inner tube to provide continuous in situ data. The various data and interpretations from the suite of technologies deployed will collectively be used to calibrate models that predict the vertical flow of CO2 and brine in porous media, and to compare the spatial resolution and sensitivity of different logging tools. 8-2 BTH 8 Rowe, Aryn M. [171872] DEVELOPING A SPATIAL INDEX FOR THE HOMESTAKE ARCHIVE ROWE, Aryn M.1, GARRAFFA, Alfred1, WEBER, Carolyn2, and PRICE, Maribeth H.3, (1) Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, aryn.rowe@mines.sdsmt.edu, (2) Archivist, Adams Museum & House, 54 Sherman Street, Deadwood, SD 57732, (3) Geology and Geological Engineering, South Dakota School Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701 Developing a Spatial Index for the Homestake Archive Aryn Rowe, Alfred Garraffa, Carolyn Weber, and Maribeth Price South Dakota School of Mines and Technology Adams Museum & House 54 Sherman Street Deadwood, South Dakota 57732 When the Homestake Gold Mine was donated to the South Dakota Technology Authority (SDTA) for conversion into a Deep Underground Science and Engineering Laboratory (DUSEL), several hundred cubic feet of maps and other materials became the property of the Adams Museum & House (AM&H) in Deadwood, South Dakota, to be preserved for historic and research purposes. These materials included thousands of detailed, hand-drawn maps. Although much of this mine information was placed in a digital database as it was collected, and is currently in use by the SDTA, the original maps provide a wealth of information not otherwise available, as well as an important historical resource. The goal of this project is to develop a spatial index and database for these map holdings in order to make them more searchable and accessible, implemented as a geodatabase within a Geographic Information System (GIS). The database will store relevant information about each map, such as the level, title, author, and the information contained, so that searches on these key words are possible. In addition, the spatial extent of each map will be plotted so that they can be displayed along with other mine information including drifts, ramps, shafts, and geology, enabling users to search for maps spatially as well as by theme or keyword. Once the desired maps are identified, the user will be able to open a scan of the map and display it with the other information and other maps in a single seamless map. The project will entail designing the geodatabase and implementing it for a small number of maps on the 4850 level, prior to initiating a major development effort to include all the holdings. 8-3 BTH 9 Hladysz, Zbigniew J. [171875] GEOTECHNICAL CHARACTERIZATION OF EXCAVATIONS FOR THE DUSEL CONSTRUCTION HLADYSZ, Zbigniew J., Mining Engineering and Management, SD School of Mines and Tech, 501 E. St. Joseph Street, Rapid City, 57701, Zbigniew.Hladysz@sdsmt.edu and ROGGENTHEN, W.M., Dept. of Geology and Geol. Eng, SD School of Mines and Tech, 501 E. St. Joseph Street, Rapid City, SD 57701 The Deep Underground Science and Engineering Laboratory (DUSEL) being planned at the site of the former Homestake Gold Mine in Lead, SD, will host physics experiments which require shielding from cosmogenic radiation. Therefore, current plans include the construction of rooms for these experiments at depths of 1.48 km (4850 ft) and 2.25 km (7400 ft) below the surface. The standard laboratory modules will consist of excavations between 50 and 100 m in length and 20 m in width. The long baseline experiment, however, will involve sending a beam of neutrinos through a chord of the Earth from northern Illinois to intercept a large detector at the 4850 level of the laboratory in Lead, SD. If it is determined that this will be a water detector, it will require one or more large cavities to be excavated that may be in the form of a right cylinder with a diameter 2010 GSA Rocky Mountain Section Meeting 7 SESSION NO. 8 of 55m and a height of 60m. These detectors would constitute the largest previous excavations at this depth by far. Construction of the cavities required the development of a geotechnical characterization program including preliminary drilling and coring, site mapping, in-situ stress measurements, and laboratory characterization of rock mechanics properties. The goals of the geotechnical work include delineation of prospective sites for the cavities. The Yates Member of the Poorman Formation, a metabasalt which is the preferred rock unit, has good rock qualities for the construction although the site may be complicated by the presence of Tertiary-age rhyolites. The rock quality at the currently identified site is excellent and the plans for the excavations are proceeding on schedule. 8-4 BTH 10 Cooper, Scott P. [172052] GAS-FLUID EVOLUTION AND THE FORMATION OF RHYOLITE DIKE-ASSOCIATED BRECCIA MARGINS, HOMESTAKE MINE, LEAD, SOUTH DAKOTA COOPER, Scott P.1, UZUNLAR, Nuri2, and LISENBEE, Alvis L.2, (1) Enhanced Oil Recovery Insitute, University of Wyoming, 1000 E. University Ave, Department 4068, Laramie, WY 82071, scott@fracturestudies.com, (2) Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995 A north-trending swarm of six to ten rhyolite dikes (individuals up to several meters wide) extends from the surface Open Cut mine to the 2440 m (8000 ft) mine level in underground workings of the former Homestake Mine. Associated breccia dikes consist of angular (chiefly rhyolite)-toextremely rounded (black schist and rhyolite) clast-supported xenoliths (to 10 cm) in a matrix of black, disarticulated, fine-grained schist fragments. In the unique mine setting breccias dikes are exposed along the crests and margins, especially the footwalls, of the east-dipping rhyolite dikes and extend upward into the Precambrian or Cambrian country rock. Such dikes vary in width from a maximum of 10 m in the upper workings to a few centimeters at their greatest depth of 1950 m (6400 Level) where they are located at the upper tips of small rhyolite dikes. Fluid inclusions in Tertiary veins are saline (up to 10% halite and sylvite inclusions) at depths below the present 880 m (2900 ft) mine level indicating a magmatic fluid origin, as δ18O values of 11.4 to 16.9 per mil for vein quartz. Above the 880 mine level fluid inclusions contain CO2 indicating evolution of a gas phase. Regional stratigraphic reconstructions show that about one kilometer of Phanerozoic strata covered the mine area at the time of dike emplacement. It is interpreted that the explosive release of magmatic-hydrothermal fluids from the magma occurred at depths to approximately three kilometers and that the release of CO2 gas, which may have added to the force of explosive behavior, occurred at about two kilometers. The explosions drove the breccia upward into the country rock and rounded and reduced the size of clasts by the process of autogenous milling. The resulting breccias served as hydrothermal passageways, were strongly annealed and, locally, were mineralized with combinations of fluorite, pyrite, molybdenite, lead and gold. Larger breccia dikes at shallower depths suggest either that explosive forces produced more clasts there or that breccias carried upward from lower levels coalesced into larger bodies. 8-5 BTH 11 Uzunlar, Nuri [172053] TERTIARY EPITHERMAL-MESOTHERMAL AU-AG MINERALIZATION IN HOMESTAKE MINE, LEAD, SOUTH DAKOTA UZUNLAR, Nuri, PATERSON, Colin J., and LISENBEE, Alvis L., Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995, nuri.uzunlar@sdsmt.edu Tertiary epithermal-mesothermal Au-Ag deposits in the northern Black Hills are spatially associated with intrusive domes in a WNW-trending alkalic igneous province, and include sedimenthosted, igneous- and breccia-hosted, and schist-hosted varieties. A 2,424 m (8000 ft) deep exposure of intrusion-related, schist-hosted mineralization is in the Homestake mine. Fluid inclusion trapping temperatures decrease gradually upwards from 480°C to 350°C in schist-hosted mineralization to the Precambrian-Cambrian nonconformity, where there is a sharp decrease in temperature to 170° to 300 °C in sediment-hosted deposits. Salinities are mostly less than 10 wt%, with minor occurrences of inclusions containing daughter halite and sylvite. Fluid composition changes from saline at depth, to a CO2-bearing fluid at intermediate levels, to a dilute aqueous fluid above the nonconformity. Igneous rock δ18O values are 8-13 per mil, and Tertiary vein quartz δ18O values are 11.4 to 16.9 per mil. Ore fluid δ18O values are 8.5 to 12.4 per mil below the 3000 level but decrease sharply to 1.7 to 4.4 per mil in the Deadwood Formation above the nonconformity. Together with fluid inclusion δD values of -47 to -91 per mil, the isotope data are consistent with the deep fluid being magmatic. The decreases in δ18O, temperature, and salinity at the nonconformity suggest that the magmatic fluid mixed with a meteoric water, a likely cause of ore deposition in sediment-hosted deposits. Associated metals Mo, W, and Bi are suggestive of a magmatic source. Previous lead isotopic data indicate a source from hydrothermal leaching of the Precambrian crust or crustal contamination of the Tertiary magmas. Although the Tertiary mineralization is clearly related to the alkalic igneous activity, the identity of the causative magma is unclear but is suspected to be deeper than presently exposed mine levels.∂ SESSION NO. 9, 8:00 AM a vertical resolution (representing deformation) of less than 1 cm. One of the more recent applications of InSAR is the evaluation of subsidence resulting from groundwater withdrawal. InSAR has proven an invaluable tool in assessing aquifer system response to groundwater use in the arid West as well as other locations. This study documents surface deformation resulting from Coal Bed Methane (CBM) production within the Powder River Basin in Eastern Wyoming. CBM production involves pumping large volumes of water (as much as 68,000,000 barrels or 8,700 acre-feet, per month, basin wide). Research performed at a newly established InSAR processing laboratory at the South Dakota School of Mines and Technology has documented multiple sites within the Powder River Basin where several centimeters of surface subsidence has occurred over areas as large as 200 square kilometers. These results may have implications for potential efficiency improvements in CBM production as well as for improved oversight and water management in the region. 9-2 BTH 13 Smith Barnes, Connie K. [171945] ARCGIS MAPPING DISPLAYS HYDROGEOLOGIC SURVEY DATA AESTHETICALLY, ACCURATELY AND EFFICIENTLY FOR SCIENTIFIC AND NON SCIENTIFIC ANALYSIS SMITH BARNES, Connie K.1, BRADFORD, Joel A.1, DINKLAGE, William1, BISHOP, Nate1, BUNDS, Michael P.1, VANWAGONER, Marc E.2, REY, Kevin1, and HORNS, Daniel1, (1) Earth Science, Utah Valley University, 800 West University Parkway, Orem, UT 84058, 10324558@ uvlink.uvu.edu, (2) 4975 South 3200 West Taylorsville, Salt Lake City, UT 84118 Tamaula, a village of approximately 400 residents in the State of Guanajuato, Mexico, is located near the top of a Pleistocene shield volcano in the Trans-Mexican Volcanic Belt. The objective of this project was to use ArcView-GIS 9.3 to create several maps of this area using data management tools to display the hydrogeologic survey, and spatial analyst to identify strategic locations for cisterns. Tamaula’s population previously relied on three local sources for water: six natural springs, two reservoirs, and rooftop catchment systems. These sources were insufficient, and additional water had to be trucked over 10 miles of dirt roads. In May 2007 and 2008 students and faculty from Utah Valley University conducted a detailed geologic and hydrologic survey of the area and proposed several potential well sites for drilling. In 2009, the UVU Earth Science Department arranged for drilling of a 50m well close in proximity to a natural spring 1 km above the village. The well was successful and yielded approximately 40 liters per second. In 2010, we conducted an additional field study and assisted the May Foundation in piping the well water down to the village into a 4000 liter cistern, providing the villagers with a local source of culinary water. Drawdown tests performed indicate that the well is in a perched aquifer system with a limited amount of water. Further development of rooftop catchment systems (cisterns) may supplement well usage and permit sufficient recharge to the aquifer. GPS was used to exact coordinates for the Hydrologic survey. Mapped features included seeps, springs, wells, outcrops, fracture traces and contour elevations. Field notes and coordinates were added to the map for efficiency in field work. The second map displays several views identifying homes, tabulated survey data and graphical information. ArcMap was used as a tool to correlate ground hydrologic features with patterns identifiable in area photos that included potential well sites and strategic cistern locations. Mapping assisted scientists in evaluating the hydrogeologic and environmental surveys. The maps instructed the villagers regarding the projects that included well drilling, monitoring well usage and cistern construction. Our goal is to assist and enable the people to preserve a local, sustainable source of culinary water. 9-3 BTH 14 Thaler, Terry [171830] MULTITEMPORAL REMOTE SENSING OF VEGETATION IN THE CHEYENNE RIVER WATERSHED OF SOUTH DAKOTA AND WYOMING THALER, Terry, Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, tlthaler@knology.net and PRICE, Maribeth H., Geology and Geological Engineering, South Dakota School Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701-3901 Monitoring vegetation in a watershed is important for understanding its overall condition and providing information on potential sediment runoff. Most runoff models use general vegetation characterizations or average conditions that do not take into account changes during wet or dry years. The increased availability and lowered cost of remotely sensed data in recent years opens new opportunities for using multi-temporal as well as multispectral techniques. This study attempts to characterize vegetation conditions in the Cheyenne River watershed of Wyoming and South Dakota as a preliminary step towards assessing runoff potential. The immediate goal is to determine which vegetation factors can be discerned from multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS) data, and to classify land cover based on vegetation changes over the growing season. The study was conducted using Enhanced Vegetation Index (EVI) values from 16-day L3 global 250m MODIS composites for 2008 (MOD13A1.A2008).We constructed an 18-band image containing EVI measurements from January to December 2008, with each band representing a 16-day composite of EVI values. Three composites with extensive cloud cover were excluded from the analysis, and cloud pixels in the remaining composites were masked using a threshold based on the red spectral band. The final 18-band image was classified using an unsupervised isodata classification. The resulting 30 classes were grouped into five superclasses by plotting representative class locations and visually inspecting them in GoogleEarth. The superclasses included forest, grassland, water/barren, cropland, and mixed vegetation. Each superclass exhibits distinctive shapes in plots of EVI versus calendar date. Additional separation within classes and characterization of vegetation condition will be attempted in the future with site visits, and with the addition of ancillary data such as soils and elevation. Wednesday, 21 April 2010 T8. GIS and Remote Sensing Applications in the Geosciences (Posters) Rushmore Plaza Civic Center, Rushmore H 9-1 BTH 12 Katzenstein, Kurt W. [171931] InSAR-IDENTIFIED SURFACE DEFORMATION RESULTING FROM COAL BED METHANE PRODUCTION IN THE POWDER RIVER BASIN, WYOMING KATZENSTEIN, Kurt W., Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, kurt.katzenstein@sdsmt.edu In the past two decades, Interferometric Synthetic Aperture Radar (InSAR) has been used to document surface displacements resulting from a myriad of anthropogenic and non-anthropogenic causes. InSAR allows for the delineation of these features with a spatial resolution that is orders of magnitude greater than traditional leveling techniques and even the most rigorous Global Positioning System (GPS) studies. Areas as large as 100 x 100 kilometers can be evaluated with 8 2010 GSA Abstracts with Programs 9-4 BTH 15 Saxton, Samantha [171841] A GIS GEOLOGIC MAP COMPILATION: THE MT. RUSHMORE QUADRANGLE, BLACK HILLS, SOUTH DAKOTA (1:24,000 SCALE) SAXTON, Samantha, Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, samantha.saxton@ mines.sdsmt.edu, REDDEN, J.A., Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, and TERRY, Michael P., Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701 On-going hydrologic studies in the central Black Hills (funded by the West Dakota Water Development District) are examining individual 7.5 minute quadrangles in order to create an atlas of aquifer characteristics for sedimentary and crystalline rocks. The first step in this effort is the creation of a geologic map. A published 7.5 minute geologic map for Mt. Rushmore quadrangle currently does not exist. Using ArcGIS, existing field geologic maps—prepared over a 40 year period by J. Norton and J. Redden—and structural data collected by S. Allard and students were digitized for publication by the South Dakota Geological Society (SDGS). Initially, the data were amalgamated and compiled onto a paper topographic map, verified and edited. The compilation was then drafted manually onto a Mylar topographic map. This Mylar map was scanned and the image was georefer- SESSION NO. 10 enced in ArcMap based on current SDGS quadrangle boundary data. A series of shapefiles were created and organized within a personal geodatabase and digitization started. Each layer (contacts, geology, structures, foliations, etc.) was attributed appropriately based on SDGS standards. The compilation of the geologic map helped identify areas needing additional field studies (underway) and allowed new interpretations of the complicated geology, e.g., recognition of rarely preserved early F1 structures. NW-trending units of phyllite, metagraywacke, metagabbro, metabasalt, granite and laterally discontinuous iron-formations are paralleled by the main existing faults. The major structures—primarily refolded folds and domes—also trend NW-SE, most likely reflecting the last major period of regional deformation. The southwestern portion of the mapping area is dominated by the massive Harney Peak granite and surrounding pegmatites, sills and dikes, e.g., that used for sculpting the presidents at Mt. Rushmore. Approximately 5% of the exposed geology is alluvium located along major perennial streams and several small outcrops of Tertiary gravel. Thus, most groundwater in this area is hosted by joints in crystalline rock or faults. 9-5 BTH 16 Zeitler, Joseph [171843] DESIGNING A SPATIAL MAP INDEX FOR GEOLOGIC MAP COLLECTIONS ZEITLER, Joseph1, BARKER, Paula2, MCKASKEY, Jonathan1, MORTON, Patrick1, and PRICE, Maribeth1, (1) Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, joseph.zeitler@mines.sdsmt.edu, (2) Department of Civil and Environmental Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701 The Department of Geology and Geological Engineering at the South Dakota School of Mines and Technology (SDSM&T) hosts an extensive collection of approximately 5,000 maps of geologic interest covering South Dakota and surrounding states, as well as other parts of the world. Some of these maps are publicly available, but others are unpublished or out of print. Currently the collection exists with only a card catalog indexed by author, theme, and location. The entire collection will soon be transferred to the new building housing the Paleontology Research Center. Students at SDSM&T are designing a spatial index for this map collection, implemented as a geodatabase within a Geographic Information System (GIS). The card index information will be entered in a spreadsheet and then into the GIS. The spatial extent of each map will be plotted as polygons to show its location and area of coverage. Additional background map data such as roads, states, counties, and geology will also be compiled for display with the map extents, enabling a user to search for maps spatially as well as by author or keyword. Eventually, each map will be scanned and georeferenced to give the user immediate digital access to the information that can be implemented within a GIS. The students are designing the format and structure of the geodatabases, and will implement it for a few dozen maps, providing a framework for eventual completion of the entire collection. Maps acquired in the future, or generated by student theses, will also be added to the collection. SESSION NO. 10, 1:20 PM Wednesday, 21 April 2010 ‘Virtual-Reality Field Trips’ project was developed over the past three years and published nationwide in January, 2010. Central to the design was data collected from surveys of geology teachers for identifying the ‘most critical’ concepts in a introductory-level geology course. A total of thirty concepts were then linked to the most appropriate national park. After creation of storyboards for each park, the author collected the highest-quality media footage from the parks - including highresolution photographs, high-definition video and 360-degree panoramas. A demonstration of the Field Trip modules will be given using the concept of Sedimentary Rocks and the setting of the Arches National Park and Capitol Reef National Park. Key features of the module will be highlighted, both from the teacher and a student perspectives and will include a discussion of techniques used for increasing a student’s Time-on-Task, promoting interactivity and critical-thinking skills by mimicking an actual field-trip experience wherein a participant can exercise free-will as for choosing where to go and what to see while in the field. 10-3 2:00 PM Breithaupt, Brent H. [171797] PUBLIC PALEONTOLOGICAL SITES AS TEACHING TOOLS IN GEOLOGY FIELD CAMPS: RESOURCE PROTECTION THROUGH RESOURCE EDUCATION BREITHAUPT, Brent H., Wyoming State Office, Bureau of Land Management, Cheyenne, WY 82003, Brent_Breithaupt@blm.gov, CAMPBELL-STONE, Erin, Department of Geology and Geophysics, University of Wyoming, 1000 E. University Ave, Laramie, WY 82071, and MATTHEWS, Neffra A., National Operations Center, USDOI-Bureau of Land Managment, Denver, CO 80225 The summer field camp program at the University of Wyoming (UW) was founded in 1923 by Samuel H. Knight of UW and James Kemp of Columbia University. These renowned geologists built the summer field program into one of national acclaim by utilizing Wyoming’s unique geological resources to teach important concepts. Today, UW’s field camp continues to attract students from around the country, exposing them to the wonders of western geology in Wyoming and neighboring states. Over the past decade, the class has successfully utilized world-class paleontological field sites under active study by UW students and staff. This holistic, hands-on approach weaves together paleontology, sedimentology and stratigraphy, as well as public outreach and resource management practice. Two unique ichnological sites have been utilized in class activities. The Middle Jurassic Red Gulch Dinosaur Tracksite in the Bighorn Basin of northern Wyoming and the Late Jurassic Seminoe Reservoir Tracksite in central Wyoming are managed (by the Bureau of Land Management and Bureau of Reclamation respectively) and preserved for current and future generations. Although most paleontological sites are unavailable for public visitation, public land sites such as these can be unique educational tools. Student activities at these sites range from scientific documentation and interpretation to management and protection discussions, exposing students to concepts of resource protection through resource education and allowing greater appreciation of public lands and resources. Working in small groups, summer camp participants make observations, collect data, and develop their own interpretations regarding the geologic history of particular localities. Importantly, researchers actively working at the sites visited with the field program’s students to walk them thought the actual process of investigation, interpretation, and management. Thus, students were exposed to both traditional (e.g., on the ground measuring and mapping) and state-of –the art documentation technologies (e.g., photogrammetry) and learned where research observations interface with research interpretations. Geoscience Education 10-4 Rushmore Plaza Civic Center, Alpine Room 10-1 1:20 PM Uzunlar, Nuri [171862] TRADITIONAL FIELD CAMPS: AN IMPORTANT INTEGRAL COMPONENT IN GEOSCIENCES EDUCATION UZUNLAR, Nuri, Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, nuri.uzunlar@sdsmt.edu and LISENBEE, Alvis L., Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995 Most field camps are traditional mapping-based geology field camps, but an increasing number are being substituted by environmental science, hydrology, and geophysics. As a result the number of traditional geology field camps is declining, although a majority of the Bachelors of Science degrees in geology/earth science still require some type of field experiences as part of the core curriculum. Many departments are allowing for field experiences other than formal field camps to be used to fulfill this requirement. Instead of the summer course an increasing number of schools offer semester field courses and/or a wide range of field trips and short weekend field experiences to introduce students to field techniques. Additionally fewer graduate programs are requiring field camp as a prerequisite for acceptance to graduate school. The combination of changing undergraduate requirements, decreased demand from graduate programs and the high costs of summer field courses, has led many students in departments to pass up the opportunity to gain valued field training. Most professionals from industry and many from academia agree that field experience is an important and unique component of geoscience education, that it provides a hands-on approach to education and that it should be encouraged as an integral part of professional training. Students who attend the traditional geology field camps offered by Black Hills Natural Sciences Field Station in the US and Turkey express their experience in following testimonial “ I learned more about geology in five weeks than I did in four years” 10-2 1:40 PM Sethi, Parvinder [172246] VIRTUAL REALITY FIELD-TRIPS FOR STUDYING THE GEOLOGY OF NATIONAL PARKS: RECENT ADVANCES & PEDAGOGY SETHI, Parvinder, Department of Geology, Radford Univ, Box - 6939, Radford, VA 24142-6939, psethi@radford.edu Engaging and retaining the interest of the typical non-science Major in an Introductory Geology course has been the Holy Grail of geoscience education. Even as debate continues about which segments of a student’s K-12 background should be strengthened, there is much that can be achieved, at the college level itself. Recent advances in multimedia technology and educational pedagogy of learner-styles have brought educators at a point-of-convergence, to re-think and re-tool what we would like to teach with more efficient, interactive and effective techniques. Just because virtual reality field-trips have been authored since two decades should not mean that we as technologically- and pedagogically-savvy educators should not re-design a time-tested idea. In fact, it should position us educators at a considerable advantage, so we can choose elements that have worked in these models and discard those that have not. This paper showcases a new model for creating virtual-reality field-trips for studying geology using the U.S. National Parks - a model which draws heavily on successes from the past and re-designs them with State-of-the-Art instructional technology available to educators today. The 2:20 PM Friberg, LaVerne M. [171802] UNIVERSITY OF AKRON FIELD CAMP, THE CAPSTONE COURSE FOR OUR GEOSCIENCE MAJORS FRIBERG, LaVerne M., Geology and Environmental Science, The University of Akron, Department of Geology and Environmental Science, The University of Akron, Akron, OH 44325-4101, lfribe1@uakron.edu Field camp has been a six credit capstone geology course since 1970 at the University of Akron. It began as a traditional six week course operating out of Casper College in Casper Wyoming. The format and base locations changed in 1991 to three different geographic locations. Field camp begins in the Black Hills, SD followed by Big Horn Mountains and Big Horn Basin and finishing in the Seminoe Mountains of south-central Wyoming. Multiple locations give the students a better opportunity to study variations in stratigraphy and structure in three different geographic areas. We changed from a single six credit course to two, three credit courses (GFC I and GFC II) in 1996 because of the high number of non-traditional and working students in our undergraduate geology program at the University of Akron. The format allows the student the flexibility of taking both courses in one summer or spread it out over two summers. A majority of the students elect to take both courses in one summer at the end of either their junior or senior year. Students electing to take field camp over more than one summer can take GFC I as early as the end of their sophomore year and generally take GFC II at the end of their senior year. The split in the course also affords students from other universities, that do not require a full 6-8 week field camp experience, to take either GFC I or GFC II depending on their undergraduate preparation. The format of the courses has remained consistent since 2004. We added GPS, and computer based GIS in the summer of 2004 for exercises in areas of low relief and/or dense forest cover where mapping on a traditional topographic base is difficult.GFC I is used for instruction in the basic field techniques of mapping structures and formations. The exercises are a series of one or two day group projects. GFC II involves more individual mapping and more in-depth interpretations of the geologic history based on the maps the students have created. Projected enrollment for summer 2010 GFC I field camp of University of Akron Students are at the highest, since our transition to two three credit courses in1996. The number of off-campus applicants also has increased for 2010. 10-5 2:40 PM Moshier, Stephen O. [171888] HISTORY AND FUTURE OF GEOLOGY FIELD INSTRUCTION AT THE WHEATON COLLEGE SCIENCE STATION, SOUTH DAKOTA BLACK HILLS MOSHIER, Stephen O., Geology and Environmental Science, Wheaton College, 501 College Ave, Wheaton, IL 60187, stephen.o.moshier@wheaton.edu and GREENBERG, Jeffrey K., Geology, Wheaton College, Wheaton, IL 60187 The Wheaton College Science Station in the Black Hills, South Dakota is the western outpost of Wheaton College, Illinois. The program was established in 1935 for undergraduate field instruction in biology and geology. The typical summer program includes the traditional geology-mapping course for geoscience majors along with advanced courses in zoology, botany and ecology for biology majors, and introductory science courses for non-science majors (offered to complete general education requirements). Thus, the scientific community of learners assembled each summer at WCSS is more diverse than at a traditional geology field camp. Advantages include the cross-disciplinary interactions of faculty and majors from different disciplines and the “full emersion” experience for non-science majors taking general education science courses. Non-science majors bring their perspectives and talents to enhance the community experience. The 4-week introductory geology course taught in the field setting is far superior to the equivalent (4 cr. hr.) 2010 GSA Rocky Mountain Section Meeting 9 SESSION NO. 10 semester course taught on campus, in terms of meeting assessment outcomes and student satisfaction. The geology major program includes two courses that run concurrently over eight weeks. Studies in Rocky Mountain Regional Geology is a 2 cr. hr. course that pertains to all field trips in the Black Hills region and a “capstone” expedition in the eighth week to Yellowstone country. Students are required to lead field-stop presentations and discussions along the way, keep a journal, and answer study questions. Field Geology is a 6 cr. hr. course that includes traditional and innovative field projects, such as measuring and drafting stratigraphic sections, quantitative analysis of structures, field mapping of various bedrock terranes, and assessment of geologic resources, including surface and groundwater. An important shift in emphasis in the past 20 years is in the application of field methods from resource exploitation to environmental management. GPS and GIS technology is increasing in use and importance in the course, as the technology develops and becomes more affordable. For the future, we wish to introduce courses and experiences for students to use the campus for study and research in sustainable development, drawing on local resources, environmental setting, and culture. REE patterns vary between fossilliferous locations, three levels of statistical comparison were completed. Thirty-three in situ fossils were collected from an outcrop in the Big Cottonwood Creek Member. Through discriminant analysis and cladistical representation, we demonstrate that these samples can be matched to each of the three facies from which they were collected. These samples were then compared to fossils from two other areas of the park that lie within the Peanut Peak Member. Fossil samples from these three sites can be matched to their original location 85.5% of the time. On a much broader scale, we compared all the specimens collected from Toadstool Geologic Park to 81 samples previously collected in Badlands National Park and found that the fossil bones can be associated with their park of origin 98.6% of the time. These data suggest that REE fingerprinting can help to pinpoint the area from which a fossil was stolen when the specimen is compared to a database of catalogued fossil sites. When coupled with a sound understanding of the geology and taphonomy of bone beds, REE fingerprinting may become a useful addition to the toolbox of current law enforcement methods to protect fossil resources on federal lands. 10-6 11-3 3:00 PM Toth, Natalie [172075] THE SOUTH DAKOTA SCHOOL OF MINES AND TECHNOLOGY’S SCIENCE EDUCATION OUTREACH PROGRAM: EXPOSING YOUNG, INQUISITIVE MINDS TO THE WONDER OF SCIENCE TOTH, Natalie, BROWN, Rachel, and SHELTON, Sally, Museum of Geology and Department of Geology and Geological Engineering, South Dakota School of Mines and Techonology, 501 East St. Joseph St, Rapid City, SD 57701, natalie.toth@mines.sdsmt.edu The South Dakota School of Mines and Technology Science Education Outreach Program works to expose students to the disciplines of science that are not part of the traditional core curriculum at their grade level. The Museum of Geology, along with various student organizations, such as PaleoClub, Tech Geologic Association (TGA), and the Society of Economic Geology (SEG), allows undergraduate and graduate students the opportunity to create and execute demonstrations for K-12 students touching on the concepts of paleontology/fossils, rocks and minerals, plants and animals in the Black Hills, and hydrology/groundwater. The presentations are unique in that they can be formatted to fit any grade level, in any location, and also allow teachers the option to incorporate the various themes into their own curriculum, while still meeting educational standards of the State of South Dakota. When a local school or organization requests an outreach subject, the School of Mines will provide teaching kits, as well as an outreach instructor (an undergraduate or graduate student from SDSM&T). These kits include books and manuals, pertinent information, hands-on activities, and even how to incorporate the presented topic into other subjects aside from science. In the case that an Outreach instructor cannot be provided when requested, the teaching kits are equipped with guidebooks for instruction to be used by the teachers to make use of in their classroom. A future goal of the Science Education Outreach Program is to provide open teacher and group leader training on using and incorporating the teaching kits in the curriculum. Similarly, students involved with the Scouts of America could have the opportunity to earn their Geology Merit Badge through work with the earth sciences in both the classroom and the field. The Science Education Outreach Program through SDSM&T will work to build a stronger connection between the community and college while exposing the youth to aspects of science they may not encounter in the classroom on a regular basis. SESSION NO. 11, 1:20 PM Wednesday, 21 April 2010 T7. Geological Studies in National Park Service Areas of the Rocky Mountain Region Rushmore Plaza Civic Center, Ponderosa Room 11-1 1:20 PM Connors, Tim [171845] THE NATIONAL PARK SERVICE GEOLOGIC RESOURCES INVENTORY; GEOLOGY ISN’T JUST FOR SCENERY ANYMORE......2010 UPDATES CONNORS, Tim, Geologic Resources Division, National Park Service, 12795 West Alameda Avenue, Denver, CO 80225, Tim_Connors@nps.gov The National Park Service (NPS) Geologic Resource Inventory (GRI) Program is a systematic approach to gather and disseminate useful digital geologic information to support natural resource management in some 270 NPS units with “significant” natural resources. This involves documenting the features, issues and processes specific to that park and to make a “crosswalk” between a digital geologic map and these features, issues and processes. Numerous steps are involved in completing a park’s GRE including conducting scoping meetings, assembling geologic bibliographies of all known applicable references, producing digital geologic maps (bedrock, surficial, abandoned mines, caves, coastal features, etc.), and then assembling all of this information into a usable database. Many cooperators are active in the entire process (federal, state, academic, private etc.)and contribute at various levels from educating park management on geologic resource issues to actually producing geologic field maps. The end result of this multifaceted cooperation is better stewardship of geologic resources in NPS areas for the enjoyment of future generations. 11-2 1:40 PM Lukens, William E. [171901] TRACKING STOLEN FOSSILS: A STUDY TO DETERMINE THE UTILITY OF RARE EARTH ELEMENTS AS A TOOL FOR VERTEBRATE FOSSIL PROTECTION LUKENS, William E.1, TERRY, Dennis O. Jr1, GRANDSTAFF, David E.1, and BEASLEY, Barbara A.2, (1) Earth and Environmental Science, Temple University, 326 Beury Hall, 1901 N. 13th St, Philadelphia, PA 19122, william.lukens@temple.edu, (2) USDA Forest Service, Nebraska National Forest, 125 N. Main Street, Chadron, NE 69337 Although the Omnibus Land Management Act of 2009 provides harsher penalties to fossil poachers, no reliable, objective method exists to test whether or not a fossil bone was excavated from federal lands. Rare earth element (REE) fingerprinting is a potentially useful tool to match stolen bones to their original localities. REE are adsorbed onto bone apatite during fossilization, imparting a signature that is both independent of faunal type and reflective of pore water chemistry. Thus, as groundwater chemistry varies through time and space, associations of fossil bones will have different concentrations of the REE series. In this study, 62 samples of fossilized brontothere and tortoise remains were collected from three outcrops of the Eocene Chadron Formation located within Toadstool Geologic Park, northwest Nebraska. To understand the degree to which 10 2010 GSA Abstracts with Programs 2:00 PM Wiles, Michael E. [171933] THE POTENTIAL EXTENT OF THE JEWEL CAVE SYSTEM: FINE-TUNING A GIS MODEL WILES, Michael E. and OHMS, René E., Division of Resource Management, Jewel Cave National Monument, 11149 US Highway 16, Custer, SD 57730, Mike_Wiles@nps.gov Previous research at Jewel Cave has shown a direct relationship between airflow at the entrance and the prevailing atmospheric pressure. This barometric airflow was used to estimate a total minimum cave volume of 1.1 x 108 m3, of which less than three percent has been discovered. The minimum areal extent of Jewel Cave was derived from estimated volume, as well as 1) the thickness and distribution of the Madison Limestone; 2) the potentiometric surface of the Madison aquifer; 3) the location and extent of potential geological obstacles; 4) the three-dimensional distribution of the cave systems within the host rock; and 5) the “cave density” at Jewel Cave and Wind Cave. Based on the calculated cave volumes and an estimated 9.3 x 1010 m3 of available limestone, the overall cave-to-rock ratio was calculated to be 0.18%. This was at the low end of the range of known “cave density” values for Jewel Cave and Wind Cave, 0.15-0.59%. New field-mapping of geologic structures has given reason to revise the boundaries of the cave potential model. With these adjustments, it appears that more of the predicted volume must exist in an area between Jewel Cave and Wind Cave; and that the new predicted value for “cave density” correlates more closely with actual values for known cave passages. The new calculations strengthen the possibility that the two volumes could be part of one large cave system. This research refines a tool that has successfully been used in support of efforts to protect the park’s primary resource, even the portions that are as-yet undiscovered. Those efforts include two mineral withdrawals and a land exchange. 11-4 2:20 PM Andersen, Allen [171796] GEOCHEMISTRY OF INKPOT SPRING, SULPHUR CREEK-SEVENMILE HOLE AREA, YELLOWSTONE CALDERA, WYOMING ANDERSEN, Allen, School of Earth and Environmental Science, Washington State University, 454 Webster Physical Sciences Building, Pullman, WA 99164-2812, a@ndersenonline.net The Yellowstone hydrothermal system consists primarily of meteoric water circulating to deep levels within and just outside of the Yellowstone Caldera (640 ka), Wyoming. Inkpot Spring is a small group of bubbling pools located adjacent to the hypothesized northern margin of the Yellowstone Caldera. Here, the Yellowstone hydrothermal system is vapor-dominated. Inkpot Spring fluids have previously been classified as acid-sulfate waters. This study presents evidence for multiple water types contributing to surface fluids at Inkpot Spring. The complex chemistry of fluids at Inkpot Spring can be attributed to mixing of multiple water types, boiling, and water-rock interaction. The geologic setting of Inkpot Spring allows fluids to react with multiple rock types during their ascension to the surface. High concentrations of mercury, boron, ammonia, and volatile light hydrocarbons at Inkpot Spring suggest that petroleum is flushed from Paleozoic or Mesozoic sediments and then distilled at high temperatures. Thermal fluids also react with basaltic andesites of the Absaroka volcanics, contributing high levels of iron, calcium, and magnesium, and producing a fluid supersaturated with pyrite. Although considered to be acid-sulfate waters, many of the pools at Inkpot Spring are near neutral. Excess ammonia combines with sulfuric acid, produced from oxidation of hydrogen sulfide, to produce ammonium sulfate and neutralize the fluids. Other possible factors controlling the amount of sulfuric acid and pH are oxidation of sulfide, disproportionation of SO2 in vapor, and sulfuric acid produced from sulfur-consuming bacteria (sulfolobus) in native sulfur deposits of buried solfataras from previous hydrothermal activity. An examination of fluid-mineral equilibria in Inkpot Spring fluids and suspended sediment has revealed several minerals at or near equilibrium with the fluids including kaolinite, alunite, opal, and montmorillonite (beidellite). This is consistent with an alteration mineral assemblage observed in the Grand Canyon of the Yellowstone River consisting of an association with quartz (opal) + kaolinite ± alunite ± dickite. 11-5 2:40 PM Brunhart-Lupo, Maria [171713] LUNETTES OF THE SAN LUIS LAKE RECREATIONAL AREA AND GREAT SAND DUNES, COLORADO BRUNHART-LUPO, Maria, Geology, Colorado School of Mines, 2415 Douglas Mountain Dr, Golden, CO 80403, mbrunhar@mymail.mines.edu The Great Sand Dunes and San Luis Lake Recreational Area is located within an embayment complex along the western side of the Sangre de Cristo Mountains, at a point where the range shifts from southeastern trending to south-southwestern trending. The aeolian sand sheets and dunes of the region of study, cover an area from the Dry Lakes in the south to Deadman Creek in the north. Within these sand sheets and aeolian deposits are well defined lunettes associated with recent and historic playa lake systems. While the largest of these lunettes is adjacent to the San Luis Lake Recreational Area, and therefore bears the marks of anthropological intervention concerning water levels in the lake, the remaining lunettes have been left in their natural state. These lunettes are of great interest pertaining to the paleoclimatic history and trends of the San Luis Valley in the lands surrounding the Great Sand Dunes. Recent work has shown that these lunettes appear to have a different internal structuring than that of typical lunettes, which may be tied to the climatic history of the region. SESSION NO. 12 11-6 3:00 PM Kowallis, Bart J. [171767] U-PB DATING OF ZIRCONS FROM THE SALT WASH MEMBER OF THE MORRISON FORMATION FROM NEAR CAPITOL REEF NATIONAL PARK, UTAH BRADSHAW, Richard W. and KOWALLIS, Bart J., Department of Geological Sciences, Brigham Young University, Provo, UT 84602, bkowallis@byu.edu Zircons were extracted and analyzed by laser ablation ICPMS from samples of both detrital sediment and altered ash beds found in the Salt Wash Member of the Morrison Formation from near the eastern boundary of Capitol Reef National Park. A sample from an altered volcanic ash near the top of the Brushy Basin Member gave an age of 151.2 ± 1.8 (2σ) Ma, compared to 150.0 ± 1.0 Ma age on sanidine previously reported for this same ash in Kowallis et al. (1998, ages recalculated with new decay constants). A second sample of altered volcanic ash from the Tidwell Member gave an age of 157.2 ± 1.9 Ma, very similar to the 156.7 ± 1.0 Ma age reported by Kowallis et al. (1998) on this same bed. Two samples of detrital zircon from the Salt Wash Member gave youngest age peaks of 151.6 ± 1.1 Ma and 148.5 ± 2.5 Ma, overlapping with the age of the Brushy Basin Member, but not with the Tidwell Member. These data suggest the possibility that the J-5 unconformity is located between the Salt Wash Member and the Tidwell Member, not between the Tidwell Member and the Summerville Formation. The ages also suggest that the span of time represented by the dinosaur bearing Brushy Basin and Salt Wash members of the Morrison Formation is fairly short, only about 2-3 million years. 11-7 3:20 PM Epstein, Jack [170542] INTERPRETIVE GEOLOGIC TRAILS IN NATIONAL PARKS; EXAMPLES FROM DETO AND DEWA EPSTEIN, Jack, US Geological Survey, MS926A, 12201 Sunrise Valley Drive, Reston, VA 20192, jepstein@usgs.gov The National Park Service requires scientific data to carry out its mission of management and interpretation of much of the nation’s public lands. Much of the unique scenery of the nation’s National Parks is based on their geologic character. Geologic mapping by the USGS, State Geologic Surveys, and academia forms the basis for a variety of potential interpretive publications including interpretive trail guides. Devils Tower National Monument (DETO), in the northwest corner of the Black Hills of South Dakota, is noted for its igneous intrusive monolith. The 2.8-mile Red Rock Trail circumnavigates and offers varied views of the tower. The hiker sees a variety of geologic phenomona, including the varied sedimentary rocks (Spearfish and Gypsum Spring Formations and the members of the Sundance Formation), and the effects of weathering on rocks of varied resistance to erosion. Park management was informed of concerns about stratigraphic uncertainties within some of these units and field investigations by geology majors was encouraged. Delaware Water Gap National Recreation Area (DEWA) in the Appalachian Mountains Valley and Ridge province along the border of northeastern Pennsylvania and New Jersey is the largest Park facility in the northeastern United States. DEWA attracts more than 4 million visitors yearly within the Boston-Washington urban corridor. Five interpretive trail maps have been prepared and designed for the general public and earth-science teachers. Stops along the trails illustrate many aspects of structural geology (folds, faults, fractures, unconformities), stratigraphy (OrdovicianDevonian sedimentary rocks), paleontology, geomorphology (origin of wind and water gaps), and Wisconsinan glacial geology. My ultimate goal was to coordinate with park officials to add biological and cultural information, and to make these multidisciplinary interpretive trail guides available to the public. SESSION NO. 12, 1:15 PM Wednesday, 21 April 2010 T11. Geology of Shale: From Source Rocks to Reservoir Rocks Rushmore Plaza Civic Center, Rushmore G 12-1 12-2 11-8 3:40 PM Gallin, William N. [171920] A FRESH LOOK AT FLUVIAL, PARALIC, AND MARINE STRATIGRAPHY IN THE JOHN HENRY MEMBER, STRAIGHT CLIFFS FORMATION, GRAND STAIRCASE-ESCALANTE NATIONAL MONUMENT, UTAH GALLIN, William N., Geology and Geophysics, University of Utah, FASB Rm. 383, 115 South 1460 East, Salt Lake City, UT 84112, w.gallin@utah.edu and JOHNSON, Cari, Geology and Geophysics, University of Utah, Salt Lake City, UT 84112 New outcrop and subcrop data from the John Henry Member of the Late Cretaceous (early Coniacian – late Santonian) Straight Cliffs Formation, Grand Staircase-Escalante National Monument, Utah illustrate regional nonmarine-marine stratigraphic correlations and address sequence stratigraphic models based on such correlations. Three measured sections and two logged cores (each >230 m), 2367 paleocurrent measurements, and examinations of lateral facies relationships were made. This data stratigraphically correlates to 43 measured sections and logged cores from previous work. Three facies associations identified in fluvial and paralic sections correlate to downdip marine and shoreline equivalents as follows: Facies association 1 (FA-1, the lowermost interval) consists of tidally influenced, laterally restricted fluvial channel belts, coastal mire, and shoreface sandstone. FA-1 correlates to a lower marine package that shows net progradation and consists of vertically thick, laterally extensive regressive shoreface sandstones intercalated with transgressive lagoonal deposits. Facies association 2 (FA-2, the middle interval) consists of laterally restricted, highly sinuous fluvial channel belts, lagoonal and estuarine coastal plain mires, bay-head deltas, isolated distributary channels and tidal channels. FA-2 correlates downdip with a middle marine package that shows net transgression and consists of vertically thin, laterally restricted regressive shoreface deposits intercalated with thick transgressive lagoonal deposits and barrier island sandstone. Facies association 3 (FA-3, the uppermost interval) consists of laterally extensive, low sinuosity fluvial channel belts and vertically amalgamated fluvial channel belt complexes, and floodplain overbank. The marine equivalent of FA-3 shows net progradation and consists of vertically thick, laterally extensive regressive shoreface sandstones intercalated with transgressive lagoonal deposits. Preserved within each marine package are multiple transgressive-regressive cycles, but the fluvial architecture does not appear to respond to this scale of cyclicity. The observed evolution of fluvial systems and the inferred relationship to relative sea level change is distinct from previous interpretations of these strata. 1:20 PM Pratt, Brian R. [171740] SYNCHROTRON IMAGING OF BURGESS SHALE FOSSILS: EVIDENCE FOR BIOCHEMICAL COPPER (HEMOCYANIN) IN THE MIDDLE CAMBRIAN ARTHROPOD MARRELLA SPLENDENS PRATT, Brian R.1, PUSHIE, M. Jake2, PICKERING, Ingird J.3, and GEORGE, Graham N.1, (1) Dept. of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada, brian.pratt@usask.ca, (2) Dept. of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7J 2T4, (3) Dept. of Geological Sciences, University of Saskatchewan, Sasaktoon, SK S7N 5E2 The Burgess Shale, a fossil Lagerstätte famous for its diversity of advanced Cambrian animals, onlaps a submarine fault scarp cutting the margin of a drowned carbonate platform in southeastern British Columbia. We conducted reconnaissance synchrotron X-ray fluorescence imaging of a handful of unweathered specimens belonging to several soft-bodied taxa. Using the HXMA beamline at the Canadian Light Source Synchrotron, this imaging affords an advantage over conventional elemental mapping in that much smaller quantities can be detected. Our analysis revealed that the composition of each fossil is distinct from its surrounding mudstone. Fe and S concentrations, for example, are especially high in the fossils, indicating precipitation of diagenetic pyrite influenced by decay. Marrella splendens Walcott 1912 is an elaborate, non-mineralized arthropod virtually always preserved compressed with a dark stain emanating from the thorax. This stain represents body fluids (most likely blood) that were expelled upon death or leaked out during decay. Elevated concentrations of Cu were observed in all five specimens scanned, mostly in the dark stain but also in other regions co-localized with the fossil, but not in other taxa or the matrix. We interpret this Cu enrichment as being due to the remnants of Cu-containing hemocyanin. Hemocyanin occurs widely in mollusks and arthropods, especially chelicerates and malacostracan crustaceans. It is utilized for transporting oxygen in the respiratory cycle. Because hemocyanin is a relatively poor oxygen-binding protein molecule (compared to iron-containing hemoglobin), Marrella likely lived in well-oxygenated waters. Given other evidence for the in situ nature of the Burgess Shale animals, rather than their transport from shallower water, this argues for fully oxygenated conditions along the fault scarp in a water depth of several hundred meters. Cu enrichment specifically in fossilized Marrella may be because this animal possessed comparatively more blood in the circulatory system of the thorax than contemporaneous Burgess Shale animals, or because of selective preservation of the blood components in the stain. The molecular clock age of the hemocyanin gene family coincides approximately with the Middle Cambrian age of the Burgess Shale, some half a billion years ago. 1:40 PM Egenhoff, Sven O. [171732] STORM DEPOSITION IN THE “ANOXIC” LOWER MISSISSIPPIAN UPPER BAKKEN SHALE OF NORTH DAKOTA - HOW DEEP WAS THE WILLISTON BASIN? EGENHOFF, Sven O., Geosciences Department, Colorado State University, Fort Collins, CO 80523-1482, sven@warnercnr.colostate.edu and FISHMAN, Neil S., U.S. Geological Survey, Box 25046 MS 939, Denver, CO 80225 Conventional depositional models for organic-rich mudstones typically envision tranquil sedimentation in anoxic marine environments. Recently, this paradigm has begun to shift because studies have revealed bed-load transport structures and erosion surfaces in mudstones. This study focuses on the influence of storms on sedimentary facies within the Lower Mississippian upper Bakken Shale, a major source rock in the Williston Basin, U.S. and Canada. Facies analysis of this shale unit reveals three distinct facies belts all containing significant amorphous organic material. On a transect from proximal to distal environments, these facies belts are: (1) a heavily bioturbated mudstone largely lacking sedimentary structures, (2) a laminated silt-rich mudstone with vertical bioturbation that partly disrupts sedimentary features, and (3) a radiolarian-rich mudstone with varying content of silt and clay. Storm deposits are evident in all facies belts as sub-millimeter thick fine silt laminae interpreted as distal tempestites. The occurrence of silt grains indicates that oxic/dysoxic water from the shallow-marine realm was transported into the deepest parts of the basin. Thus, it is unlikely that any facies belt was deposited in a continuously anoxic environment. The presence of vertical bioturbation in laminated silt-rich mudstones also argues against continuously anoxic conditions even some millimeters below the sediment-water interface. Only some of the radiolarian-rich facies, devoid of any trace fossils or tempestites, may reflect temporary anoxia, whereas others are rippled indicating bottom-current reworking during deposition. The upper Bakken shale represents a highstand unit, sandwiched between the overlying Mississippian Lodgepole Formation and the middle Bakken member. Although the basin center was at its greatest depth during periods of elevated sea-level, storms episodically influenced Bakken sedimentation, which indicates that this basin was a relatively shallow trough with maximum depth only slightly below storm wave base, perhaps <100 m. Thus, major organic-rich source rocks such as the upper Bakken shale can be deposited in relatively shallow water, above storm wave base, with tempestites being a major depositional feature. 12-3 2:00 PM Hill, Ronald [171832] BITUMEN FILLED FRACTURES IN THE BAKKEN FORMATION AND IMPLICATIONS FOR GAS SHALE SYSTEMS HILL, Ronald, Marathon Oil Company, 5555 San Felipe, Houston, TX 77056, ronaldjhill@ marathonoil.com Shales are an essential element in siliciclastic petroleum systems, acting as source rock, and seal. More recently, shales have been recognized as significant, albeit low quality reservoir rocks. In the last decade, greater effort has been focused on understanding the reservoir characteristics of shales, and the Devonian Bakken Formation has garnered significant attention. The Bakken Formation is the source rock for much of the petroleum contained in the Williston Basin and the middle Bakken siltstone/carbonate is the target of renewed oil exploration efforts. Geochemical analyses of oils from the Bakken petroleum system reveal differences in oils that are attributed to Bakken facies variability, and differences in source rock maturity. The oil geochemistry has provided insight into the evolution of the Bakken petroleum system. 2010 GSA Rocky Mountain Section Meeting 11 SESSION NO. 12 The Bakken shale contains sub-horizontal to vertical bitumen filled fractures and pores interpreted to have formed during petroleum generation. The fractures and pores are visible in both the upper and lower shale, and provide insight into migration of petroleum out of Bakken shale, suggesting fracture formation may have been an essential step in the migration process. The presence of large pores within the shale facies demonstrates development of significant pore systems is possible within the shale facies. Observations from the Bakken oil system may also provide insight into the development of gas shale systems. The cracking of retained petroleum to gas in shales is a significant source of gas for gas shales, and appears to be the primary reason marine shales that contain Type II, oil-prone kerogen can become gas charged systems at higher levels of thermal maturity. Assuming that bitumen filled fracture systems that developed in the upper and lower Bakken during petroleum generation and migration are the rule rather than the exception, this observation may help explain why marine, oil prone source rocks have the potential to deliver gas as gas shale systems. 12-4 2:20 PM Fishman, Neil [171625] CHERT BEDS IN THE UPPER DEVONIAN-LOWER MISSISSIPPIAN WOODFORD SHALE IN OKLAHOMA—POSSIBLE RESERVOIR ROCKS? FISHMAN, Neil1, ELLIS, Geoffrey2, PAXTON, Stanley T.3, ABBOTT, Marvin3, and BOEHLKE, Adam R.1, (1) U.S. Geological Survey, Box 25046 MS 939, Denver, CO 80225, nfishman@ usgs.gov, (2) U.S. Geological Survey, Box 25046 MS 939, Denver, CO 80302, (3) U.S. Geological Survey Oklahoma Water Science Center, 202 NW 66th, Bldg. 7, Oklahoma City, OK 73116 How gas is stored in shale-gas systems is a critical element in characterizing these potentially prolific, low porosity/permeability reservoirs. We have undertaken an integrated mineralogic, geochemical, and porosity/permeability study of the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, OK, at locations previously described through detailed stratigraphic and spectral gamma surveys, to further our understanding of possible mechanisms by which natural gas is stored in Woodford reservoirs in the adjacent Anadarko Basin. Rock types of interest in the Woodford are broadly divided into chert and mudstone lithofacies that display different characteristics. Woodford cherts (>85 wt% quartz, <5 wt% clays) have an average TOC content of 4.5%. Quartz, which occurs in cherts as mosaic or granular chalcedony, infilling radiolarian tests and composes much of the rock volume, formed diagenetically early from recrystallization of radiolarian skeletal parts. Organic matter in cherts is present as amorphous organic material (AOM) and fills micropores 1) between minute quartz crystals within chalcedonic masses; or 2) between the colloform, bulbous masses of chalcedony. In contrast, Woodford mudstones (26-77 wt% quartz, 10-40 wt% clays), are more organic rich (avg. TOC 13.1%), with organic matter largely present as AOM and Tasmanites microfossils. Quartz in mudstones is largely detrital but some is also authigenic monocrystalline “grains” infilling Tasmanites. Mercury injection capillary pressure analyses (at 50% Hg saturation) reveal that cherts have 1) variable porosity (0.59-4.90%), 2) low permeability (0.003-0.274 mD), and 3) small pore mean apertures (5.8-18.6 nm). In comparison, mudstone porosities are variable (1.97-11.9%), as are mudstone permeabilities (0.011-0.089 mD). Mean pore apertures of mudstones (6.2-17.8 nm) are similar to those of cherts. Microfractures also contribute to rock porosity, but appear to be lithologically controlled and are best developed in cherts (brittle), but poorly developed or absent in adjacent clay-rich mudstones (ductile). Owing to their porosity, Woodford cherts may provide important, overlooked sites of gas storage in the formation, and upon artificial stimulation may contribute a significant portion of the gas that is produced. 12-5 3:00 PM Cassle, Christopher F. [171833] DEPOSITIONAL ANATOMY OF A PHOSPHATE DOMINATED SOURCE ROCK SUCCESSION: THE MEADE PEAK MEMBER, PHOSPHORIA FORMATION, PERMIAN, USA CASSLE, Christopher F., Department of Geosciences, Colorado State University, Warner College of Natural Resources, Fort Collins, CO 80523-1482, cfcassle@cnr.colostate.edu and EGENHOFF, Sven O., Geosciences Department, Colorado State University, Fort Collins, CO 80523-1482 The late Permian Phosphoria Formation (late Leonardian to Guadalupian) is comprised of a sequence of marine sedimentary units of significant economic and scientific interest due to the presence of the world’s largest known phosphorite deposit. Additionally, the Phosphoria Formation has been reported to contain up to 32.9% total organic carbon locally, sourcing several oil fields in Wyoming. Deposition occurred along a westward-deepening ramp within the Phosphoria Sea, an epicontinental marine embayment covering approximately 400,000 Km2 of west-central Pangea (~ 20°N paleolatitude). Throughout most of the basin the Phosphoria Formation is composed of mixed carbonate-phosphorite-siltstone-chert sequences. Deposition of the organic-rich phosphorite members has been linked to marine upwelling based on the presence of phosphate, organic matter, and silt, in addition to modeled basin hydrography and wind patterns. The occurrence of phosphorite alone has often been used as the basis for identifying upwelling systems as most modern phosphate deposits involve this process. However, no modern upwelling systems act as satisfactory analogs for the Phosphoria Sea or sedimentary systems comparable to the Phosphoria Formation. This study focused on fine-scale stratigraphic relationships and microfacies analysis within the Meade Peak Member in order to illuminate the physical controls on deposition and the mechanisms responsible for phosphorite accumulation. Our results reveal that the abundant quartz silt was likely transported into the basin by marine processes due to the presence of traction structures such as ripples and intense marine bioturbation; rather than the previously suggested wind controlled mechanisms, postulated to drive upwelling. The organicrich phosphate deposits are often coarse-grained and characterized by significant reworking, indicating sedimentation in a relatively shallow-water, high-energy regime. The shallow nature and evidence of oxic conditions renders application of the traditional upwelling model difficult at best. 12-6 3:20 PM Emsbo, Poul [171952] METALLIFEROUS ORGANIC-RICH BLACK SHALES: WHERE DO THE METALS COME FROM? EMSBO, Poul, US Geological Survey, Denver Federal Center, MS 973, Box 25046, Denver, CO 80225, pemsbo@usgs.gov and BREIT, George N., U.S. Geol Survey, MS 964, Box 25046, Denver Federal Center, Denver, CO 80225 The amount of metal contained in metalliferous black shales (MBS) can rival or surpass any metal deposit on Earth. Historically there has been little consensus as to the source, means of transport, and deposition of these metals. The paradigm established over the last twenty years, however, suggests that the anomalous metal and carbon contents of these shales reflect oceanographic conditions, which enhance organic productivity/preservation and optimize extraction of metals from seawater. To date, no modern analogs of these ancient MBS have been found. Despite intense study, modern, euxinic and productive environments fail to form sediments with comparable metal enrichments and MBS. Moreover, mass balance constraints that consider the total mass and recharge of metal to the ocean, ocean circulation, and sedimentation rate suggest that typical 12 2010 GSA Abstracts with Programs seawater may not be an adequate source for the mass of metal present in some metalliferous black shales. Alternatively, the flux of metal delivered to the ocean during sedex hydrothermal events can be shown to rival their entire modern riverine fluxes into the ocean. Another overlooked aspect of sedex systems is the flux of nutrients (i.e. NH4, reduced C, trace metals, Ba, Si) that can also exceed the modern riverine flux. Significant nutrient fluxes into a sedimentary basin would undoubtedly trigger massive increases in primary bioproductivity and potentially basin-wide anoxic/euxinic conditions needed to form MBS. This model explains the temporal and spatial coincidence of anoxic/euxinic conditions, MBS, and sedex deposits through geologic time. 12-7 3:40 PM Pratt, Brian R. [171692] MOLAR-TOOTH STRUCTURE: CARBONATE MUD DIKELETS GENERATED BY SYNSEDIMENTARY EARTHQUAKES PRATT, Brian R., Dept. of Geological Sciences, University of Saskatchewan, Saskatoon, SK S7N 5E2 Canada, brian.pratt@usask.ca Molar-tooth structure is a synsedimentary feature in calcareous mudstones of mainly—but not exclusively—Precambrian age. It consists of striking arrays of closely spaced, upright veins, locally with horizontal sheets and spheroids. In plan view veins range from linear to reticulate. They are vertically to obliquely oriented, discontinuous, typically crumpled to squashed and even smeared, and often brecciated. The matrix is usually deformed; vein fragments are shingled or dispersed. These characteristics are evidence for variably directed compressional, tensile and shear stresses imposed sometimes repeatedly during the discrete rheological evolution of both components, beginning with liquefaction and plastic behavior and ending with brittle failure. Locally molar-tooth structure consists of micrite. However, usually it is composed of inclusion-free microspar crystals up to ~15 µm across. In some cases these crystals are seen to consist of calcite cement overgrowths on well-sorted rhombs and multi-faceted euhedra. These cores may be the original carbonate mud particles or a product of synsedimentary recrystallization. Depending on the composition of the host mudstone, silt and fine sand may be incorporated. Some recent explanations insist on precipitation of carbonate mud in voids created by gas generated by oxidation of organic matter. However, this mechanism cannot account for vein patterns, the concomitant sand and silt injection, and the complex and dynamic nature of the stresses indicated. The famous Pratt hypothesis, formulated in the early 1990s, calls upon cyclic loading during earthquakeinduced shaking which caused elevated fluid pressure and loss of shear strength. During abrupt dewatering, veins were jacked open by the injection of granular lime mud segregated from the matrix, and deformed by continued shaking. Vein fills quickly cemented and thus were prone to brittle failure during subsequent events, with the matrix becoming progressively stiffer each time. Molar-tooth structure opens a critical window onto the nature of Precambrian muddy sediments. Its near-absence in the Phanerozoic testifies to dramatic changes wrought by the evolution of microbial and multicellular life in the seas. SESSION NO. 13, 8:00 AM Thursday, 22 April 2010 T6. Recent Advances in Understanding the Geologic History of the White River Badlands I Rushmore Plaza Civic Center, Alpine Room 13-1 8:00 AM Benton, Rachel [170719] DEVELOPING A PALEONTOLOGICAL LOCALITY DATABASE AT BADLANDS NATIONAL PARK BENTON, Rachel, Badlands National Park, Interior, SD 57750-0006, rachel_benton@nps.gov Established in 2004, the Badlands National Park Paleontological Locality Database is the product of collaboration between paleontologists from the National Park Service and cooperating universities. A total of 253 sites have been recorded to date. Localities have been documented from Tertiary and Mesozoic stratigraphic units found within the park and include both invertebrate and vertebrate fossils. A locality is defined as a geographically contained area limited to one stratigraphic unit. When documenting a locality, paleontologists begin with the richest portion of the fossil accumulation and prospect to the outer boundaries of the deposit. The database consists of historical paleontological localities, fossil sites found through six years of surveys of the Poleslide and Scenic Members of the Brule Formation and recent discoveries made by researchers, park employees and park visitors. Over the past two years, Badlands National Park has received small grants to survey new areas where localities have not yet been documented. Each summer, a team of seasonal employees and interns prospect a designated area for potential new fossil sites. Once a locality has been defined, its geographic location is documented through the use of a Trimble GeoXT GPS unit and all locality information is stored in the park GIS database. The main portion of the Badlands National Park Paleontology Locality Database has been set up in Microsoft Access which contains the following information: stratigraphic position, major taxa, depositional environment, associated publications and a cross reference to research permits and museum records. A site assessment is also completed based on the following features: rates of erosion, access from public use areas, signs of poaching, abundance of fossils and the number of visits to the site. At present, funding can be obtained to inventory new fossil sites but not for monitoring. With the passage of the Paleontological Resource Preservation Act (Public Law 111-11), which mandates the protection of fossil sites on federal lands, it is hoped that funding can be obtained to complete follow-up monitoring as well. 13-2 8:20 AM Welsh, Ed [171703] FINDING SOMETHING NEW OUT OF SOMETHING OLD: AN INTRIGUING LEPTAUCHENINE OREODONT FROM THE UPPER BRULE IN SOUTH DAKOTA WELSH, Ed, Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. Saint Joseph St, Rapid City, SD 57701, edtwelsh@hotmail.com Fossil collecting in the White River Group has been done for over 150 years, with limited new information on the fossil fauna. A new find out of an old discovery, in this case, provides an opportunity to re-examine specimens that have been overlooked. The Museum of Geology, at SDSM&T, has a skull of Leptauchenia (Sespia) nitida that had been on display since the museum was founded. What is interesting about this particular specimen is the recorded stratigraphic location expands the genus Sespia below its traditional stratigraphic and biostratigraphic position. Previous work on biostratigraphy, chronostratigraphy, mangetostratigraphy, and lithostratigraphy has placed a physical boundary on the Whitneyan and Arikareean North American Land Mammal Ages at the contact of the Brule Fm. and Sharps Fm. in South Dakota as well as the Whitney mbr. SESSION NO. 13 and “brown siltstone” mbr. in Nebraska. That same work places Sespia well above the WhitneyanArikareean transitional marker. Measurements, taken under the convention of previous researchers, and morphological characters of the skull were used to validate the integrity of the initial identification. Measurements and morphology were compared to previously identified species and type specimens, which were used as taxonomic anchors. The study shows that this specimen is identified properly as Sepsia nitida. The lithology of the remaining matrix on the specimen was utilized to verify its geologic origin based on the recorded locality. The matrix secured to the skull is clay comparable to the Whitney member of the Brule Formation, as seen in Nebraska, which is close to the approximate physical location of the site where the specimen was collected. This new information from a skull collected about eighty years ago is providing new insights on the oreodont subfamily Leptaucheniinae and biogeography of Sespia. 13-3 8:40 AM Masciale, David M. [171735] A NEW ANALYSIS OF ANCHITHERINE EQUIDS ACROSS THE EOCENE-OLIGOCENE BOUNDARY IN THE WHITE RIVER GROUP OF THE WESTERN GREAT PLAINS MASCIALE, David M., Department of Geosciences, University of Nebraska-Lincoln, Bessey Hall, University of Nebraska-Lincoln, Lincoln, NE 68588, dmasciale@huskers.unl.edu and SECORD, Ross, Department of Geosciences, The University of Nebraska, 200 Bessey Hall, Lincoln, NE 68588 Anchitherine horses are a subfamily of equids that are abundantly represented in the late Eocene and Oligocene of North America. This group has been heavily studied in the past, but important questions remain. Some studies have focused on the Eocene-Oligocene boundary and have used these equids along with other taxa to study mammalian diet and climate change through this interval. We reexamine two anchitherine genera, Mesohippus and Miohippus, from stratigraphic sequences of the White River Group in western Nebraska and southwestern South Dakota. These sequences span the Chadronian (late Eocene), Orellan (Early Oligocene), and Whitneyan (early Oligocene) North American land-mammal ages. The most recent revision of these genera was done by Prothero and Shubin (1989) and we review the characters they used for taxonomic identification. This includes characters, such as the hypostyle and the articular facet on the third metatarsal, and dental dimensions. To avoid possible biases from combining specimens from different stratigraphic levels, we separated specimens by location and stratigraphic level. We measured the length and width of cheek teeth, and tooth rows of 488 specimens. First molar area serves as a proxy for body mass in horses and other mammals, and may be useful for distinguishing among species. We found that the morphological characters used by Prothero and Shubin were highly variable and were not useful for distinguishing between these genera. We suggest that the development of the articular facet on the third metatarsal is a function of body size and therefore is of no more use than the first molar area. Variability in the first molar area suggests the presence of 3 species in the medial and late Chadronian, 2 species in the Orellan, and probably at least 2 species in the early Whitneyan. Due to a lack of objective criteria separating Mesohippus from Miohippus, we recommend synonymy of these genera, making Mesohippus a junior subjective synonym. 13-4 9:00 AM Foss, Scott E. [171944] ENTELODONTS FROM THE BIG BADLANDS OF SOUTH DAKOTA FOSS, Scott E., Bureau of Land Management, Utah State Office, PO Box 45155, Salt Lake City, UT 84145, Scott_Foss@blm.gov Nearly half of all entelodonts have been described from the White River formations. The first, Archaeotherium mortoni, was described by Joseph Leidy in 1850 and is one of the first fossils described in North America from west of the Mississippi. Entelodonts are widely recognized as suiform artiodactys with distinct pendulous flanges developed from the jugal bone and at least one, but normally two, pairs of knob-like tubercles on the dependent margin of the mandibular ramus. Both of these derived features served a primary function of supporting a modified musculature that facilitated large gape. In the cases of extreme derivation, which is seen in ontogenetically older larger specimens, the flanges and tubercles had a secondary display function. Entelodonts display strong size dimorphism as well as ontogenetic variation. The jugal flanges and mandibular tubercles continued to modify, and in some cases enlarge, throughout the life of the animal. Thus, it is nearly impossible to find two identical skulls. The wide range of morphological variation has made it difficult to diagnose species within the family. The result has been that 56 species of entelodont have been described in the past 150 years, nearly half of these from the White River formations. Continuing study indicates that there are currently 10 recognizable species of entelodont representing two genera (Archaeotherium and Megachoerus) found in the White River formations of South Dakota. A third genus (Pelonax) is provisionally considered to be synonymous with Megachoerus. 13-5 9:20 AM Minkler, Heidi R. [171787] PALEOFAUNA FROM THE LATEST EOCENE CHADRON FORMATION, HIGHWAY 44 LOCALITY, IN SOUTHWESTERN SOUTH DAKOTA, AND ITS IMPLICATIONS CONCERNING THE EOCENE/OLIGOCENE TRANSITION MINKLER, Heidi R., Museum of Geology, South Dakoa School of Mines & Technology, 501 E. St. Joseph St, Rapid City, SD 57701, heidi.minkler@sdsmt.edu The Chadron Formation has been extensively studied for 150 years, but the assemblage from the Peanut Peak Member (late Chadronian (Ch3)) remains relatively poorly known. The Highway 44 local fauna from the upper Chadron Formation is important for understanding the climatic shift that occurred at the Eocene/Oligocene boundary. This assemblage aids in the determination of the proposed faunal turnover that has been given as evidence for climatic change. Within the Highway 44 assemblage are the first documented appearances in the South Dakota Chadron Formation of Serpentes and Cricetidae. The range of Metanoiamys, an eomyid known from the Uintan and Duchesnean of southern California and Saskatchewan, is extended upward to the late Chadronian. First appearances of the florentiamyid rodent, Ecclessimus, and the anguid lizard, Peltosaurus are extended from the Orellan to the late Chadronian. This assemblage when compared to other Chadronian and Orellan paleofaunas was found to be most similar to other Ch3 assemblages. The Highway 44 assemblage was found to contain approximately equal faual content from the Chadronian and Orellan paleofaunas suggesting this assemblage is near the Chadronian/Orellan transition. 13-6 9:40 AM Moore, Jason R. [171609] TAPHONOMIC MODES IN THE SCENIC MEMBER OF THE BRULE FORMATION: CONTINUOUS OR DISCRETE? MOORE, Jason R., Department of Geology and Geophysics, Texas A&M University, 3115 TAMU, College Station, TX 77843-3115, moore@geo.tamu.edu and KRUMENACKER, L.J., Geological Sciences, Brigham Young University, Provo, UT 84602 A taphonomic mode is a “recurring pattern of preservation of organic remains in a particular sedimentary context, accompanied by characteristic taphonomic features”, produced by the sum total of the taphonomic processes acting on a particular fossil assemblage. Given the variability in the physical characteristics of individuals preserved in a typical vertebrate fossil assemblage, individual elements experience different taphonomic microenvironments, and so, even with a constant set of biasing processes, a range of taphonomic characteristics is displayed within an assemblage. For example, if each preserved element is subject to the same amount of physical damage, less robust elements will suffer more damage than sturdier elements. It is possible to quantitatively characterise the taphonomic mode of a fossil assemblage using the unique combination of taphonomic features shared by all of the members of that modal group. By using ordination and multiple regression to study two fossil assemblages from the Scenic Member of the Brule Formation, Badlands National Park, it is possible to determine that virtually all specimens from these assemblages have a single taphonomic mode, although this is expressed as a small, but continuous range of taphonomic characteristics. No discrete groups of elements, subject to different sets of taphonomic processes, can be identified, implying that there was little mixing of elements from different environments prior to final burial. The influences of different taphonomic processes on the fossil assemblages can also be quantified, showing that taphonomic processes related to three main factors (density, shape and surface area to volume ratio) have produced this taphonomic mode. These results are used in combination with a contrasting fossil assemblage from the Cretaceous Wayan Formation to illustrate quantitative comparison of taphonomic modes, and the interpretations that are possible with such quantitative data. 13-7 10:20 AM Zwiebel, Jesse [171941] TOADSTOOL PARK VERTEBRATE TRACKWAYS (OLIGOCENE, BRULE FORMATION, NORTHWESTERN NEBRASKA): ICHNOLOGICAL STUDY ENHANCED THROUGH DIGITAL REPRODUCTION ZWIEBEL, Jesse, Dept. of Physical and Life Sciences, Chadron State College, 1000 Main St, Chadron, NE 69337, jezwie@eagles.csc.edu, LEITE, Michael B., Physical and Life Sciences, Chadron State College, 1000 Main Street, Chadron, NE 69337, BREITHAUPT, Brent H., Wyoming State Office, Bureau of Land Management, Cheyenne, WY 82003, MATTHEWS, Neffra A., National Operations Center, USDOI-Bureau of Land Managment, Denver, CO 80225, and LAGARRY, Hannan E., Department of Math, Science, & Technology, Oglala Lakota College, 490 Three Mile Creek Road, Kyle, SD 57752 Vertebrate tracks and trackways representing a diversity of track makers are preserved at Toadstool Geological Park in northwestern Nebraska. The ichnofossils are preserved at the top of a sheet sandstone in the Orella Member of the Brule Formation (White River Group, Oligocene). We interpret the best preserved tracks as those of the medium size rhinoceros Subhyracodon. Tracks of other members of the White River body fossil fauna are also recognized, including Mesohippus, entelodonts, oreodonts, birds and invertebrates. Three-dimensional photogrammetric documentation is being used facilitate ichnological and paleoecological study of the trackways, as large trackways like this one are vulnerable to rapid destruction by weathering, foot traffic and vandalism but nearly impossible to collect. Photogrammetric products like millimeter-resolution digital terrain models provide accurate reproduction of details, are easier to manipulate than both the original tracks in the outcrop and molds or casts made from them and they can be distributed widely to multiple researchers. Methods adapted from remote sensing and geographic information systems to the analysis of digital trackway data can be used to quantify track geometry and enhance visual observation of ichnological information. 13-8 10:40 AM Hartman, J.H. [171824] CORRELATING THE SOUTH DAKOTA WHITE RIVER GROUP AND ITS CONTINENTAL MOLLUSKS TO NORTH DAKOTA: A BEGINNING UP THE SLIPPERY SLOPE OF UTILIZING HISTORIC FAUNAS HARTMAN, J.H.1, WEILER, M.W.1, SCHUMAKER, K.K.1, and EVANOFF, Emmett2, (1) Department of Geology and Geological Engineering, University of North Dakota, 81 Cornell St. Stop 8358, Grand Forks, ND 58202, joseph.hartman@und.edu, (2) Earth Sciences, University of Northern Colorado, Box 100, Greeley, CO 80639 White River Group pulmonate gastropods begin their less than well-documented record in 1853 with a meeting of the players at an outlier of Chadron Formation north of the famous Mauvaises Terres of South Dakota. The majority of the eight types from Poeno Springs described by John Evans and B.F. Shumard (1854 and in Meek, 1876; planorbid, physid, and lymnaeids; four of five types lost, one figured); F.B. Meek and F.V. Hayden (1860; planorbids; one of two lost, neither figured); and Meek (1876, one lymnaeid figured) remain problematic. Our work has shown the upland surface exposures around the Poeno Creek headwaters are of the Chadron Formation. The relocated fossil pulmonates are in sec. 9, T. 2 N., R. 17 E. (Horse Tooth 7.5’ Quad., Pennington Co.). The unknown historic location (Poeno Springs) is referred to Locality L3033. We have collected from discrete carbonate areas similarly described by Hayden in 1855 as on “an elevated ridge composed of white aluminous and calcareous marl, containing slabs and concretions fully charged with fossil shells.” Apparently similar pulmonate fossils were identified by T.-C. Yen (Hansen, 1953) from Chadronlike lithologies atop buttes in southwestern North Dakota. Yen’s identifications from White (Colgrove of Hansen, not Cosgrove of Murphy et al., 1993; White Butte W and E 7.5’ Quads., Hettinger Co.), LeFor (Long of Hansen; LeFor 7.5’ Quad., Stark Co.), and Straight Buttes (White Butte NW 7.5’ Quad., Stark-Hettinger Cos.) extended the range of three Poeno Springs taxa to North Dakota deposits that can be undoubtedly identified as the South Heart Member of the Chadron Formation. In their review of the White River Group-capping buttes of southwestern North Dakota, Murphy et al. (1993) placed Yen’s (Hansen, 1953) identifications in a table, but they did not find fossils at these buttes. In 1977, Hartman and R.C. Holtzman collected pulmonates from White Butte (Locality L0079; sec. 17, T. 136 N., R. 93 W.). The present collection is exclusively of variably preserved siliceous lymnaeid internal and external molds. Specimens range in size from slightly more than 1 mm to about 8 mm. Potentially, four species are present, but assigning any to the Poeno Springs fauna is premature even though preservation and first indications suggest comparability to certain described lymnaeids. 2010 GSA Rocky Mountain Section Meeting 13 SESSION NO. 13 13-9 11:00 AM Evanoff, Emmett [171966] THE STRATIGRAPHY OF THE BRULE FORMATION IN THE NORTH UNIT, BADLANDS NATIONAL PARK EVANOFF, Emmett, Earth Sciences, University of Northern Colorado, Box 100, Greeley, CO 80639, emmettevanoff@earthlink.net The lower Oligocene Brule Formation is exposed along the Badlands Wall that extends for 80 km in the North Unit of Badlands National Park. The Brule averages 136 m thick in its most complete sections in the North Unit. The Brule Formation includes two members, the Scenic Member, characterized by alternating widespread thick sheets of mudstone beds and muddy sandstone beds, and the Poleslide Member, characterized by massive siltstone beds. The Scenic Member is exposed extensively in the lower Badland Wall between the northern upper prairies and the southern low prairies of the White River drainage. The Scenic rocks were deposited on the Chadron claystone beds on a contact that was eroded into a relief of as much as 25 m. The Scenic Member has two widespread but thin (1 to 3 m thick) mudstone marker beds that extend across the entire Badlands Wall. The lower of these two marker units contains a thin but persistent tuff bed. The lower Poleslide is characterized by thick tan siltstone beds interspersed with thick muddy sandstone sheets. The detailed stratigraphy of the lower Poleslide is remarkably consistent, with 12 thick siltstone, sandstone and mudstone units (averaging 4 m thick) being traceable for at least 50 km along the Wall. The upper Poleslide is characterized by very light gray massive siltstone beds, structureless at the base and well, but thickly bedded at the top. The upper and lower Poleslide intervals are separated by a thick persistant white layer in the eastern half of the North Unit. This white layer superficially resembles a tuff, but does not have the internal features characteristic of tuffs and pinches out to the west. The Poleslide is capped by the Sharps Formation that is represented by thick but laterally restricted paleovalley sequences (the “Sharps Channels”) in the east, and by a prominent tuff on Sheep Mountain Table in the west. The Poleslide Member has been eroded away from most of the North Unit except where it is protected from erosion by the Sharps Channels at the top of scattered high buttes. The transition from thick mudstone intervals in the Scenic to the thick siltstone intervals of the Poleslide reflect a change from fluvial and moist pedogenic processes during Scenic deposition to dry aeolian dust accumulation in the Poleslide. 13-10 11:20 AM LaGarry, Hannan E. [171942] PROPOSED LITHOSTRATIGRAPHIC REVISION, REDESCRIPTION, AND REDEFINITION OF THE WHITE RIVER GROUP (EOCENE-OLIGOCENE), SOUTH DAKOTA LAGARRY, Hannan E., Department of Math, Science, & Technology, Oglala Lakota College, 490 Three Mile Creek Road, Kyle, SD 57752, hlagarry@olc.edu and LAGARRY, Leigh Anne, Hudson-Meng Education & Research Center, 1811 Meng Drive, Crawford, NE 69339 Based on 1996-2009 lithologic descriptions and lithostratigraphic correlations in Nebraska and South Dakota, we revise, redescribe, and redefine the White River Group (Eocene-Oligocene) in South Dakota. The White River Group consists of the Chamberlain Pass, Chadron, Brule, and Rosebud formations. The Chamberlain Pass Formation is redescribed in part as pedogenically modified volcanic ash. The Chadron Fm. consists of the Ahearn, Crazy Johnson, Peanut Peak, and Big Cottonwood Creek members and the Buffalo Gap beds. The Buffalo Gap beds are fluvial sheet gravels that blanket the eastern flank of the Back Hills uplift and laterally intertongue with the Peanut Peak and Big Cottonwood Creek members. The Brule Fm. consists of the Scenic, Whitney, Poleslide, and Rockyford Ash members, the Sharps beds, and the Wanblee beds. The Rockyford Ash Member was considered part of the Sharps Formation. The Sharps beds are the remaining Sharps Fm. which we redefine as a member of the Brule Formation based on volcaniclastic content and correlations to Nebraska. The Wanblee beds are pedogenically modified, brown silty volcaniclastic claystones. The Rosebud Fm. consists of early Miocene volcaniclastic silty sandstones we consider to be the Anderson Ranch Formation of the Arikaree Group, and this use of the term “Rosebud” is rejected. Rosebud was also used for Oligocene volcaniclastic siltstones at Rosebud, South Dakota, that were correlated along the Niobrara River in Nebraska. This use is retained and the strata redefined as part of the White River Group based on volcaniclastic content and intercalation with the underlying Sharps beds. The Rosebud Formation includes the St. Francis beds, which are volcaniclastic eolian siltstones, and the Parmalee beds, which are volcaniclastic fluvial overbank siltstones and claystones, large interbedded fluvial sandstones, and pedisediment. Additional work is planned to map and describe the remainder of the Pine Ridge Reservation and Pennington, Jackson, Shannon, Bennett, and Todd counties in southern South Dakota. This research was supported by the NSF Model Institutes for Excellence Phase III and NSF Tribal College and Universities Program Phases II & III at Oglala Lakota College. 13-11 11:40 AM Gaddie, Helene [171938] PRELIMINARY DESCRIPTION OF NEWLY RECOGNIZED OLIGOCENE AND EARLY MIOCENE STRATA NEAR WANBLEE, SOUTH DAKOTA GADDIE, Helene and LAGARRY, Hannan E., Department of Math, Science, & Technology, Oglala Lakota College, 490 Three Mile Creek Road, Kyle, SD 57752, helene_quiver@ hotmail.com Based on fieldwork conducted during the spring and summer of 2009 by field parties from Oglala Lakota College and the University of Illinois, we report the newly recognized middle Oligocene Wanblee beds of the White River Group and the early Miocene Ghost Canyon beds of the Arikaree Group in Jackson County, South Dakota. These strata are widely exposed along the Pine Ridge Escarpment at Ghost Canyon, 16 km northeast of Wanblee, South Dakota. Ghost Canyon is a sacred site where Lakota people hid from smallpox and attacks from the US Calvary. It is a historical site on the Pine Ridge Reservation that holds both cultural and geological significance and is in need of preservation. Based on detailed lithologic descriptions and lithostratigraphic correlations, the stratigraphic sequence studied at Ghost Canyon includes (from the base) the Wanblee beds of the White River Group (Oligocene) and the Sharps Formation (Oligocene), Harrison Formation (Oligo-Miocene), and Ghost Canyon beds (Miocene) of the Arikaree Group. The Wanblee beds consist of 10 m massive to thickly bedded, pedogenically modified, brown silty volcaniclastic claystone. The Ghost Canyon beds consist of 25 m of massive to thinly bedded, pedogenically modified, pale brown volcaniclastic colluvial siltsone and interbeds of volcaniclastic quartz-biotite sandstone. Based on our lithostratigraphic correlations, the Wanblee beds are likely equivalent to the middle Oligocene Brule Formation (White River Group) of Nebraska, Wyoming, and South Dakota, and the Ghost Canyon beds are likely equivalent to the Anderson Ranch Formation (Arikaree Group) of northwestern Nebraska and Harksen & Macdonald’s (1969) “Rosebud Formation” (Arikaree Group) of south-central South Dakota. Additional research is planned to more completely describe the Cenozoic strata exposed in and around Ghost Canyon. This research was supported by the NSF Model Institutes for Excellence Phase III and NSF Tribal College and Universities Program Phases II & III at Oglala Lakota College. 14 2010 GSA Abstracts with Programs SESSION NO. 14, 8:00 AM Thursday, 22 April 2010 T13. Western South Dakota Hydrology Conference I “Surface-Water Modeling, Ecology, Floods, and Climate” Rushmore Plaza Civic Center, Ponderosa Room 14-1 8:00 AM Stoltenberg, Matthew B. [172057] ONLINE IRRIGATION SCHEDULING WITHIN THE BELLE FOURCHE IRRIGATION DISTRICT STOLTENBERG, Matthew B., Rangeland Scientist, RESPEC Water & Natural Resources, P.O. Box 725, Rapid City, SD 57709, Matthew.Stoltenberg@respec.com and OSWALD, Jared K., Manager, Watershed Planning and Implementation, RESPEC, PO Box 725, Rapid City, SD 57709-0725 Online irrigation scheduling consultant software is being developed for producers within the Belle Fourche Irrigation District (BFID). This project, which is funded for 3 years by a Conservation Innovation Grant through the Natural Resources Conservation Service (NRCS), is entering its third and final irrigation season. The BFID is a gravity-fed, canal-based system located in western South Dakota. Recurring droughts often limit the amount of water available for irrigation in the BFID. The purpose of this project is to provide producers with a reliable, easy-to-use means to monitor and schedule irrigations that will conserve water and reduce the amount of sedimentladen irrigation return flows that are discharged into the adjacent Belle Fourche River, historically listed as impaired for total suspended solids by the South Dakota Department of Environment and Natural Resources. The online irrigation scheduling consultant software allows producers with Internet access to create a secure, personalized Web page that provides irrigation scheduling advice for a particular field. The software collects daily weather data and uses it to estimate rainfall and calculate crop evapotranspiration (ET) using the American Society of Civil Engineers (ASCE) Penman method and locally adapted crop coefficients. Irrigation delivery amounts entered online by the producer are added to the rainfall estimates for that location. The irrigation scheduling software then calculates a soil water balance and irrigation schedule for soil types in the field. Soil moisture sensors installed at two depths are recorded to provide online tracking of relative soil water changes throughout the irrigation season. The producer has the option to adjust the calculated soil water balances or measured rainfall amounts based on observations at the field. The results of the first 2 years of irrigation scheduling were used to evaluate the online software and methods. User feedback is also being collected to fine-tune the online user interface. The third season of irrigation will continue to expand the user base and be used to further evaluate the software. 14-2 8:20 AM Tinant, Charles Jason [171878] GIS RS HABITAT MODELING APPROACHES TO IDENTIFY RIPARIAN COMMUNITIES ON THE PINE RIDGE RESERVATION TINANT, Charles Jason, BELILE, Donald, and GIRAUD, Gerald, Math and Science Depart, Oglala Lakota College, 490 Piya Wiconi Road, Kyle, SD 57752, jtinant@olc.edu We sampled woody riparian populations and habitat at forty-eight locations on the Pine Ridge Reservation in 2007-2008. In 2009, we began analyzing the field data using a variety of statistical and spatial modeling tools. Using Ward’s method on a Euclidian distance matrix with PC-ORD software, we clustered eight species present in the overstory into cottonwood-willow, hardwood, juniper, and Russian olive community types. We tested habitat variables for Plains cottonwood Populus deltoides at the seedling and adult age classes using discriminant analysis in SPSS. The analysis indicated percent bare ground, Pfankuch rating, and percent White River was positively correlated with P. deltoides seedling occurrence, and percent grass was negatively correlated with P. deltoides seedlings. Using the hydrology toolset in the Spatial Analyst extension of ArcGIS, we derived twenty-eight landscape-level variables from SSURGO soils layers and 10-meter DEM derivatives and averaged the variables at a 3rd order watershed level after generating simulated watersheds from the DEM data. We clustered the watersheds into ten physiographic regions by an isomeans clustering method after transforming the variables into their principal components using Erdas Imagine. We also classified summer and winter 2007 Landsat TM scenes by a supervised classification method using ERDAS Imagine. Our final step is modeling cottonwoods habitat using soil properties, physiographic regions, and classified Landsat layers using an ecological modeling program MaxEnt. The results of the analyses to date indicate: 1) riparian community type on the Pine Ridge reservation is strongly influenced by differences in geomorphic response to precipitation, which can be predicted by bedrock geology, and other landscape level variables, 2) we can use these landscape level variables in a final model to accurately predict riparian community type on the Pine Ridge Reservation, 3) MaxEnt ecological modeling software appears to predict cottonwoods occurrence at a much finer level of spatial detail than was possible using landscape or watershed level analyses. 14-3 8:40 AM Kenner, Scott J. [171855] ASSESSMENT OF STREAM MIGRATION RATES TO ESTIMATE BANK EROSION ON THE LOWER CHEYENNE RIVER KENNER, Scott J.1, NORTON, Parker II2, and SMITH, Barbara1, (1) Civil & Environmental Engineering, South Dakota School of Mines and Technology, 501 East St Joseph St, Rapid City, SD 57701, scott.kenner@sdsmt.edu, (2) U.S. Geological Survey South Dakota Water Science Center, 1608 Mountain View, Rapid City, SD 57702 Total suspended solids (TSS) constitute part of EPA requirements for regulated waterbodies in the United States. The Cheyenne River is currently on the 303(d) Impaired Waters list due primarily to exceeding the defined acceptable TSS parameter. It is suspected that these elevated TSS values are due to high TSS quantities in tributaries originating in the Badlands rather than anthropogenic influences. Understanding the sources of TSS are critical in establishing an obtainable plan for remediation of the impairment. An ensemble of methods were used to understand the unique conditions of this waterbody including an analysis of river channel movement over time to estimate the amount of sediment moving through the system. The river channel below Angostura Reservoir was delineated using digital aerial photography for two time periods, 1991-1998 and 2008. The delineated river channel movement was estimated by characterizing meander bend parameters and measuring the distance moved using GIS. The length of movement was divided by the time period between the two aerial photography data sets to get an average migration rate. Visual interpretation was used through four reaches to determine the length of reach affected by lateral SESSION NO. 14 migration. Cross sectional geometry of the channel was available from a physical habitat assessment done at 13 sites along the Cheyenne River main stem. Multiplying the rate of movement by the channel geometry (primarily bank height) and the length of channel reach affected, an estimate of bank erosion was made. The average annual bank erosion was then compared with FLUX estimates of average annual sediment loads to estimate the percentage of annual sediment load due to lateral channel migration and bank erosion. caught were parasitic lesions, “black spot disease,” and tumors. When comparing the fish sampling results for the four sites visited in both 2000-04 and in 2008-09, more individuals and species were collected during 2008-09 than in 2000-04 at two sites, whereas fewer were collected at the other two sites. 14-7 14-4 9:00 AM Kenner, Seth [172074] HYDROLOGIC MODEL APPLICATION OF THE LOWER CHEYENNE RIVER WATERSHED USING HSPF KENNER, Seth1, LOVE, Jason T.2, and POMARLEAU, Lacy1, (1) Surface Water Hydrologist, RESPEC Water & Natural Resources, P.O. Box 725, Rapid City, SD 57709-0725, Seth.Kenner@respec.com, (2) Vice President, RESPEC Water & Natural Resources, PO Box 725, Rapid City, SD 57709-0725 The Cheyenne River in western South Dakota is currently listed as impaired for total suspended solids (TSS) and fecal coliform bacteria. A Total Maximum Daily Load (TMDL) assessment project for the Cheyenne River Watershed in western South Dakota was initiated in the spring of 2007. A watershed model application of the Lower Cheyenne River Watershed was developed using Hydrologic Simulation Program Fortran (HSPF) to help satisfy objectives and concerns of the project. HSPF is widely considered a state-of-the-art comprehensive hydrology and water-quality modeling system. Land surface and subsurface hydrology is integrated with stream and reservoir processes with the capability of including a wide range of water-quality constituents. The Lower Cheyenne River Watershed Model application simulates hydrology as well as fecal coliform bacteria and sediment. Results were used to aid in TMDL development and also to substantiate congruent research for the Lower Cheyenne River Watershed Assessment Project. This portion of the project focuses on the development and calibration of the model application for hydrology and sediment. The model application was developed using spatial datasets representing watershed characteristics, meteorological and stream monitoring data, and general research characterizing the watershed. The simulation of sediment in the model application was developed using information obtained from sediment source tracking, physical habitat assessments, the Revised Universal Soil Loss Equation (RUSLE), and water-quality monitoring. In turn, the model was used to confirm the validity and congruency of the research performed on the Lower Cheyenne River Watershed. Best management practices (BMP) were represented within the model application to assess the potential of reducing pollutant loads in the watershed. The model results were ultimately used to measure the impact of the BMPs and their ability to attain the TMDL standard. 14-5 9:20 AM Neitzert, Kathleen M. [171346] NATIONAL RIVERS AND STREAMS ASSESSMENT (NRSA) PROGRAM ACTIVITIES, 2008-09 NEITZERT, Kathleen M., U.S. Geological Survey, 111 Kansas Ave SE, Huron, SD 57350, kmneitze@usgs.gov The U.S. Geological Survey (USGS) assessed streams throughout the State of South Dakota during 2008-09 as part of the U.S. Environmental Protection Agency’s (USEPA) National Rivers and Streams Assessment (NRSA) program. NRSA is a probability-based survey of our Nation’s rivers and streams intended to provide a comprehensive “State of the Flowing Waters” assessment. The USEPA established a set of core ecological indicators to be measured at each target site when conditions allowed. These indicators included physical habitat, in-stream characteristics, aquatic vertebrates, periphyton assemblages, benthic macroinvertebrate assemblages, field properties, and water chemistry. During 2008, the USGS-South Dakota Water Science Center conducted stream assessments at 25 of the 61 statewide target sites. A repeat assessment designed to meet established quality-assurance/quality-control requirements was conducted at one of these target sites, designated as a revisit site. During 2009, the USGS completed another 36 stream assessments at target sites, with repeat assessments conducted at three revisit sites. Additionally, three sites characterized as reference sites were visited, bringing the total of visited sites to 64 with 68 physical assessments. The USGS also was involved in the 2000-04 Environmental Monitoring and Assessment Program-West (EMAP-West). The EMAP-West study’s purpose was to develop the monitoring tools and protocols that would be used in following assessment programs. The 2008-09 program illuminated protocols that were changed from the earlier program. The following were substantial protocol changes: fish sampling was conducted using only electro-shocking techniques, utilizing only one netter (seine nets were not used); fish were vouchered (identified and sent to an EPAdesignated laboratory) at only approximately 10 percent of wadeable streams, and fish tissue samples were collected at all boatable sites (during EMAP-West fish were vouchered at each stream); a second, separate composite of benthic macroinvertebrates was collected at low-gradient streams to include information from the edge habitats (during EMAP-West only one composite was collected); and fecal indicators, chlorophyll-a, and periphyton samples were filtered in the field (rather than sent to a laboratory). 14-6 9:40 AM Harwood, Alison [171330] ASSESSMENT OF FISH ABUNDANCE AND SPECIES COMPOSITION AT SELECTED SITES IN SOUTH DAKOTA: AN OVERVIEW HARWOOD, Alison, U.S. Geological Survey, 111 Kansas Ave. SE, Huron, SD 57350, aharwood@usgs.gov The U.S. Geological Survey (USGS) conducted surveys of streams throughout the State of South Dakota during 2008-09 as part of the U.S. Environmental Protection Agency’s (USEPA) National Rivers and Streams Assessment (NRSA) Program. During 2008-09, as part of the stream assessment, the USGS completed surveys of fish populations and species composition at 64 sites. Fish were inventoried at 60 of the 64 sites, but not at four of the sites because water was too low to sustain fish or specific conductivity was too high to electroshock effectively. Four of the sites were surveyed in 2000-04 during the USEPA’s Environmental Monitoring and Assessment ProgramWest (EMAP-West) project. Two wadeable sites and two boatable sites were revisited for qualityassurance/quality-control requirements. During the study, both wadeable and boatable streams were sampled using electrofishing equipment and methods. Of the 64 sites, 62 were wadeable and 2 were boatable. Procedures for sampling wadeable streams differed slightly from procedures for boatable streams. Backpack electrofishing equipment was used for wadeable streams, whereas boat electrofishing equipment was used for boatable streams. Wadeable streams also were fished in an opposite direction than boatable streams. Several species of fish were collected during the NRSA. Species diversity ranged from 0-11 species in wadeable streams and from 6-26 species in boatable streams. Many common species were sampled during the study. The most frequently sampled fish was the sand shiner (Notropis stramineus), with 609 individuals sampled. In contrast, only one heritage species, the skipjack herring (Alosa chrysochloris), was identified during 2008-09. Common anomalies found in fish 10:20 AM Driscoll, Daniel G. [171657] A PALEOFLOOD INVESTIGATION FOR REGIONAL IMPROVEMENT OF PEAK-FLOW FREQUENCY ESTIMATES FOR THE BLACK HILLS OF WESTERN SOUTH DAKOTA DRISCOLL, Daniel G.1, O’CONNOR, Jim E.2, HARDEN, Tessa3, and STAMM, John1, (1) U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702, dgdrisco@usgs.gov, (2) U.S. Geological Survey, 2130 SW 5th, Portland, OR 97216, (3) U.S. Geological Survey, 2130 SW 5th Avenue, Portland, OR 97203 The Black Hills region of western South Dakota has a history of exceptionally large floods, such as the catastrophic flood of June 9-10, 1972, in which at least 238 people perished from flooding in the Rapid City area. Annual peak flow maxima associated with the June 9-10 storm were recorded for 24 stream gages, of which 14 were record peaks at the time and 11 still remain as peaks of record. Many of the 1972 flood peaks, as well as peaks from several other notable events, are about an order of magnitude larger than the next largest peaks in available systematic peak-flow records. Regional knowledge of peak-flow characteristics is confounded by the overwhelming abundance of exceptional high outliers in short-term data sets. In 2007, the U.S. Geological Survey (USGS), in cooperation with the South Dakota Department of Transportation (SDDOT), completed a reconnaissance-level study that demonstrated the applicability of paleoflood-hydrology techniques to improve peak-flow characterization for low-probability events. Study results are available at: http://www.state.sd.us/Applications/HR19ResearchProjects/oneproject_search.asp?projectnbr=SD2005-12. In 2008, the USGS began a full-scale study involving four primary drainages (Spring, Rapid, Boxelder, and Elk Creeks) in cooperation with SDDOT and various other local, State, and Federal agencies. The study relies primarily upon stratigraphic analysis of flood slackwater deposits and radiocarbon dating of entrained organic matter to develop high-resolution chronologies of multiple large flood events extending back several millennia. Discharge estimates based on hydraulic analyses are used to develop frequency analyses for paleoflood sites. Preliminary results indicate that over the last 2000 years, multiple floods have had peak discharges approaching or substantially exceeding 1972-scale discharges in all four drainage basins. 14-8 10:40 AM Harden, Tessa [171848] PALEOFLOOD HISTORY OF RAPID CREEK IN THE FOOTHILLS OF THE BLACK HILLS, SOUTH DAKOTA HARDEN, Tessa, U.S. Geological Survey, 2130 SW 5th Avenue, Portland, OR 97203, tharden@usgs.gov, O’CONNOR, Jim, U.S. Geological Survey, 2130 SW 5th Avenue, Portland, OR 97201, and DRISCOLL, Dan, U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702 Drainages in the Black Hills area of South Dakota can experience extreme flash flood events similar to those that occurred in 1972, which claimed 238 lives. Peaks of record for many U.S. Geological Survey (USGS) gaging stations are about an order of magnitude larger than the next largest peak flows, and existing gage records have insufficient length to adequately estimate the frequency of occurrence of extreme events. Seven sites on a 3-mile stretch of Rapid Creek in the east-central Black Hills of South Dakota were examined for paleoflood deposits. Sites were located in limestone caves and alcoves from a few feet to tens of feet above the low-flow water surface in the active channel. These sites contain deposits from the 1972 flood as well as evidence of large, unrecorded floods. Statigraphic analyses and geochronologic techniques were used to date the flood events. Geographic information systems and the US Army Corp of Engineer’s (USACE) Hydrologic Engineering Center – River Analysis System (HEC-RAS) one-dimensional hydraulic model were used to estimate the magnitude of the flood peaks. Results indicate that floods similar to or greater than the 1972 flood event, that caused extensive damage to the Rapid City area, have recurred multiple times over the last 2000 years. All sites on Rapid Creek contain evidence of floods greater than either the current peak of record (~31,000 cubic feet per second (ft3/s)) or the pre-1972 peak of record (2,600 ft3/s). The largest flooding event on Rapid Creek in the last few thousand years may have been as large as 120,000 ft3/s, which is 4-5 times the peak flow of the 1972 flood. Carbon-14 data from one site indicate that at least 10 floods equaled or exceeded 65-70,000 ft3/s between ~2000 and ~1400 years before present. 14-9 11:00 AM Smith, Melissa [171658] FACTORS AFFECTING LARGE STORM AND FLOOD EVENTS IN THE BLACK HILLS AREA OF WESTERN SOUTH DAKOTA DRISCOLL, Daniel G.1, BUNKERS, Matthew2, SMITH, Melissa2, and CARTER, Janet M.1, (1) U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702, dgdrisco@ usgs.gov, (2) National Weather Service, Rapid City, SD 57701, melissa.smith@noaa.gov The Black Hills area has a history of damaging flash floods resulting primarily from exceptionally strong thunderstorms. The best known example is the catastrophic storm of June 9–10, 1972, that caused severe flooding in several major drainages near Rapid City. The potential for storms and flooding in the Black Hills area can be affected by various climatological and physiographic factors. Thunderstorms that form over and around the Black Hills are largely terrain-driven, especially with respect to their requisite upward motion for initiation. Obstacle effects can also be substantial for the Black Hills in terms of promoting thunderstorm development. A composite of storm total precipitation amounts for 13 recent individual storm events indicates a propensity for heavy precipitation to occur east of the major axis of the Black Hills, from the northern hills (near Spearfish) toward the southeast through the eastern foothills near Hermosa. A proclivity for short-duration but intense convective precipitation events, including supercell thunderstorms, has been observed in this area. Prolonged precipitation from large-scale storm systems becomes progressively more influential with increasing drainage area and tends to be a primary driver for flooding in the mainstem of the Belle Fourche and Cheyenne Rivers. Topography and geology are two primary physiographic influences on flooding. Peak-flow characteristics for upper Rapid Creek and Spearfish Creek are small (suppressed), relative to other areas, due to generally low topographic relief and high infiltration capacities in the Limestone Plateau area. The reduced potential for development of exceptionally strong thunderstorms in this area, which is located west of the major axis of the Black Hills, may also be a factor. In contrast, the potential for exceptional floods is greatest within and near outcrops of sedimentary formations that encircle the periphery of the lower Black Hills. Narrow canyons with limited potential for attenuation of flood peaks are common, and steep topography within the canyons and associated tributaries also contributes to increased flood potential. Another factor may be increased potential for development of exceptionally strong thunderstorms in these areas. 2010 GSA Rocky Mountain Section Meeting 15 SESSION NO. 14 14-10 11:20 AM Capehart, William [171721] IMPACTS OF FRACTIONAL VEGETATION COVER AND VEGETATION TYPE ON GREAT PLAINS WEATHER AND CLIMATE CAPEHART, William1, STAUFFER, Phillip1, HENEBRY, Geoffrey2, and WRIGHT, Christopher2, (1) Institute of Atmospheric Sciences, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, William.Capehart@sdsmt.edu, (2) Geographic Information Science Center of Excellence, South Dakota State University, 1021 Medary Ave., Wecota Hall 506B, Brookings, SD 57007 Vegetation cover strongly impacts local microclimate by modulating net radiation into evaporation and sensible heat flux. The seasonal forecasts that require vegetation cover must often rely on multi-year averages. Theoretically, a more ambient (year-to-year) representation of vegetation cover may yield a more appropriate surface energy budget. The resulting alteration in the budget may also impact the pre-storm environment during the warm season and thus impact convective precipitation patterns. We shall demonstrate the impact of altering the land surface environment on weather and climate by running alternative vegetation regimes (both land use and land cover as well as fractional vegetation cover) over the Northern Great Plains and Central United States using the Weather and Research Forecast Model for several growing seasons. 14-11 11:40 AM Norton, Parker [171782] TRENDS IN TEMPERATURE AND PRECIPITATION IN THE MISSOURI RIVER BASIN FROM 1957 TO 2008 NORTON, Parker II, U.S. Geological Survey South Dakota Water Science Center, 1608 Mountain View, Rapid City, SD 57702, pnorton@usgs.gov and STAMM, John, U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702 The U.S. Global Change Research Program reported that global temperatures have increased 1.5°F since 1900 and are projected to rise from 2 to 11.5°F by 2100 with regional variations. Average temperatures have increased about 1.5°F for the Great Plains over the last 30 years relative to a 1961-1979 baseline. Precipitation has increased up to 25% in the eastern Great Plains and decreased up to 15% in the western Great Plains and northern Rocky Mountains since 1958. Here, we explore climate change and its relationship to streamflow trends in the Missouri River Basin (MRB) which covers much of the northern Great Plains. We examine temperature and precipitation records from climate stations and gridded climate datasets (PRISM; ~4 km grid resolution) and compare these data to observed trends in the streamflow record for the MRB from 1957-2008. We used the Kendall Tau non-parametric test to identify significant trends. Significant increases in annual average of minimum temperatures at climate stations largely coincide with shifts toward earlier spring runoff over the MRB. Montana, northwestern Wyoming, and western North Dakota exhibit significant upward trends in the annual average of minimum and maximum temperature, significant downward trends in annual precipitation at climate stations, and significant downward trends in streamflow. PRISM data, however, indicate no trend in precipitation in the western MRB for this period. Eastern North and South Dakota exhibit upward trends in annual precipitation, annual average of minimum temperature at climate stations, and streamflow over the period of record. Southern Nebraska and northern Kansas exhibit significant upward trends in both annual average of minimum and maximum temperature, downward trends in annual precipitation, and streamflow. These data suggest that climate change plays a significant role in the nature of streamflow in the Missouri River Basin, and the nature of this role varies across the basin. SESSION NO. 15, 8:00 AM Thursday, 22 April 2010 T13. Western South Dakota Hydrology Conference II “Mining and Land-Use Effects” Rushmore Plaza Civic Center, Rushmore G 15-1 8:00 AM Stamm, John F. [171737] CONCENTRATIONS OF SELECTED METALS IN UNCONTAMINATED ALLUVIAL DEPOSITS OF THE CHEYENNE AND BELLE FOURCHE RIVERS, SOUTH DAKOTA STAMM, John F., U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702, jstamm@usgs.gov, GEIBEL, Nicholas M., U.S. Army Corps of Engineers, Omaha District, 1616 Capitol Ave, Omaha, NE 68102, MAHAN, Shannon A., U.S. Geological Survey, Box 25046 Federal Center, Denver, CO 80225, and AZZOLINI, David C., Dept. of Earth and Planetary Sciences, Johns Hopkins University, 301 Olin Hall, 3400 N. Charles St, Baltimore, MD 21218 Sediments contaminated with various metals from mining activities in the Black Hills and potentially other anthropogenic sources have been deposited throughout downstream reaches of the Belle Fourche and Cheyenne Rivers in western South Dakota. The Water Resource Development Act of 1999 (amended in 2000) mandated a study of contaminated sediments within the Cheyenne River Basin, which is being conducted by the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers. Herein, we summarize the first part of this study, which is to determine the concentrations of selected metals in alluvial sediment deposited prior to the effects of mining and other anthropogenic activities that may have contributed to contamination in the basin. Such data provide estimates of concentrations of metals in “uncontaminated” sediment. Of particular interest are the concentrations of arsenic and mercury in sediment. Five sites identified as uncontaminated were selected for sampling: four along the Cheyenne River and one along the Belle Fourche River. Samples were collected from terraces that were well above historical maximum flood levels at each of these sites. Samples were also collected from the active channel and floodplain at two sites on the Cheyenne River above its confluence with the Belle Fourche River. The chronology of terraces on the lower Cheyenne River is largely unresolved, but previous work indicates that terraces as much as 75 meters above the channel may be as young as late Pleistocene to early Holocene. Ages of 10.7 thousand years ago (ka) to 16.5 ka, and 6.1 ka were obtained from Cheyenne River terraces at approximately 199 and 183 river kilometers upstream from the confluence with the Missouri River, respectively. Both terraces are approximately 67 meters above the channel. Other dates are forthcoming from terraces at similar heights above the channel. Arsenic concentrations from a total of 88 samples from terrace and channel sites had a geometric mean of 7.5 parts per million (ppm). The maximum arsenic concentration of the sample population was 34 ppm. An arsenic concentration of 35.6 ppm is three standard deviations greater than the geometric mean for arsenic concentrations from the 88 samples. In most samples, mercury was undetected or less than laboratory analytical reporting limits. 16 2010 GSA Abstracts with Programs 15-2 8:20 AM Larson, Lance [171660] SEDIMENT PORE-WATER EQUILIBRIUM INTERACTIONS ASSOCIATED WITH ARSENIC AND URANIUM TRANSPORT WITHIN A HISTORICAL URANIUM MINING IMPACTED WATERSHED, HARDING COUNTY, SD LARSON, Lance1, STONE, James1, STETLER, Larry2, TROYER, Lyndsay3, and BORCH, Thomas4, (1) Dept of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, Lance.Larson@mines.sdsmt.edu, (2) Dept Geology and Geological Engineering, South Dakota School Mines and Technology, Rapid City, SD 57701-3901, (3) Dept of Chemistry, Colorado State University, Fort Collins, CO 80523-1170, (4) Dept of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523-1170 The purpose of this study was to determine how localized changes in sediment redox behavior influence remobilization of As and U within impacted stream sediments of the Cave Hills uranium mining region. Five pore-water equilibration samplers (peepers) were spatially and temporally deployed, and As and U sediment pore water concentrations and speciation were determined and correlated to iron reduction, ORP, and pH behavior. Soil cores collected adjacent to pore water sampler locations were analyzed for solid-phase metal concentration using XRF. For conditions within the sedimentation pond adjacent to existing mine tailings, redox was consistently +200mV, and As concentrations increased as a function of depth for both the solid (53 mg/kg maximum) and aqueous phases (108 μg/L maximum), with As(V) existing as the predominant arsenic phase at depths greater than 5cm. Approximately 2 km downstream of the sedimentation pond at a wetlands-dominated deposition zone, oxidizing condition again existed throughout depth, and As(V) was the predominant As specie. Surface water concentrations of As (490 μg/L) were 25x background concentrations and were significantly greater than measured at the same site 3 months prior (<10 μg/L) during high-seasonal flow, suggesting seasonal conditions influence As transport. Pore-water U concentrations (781 μg/L) were 3.5x greater than the surface water, and approximately 40x background concentration. Solid phase As (53 mg/kg) and U (32 mg/kg) were consistent throughout depth, indicating that solid phase dissolution is actively occurring. For the sampling site near the Bowman-Haley reservoir backwaters, reducing conditions began directly below the sediment-water interface, and Fe(II) concentrations increased with depth as a result of iron reduction. Pore-water As concentrations peaked (41.6 μg/L) below the sediment-water interface while As(III)/As(V) ratios decreased with depth, promoting the formation of mobile As(III) under these iron reducing conditions. The study results suggest that localized redox conditions, especially those dominated by (bio)geochemically-influenced iron reductive processes, appear to influence both As and U behavior from within these contaminant watershed sediments. 15-3 8:40 AM Troyer, Lyndsay [171616] IMPACT OF REDOX CHEMISTRY ON THE ENVIRONMENTAL FATE AND TRANSPORT OF ARSENIC AND URANIUM AT ABANDONED URANIUM MINES IN HARDING COUNTY, SD TROYER, Lyndsay1, BORCH, Thomas2, LARSON, Lance3, and STONE, James3, (1) Dept of Chemistry, Colorado State University, Fort Collins, CO 80523-1170, (2) Dept of Soil and Crop Sciences, Colorado State University, Fort Collins, CO 80523-1170, (3) Dept of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701 Soil samples from the North Cave Hills abandoned uranium mine site in Harding County, SD were analyzed to determine the chemical mechanisms controlling the transport of arsenic and uranium, previously found at above background level concentrations, from the mine tailings to the surrounding watershed. Soil cores were collected anoxically, divided into 5 cm sections, and prepared for analysis. X-ray Absorption Near-Edge Spectroscopy (XANES) analyses show that the presence of As(III) is directly correlated with the soil redox potential (i.e., low Eh). XANES also indicates that the As found in the tailings is in a mineral form as opposed to being adsorbed to iron oxy (hydr) oxides at other sampling locations These results suggest remobilization of arsenic from the tailing impoundment is occurring and likely serves as a source of arsenic for the downgradient watershed. High uranium concentrations were present in reduced sediments collected within a sedimentation pond at the base of the tailings, indicating uranium immobilization is occurring, and can be attributed to the chemical reduction of U(VI) to insoluble U(IV). Sequential chemical extraction data indicate that arsenic and uranium are primarily associated with the iron oxide, manganese oxide, and clay fraction of the watershed sediments. Mineralogical characterization of iron-bearing clays and iron oxy (hydr)oxides of selected samples was performed using X-ray Diffraction (XRD) and Extended X-ray Absorption Fine Structure Spectroscopy (EXAFS). Preliminary results suggest that the anaerobic sedimentation pond efficiently sequesters uranium but is likely releasing As due to reductive processes. Iron minerals seem to play an important role in controlling the fate of arsenic and uranium downstream of the sedimentation pond. 15-4 9:00 AM Larson, Lance [171619] ARSENIC AND URANIUM IMPACTED SEDIMENT BEHAVIOR WITHIN THE BOWMAN-HALEY RESERVOIR, BOWMAN COUNTY, NORTH DAKOTA LARSON, Lance1, STONE, James1, and STETLER, Larry2, (1) Dept of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, Lance.Larson@mines.sdsmt.edu, (2) Dept Geology and Geological Engineering, South Dakota School Mines and Technology, Rapid City, SD 57701-3901 The purpose of this study was to determine the impacts of regional historical uranium mining activities (from the Cave Hills region and UMTRA Griffin uranium processing site) within the Bowman-Haley Reservoir sediments. The Bowman-Haley reservoir is a 20,400 acre feet US ACE facility built at the confluences of the North Fork of the Grand River, Alkali Creek, and Spring Creek. The extent of anthropogenic-influenced watershed impacts were quantified through the determination of sediment metals concentrations and metal enrichment factors to evaluate the potential of geochemically-influenced As and U remobilization within the reservoir sediments. Sediment cores were collected at five locations within the reservoir: Spring Creek confluence, Alkali Creek confluence, two locations within the North Fork of the Grant River confluence, and adjacent to the reservoir outfall. Sediments cores were divided into 2 cm slices to depth (up to 1 m) and analyzed for trace metal and carbon concentrations. Pearson product moment correlations established inter-core metal correlations, while sediment enrichment factors were determined relative to background concentrations found within Alkali Creek, a watershed with no historical mining activities. Enrichment factor results suggest all sampling sites may be classified as ‘minor to moderately enriched’ for As and U. Metal behavior for the three reservoir inlets indicate similar metal loading sources and post-depositional behavior, while metals migration at the reservoir outlet appear controlled by geochemical and/or physical mechanisms. For the reservoir outlet, As and U normalized Al ratios suggest vertical migration of As is occurring above the reservoir spillway, while surface-bound U remobilization is apparent within the water column immediately above the sediments. The highest U concentrations were found within the Spring Creek reservoir, and the source of this loading appears to be from the Griffin, ND uranium processing facility operations and cleanup. Overall, sediment As enrichment exists within the reservoir inlets, and elevated sediment U was found adjacent to the reservoir spillway, suggesting that As loading within the reservoir appears controlled by sediment deposition, whereas U transport appears controlled by aqueous dissolution processes. SESSION NO. 15 15-5 9:20 AM Jarding, Lilias C. [170769] PAST URANIUM MINING IN SOUTH DAKOTA: POLICY AND REGULATORY ISSUES JARDING, Lilias C., Lakota People’s Law Project, 117 Knollwood Drive, Rapid City, SD 57701, lilias@lakotalaw.org Researchers have identified environmental impacts that resulted from uranium mining and milling in the 1950s – 1970s, when that activity was essentially unregulated. These impacts on South Dakota water quality will be reviewed and summarized. Beginning in the 1970s, new federal and state laws required the maintenance of water, soil, and air quality. Yet regulators have struggled to deal with past mining issues, especially in recent years when new uranium projects have been proposed, requiring agencies to respond to these new issues. The agency response in South Dakota has included the updating of some regulations, and those updates will be reviewed as they may impact water use and water quality. Public policy issues related to these situations will then be reviewed and discussed. Recommendations for future policies will be offered. Lilias Jones Jarding, Ph.D. 15-6 9:40 AM Tinant, Charles Jason [171905] ENVIRONMENTAL IMPACTS OF THE ERDENET COPPER MOLYBDENUM MINE IN NORTH CENTRAL MONGOLIA TINANT, Charles Jason1, BERDANIER, Bruce2, BELILE, Donald1, GADDIE, Helene3, and HANSEN, M.R.4, (1) Math and Science Depart, Oglala Lakota College, 490 Piya Wiconi Road, Kyle, SD 57752, jtinant@olc.edu, (2) Civil Engineering, South Dakota State University, Brookings, SD 57007, (3) Department of Math, Science, & Technology, Oglala Lakota College, 490 Three Mile Creek Road, Kyle, SD 57752, (4) Civil Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57702 Surface and ground water and alluvial deposits were sampled in 2008 at six locations in north central Mongolia along the Khangal River, and three locations within the tailings storage complex. Metals concentrations were determined using atomic absorption (AA) flame and graphite furnace and x-ray florescence. Chromium (Cr) from 0.1 to 7.1 mg/kg, arsenic (As) from 1.8 to 5.1 mg/kg, lead (Pb) from 0.1 to 0.9 mg/kg, and copper (Cu) from 2.7 to 58.7 mg/kg were detected in stream and terrace deposit sediment samples. Chromium (Cr) from 6.9 to 13.1 mg/kg, arsenic (As) from 9.3 to 10.7 mg/kg, lead (Pb) from 0.2 to 2.3 mg/kg, and copper (Cu) from 61.4 to 96.1 mg/kg were detected in tailings storage facility samples. Arsenic was identified as a parameter of concern in water samples with values ranging from 6.0 to 13.8 ug/L in ground water and 3.7 to 24.6 ug/L in surface water. Based on measured stream flow rates, arsenic loading rates ranged from 40 to 470 g/day. Naturally high levels of arsenic occur in the study area ground water, however, arsenic levels in the stream are elevated by mining activities. Wind direction and distance from the mine tailings on copper concentration in sediments were analyzed by linear, exponential, and curvilinear model fitting. The linear distance model best fit the data with a Pearson’s correlation coefficient (R2) of 0.77. The linear distance model predicted metal concentrations return to baseline levels at a distance of 6.4 km from the mine tailings dam. Our future work is to independently test our linear distance model using street dust and tree bark samples taken at the time of the stream sediment sampling. 15-7 10:20 AM Sundareshwar, P.V. [171967] NATURE VERSUS NURTURE: FUNCTIONAL ASSESSMENT OF RESTORATION EFFECTS SUNDARESHWAR, P.V., Atmospheric Sciences, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, pv.sundareshwar@sdsmt.edu Land-use change has altered the ability of wetlands to provide vital services such as nutrient retention. While compensatory practices attempt to restore degraded wetlands and their functions, it is difficult to evaluate the recovery of soil biogeochemical function that are critical for restoration of ecosystem services. Using solution 31P Nuclear Magnetic Resonance Spectroscopy, we examined the chemical forms of phosphorus (P) in soils from wetlands located across a landuse gradient. We report that soil P diversity, a functional attribute, declined upon conversion to agriculture, but recovered following restoration. Soil P diversity increased with age of restoration, and asymptotic profiles approached those observed from native wetlands. The trend in P diversity was opposite that of documented soil microbial diversity at our study site, indicating restoration of ecosystem function. The findings provide insights into links between ecosystem structure and function and provide a tool for evaluating the success of ecosystem restoration efforts. 15-8 10:40 AM Morlok, Brett A. [171860] PHYSICAL HABITAT ASSESSMENT OF THE CHEYENNE RIVER WATERSHED MORLOK, Brett A., South Dakota School of Mines & Technology, P.O. Box 725, Rapid City, SD 57701, Brett.Morlok@mines.sdsmt.edu, KENNER, Scott J., Civil & Environmental Engineering, South Dakota School of Mines and Technology, 501 East St Joseph St, Rapid City, SD 57701, and FOREMAN, Cory S., Manager, Water and Geologic Characterization, RESPEC, P.O. Box 725, Rapid City, SD 57709 The Cheyenne River in western South Dakota is currently listed as being impaired for total suspended solids (TSS). In 2005, physical habitat assessments were performed at 48 sites thoughout the Cheyenne River Watershed to understand sediment source regions in the Cheyenne River Watershed and the impacts excess sediment loadings have on stream channel morphology. Using metrics calculated from the habitat data, a principal component analysis (PCA) was conducted to describe habitat variability in the watershed. The PCA was used to define regions with similar habitat characteristics. After the completion of the PCA, data gaps were identified in the Badlands and eastern regions of the watershed. For this reason, physical habitat assessments were performed at 16 additional sites in 2007. The addition of the 16 sites collected in 2007, combined with the original 48 sites, added to the understanding gained from the original PCA. At three sites on different Badlands tributaries, physical habitat data were collected showing geomorphic similarities between the Badlands tributaries and the main stem of the Cheyenne River. Physical habitat data were also collected at sites in the northeast region of the watershed identifying substrate similarities to the Badlands sites, even though the watershed characteristics in the two regions is very different. This similarity indicates that the northeast portion of the watershed may contribute a significant sediment load to the Cheyenne River in the lower reaches. Additionally, the added sites, specifically near the confluence of the Belle Fourche River, solidified a hypothesis that local parent geology has a large influence on channel morphology on both the Cheyenne and Belle Fourche Rivers in the region near the confluence and may override some of the influences of the large upstream sediment load. The analysis of all 64 sites gave a more complete understanding of the watershed, specifically when relating physical habitat characteristics to TSS loadings in the Cheyenne River. 15-9 11:00 AM Dreis, Erin [172072] ENVIRONMENTAL IMPLICATIONS OF THE LAND APPLICATION OF MANURE CONTAINING ANTIMICROBIALS TYLOSIN AND CHLORTETRACYCLINE DREIS, Erin1, STONE, James1, LUPO, Christopher1, and CLAY, Sharon2, (1) Department of Civil and Environmental Engineering, South Dakota School of Mines and Technology, 501 E. Saint Joseph St, Rapid City, SD 57701, Erin.Dreis@mines.sdsmt.edu, (2) Department of Plant Sciences, South Dakota State University, Box 2140C Room 245C, Brookings, SD 57007 Antimicrobial and antibiotic compounds are used in therapeutic doses in the agricultural industry to prevent disease and at sub-therapeutic levels to enhance growth promotion and feed efficiency. These compounds are specifically designed to poorly adsorb into the gut of the animal, and as a result > 90% of the antibiotic parent compound can be excreted from the animal in a biologicallyactive form. The predominant pathway for these antibiotics to enter the environment is through land application of antibiotic-laden manure. The purpose of this research was to ascertain how land application of antimicrobial swine manure could impact soil-microbe interactions that naturally exist within common eastern South Dakota soils. The research consisted of two phases: soil-manure batch reactors and manure loading soil column experiments. The objective for the batch reactor experiments was to determine the impacts of CTC and tylosin containing manure on aerobic soil microbial respiration rates. For the soil column experiments, the objective was to determine whether and how CTC and tylosin containing manure affects the migration or transformation of essential crop nutrients nitrogen, phosphorous, and carbon within a simulated A soil horizon. Batch reactor experimental results indicated that soils amended with the tylosin manure reduced CO2 production compared to CTC and no antimicrobial containing manures. Tylosin was further found to inhibit biological carbon mineralization within the soil columns at rates similar to the no manure control. CTC was found to have limited impacts on both aerobic respiration rates and nutrient transport and transformation within the soil columns, suggesting limited environmental implications exist for the land application of CTC containing manure within aerobic soils. 15-10 11:20 AM Jinka, Ramith [172070] LIFE CYCLE ASSESSMENT MODEL FOR A MODERN UPPER GREAT PLAINS U.S. CONFINED SWINE PRODUCTION FACILITY JINKA, Ramith1, STONE, James J.1, DOLLARHIDE, Christopher2, AURAND, Katherine1, CLAY, David3, and THALER, Robert4, (1) Department of Civil and Environmental Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph St, Rapid City, SD 57701, ramith.jinka@mines.sdsmt.edu, (2) Dept Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, (3) Dept of Soil Sciences, South Dakota State University, Brookings, SD 57007, (4) Dept of Animal and Range Science, South Dakota State University, Brookings, SD 57007 A life cycle assessment (LCA) model was developed for a typical modern upper Great Plains U.S. swine facility to assess the net environmental impacts associated with a normalized unit weight of pork produced at the facility. The SimaPro 7.1 LCA model was developed following a “gate to gate” prospective focusing solely on facility operations and not including feed production and final pork product transportation to the marketplace. Model input data was normalized using a function unit of per head of swine, and categorized into five operation sub-processes, including: feed handling and transport, manure handling, metabolic emissions, power usage, and water. Following EcoIndicator 99 assessment protocol, climate change impacts were found to be largely attributed to swine metabolic emissions (6.91E-05 DALY) and manure emissions (9.56E-06 DALY), with significant reductions occurring when including the use of antimicrobial compound chlortetracycline within the revised facility LCA model. Manure handling resulted in the greatest acidification and eutrophication potential (8.18 PDF m2 yr), while facility power resulted in the greatest ecotoxicity impact (2.39 PAF m2 yr) and fossil fuel surplus (15.56 MJ) of the facility processes evaluated. Results from this baseline facility LCA model provide the swine producer and environmental practitioner with a powerful management tool for meeting future requirements set forth within a carbon-constrained marketplace. 15-11 11:40 AM Stone, James [171676] LIFE CYCLE ASSESSMENT OF TYLOSIN AND CHLORTETRACYCLINE ANTIMICROBIAL USE AT SWINE PRODUCTION FACILITIES STONE, James1, AURAND, Katie1, DOLLARHIDE, Christopher2, JINKA, Ramith1, THALER, Robert3, CLAY, David4, and CLAY, Sharon5, (1) Dept of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, james.stone@ sdsmt.edu, (2) Dept of Chemical and Biological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, (3) Dept of Animal and Range Science, South Dakota State University, Brookings, SD 57007, (4) Dept of Soil Sciences, South Dakota State University, Brookings, SD 57007, (5) Dept of Plant Sciences, South Dakota State University, Brookings, SD 57007 This study investigates the environmental effects associated with tylosin and chlortetracycline (CTC) antimicrobial sub-therapeutic use within upper Midwestern US swine production facilities following life cycle assessment (LCA) methodology. Environmental LCA-associated impacts were modeled using SimaPro and assessed using EcoIndicator 99 for antimicrobial manufacturing, feed blending and transport, metabolic and manure emissions, and facility operations for starter, grower, and finishing swine operations. LCA results suggest current high energy demands associated with manufacturing processes and large transport distances to producers of CTC and tylosin increased disability adjusted life year (DALY) climate change impacts compared to no antimicrobial use. Feeding CTC resulted in several local positive changes including increased feed utilization and reduced manure greenhouse gas emissions. However, these positive changes in the local environment did not offset negative global impacts associated with material manufacturing and transport. Using renewable energy sources for production and transport would result in net environmental enhancement. 2010 GSA Rocky Mountain Section Meeting 17 SESSION NO. 16 SESSION NO. 16, 8:00 AM Thursday, 22 April 2010 T6. Recent Advances in Understanding the Geologic History of the White River Badlands (Posters) Rushmore Plaza Civic Center, Rushmore H 16-1 BTH 1 Terry, Dennis O. [171741] VERTICAL CHANGES IN PALEOSOLS, SEDIMENTOLOGY, AND VERTEBRATE TAPHONOMY WITHIN THE OLIGOCENE POLESLIDE MEMBER OF THE BRULE FORMATION, BADLANDS NATIONAL PARK, SD TERRY, Dennis O. Jr, Earth and Environmental Science, Temple University, 326 Beury Hall, 1901 N. 13th St, Philadelphia, PA 19122, doterry@temple.edu, KOSMIDIS, Paul G., Geoscience, University of Nevada, Las Vegas, Las Vegas, NV 89154, MINTZ, Jason S., Department of Geology, Baylor University, One Bear Place #97354, Waco, TX 76798-7354, and STINCHCOMB, Gary, Terrestrial Paleoclimatology Division, Dept. of Geology, Baylor University, One Bear Place #97354, Waco, TX 76798-7354 The Poleslide Member of the Brule Formation is composed of 53 m of fossiliferous fluvial, lacustrine, and eolian deposits. Changes between these depositional environments is recognized as distinct facies associations, paleosols, and vertebrate fossil taphonomic modes ranging from isolated to articulated elements which likely reflect the influence of paleogeomorphic conditions. The bottom contact of the Poleslide Member is marked by the lithologic transition from mudstones of the underlying Scenic Member to muddy siltstones, as well as a newly recognized, regionally extensive volcanic tuff, the Cactus Flat Bentonite bed. The bottom of the Poleslide Member is dominated by fluvial deposits. Paleosols formed within fining upward overbank deposits, with vertebrate fossils primarily preserved as isolated elements, except for the very bottom of the Poleslide Member which preserves a relatively dense accumulation of vertebrate material in various stages of articulation. Fluvial conditions give way vertically to a period of relative landscape stability across the region marked by well developed lacustrine facies and an increase in soil maturity. Lacustrine facies are preserved as a springfed carbonate lake deposit with ostracodes, charophytes, aquatic snails, fish, and stromatolites. Lateral to these deposits, up to 5 km away, paleosols preserve evidence of wetter conditions, including hydromorphy and increased weathering. Environments shift to eolian dominated conditions up section and preserve a combination of vertical accretion episodes vs. periods of landscape stability. Periods of eolian vertical accretion are marked by massive volcaniclastic sitlstones with interspersed root traces and soil nodules, and bones that are randomly distributed throughout. Periods of stability are marked by well defined and resistant layers representing former A horizons. Both vertebrate and invertebrate fossils are concentrated within these resistant intervals, suggesting attritional accumulation during periods of increased soil formation. A brief period of fluvial deposition with rare fossils as lag replaces the eolian facies high in the section, but reverts back to eolian deposition before being capped by the Rockyford Ash Member of the overlying Sharps Formation. 16-2 BTH 2 Sahy, Diana [171766] RADIO-ISOTOPIC DATING OF VOLCANIC ASH LAYERS FROM THE WHITE RIVER GROUP, WYOMING AND NEBRASKA SAHY, Diana1, FISCHER, Anne2, TERRY, Dennis O. Jr3, CONDON, Daniel1, and KUIPER, Klaudia2, (1) British Geological Survey, Keyworth, Nottingham, NG12 5GG, United Kingdom, dihy@bgs.ac.uk, (2) Faculty of Earth and Life Sciences, Vrije Universiteit, 1085 De Boelelaan, Amsterdam, 1081 HV, Netherlands, (3) Earth and Environmental Science, Temple University, 326 Beury Hall, 1901 N. 13th St, Philadelphia, PA 19122 High precision U-Pb and 40Ar/39Ar dating of U- and K-bearing minerals (primarily zircon and sanidine) from volcanic ash layers from the Eocene-Oligocene White River Group is being undertaken as part of the GTSnext project (http://www.gtsnext.eu) in an attempt to develop improved constraints for the Paleogene timescale. The work currently being carried out focuses on events at and near the Chadronian-Orellan boundary and their correlation to the Eocene-Oligocene boundary in Europe. 17 ash layers from the Flagstaff Rim (Wyoming) and Toadstool Park (Nebraska) sections have been sampled so far. At Flagstaff Rim, the Chadronian-Orellan boundary coincides with an erosional unconformity but sedimentation appears to have been continuous during accumulation of the Chadron Formation, which hosts over 15 ash layers labeled A-J in chronological order. At Toadstool Park, sedimentation was continuous across the Chadronian-Orellan boundary, which is bracketed by two ash layers, the Upper Purplish White layer (UPW), and the Serendipity ash. Previous radio-isotopic constraints constrain the interval between ashes B and J at Flagstaff Rim to 35.87 and 34.81 Ma according to single-crystal laser fusion 40Ar/39Ar sanidine dates obtained by Obradovich (1995), and 36.34 and 35.17 Ma according to Swisher and Prothero (1990) (both recalculated using an age of 28.201 Ma for the Fish Canyon sanidine (Hilgen and Kuiper, 2009)). According to Prothero and Swisher (1992), Ash J is situated just above the base of magnetic polarity zone C13r, ashes D-I are in magnetic polarity zone C15r, while Ash B is in normal polarity zone C16n. At Toadstool Park, the base of polarity zone C13n is 9 meters above the UPW, and the top of C13n is 28 m above the UPW (or 6 m above the Serendipity Ash). Our aim is to obtain high precision U-Pb (zircons) and 40Ar/39Ar (sanidine) data from the sampled ash layers in order to better constrain the age of these key terrestrial sections that span the EoceneOligocene transition. 16-3 BTH 3 Brave, Dylan [171939] PRELIMINARY LITHOLOGIC DESCRIPTION OF THE CHADRON FORMATION NEAR RED SHIRT, SOUTH DAKOTA, WITH NOTES ON THE INVERTEBRATE AND VERTEBRATE TRACE FOSSILS BRAVE, Dylan, Department of Math, Science, & Technology, Oglala Lakota College, 490 Three Mile Creek Road, Kyle, SD 57752, hlagarry@olc.edu Based on preliminary observations of lithology and sedimentary structures during the summer of 2009, we describe the lithostratigraphy and trace fossils of the Chadron Formation on the Pine Ridge Reservation and adjacent Buffalo Gap National Grassland along Battle Creek near Red Shirt, South Dakota. In this area the Chadron Formation (Eocene) unconformably overlies the Yellow Mounds Paleosol equivalent developed in the Pierre Shale (Cretaceous). We recognize (from bottom) the Ahearn, Crazy Johnson, Peanut Peak, and Big Cottonwood Creek members of the Chadron Formation exposed in the canyons and small hills on the north side of the Battle Creek Valley. The Chadron Formation is the youngest stratum exposed in this area. The Ahearn Member consists of coarse-grained white fluvial sandstone with stringers and lags of rounded 18 2010 GSA Abstracts with Programs pebble to cobble-sized clasts of various Black Hills igneous and metamorphic lithologies. The Crazy Johnson Member consists of interbedded red claystones and red, brown, green, and white fluvial sandstones with locally abundant coarse clasts. The Peanut Peak Member consists of olive green volcaniclastic claystone and interbedded brown fluvial sandstones. The Big Cottonwood Creek Member consists of grayish green volcaniclastic silty claystones and interbedded brown fluvial sandstones. The fluvial sandstone interbeds within the Big Cottonwood Creek Member contain locally abundant tubular and meniscate invertebrate burrows, and multiple sets of poorly defined footprints of mammalian quadrupeds of varying sizes. Additional work is being planned to inventory and describe invertebrate traces and vertebrate trackways within Paleogene strata exposed on the Pine Ridge Reservation. This research was supported by the NSF Model Institutes for Excellence Phase III and NSF Tribal College and Universities Program Phases II & III at Oglala Lakota College. 16-4 BTH 4 Hanneman, Debra L. [171948] WHITE RIVER GROUP EQUIVALENTS IN MONTANA HANNEMAN, Debra L., Whitehall Geogroup, Inc, 107 Whitetail Road, Whitehall, MT 59759, hanneman@jeffersonvalley.net and WIDEMAN, Charles J., Emeritus, Geophysical Engineering, Montana Tech of the University of Montana, Park Street, Butte, MT 59701 White River Group equivalents in Montana have previously been known by a plethora of lithostratgraphic names and were placed within the lower Renova Formation. More recently these units have been correctly identified as laterally equivalent basin deposits and are informally known as Cenozoic Sequence 2. Sequence 2 is bounded by regional unconformities and is age constrained by biostratigraphic and radiometric data. These data yield an age range of about 37 Ma to about 30 Ma for Sequence 2. An oxic paleosol consistently marks the unconformity where Sequence 2 rests upon preTertiary or Sequence 1 (about 55 Ma to about 43 Ma in age) rocks. Sequence 2 contains mudstone, siltstone, sandstone, and conglomerate, although the coarser-grained lithologies are typically lensoidal. Fluvial depositional systems dominate Sequence 2. The sandstones are typically ribbon sandstones suggesting a preponderance of fixed channel systems. Mudstone makes up as much as 80% of the Sequence 2 fluvial system rocks. Other minor depositional components of Sequence 2 include debris flow units that contain conglomerate lenses and some sheets, and lacustrine lenses of shale and carbonate. Calcic pedocomplexes typically cap the sequence where it occurs in mid-basin to basin-margin settings. The hiatus between Sequence 2 and overlying sequences in some areas is only approximately 3 Ma, however, in many areas, it is often at least approximately 14 Ma. This is the real “midTertiary” unconformity, in that its maximum age is tied to the top of Sequence 2 at approximately 30 Ma. This mid-Tertiary unconformity is angular in a number of locations, but in some locations is simply a disconformity. SESSION NO. 17, 8:00 AM Thursday, 22 April 2010 T10. Hydrologic and Geologic Framework of the Central Missouri River Corridor (Posters) Rushmore Plaza Civic Center, Rushmore H 17-1 BTH 5 Martin, James E. [171654] NEW MEMBERS OF THE DeGrey FORMATION, PIERRE SHALE GROUP (UPPER CRETACEOUS) FROM CENTRAL SOUTH DAKOTA MARTIN, James E., Museum of Geology, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, James.Martin@sdsmt.edu and PARRIS, David C., Bureau of Natural History, New Jersey State Museum, Trenton, NJ 08625 For over twenty years, lithostratigraphical and biostratigraphical studies have been undertaken concerning Late Cretaceous marine rocks and assemblages of South Dakota under the direction of the authors. During these investigations, distinct lithostratigraphic units were noted that extend over great areas and appear more than simple lithofacies. As a result in 2007 (Martin et al.), the Pierre Shale, which had been considered of formational rank, was elevated to group status, and most of the previously named members were elevated to formational status. One of the new formations of the Pierre Shale Group is the DeGrey Formation, which had a varied nomenclatural history and was finally well established in 1950 (Crandell). This formation is well exposed along the Big Bend of the Missouri River where five members can be recognized. Of Crandell’s original DeGrey designation, two distinct, laterally extensive lithologies have been noted that will be named as new members: a lower bentonitic gray shale with thin yellow concretionay layers and an overlying light gray siliceous shale unit containing relatively numerous interbedded bentonites and in some areas characterized by abundant FeMn concretionary layers. Normally, the Crow Creek Member, a tan, siltstone/marl occurs at the base of the gray bentonitic shale. The Crow Creek was considered a member of the Pierre Shale and recently was assigned as a member of the DeGrey Formation (2007). During our investigations, we noted another tan unit similar to the Crow Creek Member lying higher in the section occurring intermittently along the Missouri River. This unit was informally termed the Fort Thompson beds (Hanczaryk and Gallagher, 2007), and this calcareous, sandy siltstone will be formalized as a member of the DeGrey Fm., as well as the bentonitic shale unit that intervenes between the two tan siltstone units. The type sections of these new members occur in the Big Bend area of the Missouri River, although the members can occur throughout the Missouri River breaks of central South Dakota. 17-2 BTH 6 Stamm, John F. [171743] AGES OF ALLUVIAL TERRACE DEPOSITS AND DYNAMICS OF THE CHEYENNE AND BELLE FOURCHE RIVERS, SOUTH DAKOTA STAMM, John F., U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702, jstamm@usgs.gov, GEIBEL, Nicholas M., U.S. Army Corps of Engineers, Omaha District, 1616 Capitol Ave, Omaha, NE 68102, MAHAN, Shannon A., U.S. Geological Survey, Box 25046 Federal Center, Denver, CO 80225, ZAPROWSKI, Brent J., Department of Geography and Geosciences, Salisbury University, Salisbury, MD 21801, and AZZOLINI, David C., Dept. of Earth and Planetary Sciences, Johns Hopkins University, 301 Olin Hall, 3400 N. Charles St, Baltimore, MD 21218 The Water Resource Development Act of 1999 (amended in 2000) mandated a study of contaminated sediments within the Cheyenne River Basin, which is being conducted by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers. Initial work for this study Program ROCKY MOUNTAIN Section Meeting 62nd Annual Meeting of the Rocky Mountain Section, GSA Rushmore Plaza Civic Center Rapid City, South Dakota, USA 21–23 April 2010 www.geosociety.org/sectdiv/rockymtn/2010mtg/ 62nd Annual Meeting Rocky Mountain Section of the Geological Society of America in association with the Western South Dakota Hydrology Conference hosted by South Dakota School of Mines and Technology “From Ancient Rocks to New Knowledge of the Universe” Local Committee Meeting Co-chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Michael P. Terry Meeting Co-chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Larry D. Stetler Technical Program Chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. Foster Sawyer Exhibits Chair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kelli A. McCormick Fieldtrip Co-chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Alvis L. Lisenbee Field trip Co-chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Colin J. Paterson Student Help Coordinator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Natalie G. Toth Rocky Mountain Section GSA Officers Chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Michael P. Terry Vice-Chair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Larry D. Stetler Secretary Treasurer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neil S. Fishman Past Chair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bart J. Kowallis Past Vice-Chair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Daniel Horns 20 2010 GSA Abstracts with Programs 50% Total Recovered Fiber 10% Post-Consumer General Information Setting The 62nd Annual Meeting of the Rocky Mountain Section is being hosted by the Department of Geology and Geological Engineering, South Dakota School of Mines and Technology. The meeting will be held at the Rushmore Plaza Civic Center located in Rapid City, South Dakota (population 67,000). Geographically, Rapid City is located in westernmost South Dakota on the eastern edge of the Rocky Mountains. Rapid City and the surrounding area offers visitors spectacular outdoor recreational opportunity because of its proximity to the Black Hills National Forest, Custer State Park, and the Norbeck Wildlife Preserve. Tourism is central to the economy due to the large number of well-known, world-class attractions such as nearby Mount Rushmore National Monument, Harney Peak and the Needles Highway Region, Badlands National Park, and the historic town of Deadwood. Geologically, Rapid City is located on the easternmost Laramide domal uplift in the Rocky Mountains which offers exposure of rocks ranging in age from late Archean to the present in very close proximity to the meeting location. The uplift is cored by Precambrian metamorphosed sedimentary and igneous rocks including the world class Harney Peak Granite (1.715 Ga). Paleozoic and younger rocks are exposed on the margin of the uplift and offer exceptional record of the younger geologic evolution. The northern part of the uplift is a historic gold mining district that has produced about 50 million ounces of gold associated with Tertiary intrusive rocks and a Precambrian iron formation-hosted gold deposit. The largest producer of gold was the Homestake Mine which is now the new Deep Underground Science and Engineering Laboratory (DUSEL) that will be the site for a range of multidisciplinary experiments including the geosciences, biology, and physics. The exposed rocks combined with ongoing and future DUSEL experiments will allow scientific discoveries extending from ancient rocks to new knowledge of the universe. Getting Here Rapid City is located on Interstate 90 that allows easy access from the east or west for participants driving to the meeting. If coming from the south or southwest, connecting to Interstate 25 north and traveling through Hot Springs will bring participants to Rapid City. From the north or northwest, there are numerous connections to Interstate 90 that will bring participants to Rapid City. For those flying, the Rapid City Airport is located about 10 miles east of Rapid City. There are direct flights from Denver, Salt Lake City, Las Vegas, Dallas, Chicago, and Minneapolis. There are commercial shuttles available at the airport at a modest cost to participants. For those renting a vehicle, follow Hwy 44 west from the airport. Registration All participants in the GSA meeting events must be official registrants. General public and students attending the Western South Dakota Hydrology Conference must obtain a badge at the registration desk on Thursday, 22 April. Preregistrants may pick up their badges at the GSA desk located between the stairs and escalator at the southern end of the Upper East Concourse of the Rushmore Plaza Civic Center. Badges must be worn for access to all activities Wednesday through Friday. Guest registration is required for any guest attending meeting activities, including technical sessions. A professional or student registrant must accompany guests. Student and K–12 professionals must show current ID to qualify for on-site registration at reduced rates; otherwise, professional rates will apply. All requests for registration changes or cancellations must have been made in writing and received by 9 April 2010. No refunds will be made after this date. On-Site Registration Hours Tuesday, 20 April........... 5–7 p.m. Wednesday, 21 April...... 7 a.m.–4 p.m. & 7–9 p.m. Thursday, 22 April......... 7 a.m.–4 p.m. Friday, 23 April.............. 7–9 a.m. On-Site Registration Fees (All Fees are in U.S. Dollars) Full Meeting One Day Professional Member.........................$170.............. $100 Professional Nonmember..................$190.............. $140 Student Member...............................$65................ $55 Student Nonmember........................$75................ $65 K–12 Teacher....................................$55................ $40 Guest or Spouse................................$40................ $25 2010 GSA Rocky Mountain Section Meeting 21 Location Map Special Events Wednesday 21 April Map Blast. Exhibit Hall H, 7–9 p.m. Welcoming Reception. Exhibit Hall H, 7–9 p.m. Thursday 22 April Hydrology Conference Luncheon. noon–1 p.m. Rocky Mountain Section Business Meeting. noon– 1 p.m. Rocky Mountain Section Banquet. Journey Museum, 6:30–9:30 p.m. Visit to new Paleontology Building at South Dakota School of Mines and Technology. 5–6:30 p.m. Meet in lobby of Rushmore Plaza Holiday Inn hotel. Field Trips Unless otherwise stated, all field trips will depart from and return to the south entrance of the Rushmore Plaza Holiday Inn, 5th Street, Rapid City. The field trip chairs 22 2010 GSA Abstracts with Programs are Colin J. Paterson, +1-605-394-5114, colin.paterson@ sdsmt.edu, and Alvis L. Lisenbee, +1-605-394-2463, alvis. lisenbee@sdsmt.edu. For detailed information on individual field trips, please contact the field trip leaders. Pre-meeting 1. Geology of the Homestake Gold Mine (Deep Underground Science and Engineering Laboratory [DUSEL]) in Lead, South Dakota. Tuesday, 20 April. Colin J. Paterson, SD School of Mines and Technology, +1-605-394-5114, colin.paterson@sdsmt.edu; Michael P. Terry, South Dakota School of Mines and Technology. Max: 20. Cost: US$55 (includes lunch, refreshments, transportation, and guidebook). NOTE: Underground tour is contingent upon DUSEL approval, and could be subject to last-minute cancellation if conditions warrant. 3. Karst and Fractured Aquifer Hydrogeology. Tuesday, 20 April. Larry D. Putnam, US Geological Survey, +1-605-394-3212, ldputnam@usgs.gov; J. Foster Sawyer, South Dakota School of Mines and Technology; Perry H. Floor Plan Rushmore Plaza Civic Center Rahn, South Dakota School of Mines and Technology; Mark T. Anderson, US Geological Survey. Max: 25. Cost: US$60 (includes lunch, refreshments, transportation, and guidebook). 4. The Black Hills and I-90—Hwy 79 Development Corridor. Tuesday, 20 April. Larry D. Stetler, SD School of Mines and Technology, +1-605-394-2464, larry.stetler@ sdsmt.edu; Alvis Lisenbee, South Dakota School of Mines and Technology; Jack Epstein, United States Geological Survey; Kurt Katzenstein, South Dakota School of Mines and Technology. Max: 20. Cost: US$70. (includes lunch, refreshments, transportation, and guidebook). 9. Trace Fossils at the Cambrian-Precambrian Nonconformity, West of Rapid City, Black Hills. Tuesday, 20 April. Jack Redden, South Dakota School of Mines and Technology, +1- 605-394-5114. Max: 20. Cost: US$52 (includes lunch, refreshments, transportation, and guidebook). 10. Mammoth Site in Hot Springs, South Dakota. Tuesday, 20 April. Larry Agenbroad, Mammoth Site, +1- 605-745-6017, larrya@mammothsite.org. Max: 20. Cost: US$60 (includes lunch, refreshments, transportation, and guidebook). 11. Paleozoic Stratigraphy of the Northern Black Hills. Tuesday, 20 April. Mark Fahrenbach. South Dakota Geological Survey, +1-605-394-6830, mark.fahrenbach@ state.sd.us. Max: 20. Cost: US$60 (includes lunch, refreshments, transportation, and guidebook). Post-meeting 2. Structural and Tectonic Evolution of the Proterozoic Trans-Hudson-Archean Wyoming Province Boundary. Saturday–Sunday, 24–25 April. Michael P. Terry, SD School of Mines and Technology, +1-605-394-5286, michael.terry@ sdsmt.edu; Jack Redden, South Dakota School of Mines and Technology, Edward F. Duke, South Dakota School of Mines and Technology, Stephen J. Allard, Winona State University. Max.: 18. Cost: US$170. (includes lodging, lunches, refreshments, transportation, and guidebook). 5. Laramide Tectonics and Stratigraphy of the Northern Rocky Mountains and Great Plains. Saturday–Sunday, 24–25 April. Alvis Lisenbee, SD School of Mines and Technology, +1-605-394-2461, alvis.lisenbee@sdsmt.edu; Eric Erslev, University of Wyoming. Max: 30. Cost: US$175 (includes lodging, lunches, refreshments, transportation, and guidebook). 6. Recent Advances in Understanding the Geologic History of the White River Badlands. Saturday–Sunday, 24–25 April. Emmett Evanoff, University of Northern Colorado, +1-970-351-2437, emmett.evanoff@unco.edu; 2010 GSA Rocky Mountain Section Meeting 23 Patrick Burkhart, Slippery Rock University; Rachel Benton, Badlands National Park; Dennis Terry, Temple University. Max: 30. Cost: US$135 (includes lodging, lunches, refreshments, transportation, park entrance fees, and guidebook). 7. Environmental Geology of Abandoned Uranium Mines, Harding County. Saturday, 24 April. Larry D. Stetler, South Dakota School of Mines and Technology, +1-605-394-2464, larry.stetler@sdsmt.edu; James J Stone, South Dakota School of Mines and Technology. Max: 20. Cost: US$85 (includes lunch, refreshments, transportation, and guidebook). 8. Holocene Paleoflood Events in the Black Hills: Evidence Preserved in Alcoves and Caves. Saturday, 24 April. John Stamm, US Geological Survey, +1-605-394-3222, jstamm@usgs.gov; Dan Driscoll, USGS; Tessa Harden, USGS. Max: 21. Cost: US$60 (includes lunch, refreshments, transportation, and guidebook). Technical Program Technical presentations are 17 minutes in length with 3 minutes for questions. Only digital media presentations (PowerPoint) are allowed (no slides). Presenters may not use their own laptops. Speakers must provide their presentations on either CD-R or flash drive (both are recommended with one as back-up) to the projectionist in their room before the morning session begins (for a.m. talks) or before the afternoon session begins (for p.m. talks). The Speaker Ready Room (Room 102) is available for presentation reviewing. Poster Sessions Poster sessions are in Exhibit Hall H. Individual poster space will be 4 ft × 8 ft. Authors are required to be present for at least two hours during their poster session. Theme Sessions T1. Geoscience and Engineering at the Deep Underground Science and Engineering Laboratory (DUSEL) in Lead, South Dakota. William Roggenthen, william.roggenthen@ sdsmt.edu. T2. Structural and Tectonic Evolution of the Proterozoic Trans-Hudson-Archean Wyoming Province Boundary. Michael P. Terry, michael.terry@sdsmt.edu; Jack Redden, jack.redden@sdsmt.edu. T4. Geologic Hazards of the Rocky Mts. and Great Plains. Larry D. Stetler, larry.stetler@sdsmt.edu; Kurt Katzenstein, kurt.katzenstein@sdsmt.edu. T5. Laramide Tectonics and Stratigraphy of the Northern Rocky Mountains and Great Plains. Alvis Lisenbee, alvis.lisenbee@sdsmt.edu; Eric Erslev, erslev@ warnercnr.colostate.edu. T6. Recent Advances in Understanding the Geologic History of the White River Badlands. Emmett Evanoff, emmettevanoff@earthlink.net; Patrick Burkhart, patrick.burkhart@sru.edu; Rachel Benton, rachel_benton@ nps.gov. 24 2010 GSA Abstracts with Programs T7. Geological Studies in National Park Service Areas of the Rocky Mountain Region. Tim Connors, tim_connors@nps.gov. T8. GIS and Remote Sensing Applications in the Geosciences. Maribeth Price, maribeth.price@sdsmt.edu. T10. Hydrologic and Geologic Framework of the Central Missouri River Corridor. Scott C. Lundstrom, sclundst@ usgs.gov; Tim Cowman, tcowman@usd.edu. T11. Geology of Shale: From Source Rocks to Reservoir Rocks. Neil S. Fishman, nfishman@usgs.gov; Sven Egenhoff, sven@warnercnr.colostate.edu. T13. Western South Dakota Hydrology Conference. Janet M Carter, jmcarter@usgs.gov; Arden Davis, arden.davis@ sdsmt.edu. T18. Undergraduate Research (Posters). Kurt Katzenstein, kurt.katzenstein@sdsmt.edu. General Session In addition to specific theme sessions, general oral and poster sessions include the following categories. Oral Sessions Paleontology Economic Geology Geoscience Education Hydrogeology Sedimentation, Stratigraphy, and Geomorphology Structural Geology, Tectonics, and Petrology Poster Sessions Paleontology Engineering Geology and Geophysics Hydrogeology Sedimentation, Stratigraphy, and Geomorphology Structural Geology, Tectonics, and Petrology Undergraduate Research Student Activities Roy J. Shlemon Mentor Program in Applied Geoscience. Wednesday, 21 April noon–1 p.m. Room 205. Cosponsored by the GSA Foundation. The Shlemon Mentor Program is designed to extend the mentoring reach of individual professionals from applied geology to undergraduates and graduate students attending GSA Section Meetings. Over FREE LUNCH, mentors discuss professional opportunities and challenges that await students after graduation. Every registered student will receive a free ticket to the Shlemon Luncheon along with his/her badge; however, attendance is limited, and meals are on a first come, first served basis. The John Mann Mentors in Applied Hydrogeology Program. Friday, 23 April, noon–1 p.m. Room 205. Cosponsored by the GSA Foundation. The Mann Mentors in Applied Hydrogeology Program presents mentoring opportunities for undergraduate, graduate, and recent graduate students with a declared interest in applied hydrogeology as a career to interact and network with practicing hydrogeology professionals. This relaxed, but focused, small-scale event features a FREE LUNCH for student and professional participants. Every registered student will receive a free ticket to the Mann Luncheon along with his/her badge; however, attendance is limited, and meals are on a first come, first served basis. Other Hotels Within Walking Distance Student Awards Howard Johnson, 950 North Street Rapid City, SD 57701-1149 +1-605-737-4656 Radisson Hotel Rapid City/Mount Rushmore 445 Mt Rushmore Rd Rapid City, SD 57701 +1-605-348-8300 Awards are given for best student oral (undergraduate or graduate) and poster (undergraduate only) presentations. To be eligible, students must be lead authors and presenters and should clearly identify their abstracts as student work. Hotel Alex Johnson 523 6th St. Rapid City, SD 57701 +1-800-888-2539 Exhibits Exhibits are located in the Rushmore Plaza Civic Center, Hall H, and are open at the following times: Wednesday, 21 April...... 8 a.m.–6 p.m. & 7 p.m.–9 p.m. Thursday, 22 April......... 8 a.m.–6 p.m. Friday, 23 April.............. 8 a.m.–4 p.m. Accommodations Conference Center Hotel: Holiday Inn Rapid City– Rushmore Plaza Hotel 505 N. 5th Street, Rapid City, SD 57701, USA; +1-605-348-4000 Town House Motel 210 Saint Joseph St Rapid City, SD 57701-2827 +1-605-342-8143 Parking Ample free parking is available at the east and west entrances of Rushmore Plaza Civic Center. Additional Information For additional information, contact Co-chairs Michael P. Terry, michael.terry@sdsmt.edu or Larry D. Stetler, larry.stetler@sdsmt.edu. 2010 GSA Rocky Mountain Section Meeting 25 Schedule of Events Event Time Location Tuesday, 20 April 2010 Field Trips F1. Geology of the Homestake Gold Mine (Deep Underground Science and Engineering Lab [DUSEL]) in Lead, South Dakota 7 a.m. Holiday Inn Lobby F3. Karst and Fractured Aquifer Hydrogeology: Recent Advances in the Conceptualization, Characterization, and Interpretation of Fluid Movement and Transport Dynamics 7:30 a.m. Holiday Inn Lobby F4. The Black Hills and I-90-Hwy 79 Development Corridor 7:45 a.m. Holiday Inn Lobby F9. Trace Fossils at the Cambrian-Precambrian Nonconformity, West of Rapid City, Black Hills 7:45 a.m. Holiday Inn Lobby F10. Mammoth Site in Hot Springs, South Dakota 7:45 a.m. Holiday Inn Lobby F11. Paleozoic Stratigraphy of the Northern Black Hills 7:30 a.m. Holiday Inn Lobby 5–7 p.m. Upper East Concourse Registration Wednesday, 21 April 2010 Morning Registration 7 a.m.–9 p.m. Upper East Concourse Exhibits 8 a.m.–6 p.m. & 7–9 p.m. Rushmore H Roy J. Shlemon Mentor Program in Applied Geoscience noon–1 p.m. Room 205 Rocky Mountain Section Business Meeting noon–1 p.m. Room 201 Welcome Reception/Map Blast 7–9 p.m. Rushmore H Paleontology 8–10 a.m. Rushmore G GIS and Remote Sensing Applications in the Geosciences 8–10 a.m. Ponderosa Room Geoscience and Engineering at the Deep Underground Science and Engineering Lab (DUSEL) in Lead, South Dakota 8 a.m.–noon Alpine Room Economic Geology 10:20 a.m.–noon Rushmore G Geologic Hazards of the Rocky Mountains and Great Plains 10:20 a.m.–noon Ponderosa Room Geology of Shale: From Source Rocks to Reservoir Rocks 1:15 p.m.–4 p.m. Rushmore G Geoscience Education 1:20 p.m.–3:20 p.m. Alpine Room Geological Studies in National Park Service Areas of the Rocky Mountain Region 1:20 p.m.–4 p.m. Ponderosa Room Oral Sessions Afternoon Oral Sessions 26 2010 GSA Abstracts with Programs Event Time Location Engineering Geology and Geophysics 8 a.m.–6 p.m. Rushmore H Paleontology 8 a.m.–6 p.m. Rushmore H Geoscience and Engineering at the Deep Underground Science and Engineering Lab (DUSEL) in Lead, South Dakota 8 a.m.–6 p.m. Rushmore H GIS and Remote Sensing Applications in the Geosciences 8 a.m.–6 p.m. Rushmore H All Day Poster Sessions (Authors will be present from 4 to 6 PM) Thursday, 22 April 2010 Morning Registration 7 a.m.–4 p.m. Upper East Concourse Exhibits 8 a.m.–6 p.m. Rushmore H Western South Dakota Hydrology Conference Lunch noon–1 p.m. Rushmore F John Mann Mentors in Applied Hydrogeology Program noon–4 p.m. Room 205 Visit to the new Paleontology building (SDSMT) 5–6:30 p.m. Holiday Inn Lobby Rocky Mountain Section Annual Banquet 6:30–9:30 p.m. Journey Museum Recent Advances in Understanding the Geologic History of the White River Badlands I 8 a.m.–noon Alpine Room Western South Dakota Hydrology Conference I “Surface-Water Modeling, Ecology, Floods, and Climate” 8 a.m.–noon Ponderosa Room Western South Dakota Hydrology Conference II “Mining and Land-Use Effects” 8 a.m.–noon Rushmore G Recent Advances in Understanding the Geologic History of the White River Badlands II 1:20 p.m.–3 p.m. Alpine Room Western South Dakota Hydrology Conference III “Surface-Water Quality” 1:20 p.m.–4 p.m. Ponderosa Room Western South Dakota Hydrology Conference IV “Ground-Water Quality and Hydrology” 1:20 p.m.–4 p.m. Rushmore G Recent Advances in Understanding the Geologic History of the White River Badlands 8 a.m.–6 p.m. Rushmore H Hydrologic and Geologic Framework of the Central Missouri River Corridor 8 a.m.–6 p.m. Rushmore H Western South Dakota Hydrology Conference 8 a.m.–6 p.m. Rushmore H Undergraduate Research 8 a.m.–6 p.m. Rushmore H Oral Sessions Afternoon Oral Sessions All Day Poster Sessions (Authors will be present from 4 to 6 PM) 2010 GSA Rocky Mountain Section Meeting 27 Event Time Location Friday, 23 April 2010 Morning Registration 7–9 a.m. Upper East Concourse Exhibits 8 a.m.–4 p.m. Rushmore H Structural and Tectonic Evolution of the Proterozoic Trans-Hudson– Archean Wyoming Province Boundary 8–10 a.m. Alpine Room Hydrogeology 8–11 a.m. Ponderosa Room Laramide Tectonics and Stratigraphy of the Northern Rocky Mountains and Great Plains 10:20–noon Alpine Room noon–1 p.m. Room 205 Structural Geology, Tectonics, and Petrology 1:20 p.m.–2:30 p.m. Alpine Room Sedimentation, Stratigraphy, and Geomorphology 1:20 p.m.–2:30 p.m. Ponderosa Room Hydrogeology 8 a.m.–4 p.m. Rushmore H Sedimentation, Stratigraphy, and Geomorphology 8 a.m.–4 p.m. Rushmore H Structural Geology, Tectonics, and Petrology 8 a.m.–4 p.m. Rushmore H Structural and Tectonic Evolution of the Proterozoic Trans-Hudson– Archean Wyoming Province Boundary 8 a.m.–4 p.m. Rushmore H Oral Sessions John Mann Mentors in Applied Hydrogeology Program Afternoon Oral Sessions All Day Poster Sessions (Authors will be present from noon to 1:20 PM) Saturday, 24 April 2010 Field Trips F7. Environmental Geology of Abandoned Uranium Mines, Harding County 7:15 a.m. Holiday Inn Lobby F8. Holocene Paleoflood Events in the Black Hills: Evidence Preserved in Alcoves and Caves 7:45 a.m. Holiday Inn Lobby Saturday–Sunday, 24–25 April 2010 Field Trips F2. Structural and Tectonic Evolution of the Proterozoic Trans-HudsonArchean Wyoming Province Boundary 7:45 a.m. Holiday Inn Lobby F5. Laramide Tectonics and Stratigraphy of the Northern Rocky Mountains and Great Plains 7:45 a.m. Holiday Inn Lobby F6. Recent Advances in Understanding the Geologic History of the White River Badlands 7:30 a.m. Holiday Inn Lobby 28 2010 GSA Abstracts with Programs Technical Sessions A no-smoking policy has been established by the Programme Committee and will be followed in all meeting rooms for technical sessions. Meeting policy prohibits the use of cameras or sound-recording equipment at technical sessions and poster sessions. Notice In the interest of public information, the Geological Society of America provides a forum for the presentation of diverse opinions and positions. The opinions (views) expressed by speakers and exhibitors at these sessions are their own and do not necessarily represent the views or policies of the Geological Society of America. Note index system Numbers (3-4, 15-4) indicate session and order of presentation within that session. *denotes speaker WEDNESDAY, 21 APRIL 2010 morning Oral Technical Sessions 2-2 8:20 AM Pagnac, Darrin*: THE EARLIEST PROBOSCIDEAN IN SOUTH DAKOTA FROM THE MIDDLE MIOCENE (BARSTOVIAN) FORT RANDALL FORMATION 2-3 8:40 AM Martin, James E.*: A NEW PALEONTOLOGICAL REPOSITORY AT THE MUSEUM OF GEOLOGY, SOUTH DAKOTA SCHOOL OF MINES AND TECHNOLOGY 2-4 9:00 AM Mahan, Shannon A.*; Holen, Steven; May, David W.: THE ANGUS MAMMOTH CONTROVERSY: RESOLVED? 2-5 9:20 AM Bunds, Michael P.*; Emerman, Steven H.; Bhattarai, Tara N.; Anderson, Ryan B.; Adhikari, Narayan; Karki, Kabita; Palmer, Mallory A.: USING LICHENOMETRY TO ASSESS LONG TERM GLOF AND LANDSLIDE FREQUENCY IN THE NEPAL HIMALAYA 2-6 9:40 AM Hasiotis, Stephen T.*; Halfen, Alan F.: BIOTA AS A MAJOR SOIL-FORMING FACTOR AND ECOSYSTEM ENGINEERS THROUGH RECENT EARTH HISTORY BASED ON CONTINENTAL TRACE FOSSILS—SOIL BIOTA AS GEOENGINEERS SESSION NO. 1 Economic Geology 10:20 AM, Rushmore Plaza Civic Center, Rushmore G Nuri Uzunlar, Presiding 1-1 10:20 AM Felsman, Jason M.*: GEOLOGY, HYDROTHERMAL ALTERATION, AND GOLD MINERALIZATION IN THE VICINITY OF TAYLOR RIDGE AND CARBON HILL, BEAR LODGE MOUNTAINS, CROOK COUNTY, WYOMING 1-2 10:40 AM Sears, James*: GOLD-BEARING VEINS IN THE GARNET MINING DISTRICT, GRANITE COUNTY, MONTANA: SYNTECTONIC MINERALIZATION ALONG THE LEWIS AND CLARK LINE SHEAR ZONE 1-3 11:00 AM Harp, Michael T.*; Friberg, LaVerne M.: DEVELOPING A USEFUL SET OF PROXY ELEMENTS FOR TARGETING GOLD DEPOSITS IN THE BLACK HILLS, SOUTH DAKOTA SESSION NO. 3 1-4 11:20 AM Lufkin, John L.*; Cantorin, Maritza: ORIGIN OF ORE TEXTURES: PORPHYRY COPPER DEPOSITS T1. Geoscience and Engineering at the Deep Underground Science and Engineering Lab (DUSEL) in Lead, South Dakota 1-5 11:40 AM Samimi, Hadi*; Patruyo, David; Larter, Stephen R.; Spencer, Ronald J.; Gates, Ian; Hubbard, Stephen M.; Marcano, Norka: INVESTIGATING AND MODELING FLUID AND RESERVOIR ROCK HETEROGENEITIES OF AN OIL SANDS RESERVOIR, A CASE STUDY FROM WESTERN CANADIAN SEDIMENTARY BASIN 8:00 AM, Rushmore Plaza Civic Center, Alpine Room William M. Roggenthen, Presiding 3-1 8:00 AM Rempe, Norbert T.*: GEOLOGIC WASTE REPOSITORIES, UNDERGROUND SCIENCE LABORATORIES, AND RADIOACTIVITY: A PARADIGM SHIFT 3-2 8:20 AM Roggenthen, W.M.*: DEVELOPMENT OF THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY (DUSEL) 3-3 8:40 AM Popielak, Roman S.; Weinig, Walter*; Vardiman, David M.: CIVIL ENGINEERING AND MINING PROJECTS— RECONCILIATION OF DESIGN PHILOSOPHIES 3-4 9:00 AM Terry, Michael*; Lisenbee, Alvis L.: 3-D GEOLOGIC MODEL OF THE LARGE CAVITY AREA AT THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY, HOMESTAKE MINE, SOUTH DAKOTA SESSION NO. 2 Paleontology 8:00 AM, Rushmore Plaza Civic Center, Rushmore G James E. Martin, Presiding 2-1 8:00 AM Hasiotis, Stephen T.*; Rasmussen, Donald L.: ENIGMATIC, LARGE- AND MEGA-DIAMETER BURROWS IN THE LOWER PERMIAN CEDAR MESA SANDSTONE, COMB RIDGE AND MOQUI DUGWAY, SOUTHEASTERN UTAH 2010 GSA Rocky Mountain Section Meeting 29 SESSION NO. 3 3-5 9:20 AM Stetler, Larry*; Davis, Arden D.; Salve, Rohit; Volk, James; VanBeek, Jason: HYDROLOGIC, CLIMATIC, AND GROUND MOTION STUDIES AT HOMESTAKE DUSEL 5-4 9:00 AM Webb, David A.*: ADAPTING PROVEN LIDAR TECHNOLOGY TO COST EFFECTIVE SOLUTIONS FOR 1-FOOT CONTOURS WITH THE FLI-MAP FX 3-6 9:40 AM Jones, Tessa L.*; Van Beek, Jason K.; Wang, Joe S.; Davis, Arden D.: FROM BASIC PHYSICS TO COMPLEX HYDROGEOLOGY: A UNIQUE APPROACH FOR DERIVING HYDRAULIC CONDUCTIVITY IN AN UNDERGROUND LAB 5-5 9:20 AM Minnick, Matthew*; Zhou, Wendy: GIS AND WEB BASED WATER RESOURCES MANAGEMENT FOR OIL SHALE DEVELOPMENT IN THE WESTERN UNITED STATES, STAGE I 5-6 9:40 AM Murray, Kyle Edward*; Le, Tuan: COMPUTING GeoVolumes FOR GROUNDWATER SYSTEMS USING GIS 10:00 AM Break 3-7 10:20 AM Muxen, Andrew B.*; Tolle, Charles R.; McGough, Jeffery: AUTONOMOUS UNDERWATER VEHICLES AND THEIR APPLICATION TO UNDERGROUND MAPPING AND EXPLORATION 3-8 10:40 AM Sonnenthal, Eric*; Elsworth, Derek; Freifeld, Barry; Lowell, Robert; Maher, Kate; Mailloux, Brian J.; Uzunlar, Nuri: A COUPLED THERMAL-HYDROLOGICAL-MECHANICALCHEMICAL-BIOLOGICAL EXPERIMENTAL FACILITY AT DUSEL HOMESTAKE 3-9 3-10 3-11 11:00 AM Tuffour, Peprah*; Paterson, Colin J.; Terry, Michael P.: MINERAL CHEMISTRY OF CHLORITE, HOMESTAKE GOLD DEPOSIT, NORTHERN BLACK HILLS, SOUTH DAKOTA: IMPLICATIONS FOR GOLD DEPOSITION IN IRONFORMATION-HOSTED GOLD DEPOSITS 11:20 AM Ellingson, William*; Paterson, Colin J.; Terry, Michael P.: CONTROLS ON PREFERRED LOCALIZATION OF GOLD ORE IN SYNCLINES WITHIN THE HOMESTAKE MINE, LEAD, SOUTH DAKOTA, USA 11:40 AM Hamer, Rayburn C.*; Paterson, Colin J.: HYDROTHERMAL ALTERATION AND GOLD DEPOSITION IN THE HOMESTAKE IRON-FORMATION-HOSTED GOLD DEPOSIT, LEAD, SOUTH DAKOTA Poster Technical Sessions SESSION NO. 6 Engineering Geology and Geophysics (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from 4 to 6 PM Booth # 6-1 1 Tuffour, Peprah*; Stetler, Larry: LANDSLIDE HAZARD ZONATION MAPS FOR RAPID CITY, SOUTH DAKOTA 6-2 2 Ward, Dustin*; Mahan, Kevin: RELATIVE INFLUENCE OF QUARTZ MICROSTRUCTURE ON CRUSTAL SEISMIC ANISOTROPY 6-3 3 Schneider, John M.*; Goodman, William M.: TWO-DIMENSIONAL SEISMIC REFLECTION EVALUATION OF THE I&W BRINE CAVERN CARLSBAD, NEW MEXICO SESSION NO. 7 Paleontology (Posters) SESSION NO. 4 8:00 AM, Rushmore Plaza Civic Center, Rushmore H T4. Geologic Hazards of the Rocky Mountains and Great Plains Authors will be present from 4 to 6 PM 10:20 AM, Rushmore Plaza Civic Center, Ponderosa Room Larry Stetler and Kurt Katzenstein, Presiding 7-1 4 Rowe, Becci J.*; Gabel, Mark L.; Shelton, Sally Y.: MIOCENE FLORA OF THE ALVORD CREEK FORMATION, OREGON; INTERPRETATION OF ANCIENT CLIMATE 7-2 5 Wahl, William R.*: THE REDESCRIPTION AND EXCAVATION OF WILBUR KNIGHT’S 1895 MEGALNEUSAURUS REX SITE 7-3 6 Lomax, Dean R.; Racay, Christopher A.*: A LONG MORTICHNIALTRACKWAY OF MESOLIMULUS WALCHI FROM THE TITHONIAN STAGE OF THE UPPER JURASSIC SOLNHOFEN LITHOGRAPHIC LIMESTONE NEAR WINTERSHOF, GERMANY 4-1 10:20 AM Stetler, Larry*: LANDUSE MODELING IN THE BLACK HILLS FOR RESPONSIBLE DEVELOPMENT 4-2 10:40 AM Anderson, Fred J.*: LANDSLIDES IN NORTH DAKOTA: AN OVERVIEW OF THE LANDSLIDE INVENTORY MAPPING PROGRAM AT THE NORTH DAKOTA GEOLOGICAL SURVEY 4-3 11:00 AM Pellowski, Christopher J.*; Lisenbee, Alvis L.: THE HERMOSA FLOOD OF AUGUST 17, 2007: EXTENT, EFFECTS, AND COMPARISON TO FEMA FLOOD INSURANCE RATE MAP 4-4 11:20 AM Epstein, Jack*: EVAPORITE KARST IN THE BLACK HILLS, SOUTH DAKOTA AND WYOMING 4-5 11:40 AM Goodman, Brian S.*; Pierson, M. Patrick: ERIONITE, A NATURALLY OCCURRING FIBROUS MINERAL HAZARD IN THE TRI-STATE AREA OF NORTH DAKOTA, SOUTH DAKOTA, AND MONTANA SESSION NO. 5 Booth # SESSION NO. 8 T1. Geoscience and Engineering at the Deep Underground Science and Engineering Lab (DUSEL) in Lead, South Dakota (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from 4 to 6 PM Booth # 8-1 7 Dobson, Patrick F.; Peters, Catherine A.*; Ramakrishnan, T.S.; Stabinski, Eric; Liang, Kenneth; Verma, Sandeep; Oldenburg, Curtis M.; Freifeld, Barry M.; Wang, Joseph S.: MONITORING FLUID CONCENTRATION AND PHASE CHANGES IN FLOW EXPERIMENTS AT THE PROPOSED DUSEL CO2 FACILITY T8. GIS and Remote Sensing Applications in the Geosciences 8:00 AM, Rushmore Plaza Civic Center, Ponderosa Room Maribeth H. Price, Presiding 5-1 8:00 AM Agenbroad, Larry; Esker, Donald Anton*; Wilkins, W.J.: THE MAMMOTH SITE OF HOT SPRINGS SD, THE MAPPING OF A LONG TERM EXCAVATION SITE 8-2 8 Rowe, Aryn M.*; Garraffa, Alfred; Weber, Carolyn; Price, Maribeth H.: DEVELOPING A SPATIAL INDEX FOR THE HOMESTAKE ARCHIVE 5-2 8:20 AM Matthews, Neffra A.*; Christensen, Tom; Titus, Alan L.; Noble, Tommy A.; Breithaupt, Brent H.: USING GIS TO TRACK FOSSIL FOOTPRINTS: TAKE It OUTSIDE AT THE JURASSIC MOCCASIN MOUNTAIN TRACKSITE, UTAH 8-3 9 Hladysz, Zbigniew J.*; Roggenthen, W.M.: GEOTECHNICAL CHARACTERIZATION OF EXCAVATIONS FOR THE DUSEL CONSTRUCTION 5-3 8:40 AM Marini, Brandon L.*; Ryczek, Daniel; Linn, Thomas; LeRoy, Janine; Price, Maribeth: LOCALITY DATABASE FOR MUSEUM OF GEOLOGY PALEONTOLOGICAL COLLECTIONS 30 2010 GSA Abstracts with Programs 8-4 10 Cooper, Scott P.*; Uzunlar, Nuri; Lisenbee, Alvis L.: GAS-FLUID EVOLUTION AND THE FORMATION OF RHYOLITE DIKEASSOCIATED BRECCIA MARGINS, HOMESTAKE MINE, LEAD, SOUTH DAKOTA SESSION NO. 12 8-5 11 Uzunlar, Nuri*; Paterson, Colin J.; Lisenbee, Alvis L.: TERTIARY EPITHERMAL-MESOTHERMAL AU-AG MINERALIZATION IN HOMESTAKE MINE, LEAD, SOUTH DAKOTA SESSION NO. 11 SESSION NO. 9 1:20 PM, Rushmore Plaza Civic Center, Ponderosa Room T8. GIS and Remote Sensing Applications in the Geosciences (Posters) T7. Geological Studies in National Park Service Areas of the Rocky Mountain Region Tim Connors, Presiding 11-1 1:20 PM Connors, Tim*: THE NATIONAL PARK SERVICE GEOLOGIC RESOURCES INVENTORY; GEOLOGY ISN’T JUST FOR SCENERY ANYMORE......2010 UPDATES 11-2 1:40 PM Lukens, William E.*; Terry, Dennis O. Jr.; Grandstaff, David E.; Beasley, Barbara A.: TRACKING STOLEN FOSSILS: A STUDY TO DETERMINE THE UTILITY OF RARE EARTH ELEMENTS AS A TOOL FOR VERTEBRATE FOSSIL PROTECTION 11-3 2:00 PM Wiles, Michael E.*; Ohms, René E.: THE POTENTIAL EXTENT OF THE JEWEL CAVE SYSTEM: FINE-TUNING A GIS MODEL 11-4 9-3 14 Thaler, Terry*; Price, Maribeth H.: MULTITEMPORAL REMOTE SENSING OF VEGETATION IN THE CHEYENNE RIVER WATERSHED OF SOUTH DAKOTA AND WYOMING 2:20 PM Andersen, Allen*: GEOCHEMISTRY OF INKPOT SPRING, SULPHUR CREEK-SEVENMILE HOLE AREA,YELLOWSTONE CALDERA, WYOMING 11-5 9-4 15 Saxton, Samantha*; Redden, J.A.; Terry, Michael P.: A GIS GEOLOGIC MAP COMPILATION: THE MT. RUSHMORE QUADRANGLE, BLACK HILLS, SOUTH DAKOTA (1:24,000 SCALE) 2:40 PM Brunhart-Lupo, Maria*: LUNETTES OF THE SAN LUIS LAKE RECREATIONAL AREA AND GREAT SAND DUNES, COLORADO 11-6 9-5 16 Zeitler, Joseph*; Barker, Paula; McKaskey, Jonathan; Morton, Patrick; Price, Maribeth: DESIGNING A SPATIAL MAP INDEX FOR GEOLOGIC MAP COLLECTIONS 3:00 PM Bradshaw, Richard W.; Kowallis, Bart J.*: U-PB DATING OF ZIRCONS FROM THE SALT WASH MEMBER OF THE MORRISON FORMATION FROM NEAR CAPITOL REEF NATIONAL PARK, UTAH 11-7 3:20 PM Epstein, Jack*: INTERPRETIVE GEOLOGIC TRAILS IN NATIONAL PARKS; EXAMPLES FROM DETO AND DEWA 11-8 3:40 PM Gallin, William N.*; Johnson, Cari: A FRESH LOOK AT FLUVIAL, PARALIC, AND MARINE STRATIGRAPHY IN THE JOHN HENRY MEMBER, STRAIGHT CLIFFS FORMATION, GRAND STAIRCASE-ESCALANTE NATIONAL MONUMENT, UTAH 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from 4 to 6 PM Booth # 9-1 12 Katzenstein, Kurt W.*: InSAR-IDENTIFIED SURFACE DEFORMATION RESULTING FROM COAL BED METHANE PRODUCTION IN THE POWDER RIVER BASIN, WYOMING 9-2 13 Smith Barnes, Connie K.*; Bradford, Joel A.; Dinklage, William; Bishop, Nate; Bunds, Michael P.; VanWagoner, Marc E.; Rey, Kevin; Horns, Daniel: ARCGIS MAPPING DISPLAYS HYDROGEOLOGIC SURVEY DATA AESTHETICALLY, ACCURATELY AND EFFICIENTLY FOR SCIENTIFIC AND NON SCIENTIFIC ANALYSIS afternoon Oral Technical Sessions SESSION NO. 10 SESSION NO. 12 Geoscience Education T11. Geology of Shale: From Source Rocks to Reservoir Rocks 1:20 PM, Rushmore Plaza Civic Center, Alpine Room 1:15 PM, Rushmore Plaza Civic Center, Rushmore G Nuri Uzunlar, Presiding Neil S. Fishman and Sven Egenhoff, Presiding 10-1 1:15 PM Introductory Remarks 12-1 1:20 PM Pratt, Brian R.*; Pushie, M. Jake; Pickering, Ingird J.; George, Graham N.: SYNCHROTRON IMAGING OF BURGESS SHALE FOSSILS: EVIDENCE FOR BIOCHEMICAL COPPER (HEMOCYANIN) IN THE MIDDLE CAMBRIAN ARTHROPOD MARRELLA SPLENDENS 1:20 PM Uzunlar, Nuri*; Lisenbee, Alvis L.: TRADITIONAL FIELD CAMPS: AN IMPORTANT INTEGRAL COMPONENT IN GEOSCIENCES EDUCATION 10-2 1:40 PM Sethi, Parvinder*: VIRTUAL REALITY FIELD-TRIPS FOR STUDYING THE GEOLOGY OF NATIONAL PARKS: RECENT ADVANCES & PEDAGOGY 10-3 2:00 PM Breithaupt, Brent H.*; Campbell-Stone, Erin; Matthews, Neffra A.: PUBLIC PALEONTOLOGICAL SITES AS TEACHING TOOLS IN GEOLOGY FIELD CAMPS: RESOURCE PROTECTION THROUGH RESOURCE EDUCATION 12-2 1:40 PM Egenhoff, Sven O.*; Fishman, Neil S.: STORM DEPOSITION IN THE “ANOXIC” LOWER MISSISSIPPIAN UPPER BAKKEN SHALE OF NORTH DAKOTA - HOW DEEP WAS THE WILLISTON BASIN? 12-3 10-4 2:20 PM Friberg, LaVerne M.*: UNIVERSITY OF AKRON FIELD CAMP, THE CAPSTONE COURSE FOR OUR GEOSCIENCE MAJORS 2:00 PM Hill, Ronald*: BITUMEN FILLED FRACTURES IN THE BAKKEN FORMATION AND IMPLICATIONS FOR GAS SHALE SYSTEMS 12-4 10-5 2:40 PM Moshier, Stephen O.*; Greenberg, Jeffrey K.: HISTORY AND FUTURE OF GEOLOGY FIELD INSTRUCTION AT THE WHEATON COLLEGE SCIENCE STATION, SOUTH DAKOTA BLACK HILLS 2:20 PM Fishman, Neil*; Ellis, Geoffrey; Paxton, Stanley T.; Abbott, Marvin; Boehlke, Adam R.: CHERT BEDS IN THE UPPER DEVONIAN-LOWER MISSISSIPPIAN WOODFORD SHALE IN OKLAHOMA—POSSIBLE RESERVOIR ROCKS? 2:40 PM Break 10-6 3:00 PM Toth, Natalie*; Brown, Rachel; Shelton, Sally: THE SOUTH DAKOTA SCHOOL OF MINES AND TECHNOLOGY’S SCIENCE EDUCATION OUTREACH PROGRAM: EXPOSING YOUNG, INQUISITIVE MINDS TO THE WONDER OF SCIENCE 12-5 3:00 PM Cassle, Christopher F.*; Egenhoff, Sven O.: DEPOSITIONAL ANATOMY OF A PHOSPHATE DOMINATED SOURCE ROCK SUCCESSION: THE MEADE PEAK MEMBER, PHOSPHORIA FORMATION, PERMIAN, USA 12-6 3:20 PM Emsbo, Poul*; Breit, George N.: METALLIFEROUS ORGANICRICH BLACK SHALES: WHERE DO THE METALS COME FROM? 12-7 3:40 PM Pratt, Brian R.*: MOLAR-TOOTH STRUCTURE: CARBONATE MUD DIKELETS GENERATED BY SYNSEDIMENTARY EARTHQUAKES 2010 GSA Rocky Mountain Section Meeting 31 SESSION NO. 13 THURSDAY, 22 APRIL 2010 morning Oral Technical Sessions 14-2 8:20 AM Tinant, Charles Jason*; Belile, Donald; Giraud, Gerald: GIS RS HABITAT MODELING APPROACHES TO IDENTIFY RIPARIAN COMMUNITIES ON THE PINE RIDGE RESERVATION 14-3 8:40 AM Kenner, Scott J.*; Norton, Parker II.; Smith, Barbara: ASSESSMENT OF STREAM MIGRATION RATES TO ESTIMATE BANK EROSION ON THE LOWER CHEYENNE RIVER 14-4 9:00 AM Kenner, Seth*; Love, Jason T.; Pomarleau, Lacy: HYDROLOGIC MODEL APPLICATION OF THE LOWER CHEYENNE RIVER WATERSHED USING HSPF 14-5 9:20 AM Neitzert, Kathleen M.*: NATIONAL RIVERS AND STREAMS ASSESSMENT (NRSA) PROGRAM ACTIVITIES, 2008-09 14-6 9:40 AM Harwood, Alison*: ASSESSMENT OF FISH ABUNDANCE AND SPECIES COMPOSITION AT SELECTED SITES IN SOUTH DAKOTA: AN OVERVIEW SESSION NO. 13 T6. Recent Advances in Understanding the Geologic History of the White River Badlands I 8:00 AM, Rushmore Plaza Civic Center, Alpine Room Emmett Evanoff, Patrick Burkhart, and Rachel Benton, Presiding 13-1 8:00 AM Benton, Rachel*: DEVELOPING A PALEONTOLOGICAL LOCALITY DATABASE AT BADLANDS NATIONAL PARK 13-2 8:20 AM Welsh, Ed*: FINDING SOMETHING NEW OUT OF SOMETHING OLD: AN INTRIGUING LEPTAUCHENINE OREODONT FROM THE UPPER BRULE IN SOUTH DAKOTA 13-3 10:00 AM Break 14-7 8:40 AM Masciale, David M.*; Secord, Ross: A NEW ANALYSIS OF ANCHITHERINE EQUIDS ACROSS THE EOCENEOLIGOCENE BOUNDARY IN THE WHITE RIVER GROUP OF THE WESTERN GREAT PLAINS 10:20 AM Driscoll, Daniel G.*; O’Connor, Jim E.; Harden, Tessa; Stamm, John: A PALEOFLOOD INVESTIGATION FOR REGIONAL IMPROVEMENT OF PEAK-FLOW FREQUENCY ESTIMATES FOR THE BLACK HILLS OF WESTERN SOUTH DAKOTA 14-8 10:40 AM Harden, Tessa*; O’Connor, Jim; Driscoll, Dan: PALEOFLOOD HISTORY OF RAPID CREEK IN THE FOOTHILLS OF THE BLACK HILLS, SOUTH DAKOTA 13-4 9:00 AM Foss, Scott E.*: ENTELODONTS FROM THE BIG BADLANDS OF SOUTH DAKOTA 14-9 13-5 9:20 AM Minkler, Heidi R.*: PALEOFAUNA FROM THE LATEST EOCENE CHADRON FORMATION, HIGHWAY 44 LOCALITY, IN SOUTHWESTERN SOUTH DAKOTA, AND ITS IMPLICATIONS CONCERNING THE EOCENE/OLIGOCENE TRANSITION 11:00 AM Driscoll, Daniel G.; Bunkers, Matthew; Smith, Melissa*; Carter, Janet M.: FACTORS AFFECTING LARGE STORM AND FLOOD EVENTS IN THE BLACK HILLS AREA OF WESTERN SOUTH DAKOTA 14-10 11:20 AM Capehart, William*; Stauffer, Phillip; Henebry, Geoffrey; Wright, Christopher: IMPACTS OF FRACTIONAL VEGETATION COVER AND VEGETATION TYPE ON GREAT PLAINS WEATHER AND CLIMATE 14-11 11:40 AM Norton, Parker II.*; Stamm, John: TRENDS IN TEMPERATURE AND PRECIPITATION IN THE MISSOURI RIVER BASIN FROM 1957 TO 2008 13-6 9:40 AM Moore, Jason R.*; Krumenacker, L.J.: TAPHONOMIC MODES IN THE SCENIC MEMBER OF THE BRULE FORMATION: CONTINUOUS OR DISCRETE? 10:00 AM Coffee Break 13-7 10:20 AM Zwiebel, Jesse*; Leite, Michael B.; Breithaupt, Brent H.; Matthews, Neffra A.; LaGarry, Hannan E.: TOADSTOOL PARK VERTEBRATE TRACKWAYS (OLIGOCENE, BRULE FORMATION, NORTHWESTERN NEBRASKA): ICHNOLOGICAL STUDY ENHANCED THROUGH DIGITAL REPRODUCTION 13-8 10:40 AM Hartman, J.H.*; Weiler, M.W.; Schumaker, K.K.; Evanoff, Emmett: CORRELATING THE SOUTH DAKOTA WHITE RIVER GROUP AND ITS CONTINENTAL MOLLUSKS TO NORTH DAKOTA: A BEGINNING UP THE SLIPPERY SLOPE OF UTILIZING HISTORIC FAUNAS 13-9 11:00 AM Evanoff, Emmett*: THE STRATIGRAPHY OF THE BRULE FORMATION IN THE NORTH UNIT, BADLANDS NATIONAL PARK 13-10 11:20 AM LaGarry, Hannan E.*; LaGarry, Leigh Anne: PROPOSED LITHOSTRATIGRAPHIC REVISION, REDESCRIPTION, AND REDEFINITION OF THE WHITE RIVER GROUP (EOCENEOLIGOCENE), SOUTH DAKOTA 13-11 11:40 AM Gaddie, Helene*; LaGarry, Hannan E.: PRELIMINARY DESCRIPTION OF NEWLY RECOGNIZED OLIGOCENE AND EARLY MIOCENE STRATA NEAR WANBLEE, SOUTH DAKOTA SESSION NO. 15 T13. Western South Dakota Hydrology Conference II “Mining and Land-Use Effects” 8:00 AM, Rushmore Plaza Civic Center, Rushmore G Janet M. Carter, Presiding 15-1 8:00 AM Stamm, John F.*; Geibel, Nicholas M.; Mahan, Shannon A.; Azzolini, David C.: CONCENTRATIONS OF SELECTED METALS IN UNCONTAMINATED ALLUVIAL DEPOSITS OF THE CHEYENNE AND BELLE FOURCHE RIVERS, SOUTH DAKOTA 15-2 8:20 AM Larson, Lance*; Stone, James; Stetler, Larry; Troyer, Lyndsay; Borch, Thomas: SEDIMENT PORE-WATER EQUILIBRIUM INTERACTIONS ASSOCIATED WITH ARSENIC AND URANIUM TRANSPORT WITHIN A HISTORICAL URANIUM MINING IMPACTED WATERSHED, HARDING COUNTY, SD 15-3 8:40 AM Troyer, Lyndsay*; Borch, Thomas; Larson, Lance; Stone, James: IMPACT OF REDOX CHEMISTRY ON THE ENVIRONMENTAL FATE AND TRANSPORT OF ARSENIC AND URANIUM AT ABANDONED URANIUM MINES IN HARDING COUNTY, SD 15-4 9:00 AM Larson, Lance*; Stone, James; Stetler, Larry: ARSENIC AND URANIUM IMPACTED SEDIMENT BEHAVIOR WITHIN THE BOWMAN-HALEY RESERVOIR, BOWMAN COUNTY, NORTH DAKOTA 15-5 9:20 AM Jarding, Lilias C.*: PAST URANIUM MINING IN SOUTH DAKOTA: POLICY AND REGULATORY ISSUES 15-6 9:40 AM Tinant, Charles Jason*; Berdanier, Bruce; Belile, Donald; Gaddie, Helene; Hansen, M.R.: ENVIRONMENTAL IMPACTS OF THE ERDENET COPPER MOLYBDENUM MINE IN NORTH CENTRAL MONGOLIA SESSION NO. 14 T13. Western South Dakota Hydrology Conference I “Surface-Water Modeling, Ecology, Floods, and Climate” 8:00 AM, Rushmore Plaza Civic Center, Ponderosa Room Janet M. Carter and Arden Davis, Presiding 14-1 8:00 AM Stoltenberg, Matthew B.*; Oswald, Jared K.: ONLINE IRRIGATION SCHEDULING WITHIN THE BELLE FOURCHE IRRIGATION DISTRICT 32 2010 GSA Abstracts with Programs 10:00 AM Break SESSION NO. 19 15-7 10:20 AM Sundareshwar, P.V.*: NATURE VERSUS NURTURE: FUNCTIONAL ASSESSMENT OF RESTORATION EFFECTS 15-8 10:40 AM Morlok, Brett A.*; Kenner, Scott J.; Foreman, Cory S.: PHYSICAL HABITAT ASSESSMENT OF THE CHEYENNE RIVER WATERSHED 15-9 11:00 AM Dreis, Erin*; Stone, James; Lupo, Christopher; Clay, Sharon: ENVIRONMENTAL IMPLICATIONS OF THE LAND APPLICATION OF MANURE CONTAINING ANTIMICROBIALS TYLOSIN AND CHLORTETRACYCLINE 15-10 11:20 AM Jinka, Ramith*; Stone, James J.; Dollarhide, Christopher; Aurand, Katherine; Clay, David; Thaler, Robert: LIFE CYCLE ASSESSMENT MODEL FOR A MODERN UPPER GREAT PLAINS U.S. CONFINED SWINE PRODUCTION FACILITY 15-11 11:40 AM Stone, James*; Aurand, Katie; Dollarhide, Christopher; Jinka, Ramith; Thaler, Robert; Clay, David; Clay, Sharon: LIFE CYCLE ASSESSMENT OF TYLOSIN AND CHLORTETRACYCLINE ANTIMICROBIAL USE AT SWINE PRODUCTION FACILITIES Poster Technical Sessions 17-5 9 Paces, James B.*; Lundstrom, Scott C.; Moscati, Richard J.; Pigati, Jeffrey S.: TIMING AND SOURCES OF POSTGLACIAL GROUNDWATER DISCHARGE NEAR THE GLACIAL LIMIT OF THE JAMES LOBE OF THE LAURENTIDE ICE SHEET, SOUTH DAKOTA 17-6 10 Moreno-Ward, April DeAnn*; Erickson, Eli N.; Holbrook, John: GEOMORPHOLOGICAL INTERACTIONS OF THE JAMES RIVER AND MISSOURI RIVER DURING A PORTION OF THE HOLOCENE SESSION NO. 18 T13. Western South Dakota Hydrology Conference (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from 4 to 6 PM Booth # 18-1 11 Thompson, Ryan*: VIEWING DIGITAL BOUNDARIES OF HYDROLOGIC UNITS FOR SOUTH DAKOTA USING GOOGLE EARTH 18-2 12 Wilson, Marcia*: WATER QUALITY MONITORING AT GREAT PLAINS NATIONAL PARKS SESSION NO. 19 SESSION NO. 16 T18. Undergraduate Research (Posters) T6. Recent Advances in Understanding the Geologic History of the White River Badlands (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from 4 to 6 PM Booth # 16-1 Authors will be present from 4 to 6 PM Booth # 19-1 13 Bartling, Jamie*: MICROSTRUCTURAL ANALYSIS OF THE YATES UNIT AT THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY 1 Terry, Dennis O. Jr.*; Kosmidis, Paul G.; Mintz, Jason S.; Stinchcomb, Gary: VERTICAL CHANGES IN PALEOSOLS, SEDIMENTOLOGY, AND VERTEBRATE TAPHONOMY WITHIN THE OLIGOCENE POLESLIDE MEMBER OF THE BRULE FORMATION, BADLANDS NATIONAL PARK, SD 19-2 14 Dannenbring, Scot E.*: MICROSTRUCTURAL AND PETROGRAPHIC STUDY OF ROCKS WITH CONTRASTING RHEOLOGIC PROPERTIES DURING HIGH-TEMPERATURE DEFORMATION, CUSTER COUNTY, SOUTH DAKOTA 16-2 2 Sahy, Diana*; Fischer, Anne; Terry, Dennis O. Jr.; Condon, Daniel; Kuiper, Klaudia: RADIO-ISOTOPIC DATING OF VOLCANIC ASH LAYERS FROM THE WHITE RIVER GROUP, WYOMING AND NEBRASKA 19-3 15 Robertson, Scott*; Schoenrock, Jared K.; Witt, Dallin Christopher; Bunds, Michael P.; Emerman, Steven H.; Bradford, Joel A.: VOLCANOSTRATIGRAPHY OF THE DIVISADERO TUFF IN RIO SAN IGNACIO CANYON, CREEL, MEXICO 16-3 3 Brave, Dylan*: PRELIMINARY LITHOLOGIC DESCRIPTION OF THE CHADRON FORMATION NEAR RED SHIRT, SOUTH DAKOTA, WITH NOTES ON THE INVERTEBRATE AND VERTEBRATE TRACE FOSSILS 19-4 16 Jetson, Melissa K.*; Terry, Michael P.: A STRUCTURAL AND PETROGRAPHIC STUDY OF A PALEOPROTEROZOIC D1 FOLD IN METAMORPHOSED SEDIMENTARY ROCKS, SOUTH DAKOTA 16-4 4 Hanneman, Debra L.*; Wideman, Charles J.: WHITE RIVER GROUP EQUIVALENTS IN MONTANA SESSION NO. 17 T10. Hydrologic and Geologic Framework of the Central Missouri River Corridor (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from 4 to 6 PM Booth # 17-1 5 Martin, James E.*; Parris, David C.: NEW MEMBERS OF THE DeGrey FORMATION, PIERRE SHALE GROUP (UPPER CRETACEOUS) FROM CENTRAL SOUTH DAKOTA 17-2 6 Stamm, John F.*; Geibel, Nicholas M.; Mahan, Shannon A.; Zaprowski, Brent J.; Azzolini, David C.: AGES OF ALLUVIAL TERRACE DEPOSITS AND DYNAMICS OF THE CHEYENNE AND BELLE FOURCHE RIVERS, SOUTH DAKOTA 17-3 7 Alexander, Jason*; Woodward, Brenda; Stamm, John F.; Lamothe, Paul; Maddox, Ashli; Howle, James; Larson, Darin: LEGACY MINE TAILINGS AND ALLUVIAL DEPOSITS ALONG THE BELLE FOURCHE RIVER, SOUTH DAKOTA: AN INTEGRATED, MULTISCALE INVESTIGATION OF CHANNEL DYNAMICS 17-4 8 Lundstrom, Scott*; Cowman, Tim; Holbrook, John M.; Paces, James B.: LATE PLEISTOCENE GLACIATION OF EASTERN SOUTH DAKOTA AND RELATIONS TO THE GEOLOGIC FRAMEWORK OF THE CENTRAL MISSOURI RIVER 19-5 17 Schwabe, Kathleen*: DEPOSITIONAL ENVIRONMENTS OF DINOSAUR EGG-BEARING STRATA OF CENTRAL MONGOLIA (ULAAN TSAV LOCALITY) 19-6 18 Thomson, Olivia A.*; Pauls, Kathryn N.; Rocha-Campos, A.C.; Cotter, James F.P.: DISTINGUISHING BETWEEN THE SAND UNITS OF THE CARBONIFEROUS ITARARé SUBGROUP AND THE DEVONIAN FURNAS FORMATION IN PARANA STATE, BRAZIL 19-7 19 Rathbun, Kathryn*; Sweeney, Mark: SOURCE AND PALEOCLIMATIC SIGNIFICANCE OF LOESS IN SOUTHEAST SOUTH DAKOTA 19-8 20 Holte, Sharon E.*; Agenbroad, Larry; Pagnac, Darrin: IDENTIFICATION OF AN UNKNOWN CARNIVORAN HUMERUS FROM THE MAMMOTH SITE, OF HOT SPRINGS, SOUTH DAKOTA 19-9 21 Thaler, Jacob A.*; Paterson, Colin J.: PETROGRAPHIC AND GEOCHEMICAL ANALYSIS OF A DRILL HOLE IN REUTER CANYON, BEAR LODGE MOUNTAINS, CROOK COUNTY, WYOMING: IMPLICATIONS FOR TERTIARY-AGED CARLIN-LIKE GOLD MINERALIZATION 19-10 22 Nolan, Wyatt C.*; Brugger, Keith A.: ROCK GLACIER AGES IN THE SAWATCH RANGE, COLORADO 19-11 23 Leithauser, Eric*; Burkhart, Patrick; Baldauf, Paul: HOLOCENE PALEOSOL RADIOCARBON AGES AND SOD TABLE MORPHOLOGY IN THE WHITE RIVER BADLANDS REVEAL EROSION RATES OF 1-4 CM/YR, OR MORE, IN THE LAST 800 YEARS 19-12 24 Testin, Jason James*: ANALYSIS OF DENTITION MORPHOLOGY OF ALLOSAURUS FRAGILIS (THERAPODA: AVETHEROPODA): 2010 GSA Rocky Mountain Section Meeting 33 SESSION NO. 19 IMPLICATIONS ON TAXONOMIC UTILIZATION OF ISOLATED SHED TEETH FROM LARGE BODIED THEROPODS 19-13 25 Trumbull, Con B.*; Connely, Melissa V.: NEW ICHNOTAXA FROM THE MOWRY SHALE OF WYOMING MAY BE VERTEBRATE IN ORIGIN 19-14 26 Korf, Jason J.*: SCANNING ELECTRON MICROSCOPY AND ELECTRON MICROSCOPY OF BONE FRAGMENTS FROM A CAMARASAURUS (DINOSAURIA, SAUROPODA) FEMUR 19-15 27 Olinger, Danielle*: PETROLOGIC ANALYSIS AND ECONOMIC STUDY OF SKARNS IN THE KORAMAZ AREA, ÇELEBI, KIRIKKALE PROVINCE, CENTRAL TURKEY 21-6 3:20 PM Upadhayay, Sikchya*; Abessa, Mebratu; Sundareshwar, P.V.: DIDYMOSPHENIA GEMINATA STUDY IN RAPID CREEK, SOUTH DAKOTA 21-7 3:40 PM Betemariam, Hailemelekot*; Stone, James; Stetler, Larry; McCutcheon, Cindie; Chipps, Steve; DeSutter, Thomas; Penn, Michael; Urban, Noel: SEDIMENT MERCURY BEHAVIOR IN SOUTH DAKOTA LAKES AND IMPOUNDMENTS SESSION NO. 22 T13. Western South Dakota Hydrology Conference IV “Ground-Water Quality and Hydrology” 1:20 PM, Rushmore Plaza Civic Center, Rushmore G afternoon Oral Technical Sessions SESSION NO. 20 Janet M. Carter and Arden Davis, Presiding 22-1 1:20 PM Betemariam, Hailemelekot*; Davis, Arden D.; Dixon, David; Hansen, Marion: ARSENIC CONTAMINATION IN THE MOUNT RUSHMORE AREA AND PROPOSED REMOVAL TECHNIQUES 22-2 1:40 PM Salvatore, Michelle*; LaGarry, Hannan E.; Lee, Patrick; One Feather, Leola: PRELIMINARY REPORT: ISOLATION AND DETECTION OF FILTERABLE CONTAMINANTS IN DRINKING WATER, PINE RIDGE RESERVATION, SOUTH DAKOTA 22-3 2:00 PM Davis, Arden D.*; Lisenbee, Alvis L.; Miller, Scott L.: GROUNDWATER VULNERABILITY OF THE KARSTIC MADISON AQUIFER IN THE EASTERN BLACK HILLS 22-4 2:20 PM Saxton, Samantha L.*; Brown, Rachel A.; Schneider, John M.; Price, Maribeth H.: THE BLACK HILLS ATLAS OF AQUIFER SUSCEPTIBILITY AND VULNERABILITY 22-5 2:40 PM Valder, Joshua F.*; Long, Andrew J.; Davis, Arden D.; Kenner, Scott J.: END-MEMBER MIXING ANALYSIS APPLIED TO THE KARSTIC MADISON AQUIFER USING WATER CHEMISTRY IN THE SOUTHERN BLACK HILLS, SOUTH DAKOTA T6. Recent Advances in Understanding the Geologic History of the White River Badlands II 1:20 PM, Rushmore Plaza Civic Center, Alpine Room Emmett Evanoff, Patrick Burkhart, and Rachel Benton, Presiding 20-1 1:20 PM Terry, Dennis O. Jr.*; Factor, Lewis; McCoy, Matt; Metzger, Christine A.: LATERAL CHANGES IN PALEOSOLS, SEDIMENTOLOGY, AND VERTEBRATE TAPHONOMY WITHIN THE OLIGOCENE SCENIC MEMBER OF THE BRULE FORMATION, BADLANDS NATIONAL PARK, SD 20-2 1:40 PM Kennedy, Raymond*; Terry, Dennis O. Jr.: LOCAL VARIABILITY IN EARLY OLIGOCENE PALEOSOLS AS A RESULT OF ANCIENT SOIL CATENARY RELATIONSHIPS, BRULE FORMATION, TOADSTOOL PARK, NEBRASKA 20-3 2:00 PM Griffis, Neil*; Terry, Dennis O. Jr.: VERTICAL CHANGES IN PALEOSOL MORPHOLOGY WITHIN THE WHITE RIVER SEQUENCE AT FLAGSTAFF RIM, WYOMING: IMPLICATIONS FOR PALEOCLIMATIC CHANGE LEADING UP TO THE EOCENE-OLIGOCENE TRANSITION 20-4 2:20 PM Burkhart, Patrick*; Livingston, Jack; Mickle, Katherine: OVERVIEW OF FINDINGS FROM A DECADE OF RESEARCH EXAMINING THE HOLOCENE SOD TABLES IN THE WHITE RIVER BADLANDS 20-5 2:40 PM Yamnitsky, Steven J. IV.*; Martin, Tyler Q.; Livingston, Jack; Burkhart, Patrick A.: CHARACTERIZATION OF THE INCEPTISOLS IN HOLOCENE SOD TABLES, BADLANDS NP, SD 3:00 PM Break 22-6 3:20 PM Long, Andrew J.*; Gilcrease, Patrick C.: TEMPERATURE: A USEFUL TRACER FOR SEPARATING CONDUIT AND DIFFUSE FLOW IN THE KARSTIC MADISON AQUIFER 22-7 3:40 PM Mergenthal, Daniel*; Stetler, Larry: EFFECTS OF HOMESTAKE MINE WORKINGS ON SUBSURFACE AND SURFACE HYDROLOGY FRIDAY, 23 APRIL 2010 SESSION NO. 21 morning Oral Technical Sessions T13. Western South Dakota Hydrology Conference III “Surface-Water Quality” 1:20 PM, Rushmore Plaza Civic Center, Ponderosa Room Janet M. Carter, Presiding SESSION NO. 23 21-1 1:20 PM Snyder, Patrick L.*: SOUTH DAKOTA SURFACE WATER QUALITY STANDARDS AND MONITORING Hydrogeology 21-2 1:40 PM Foreman, Cory S.*; Kenner, Scott J.; Troelstrup, Nels H.: TOTAL MAXIMUM DAILY LOAD DEVELOPMENT FOR THE LOWER CHEYENNE RIVER WATERSHED Derric L. Iles, Presiding 21-3 2:00 PM Love, Jason T.*; Oswald, Jared K.; Foreman, Cory S.: DEVELOPING A BACTERIA TOTAL MAXIMUM DAILY LOAD FOR THE BIG SIOUX RIVER 21-4 2:20 PM Stone, James*; Stetler, Larry; McCutcheon, Cindie; Betemariam, Hailemelekot; Chipps, Steve: MERCURY TMDL DEVELOPMENT FOR SOUTH DAKOTA 21-5 2:40 PM Baker, Kevin K.*; Stamm, John; Kenner, Scott J.: MONITORING STORM-WATER QUALITY IN THE ARROWHEAD DRAINAGE BASIN, RAPID CITY, SD 2008-2009 3:00 PM Break 34 2010 GSA Abstracts with Programs 8:00 AM, Rushmore Plaza Civic Center, Ponderosa Room 23-1 8:00 AM Garcia, Patricia K.*; Schoenrock, Jared K.; Emerman, Steven H.; Bradford, Joel A.; Anderson, Ryan B.; Kemp, Tracy L.; Durand, James P.; Palmer, Mallory A.; Bunds, Michael P.: HYDROGEOLOGY OF A SHIELD VOLCANO IN THE TRANS-MEXICAN VOLCANIC BELT 23-2 8:20 AM Emerman, Steven H.*; Prasai, Tista; Anderson, Ryan B.; Palmer, Mallory A.: ARSENIC CONTAMINATION OF GROUNDWATER IN KATHMANDU VALLEY, NEPAL, AS A CONSEQUENCE OF RAPID EROSION 23-3 8:40 AM Gilmore, Adam Matthew*; Cory, Rose M.; Oweimrin, Michael: ENHANCED MEASUREMENTS OF CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) FOR WATER SESSION NO. 28 QUALITY ANALYSIS USING A NEW SIMULTANEOUS ABSORBANCE AND FLUORESCENCE INSTRUMENT 25-2 10:40 AM Cooper, Scott P.*; Lorenz, John C.: FRACTURE PATTERNS ASSOCIATED WITH LARAMIDE ANTICLINES 23-4 9:00 AM Schoenrock, Jared K.*; Robertson, Scott A.; Witt, Dallin; Bunds, Michael P.; Emerman, Steven H.; Bradford, Joel: VOLCANOSTRATIGRAPHIC AND HYDROGEOLOGIC STUDY TO SITE A WELL IN BASIGORABO, SIERRA TARAHUMARA, MEXICO 25-3 11:00 AM Hamlin, Laura*; Erslev, Eric A.; Hennings, Peter: KINEMATIC ANALYSIS OF THE STRUCTURALLY COMPLEX, EASTERNMOST WIND RIVER BASIN USING FRACTURE CHARACTERIZATION AND 3D RESTORATION 25-4 23-5 9:20 AM Anderson, Ryan B.*; Emerman, Steven H.; Bhandari, Sushmita; Bhattarai, Roshan R.; Palmer, Mallory A.; Bhattarai, Tara N.; Bunds, Michael P.: ARSENIC AND OTHER HEAVY METALS IN THE SUN KOSHI AND SAPTA KOSHI RIVERS, EASTERN NEPAL 11:20 AM Lisenbee, Alvis L.*: PRECAMBRIAN TEMPLATE FOR LARAMIDE STRUCTURES, EASTERN BLACK HILLS UPLIFT 23-6 9:40 AM Mead, Jack*; Tuffour, M.; Toth, Natalie; Anderson, Fred J.; Davis, Arden; Lisenbee, Alvis L.: WATER PRODUCTION FROM FRACTURED PRECAMBRIAN CRYSTALLINE AQUIFERS, CENTRAL BLACK HILLS, SOUTH DAKOTA 10:00 AM Break 23-7 10:20 AM Kemp, Tracy L.*; Anderson, Ryan B.; Emerman, Steven H.; Van Wagoner, Marc E.: GROUNDWATER RECHARGE BY GLACIAL LAKES IN THE WASATCH RANGE AND UINTA MOUNTAINS, UTAH 23-8 10:40 AM Nelson Hadley, Janae; Thayne, Michael; Garcia, Patricia K.*; Emerman, Steven H.; Van Wagoner, Marc E.; Bunds, Michael P.; Bradford, Joel A.: USE OF AQUEOUS CHEMISTRY OF SPRINGS TO DELINEATE AQUIFERS IN THE SIERRA TARAHUMARA, CHIHUAHUA, MEXICO Poster Technical Sessions SESSION NO. 26 Hydrogeology (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from noon to 1:20 PM 1 Nichols, Christopher*; Terry, Michael: LIGHT DETECTION AND RANGING (LIDAR) USE TO DEVELOP AN ALTERNATE PROCEDURE TO CONDUCT FRACTURE ANALYSIS IN THE ROCHFORD QUADRANGLE, BLACK HILLS, SOUTH DAKOTA 26-2 2 Witt, Dallin Christopher*; Schoenrock, Jared K.; Bunds, Michael P.; Robertson, Scott: VOLCANOSTRATIGRAPHY OF THE DIVISADERO TUFF IN THE SIERRA TARAHUMARA NEAR ESCUELA SAN ELIAS, CHIHUAHUA, MEXICO 26-3 3 Thayne, Michael*; Nelson Hadley, Janae; Garcia, Patricia K.; Van Wagoner, Marc E.; Emerman, Steven H.; Bunds, Michael P.; Bradford, Joel A.: MAPPING OF SPRINGS TO DETERMINE FRACTURE PATHWAYS FOR GROUNDWATER IN THE SIERRA TARAHUMARA, CHIHUAHUA, MEXICO SESSION NO. 24 T2. Structural and Tectonic Evolution of the Proterozoic Trans-Hudson–Archean Wyoming Province Boundary 8:00 AM, Rushmore Plaza Civic Center, Alpine Room Michael Terry, Presiding 24-1 24-2 24-3 8:00 AM Dahl, Peter S.*; Hark, Jessica S.; Frei, Robert; Ghosh, Amiya K.; Whitehouse, Martin J.; Wooden, Joseph L.: MORE EVIDENCE THAT THE BLACK HILLS DOMAIN WAS ORIGINALLY PART OF THE ARCHEAN WYOMING CRATON: OCCURRENCES OF 3.8-2.6 GA DETRITAL ZIRCONS IN 2.5-1.9 GA METASEDIMENTARY ROCKS 8:20 AM Hark, Jessica S.*; Dahl, Peter S.; Frei, Robert; Ghosh, Amiya K.; Whitehouse, Martin J.; Wooden, Joe; Redden, Jack A.: U-PB AGES OF ZIRCON, MONAZITE, AND XENOTIME IN THE HARNEY PEAK GRANITE, BLACK HILLS, SD: IMPLICATIONS FOR THE TIMING AND DURATION OF SYN- TO POST-OROGENIC MAGMATISM 8:40 AM Bauer, Robert L.*; Tomlin, Kenneth; Goergen, Eric: MULTIPHASE PROTEROZOIC REWORKING OF THE SOUTHEASTERN MARGIN OF THE WYOMING ARCHEAN PROVINCE IN THE CENTRAL LARAMIE MOUNTAINS, WYOMING 24-4 9:00 AM Allard, Stephen T.*: RETHINKING THE PROTEROZOIC ASSEMBLING OF THE NORTH-CENTRAL US 24-5 9:20 AM Nabelek, Peter*; Van Boening, Angela: TECTONIC IMPLICATIONS OF PALEOPROTEROZOIC MAFIC ROCKS IN THE BLACK HILLS, SOUTH DAKOTA 24-6 9:40 AM Jones, Daniel S.*; Premo, Wayne R.; Mahan, Kevin H.; Snoke, Arthur W.: IS THE CHEYENNE BELT THE MAZATZAL DEFORMATION FRONT?: EVIDENCE FOR REACTIVATION OF THE CHEYENNE BELT AT ~1.65–1.63 GA SESSION NO. 25 T5. Laramide Tectonics and Stratigraphy of the Northern Rocky Mountains and Great Plains 10:20 AM, Rushmore Plaza Civic Center, Alpine Room Alvis L. Lisenbee and Eric Erslev, Presiding 25-1 10:20 AM Erslev, Eric A.*; Gillett, Cyrus; Thompson, Ryan C.; Allen, Cody Lee: MULTIPLE AGES AND ORIGINS OF EXTENSIONAL FRACTURES IN THE ROCKY MOUNTAINS Booth # 26-1 SESSION NO. 27 Sedimentation, Stratigraphy, and Geomorphology (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from noon to 1:20 PM Booth # 27-1 4 Darbyshire, Jane; Miller, Matthew*: EVIDENCE FOR EOLIAN DEPOSITION AND DUNE EVOLUTION IN TWO UNDESCRIBED SECTIONS OF THE UNKPAPA FORMATION, BLACK HILLS, SOUTH DAKOTA 27-2 5 Fandrich, Joe W.*: AQUAVORTEX: A MODEL FOR THE FORMATION OF CERTAIN PIPE STRUCTURES NEAR THE PermoTriassic BOUNDARY IN SOUTHERN UTAH 27-3 6 Shurr, George W.*: TRANSPARENCY MEASUREMENTS IN A PRAIRIE STREAM--THE KANARANZI CREEK OF SOUTHWESTERN MINNESOTA AND NORTHWESTERN IOWA 27-4 7 Straw, Byron M.*; Hopkins, Kenneth D.: GLACIAL AND PERIGLACIAL DEPOSITS OF THE LAKE OF THE CLOUDS CIRQUE, NEVER SUMMER MOUNTAINS, COLORADO SESSION NO. 28 Structural Geology, Tectonics, and Petrology (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from noon to 1:20 PM Booth # 28-1 8 Wall, Zackary S.*; Johnson, Adam C.; Sears, James: TRACKING THE UPLIFT OF YELLOWSTONE’S THERMAL DOME IN SW MONTANA 28-2 9 Tarbert, Kevin D.*; Larson, Peter B.: PRELIMINARY GEOCHEMISTRY OF SAMPLES FROM YELLOWSTONE NATIONAL PARK 28-3 10 Johnson, Adam Collier*; Wall, Zackary S.; Sears, James: TESTING THE BULGE: USE OF NEOGENE BEDROCK PALEO-VALLEYS 2010 GSA Rocky Mountain Section Meeting 35 SESSION NO. 28 TO TEST MODELS OF THE YELLOWSTONE THERMAL DOME AND RELATED DEFORMATION 28-4 11 Alward, William S.; Bauer, Robert L.*: LARAMIDE REACTIVATION OF THE CLEAR CREEK FAULT, SOUTHWEST WIND RIVER BASIN, WY: EFFECTS ON LARAMIDE FOLD GEOMETRIES 28-5 12 Tielke, Jacob A.*; Terry, Michael P.; Lisenbee, Alvis L.: EXAMINING THE PALEOSTRESSES RESPONSIBLE FOR THE BLACK HILLS UPLIFT THROUGH ANALYSIS OF CALCITE DEFORMATION TWINS USING ELECTRON BACKSCATTER DIFFRACTION 30-2 1:40 PM Rahn, Perry H.*: EARLY CENOZOIC DENUDATION OF THE BLACK HILLS 30-3 2:00 PM Wiles, Michael E.*: THE GEOLOGY OF JEWEL CAVE: NEW PIECES TO AN UNEXPECTED PUZZLE 30-4 2:20 PM Anderson, Heidi*; Grader, George W. Jr.; Di Pasquo, Mercedes; Isaacson, Peter E.: ICE-PROXIMAL STRATIGRAPHY AND ACTIVE TECTONICS: AN EXAMPLE FROM SOUTHERN BOLIVIA 30-5 2:40 PM Santos, Joao*; Cunha, Lucio: ALLUVIAL TERRACES OF THE LOWER MONDEGO RIVER VALLEY: PRODUCT OF LATE QUATERNARY EUSTATIC AND CLIMATIC FLUCTUATIONS IN CENTRAL PORTUGAL 30-6 3:00 PM Hartwick, Emily E.*: EOLIAN ARCHITECTURE OF SANDSTONE RESERVOIRS IN THE COVENANT FIELD, SEVIER COUNTY, UTAH SESSION NO. 29 T2. Structural and Tectonic Evolution of the Proterozoic Trans-Hudson–Archean Wyoming Province Boundary (Posters) 8:00 AM, Rushmore Plaza Civic Center, Rushmore H Authors will be present from noon to 1:20 PM Booth # SESSION NO. 31 29-1 13 McCormick, Kelli A.*: TERRANE MAP OF THE PRECAMBRIAN BASEMENT, SOUTH DAKOTA 29-2 14 Schmidt, Chris*; Allard, Stephen T.: CHARACTERIZING A PROTEROZOIC LEUCOGRANITE WITHIN THE ARCHEAN LITTLE ELK TERRANE, BLACK HILLS S.D 29-3 15 Chasten, Lindsay E.*; Terry, Michael P.: EPISODES OF MONAZITE GROWTH FROM THE HOMESTAKE IRON FORMATION, LEAD, SOUTH DAKOTA, U.S.A 29-4 16 Matzek, Carl D.*; Allard, Stephen T.: A QUANTITATIVE STUDY TO DIFFERENTIATE SIMILAR GNEISSES IN THE ARCHEAN LITTLE ELK TERRANE, BLACK HILLS, SOUTH DAKOTA 29-5 17 Jordan, Brennan T.*; Terry, Michael P.: GEOCHEMISTRY AND TECTONICS OF THE YATES UNIT OF THE POORMAN FORMATION (DUSEL BEDROCK) IN THE CONTEXT OF OTHER NORTHERN BLACK HILLS AMPHIBOLITES 29-6 18 Terry, Michael*: KINEMATIC ANALYSIS OF STRUCTURAL FABRICS ASSOCIATED WITH BLACK HILLS OROGENY AND THEIR TECTONIC IMPLICATIONS FOR THE SOUTHEASTERN MARGIN OF THE WYOMING CRATON 29-7 19 Morton, Patrick*; Terry, Michael: CRYSTALLOGRAPHIC FABRICS OF QUARTZ IN THE ELLISON FORMATION: INSIGHTS ON DEFORMATION MECHANISMS AND METAMORPHIC CONDITIONS AT THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY (DUSEL) AT HOMESTAKE, SD afternoon Oral Technical Sessions SESSION NO. 30 Sedimentation, Stratigraphy, and Geomorphology 1:20 PM, Rushmore Plaza Civic Center, Ponderosa Room Michael E. Wiles, Presiding 30-1 1:20 PM Balmat, Jennifer L.*; Leite, Michael B.: POST-LARAMIDE TECTONICS AND TECTOGENIC SEDIMENTATION IN THE BLACK HILLS-PINE RIDGE REGION 36 2010 GSA Abstracts with Programs Structural Geology, Tectonics, and Petrology 1:20 PM, Rushmore Plaza Civic Center, Alpine Room Michael P. Terry, Presiding 31-1 1:20 PM Sandvol, Eric; Nabelek, Peter*; Duke, Edward F.; Gao, Stephen; Liu, Kelley; Snelson, Catherine; Dahl, Peter S.; Terry, Michael P.; McCormick, Kelli A.: STRUCTURE OF THE NORTHERN GREAT PLAINS AND IMPLICATIONS FOR CONTINENTAL ASSEMBLY AND EVOLUTION 31-2 1:40 PM Shah, Afroz A.*: PRESSURE-TEMPERATURE PATHS FROM FIAs, P-T PSEUDOSECTIONS AND ZONED GARNETS: SIGNIFICANCE AND POTENTIAL FOR ~1700 AND ~1400 MA DEFORMATION AND METAMORPHISM IN THE BIG THOMPSON REGION OF COLORADO ROCKIES, USA 31-3 2:00 PM Cross, William M.*: LUNAR REGOLITH SIMULANT MATERIAL CHARACTERIZATION 31-4 2:20 PM Erslev, Eric*; Sheehan, Anne; Anderson, Megan; Siddoway, Christine; Miller, Kate C.; Harder, Steven: IMAGING THE ROOTS OF ROCKY MOUNTAIN ARCHES: THE NSFEarthScope BIGHORN PROJECT ■ Geologic Map of the Western Blue Ridge and Portions of the Eastern Blue Ridge and Valley and Ridge Provinces in Southeast Tennessee, Southwest North Carolina, and Northern Georgia compiled by J. Ryan Thigpen and Robert D. Hatcher Jr., 2009 This map represents a synthesis of southern Appalachian Blue Ridge and adjacent Valley and Ridge detailed geologic mapping by numerous authors. The western Blue Ridge in this region, which is bound to the northwest by the Great Smoky and Miller Cove–Cartersville faults, and to the southeast by the Allatoona-Hayesville fault, preserves Neoproterozoic-Ordovician synrift, rift-to-drift, and platform rocks deposited along the southeastern Laurentian margin following the ca. 700 Ma rifting and ca. 565 Ma drifting of Rodinia, and Middle Ordovician clastic wedge rocks (Murphy belt) deposited during the Taconic (Ordovician) orogeny. Southeast of the Allatoona-Hayesville fault, rocks of the central Blue Ridge are dominantly composed of high-grade gneiss, schist, and amphibolite. East of the Chattahoochee–Holland Mountain fault, the eastern Blue Ridge (Tugaloo terrane) consists of the Ashe–Tallulah Falls Formation and Grenville basement in the Toxaway and Tallulah Falls domes. Several Middle Ordovician to Mississippian granitic (granodiorite, some tonalite) plutons are also present. This sequence was originally deformed and metamorphosed ca. 455 Ma during the Taconic and then transported westward during the Alleghanian (Permian) orogeny. MCH097F, 1 color plate (36" × 74") | sale price $25.00—folded (sorry, no additional discounts) MCH097R, 1 color plate (36" × 74") | sale price $25.00—rolled (sorry, no additional discounts) ■ Quaternary fault and lineament map of Owens Valley, Inyo County, eastern California compiled by D.B. Slemmons, E. Vittori, A.S. Jayko, G.A. Carver, and S.N. Bacon, 2008 This study investigates the active tectonic setting of the Owens Valley graben in the area of the great 1872 earthquake rupture along the Owens Valley fault zone. The area is critical for understanding the tectonics of the southern Walker Lane at the boundary between the Sierra Nevada block and Basin and Range Province. The report compiles known mapped Quaternary faults, provides a context for identifying fault sections, and rationale for delineating major structural blocks in the graben. Many new Late Pleistocene and Holocene faults, particularly west of the 1872 Owens Valley rupture are identified by special low-sun-angle photography. These structures accommodate part of the late Quaternary strain within the eastern California seismic belt. MCH096F, 2 color plates on 1 folded sheet (30" × 60"), 25 p. text | sale price $30.00—folded (sorry, no additional discounts) MCH096R, 2 color plates on 1 rolled sheet (30" × 60"), 25 p. text | sale price $30.00—rolled (sorry, no additional discounts) ■ Geologic map and cross sections of the Flynn Creek impact structure, Tennessee compiled by Jonathan C. Evenick and Robert D. Hatcher Jr., 2007 ■ The Geology of Plate Tectonics by Gregory R. Wessel, 2005 This chart belongs in every geology classroom and lab! Printed in full color, it attempts to organize the types of plate boundaries and displays them in a useful graphic form. The chart describes geologic features with each type. MCH059rev, 1 folded sheet (color; 36" × 53") | sale price $9.95 (sorry, no additional discounts) $5.00 each by Radoslav Nakov, B. Clark Burchfiel, Tzanko Tzankov, and L.H. Royden, 2001 n o a d d it i o n a l d i s c o u n t s . ■ Geological Map of the Northern Main Ethiopian Rift by Tsegaye Abebe, Piero Manetti, Marco Bonini, Giacomo Corti, Fabrizio Innocenti, and Francesco Mazzarini, 2005 One of the main objectives in unraveling the complex development of a continental rift is to set on the structural evolution and magmatism of the rifting system. In this work we present a new geological map of the Northern Main Ethiopian Rift, compiled using data from field work, analysis of aerial photographs, satellite images, topographic maps, and petrographic and geochemical analyses on rock samples. The new data provided an insight on the timing of rift activity and its tectonomagmatic evolution, evidencing a two-stage evolution of deformation and associated magmatic activity from a Pliocene orthogonal extension to a Quaternary oblique one. MCH094F, 1 folded sheet (color; 31" × 40"), 20 p. text ■ Geology of the Scott-Reedy Glaciers Area, Southern Transantarctic Mountains, Antarctica by M.B. Davis and D.D. Blankenship, 2005 MCH093F, 1 folded sheet (color; 46" × 26") The Flynn Creek impact structure is located in northeastern central Tennessee, on the northeast flank of the Nashville dome. Remapping the structure has better delimited the depositional history and impact structure evolution. The structure contains many features characteristic of complex impact structures: concentric normal faults, central uplift, shatter cones, impact breccia, and a modern internal drainage system. In addition, it contains some distinctive impact-related compressional structures, such as thrust faults and buckle folds in the modified crater rim. MCH095F, 1 color plate (36" × 66") | sale price $30.00—folded (sorry, no additional discounts) ■ Late Miocene to Recent Sedimentary Basins of Bulgaria $10.00 each S o rry, S o rry, n o a d d it i o n a l d i s c o u n t s . MCH088, 2 b&w plates (30" × 52"; 42" × 37"), with 28-page booklet ■ Geology of the Nevado de Toluca Volcano and Surrounding Areas, Central Mexico ■ An Earth Scientist’s Periodic Table of the Elements and Their Ions by L. Bruce Railsback, 2004 MCH092F, 1 folded sheet (color; 36" × 76"), 7 p. text ■ Geologic Map of the Batesburg and Emory Quadrangles, Lexington and Saluda Counties, South Carolina edited by Donald T. Secor Jr. and Arthur W. Snoke, 2002 MCH091, 1 folded plate (color; 36" × 57"), 32-page booklet ■ Geology of Kangmar Dome, Southern Tibet by A. García-Palomo, J.L. Macías, J.L. Arce, L. Capra, V.H. Garduño, and J.M. Espíndola, 2002 by Jeffrey Lee, William S. Dinklage, Yu Wang, and Jing Lin Wan, 2002 MCH089, 1 color map (36" × 38"), with 26-page booklet MCH090, 1 folded sheet (b&w; 33" × 52") GSA SALES AND SERVICE P.O. Box 9140, Boulder, CO 80301-9140, USA +1.303.357.1000, option 3 • Toll-free 1.888.443.4472 • Fax +1.303.357.1071 e r pric e b m me 0 $33.0 Hydrothermal Processes above the Yellowstone Magma Chamber: Large Hydrothermal Systems and Large Hydrothermal Explosions by Lisa A. Morgan, W.C. Pat Shanks III, and Kenneth L. Pierce Home to more than 10,000 thermal features, Yellowstone has experienced over 20 large hydrothermal explosions producing craters from 100 to >2500 meters in diameter during the past 16,000 years. Using new mapping, sampling, and analysis techniques, this volume documents a broad spectrum of ages and geologic settings for these events and considers additional processes and alternative triggering mechanisms that have not been explored in previous studies. Although large hydrothermal explosions are rare on the human time scale, the potential for future explosions in Yellowstone is not insignificant, and events large enough to create a 100-m-wide crater might be expected every 200 years. This work presents information useful for determining the timing, distribution, and possible causes of these events in Yellowstone, which will aid in the planning of monitoring strategies and the anticipation of hydrothermal explosions. SPE459, 95 p., ISBN 9780813724591 $45.00, member price $33.00 GSA Sales and Service Special Paper 459 P.O. Box 9140, Boulder, CO 80301-9140, USA +1-303-357-1000, option 3 toll-free +1-888-443-4472 fax +1-303-357-1071 Buy online at www.geosociety.org/bookstore SESSION NO. 18 includes the measurement of concentrations of metals in “uncontaminated” sediment. Sites were identified as uncontaminated if no evidence of negative effects by anthropogenic activity existed and their elevations are well above historical maximum flood levels. Four terraces sites on the Cheyenne River were selected for the study, at 108, 117, 183, and 199 river-kilometers upstream from the confluence with the Missouri River. Terrace elevations at these sites were 85, 85, 67, and 67 meters above the channel, respectively. The chronology of terraces on the lower Cheyenne River is largely unresolved, but previous work assigned the name Farmingdale to terraces along Rapid Creek with ages as young as Late Pleistocene to Early Holocene. On Rapid Creek, the Farmingdale terraces rise in the downstream direction over at distance of 22 kilometers from the level of the active floodplain to approximately 55 meters above the channel, at the confluence with the Cheyenne River. This confluence is 226 river-kilometers upstream from the Missouri River. Previous studies of terrace deposits on the lower Cheyenne River include optically stimulated luminescence (OSL) dates that range from 8.3 thousand years ago (ka) to 14.1 ka on a terrace approximately 75 meters above the channel at 16 river-kilometers upstream from the Missouri River confluence. Ages of terrace deposits at the current sample sites were obtained to further evaluate the Late Pleistocene and Holocene dynamics of the Cheyenne River system. Terrace deposits at 183 river-kilometers, at 67 meters above the channel, had an age of 6.1 ka (2 OSL samples). Terrace deposits at 199 river-kilometers, also at 67 meters, had ages of 10.7 to 16.5 ka (3 OSL samples) and 27.8 to 32.0 ka (2 radiocarbon samples). Dates at other sites are forthcoming. These data indicate incision rates on the order of 0.2 to 1.1 meters per century. Causes of these high incision rates remain unclear but may include climate change, regional uplift, stream capture events, removal of glacial dams, and glacial isostatic rebound. 17-3 BTH 7 Alexander, Jason [171881] LEGACY MINE TAILINGS AND ALLUVIAL DEPOSITS ALONG THE BELLE FOURCHE RIVER, SOUTH DAKOTA: AN INTEGRATED, MULTI-SCALE INVESTIGATION OF CHANNEL DYNAMICS ALEXANDER, Jason1, WOODWARD, Brenda1, STAMM, John F.2, LAMOTHE, Paul3, MADDOX, Ashli4, HOWLE, James5, and LARSON, Darin4, (1) U.S. Geological Survey, 5231 S. 19th Street, Lincoln, NE 68512, jalexand@usgs.gov, (2) U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702, (3) Crustal Imaging and Characterization Team, U.S. Geological Survey, Box 25046, M.S. 964, Denver Federal Center, Denver, CO 80225-0046, (4) U.S. Geological Survey, 111 Kansas Ave. SE, Huron, SD 57350, (5) U.S. Geological Survey, P.O. Box 1360, Carnelian Bay, CA 96140 The Belle Fourche River is the largest tributary by volume to the Cheyenne River, which in turn is a major tributary to the Missouri River in South Dakota. For nearly a century, the Belle Fourche River received large volumes of raw mine tailings from the Homestake Mine near Lead, South Dakota. In 1977, the influx of mine tailings was virtually eliminated by the closure of a tailings retention pond at the mine. The legacy mine tailings remaining in the Belle Fourche river system are a potential ongoing ecological and human-health risk, because they contain toxic concentrations of heavy metals, including arsenic. Previous research has indicated that significant proportions of these legacy mine tailings were stored in the floodplains and terraces adjacent to the river. In 2008, record flooding widened the main channel of the Belle Fourche River and remobilized some of the legacy mine tailings, and these tailings may continue to contaminate the bottomlands and the Missouri River system for decades to come. To understand the nature and magnitude of the ongoing risk associated with legacy mine tailings, the USGS, in cooperation with the U.S. Army Corps of Engineers, is documenting the dynamics of river channel adjustment at different time scales and spatial scales using a combination of LiDAR, geomorphic mapping, dendrochronology, and field geochemistry. The channel adjustments will be compared to the hydrologic record and mining history. This project will provide a case-study of river channel response to both increased and decreased sediment loads, with a special emphasis on the effects of historical land management and its ongoing influence on the water-quality of receiving streams. 17-4 BTH 8 Lundstrom, Scott [171937] LATE PLEISTOCENE GLACIATION OF EASTERN SOUTH DAKOTA AND RELATIONS TO THE GEOLOGIC FRAMEWORK OF THE CENTRAL MISSOURI RIVER LUNDSTROM, Scott, U.S. Geological Survey, Box 25046 Federal Center, MS 980, Denver, CO 80225, sclundst@usgs.gov, COWMAN, Tim, South Dakota Geological Survey and USD Missouri River Institute, 414 E Clark St, Akeley-Lawrence Science Center, Vermillion, SD 57069, HOLBROOK, John M., Earth and Environmental Sciences, University of Texas at Arlington, Arlington, TX 76019, and PACES, James B., U.S. Geological Survey, Box 25046, MS963, Denver Federal Center, Denver, CO 80225 Several features of the late Wisconsin glacial geology and geomorphology of eastern South Dakota form salient aspects of the hydrogeologic framework of the central Missouri River, the course of which is located at or near the Wisconsin limit of the James Lobe of the Laurentide Ice Sheet. A lowland valley of 80-100 km width, with the James River generally at its central axis, lies between upland areas of the Prairie Coteau and the Missouri Coteau and Trench that contained the margins of this 250 km wide ice lobe. The James Valley marks a generally southward direction of past ice flow and decreasing glacial water potential gradient. In contrast to the Prairie Coteau which forms a prow-shaped upland on the east flank and to most of the Missouri Coteau of North Dakota, the Missouri Coteau of South Dakota is breached by broad valleys of 4 sublobes that record a distinctive character of westward ice flow toward the Missouri River Trench. Each of the sublobe footprints (which have been suggested to originate as preglacial valleys trending eastward across the present course of the Missouri River) has a broad low transverse ridge within it that suggests a recessional or readvance moraine correlative to the DeSmet advance limit (Martin and others, 2004) which trends southward to Yankton. The James lobe advanced to this limit across a partly forested parkland that has yielded many 14C ages on wood of ~12,500 14 C years BP (~14,500 Cal) , thus providing somewhat younger outwash to the Missouri River Valley at Yankton and to the Missouri River Trench from the sublobes upstream. The re-advance was followed closely by calcite precipitation from groundwater, as constrained by U-series, Sr, C, and O isotope data. Postglacial deposits of the river valley are underlain by late Wisconsin glacial and glaciofluvial deposts. There is particular interest in understanding the relation of buried Pleistocene glaciofluvial gravel to the modern river channel; these gravel deposits may be a primary control on groundwater/surface water interactions as well as a source of gravel-cobble substrate needed for spawning of endangered sturgeon. 17-5 BTH 9 Paces, James B. [171922] TIMING AND SOURCES OF POSTGLACIAL GROUNDWATER DISCHARGE NEAR THE GLACIAL LIMIT OF THE JAMES LOBE OF THE LAURENTIDE ICE SHEET, SOUTH DAKOTA PACES, James B.1, LUNDSTROM, Scott C.2, MOSCATI, Richard J.1, and PIGATI, Jeffrey S.3, (1) U.S. Geological Survey, Box 25046, MS963, Denver Federal Center, Denver, CO 80225, jbpaces@usgs.gov, (2) U.S. Geological Survey, Box 25046, MS980, Denver Federal Center, Denver, CO 80225, (3) U.S. Geological Survey, Box 25046, MS 980, Denver Federal Center, Denver, CO 80225 Deposits of tufa, travertine, and carbonate cements are scattered north of the Missouri River within 20 km of the known glacial limit of the James Lobe of the Laurentide continental ice sheet. These deposits drape and cement late Wisconsin glacial sediments and are being studied to investigate potential constraints on conceptual models of groundwater flow associated with glacial advance and retreat. Five study sites are distributed on the south and west sides of the James Lobe near Yankton and Pierre, respectively. Modern springs with high dissolved-ion contents (conductivities >2000 µS/cm) discharge at or near all sites. Deposits near Yankton are poorly exposed in the eastern alluvial scarp of the James River valley and consist of calcite-cemented glacial sediment and porous tufa cut by banded travertine veins. Modern springs have δ2H and δ18O values (-63 and -8.8‰, respectively) that are consistent with recharge of modern precipitation in shallow aquifers, along with elevated U concentrations (19–31 ppb) indicative of oxidizing conditions. Deposits near Pierre are better exposed and include a variety of tufa with abundant iron and manganese oxides. Springs associated with these deposits have much lower δ2H values (-129 to -139‰) and indicators of reducing conditions including abundant Fe-Mn hydroxide precipitates and relatively low U concentrations (0.6-1.4 ppb). These springs have affinities with deep artesian groundwater with Pleistocene isotopic signatures and likely reflect upward leakage into shallow aquifers. Yankton-area travertines have high U/Th and precise U-series ages ranging from 13.0 to 10.5 ka for main-stage vein material with late-stage vug-fillings as young as 5.8 ka. Both initial U isotopic compositions and δ13C and δ18O values vary slightly but systematically with age. Nevertheless, all calcite δ18O values are consistent with modern discharge rather than with values expected for glacial meltwater. Dating of Pierre-area tufas is complicated by lower U concentrations and U/Th due to high Fe-Mn oxide abundances, but also indicate late-Pleistocene to Holocene ages. Calcite δ18O values in these materials show a much larger range and are consistent with formation from mixtures of both deep and shallow groundwater sources. 17-6 BTH 10 Moreno-Ward, April DeAnn [170980] GEOMORPHOLOGICAL INTERACTIONS OF THE JAMES RIVER AND MISSOURI RIVER DURING A PORTION OF THE HOLOCENE MORENO-WARD, April DeAnn, Geology, University of Texas at Arlington, Arlington, TX 76019, april.moreno@mavs.uta.edu, ERICKSON, Eli N., Earth Sciences, University of South Dakota, 414 E Clark St, Vermillion, SD 57069, and HOLBROOK, John, Dept. of Earth and Environmental Sciences, The Univ of Texas at Arlington, Dept. of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, TX 76019-0049 The James River flows into the Missouri River east of Yankton, SD. The degree to which the morphological changes of the Missouri River had an impact on the course of the James River is debatable. After mapping the Mission Hill and Menominee quadrangles, surficial maps have been made showing the preserved allounits of the area. Hand augers were used to ground-truth surface features located through the use of aerial photographs, topographic maps, and to confirm features on the surficial maps made. OSL samples were taken from both quadrangles and also from Meckling and Saint Helena; the latter two were mapped during the summer of 2007. A chronology of preserved fragments of the Missouri River valley in the study area was made based on OSL dating; this will aid in building a clear sedimentological picture of the study area. The main questioned that has been answered is the chronology of where the James joined the Missouri throughout the Holocene and how the interaction of both rivers evolved during this time period. SESSION NO. 18, 8:00 AM Thursday, 22 April 2010 T13. Western South Dakota Hydrology Conference (Posters) Rushmore Plaza Civic Center, Rushmore H 18-1 BTH 11 Thompson, Ryan [171750] VIEWING DIGITAL BOUNDARIES OF HYDROLOGIC UNITS FOR SOUTH DAKOTA USING GOOGLE EARTH THOMPSON, Ryan, U.S. Geological Survey, 111 Kansas Ave SE, Huron, SD 57350, rcthomps@usgs.gov The U.S. Geological Survey completed the Watershed Boundary Dataset (WBD) for South Dakota in early 2008, and the WBD has recently been completed for the United States. The WBD subdivided 8-digit hydrologic units (subbasins) into watersheds with 10-digit codes and subwatersheds with 12-digit codes. The final product of the WBD consists of electronic drainage area and boundary data layers for use in geographic information system (GIS) software. Because of the scale and level of detail inherent in the WBD, publishing a paper map is impractical. The GIS format of the WBD is well-suited to mapping and spatial analysis, but requires the individual to own expensive GIS software. In order to make the WBD available to a wider audience of landowners, education institutions and the general public, the U.S. Geological Survey developed an internet resource page in cooperation with the Hyde County Conservation District and the South Dakota Association of Conservation Districts. In recent years, public domain software such as Google Earth made it possible for anyone to view maps and high-resolution imagery of the earth’s surface. Converting the WBD GIS data layers to a Keyhole Markup Language (kml) file makes them available as data layers that will display in Google Earth. Users need only download a free copy of Google Earth software to a home computer or access a computer at a public library or other location that already has Google Earth installed. A kmz file (zipped kml file) of the WBD downloaded from http://sd.water.usgs.gov/ projects/GoogleHuc/GoogleHUC.html may then be opened in Google Earth. The displayed map of watershed boundaries can be used to determine what water bodies may be within or immediately downstream from a watershed of interest. There are 2,411 subwatersheds within 457 watersheds across South Dakota viewable through this tool. This poster will describe how users may view the South Dakota Watershed Boundary Dataset in Google Earth, provide user tips, and highlight features of the product. 2010 GSA Rocky Mountain Section Meeting 39 SESSION NO. 18 18-2 BTH 12 Wilson, Marcia [171936] WATER QUALITY MONITORING AT GREAT PLAINS NATIONAL PARKS WILSON, Marcia, National Park Service, 231 East Saint Joseph Street, Rapid City, SD 57701, marcia_wilson@nps.gov Northern Great Plains Network (NGPN), as part of the National Park Service’s (NPS) Inventory & Monitoring Program, is measuring status and trends of core water quality parameters in NPS units in the Dakotas, eastern Wyoming and Nebraska. To accomplish this objective we must optimize efficiency, effectiveness, and quality of inference from this monitoring effort while considering budget constraints. The impact of multiple sources of variation regarding statistical power analyses must be considered. We need to take into account the impact that within-park spatial variation as well as systematic and random diurnal, seasonal, and yearly temporal variation have on statistical precision and power. For this effort we are examining pilot and historic data to address 3 key questions. First, for which parks is spatial variability in core parameters minimal so that one monitoring site (or group of subsites) is adequate for representing the river/stream reaches of interest? Examination of pilot data indicate that for NGPN parks with relatively short stretches of rivers, one monitoring site per park will represent core parameters adequately. In addition, pilot data suggest that widely separated sites in a park show similar values in water temperature, pH, and dissolved oxygen. However, data indicate higher spatial variability for conductivity. Additional pilot data will be collected to refine estimates of spatial variation at the parks. Second, regarding expected variability at diurnal, weekly, and monthly scales within a season, is monitoring effort best focused on repeated field visits to periodically measure core parameters or on deployment of continuous monitors to collect measurement throughout the season? Pilot data from continuous probes deployed at 10 locations during 2008-2009 are being used to compare expected accuracy between periodic field visits and continuous monitoring. Third, what effect do alternative sampling strategies and revisit intervals have on our expected power to assess water quality trends at each park? To address this question, we are examining long-term historic data (10+ years) to quantify variation in core parameters for select rivers/streams. 19-3 BTH 15 Robertson, Scott [171957] VOLCANOSTRATIGRAPHY OF THE DIVISADERO TUFF IN RIO SAN IGNACIO CANYON, CREEL, MEXICO ROBERTSON, Scott1, SCHOENROCK, Jared K.2, WITT, Dallin Christopher3, BUNDS, Michael P.2, EMERMAN, Steven H.2, and BRADFORD, Joel A.2, (1) Department of Earth Science, Utah Valley University, 800 W University Parkway, Orem, UT 84058, 10282399@ uvlink.uvu.edu, (2) Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, (3) Earth Science, Utah Valley University, 800 W University Parkway, Orem, UT 84058 The Sierra Madre Occidental Volcanic Field in northwestern Mexico is one of the largest ignimbrite provinces in the world yet much of it has been mapped only at the reconnaissance level. The local Jesuit Mission in Creel, Chihuahua, Mexico, has been drilling wells for Tarahumaran Indian villages situated in the volcanic field, but many wells have been unproductive due to a lack of knowledge of the hydrogeology. Utah Valley University students and faculty traveled to Creel, in October 2009 as part of an ongoing hydrogeologic study to aid the Mission’s well-drilling program. The area in which the mission’s well drilling program is focused has previously only been mapped as the undifferentiated 29 Ma Divisadero Tuff. Our work in the area suggests that welded tuffs at the bases of cooling units within the Divisadero Tuff are susceptible to fracturing and are better potential aquifers than unwelded tuffs. Consequently, we are working to document the volcanostratigraphy of the Divisadero Tuff. Herein we report on a section through the Divisadero Tuff along the road to Rekowata Hot Springs in the Rio San Ignacio canyon, which has over 350 m relief. Two distinct flat-lying cooling units were identified, along with a possible third. Each cooling unit exhibits a transition from moderately welded, pumice rich tuff, found in the upper sections, to a strongly welded tuff with highly flattened pumice in the lower portions. The stratigraphically lowest identified cooling unit has a thickness of ~187 m, the upper cooling unit has a thickness of ~160 m. The cooling units are separated by clastic sedimentary strata about 30 m in thickness, indicating a significant time period between eruptions. In the nearby village of Basigorabo we identified a welded tuff that overlies a moderately welded tuff and is stratigraphically above the two units in the canyon. The welded tuff in Basigorabo is probably the base of a third, younger cooling unit and is under further study by other members of our group. SESSION NO. 19, 8:00 AM 19-4 Thursday, 22 April 2010 T18. Undergraduate Research (Posters) Rushmore Plaza Civic Center, Rushmore H 19-1 BTH 13 Bartling, Jamie [171940] MICROSTRUCTURAL ANALYSIS OF THE YATES UNIT AT THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY BARTLING, Jamie, TERRY, Michael, and VANBEEK, Jason, Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57702, jamie.bartling@mines.sdsmt.edu Recent drilling at the Deep Underground Science and Engineering Laboratory (DUSEL) on the 4850 level provides an opportunity to understand the Paleoproterozoic structural evolution in the Lead anticlinorium and the northern Black Hills. Partitioning of late deformation may allow folded rock fabric in the Yates unit of the Poorman Formation amphibolite to have preserved the earliest parts of the Black Hills deformation history. Geochemistry and field relations of the amphibolite in the Yates unit indicate are similar to amphibolite around other areas of the Black Hills. The earliest structural events associated with an episode of NW-vergent, thin-skinned thrusting (D1). The details of this event are still unknown, due to the lack of metamorphism or foliation evidence. The D1 event that led to the foliation the primary bedding occurred as early as ~1785 Ma and is attributed to the NW-directed accretion of the Central Plains island-arcs. Logging of oriented core from drill holes 3 and D indicate a folded foliation defined by the alignment of hornblende. The latest folds yet identified, plunge gently to the SE and have a similar trend to the Lead anticlinorium. Detailed descriptions of thin-sections from oriented samples taken from upper, middle, and lower sections of the drill holes will show structural and petrologic evidence, characterizing important deformational events and specifically answer questions about how the Paleoproterozoic rock fabrics and microstructures observed in the Yates unit of the Poorman Formation correlate with known regional deformational events. 19-2 BTH 14 Dannenbring, Scot E. [171947] MICROSTRUCTURAL AND PETROGRAPHIC STUDY OF ROCKS WITH CONTRASTING RHEOLOGIC PROPERTIES DURING HIGH-TEMPERATURE DEFORMATION, CUSTER COUNTY, SOUTH DAKOTA DANNENBRING, Scot E., Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, scot.dannenbring@mines.sdsmt.edu Metamorphosed sedimentary rocks located in the southeastern Black Hills near Grace Coolidge Creek have been folded and metamorphosed multiple times in different orogenic events. The most recent of these Paleoproterozoic events occurred during emplacement of the Harney Peak granite (1.715 Ma). This event is associated with high-grade metamorphism as indicated by the presence of sillimanite and recrystallization. The outcrop contains a mica rich layer and quartz rich layers of schist with a pegmatite dyke crosscutting the lithologies. Two-dimensional strains estimated using the deformed dike indicate that mica rich and quartz rich layers have different amounts of strain. Initial modeling indicates that the quartz rich layers were deformed mainly by pure and simple shear. The mica rich layers were deformed at much higher strains and have much larger component of simple shear. This study will focus on determining the differences in lithologies which influence the different strains as indicated by varying amounts pure and simple shear. This research will provide more insight into how mineral assemblages can influence crustal deformation. Initial results indicate that the strain in this outcrop is controlled by the presence and percentage of mica. Detailed descriptions and measurements of lineation and foliation have been made. Oriented samples of each lithology were collected and photographed. Petrographic microscopic analysis will consist of looking at the mineral percentage as well as texture and microstructure. A complete petrologic description will be taken, and the percentage of quartz, feldspars, and mica will be compared in each lithology. 40 2010 GSA Abstracts with Programs BTH 16 Jetson, Melissa K. [171961] A STRUCTURAL AND PETROGRAPHIC STUDY OF A PALEOPROTEROZOIC D1 FOLD IN METAMORPHOSED SEDIMENTARY ROCKS, SOUTH DAKOTA JETSON, Melissa K., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, melissa.jetson@ mines.sdsmt.edu and TERRY, Michael P., Department of Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701 Along Sheridan Lake Road in the Black Hills uplift is an exposure of metamorphosed sedimentary rocks that displays structures from the first two Paleoproterozoic deformation events in the Black Hills. This study is focused on the folded and metamorphosed sediments exposed in a 60 m long roadcut. The exposed rocks are interpreted to be part of a turbidite sequence composed of two rock types including an impure quartzite and a biotite-chlorite phyllite. Relict graded bedding indicates that bedding is overturned. The fold is steeply plunging to the SE and has been interpreted by previous workers to represent a classic example of a fold associated with earliest Paleoproterozoic deformation event (D1). No fabrics associated with this first event have yet to be identified in this outcrop, however; these rocks do display a strong foliation which strikes approximately S30oE and dips approximately 80oSW. This foliation is interpreted to be related to the second deformation event (D2) that may have overprinted evidence of original fabrics related to D1. The NW limb of the fold is over turned and dips to the NE, and the SE limb has a dip to the SW. Analysis of microstructures in orientated samples taken at the site will be tested for the presence of D1 fabrics. This analysis will be used to further characterize the structural features related to the D1 event. This will improve correlation to the regional deformation events. 19-5 BTH 17 Schwabe, Kathleen [171734] DEPOSITIONAL ENVIRONMENTS OF DINOSAUR EGG-BEARING STRATA OF CENTRAL MONGOLIA (ULAAN TSAV LOCALITY) SCHWABE, Kathleen, Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. Saint Joseph ST, Rapid City, SD 57701, kathleen.schwabe@mines.sdsmt.edu Mongolia’s Gobi desert is famous for its substantial quantity of dinosaur egg-bearing strata, as well as fossilized skeletons. Depositional environments can yield information regarding Mongolia’s past life based on sedimentological analysis. Inferences can be made concerning how ancient organisms interacted with their surroundings and other forms of life and in what settings they thrived. Depositional environments can also indicate what varieties of life forms inhabited a certain location. For instance, an aquatic environment would be inhabited by vastly different organisms than a terrestrial one. In this study, sedimentological characteristics will be used to interpret the type of environment that a group of unidentified species of dinosaur chose as its nesting grounds. The nests, discovered during the summer of 2009 by Dr. Gerald Grellet-Tinner, Dr. J. Foster Sawyer, and Dr. Michael Terry of the South Dakota School of Mines and Technology, are located in central Mongolia’s Gobi desert. Although there are no known studies on dinosaur nesting sites at this specific locality, there have been previous studies of other nesting sites in Mongolia, which will be discussed. The depositional environment of the Ulaan Tsav locality is unknown, though there are multiple hypotheses. The unidentified species could have been nesting in specific physical environments; such as at the base of dunes, near outcroppings of rock, in a floodplain, near a stream in basins, or on plateaus. This study will use sedimentological analysis to identify the paleoenvironment of the dinosaur nesting sites at the Ulaan Tsav locality. An analysis of fifteen samples (collected by Dr. J. Foster Sawyer) will provide information on the depositional environment of the sediments containing the fossilized nests and shed light on the paleoenvironmental conditions. SESSION NO. 19 19-6 BTH 18 Thomson, Olivia A. [171792] DISTINGUISHING BETWEEN THE SAND UNITS OF THE CARBONIFEROUS ITARARé SUBGROUP AND THE DEVONIAN FURNAS FORMATION IN PARANA STATE, BRAZIL THOMSON, Olivia A., Department of Geological Sciences, University of Idaho, PO Box 443022, Moscow, ID 83844-3022, othomson@vandals.uidaho.edu, PAULS, Kathryn N., Geology Department, Augustana College, 639 38th St #1699, Rock Island, IL 61202, ROCHA-CAMPOS, A.C., Instituto des Geosciências, Universidade de São Paulo, Sao Paulo, 05450-001, Brazil, and COTTER, James F.P., Geology Discipline, University of Minnesota, Morris, Morris, MN 56267 Late Paleozoic glacial deposits of the Itararé Subgroup in the Paraná Basin, southern Brazil were generated during multiple advance-retreat phases of the Gondwanan ice sheet. The resulting glacigenic sediments were deposited on a glacially produced erosional contact with the Devonian Furnas Formation. The Carboniferous Itararé Subgroup contains interbedded layers of diamictite and sandstone (quartz arenite) and overlies cross-bedded sandstones (quartz arenites) of the Devonian Furnas Formation. Sandstones from both the Itararé and the Furnas are similar in hand sample and are difficult to distinguish from one another in the field. Normal faulting of horizontal stratigraphy in the Witmarsum area of Paraná State, southern Brazil as well as the different advance-retreat phases within the Itararé Subgroup makes mapping of these units difficult. This study focuses on distinguishing between the sandstones of the Furnas Formation and the sandstones of the Itararé Subgroup. Samples were collected from known field exposure locations of the Itararé Subgroup and Furnas Formation as well as drill core into the Furnas Formation. Both point counting of disaggregated sandstone samples (2 phi size) and SEM imaging of the grains were used to differentiate the sandstones. While the sandstones are similar in grain size and sorting, differences where noted. The Itararé Subgroups sand grains appear more weathered than the Furnas sand grains. Additionally, the Itararé sands contain greater amounts of lithics than the Furnas sands. Research for this study was funded by a grant from the N.S.F.-R.E.U Program (NSF-EAR 0640575). 19-7 BTH 19 Rathbun, Kathryn [171817] SOURCE AND PALEOCLIMATIC SIGNIFICANCE OF LOESS IN SOUTHEAST SOUTH DAKOTA RATHBUN, Kathryn, Earth Sciences Dept, University of South Dakota, 414 E Clark St, Vermillion, SD 57069, Kathryn.Rathbun@usd.edu and SWEENEY, Mark, Earth Sciences, University of South Dakota, 414 E. Clark Street, University of South Dakota, Vermillion, SD 57069 The Great Plains region of North America is covered by some of the most extensive loess deposits in the world. In South Dakota, loess deposits reach their maximum thickness in the extreme southeastern corner of the state. Loess can provide valuable paleoclimate information including paleowind patterns, and may provide clues to the timing of glacial retreat. Geochemical analysis via XRF and grain size analysis were performed to determine the character and provenance of South Dakota loess, and optically stimulated luminescence (OSL) dating was performed to determine the timing of deposition. Initial study results indicate that South Dakota loess has a similar character to Peoria Loess in Nebraska. The South Dakota loess samples exhibit a relative uniformity in grain size and geochemistry, and show a similar grain size distribution and K/Rb ratios to Peoria Loess. Ti/Nb ratios are slightly higher in South Dakota loess, possibly due to a dust source from Missouri River sediment. Results from OSL dating will confirm if South Dakota loess is time equivalent to the Peoria Loess. In addition, ages of loess mantling till may provide a minimum age for the retreat of the James Lobe of the Laurentide ice sheet in southeastern South Dakota during the Late Wisconsinan glaciation. 19-8 BTH 20 Holte, Sharon E. [171819] IDENTIFICATION OF AN UNKNOWN CARNIVORAN HUMERUS FROM THE MAMMOTH SITE, OF HOT SPRINGS, SOUTH DAKOTA HOLTE, Sharon E., Biological Sciences, East Tennessee State University, Johnson City, TN 37604, sharonholte@yahoo.com, AGENBROAD, Larry, Mammoth Site of Hot Springs, South Dakota, 1800 Highway 18 Bypass, Hot Springs, SD 57747, and PAGNAC, Darrin, Museum of Geology, South Dakota School of Mines and Technology, 501 E Saint Joseph Street, Rapid City, SD 57701 In 2003, an incomplete humerus was excavated from the Mammoth Site, a Pleistocene sinkhole in Hot Springs, South Dakota. Consisting only of a partial shaft and distal end, this humerus was initially identified as an unspecified large carnivoran. The shape, size, and morphological characters of the bone indicate that it belongs to either an American lion (Panthera atrox) or a giant short-faced bear (Arctodus simus). Measurements were taken on the humerus (MS03021) and compared to those of P. atrox and A. simus from the La Brea Tar Pits in Los Angeles, California. Morphometic and statistical analyses were conducted by constructing bivariate plots of the humeri measurements. The majority of these ratios are in-line with A. simus, and outside the range of P. atrox. Thus, MS03021, the unknown Mammoth Site humerus, is here referred to an A. simus individual. It is quite possible that this represents an additional element of the partial A. simus skeleton previously known from the site. 19-9 BTH 21 Thaler, Jacob A. [171852] PETROGRAPHIC AND GEOCHEMICAL ANALYSIS OF A DRILL HOLE IN REUTER CANYON, BEAR LODGE MOUNTAINS, CROOK COUNTY, WYOMING: IMPLICATIONS FOR TERTIARYAGED CARLIN-LIKE GOLD MINERALIZATION THALER, Jacob A., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, jacob.thaler@gmail.com and PATERSON, Colin J., Department of Geology and Geological Engineering, South Dakota School of Mines &Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995 The Bear Lodge Complex is located in northeastern Wyoming along a WNW- trending zone of Tertiary alkalic intrusions that extends into the northern Black Hills where intrusion-hosted and Carlin-type gold-silver deposits have been mined since the late 1800s. The sedimentary hosts are Paleozoic, and consist of shelf carbonates and clastics. A recent drill-hole SUN 024c near Reuter Canyon extends 1600 feet at an inclination of 60° and bearing of 280° from Mississippian-aged Pahasapa Limestone through Cambrian-aged Deadwood Formation. The sequence is inflated by numerous sills and laccoliths of phonolite, trachyte and latite. A stratigraphic column correlated with geochemistry assays reveals that high gold grades occurred in the upper 114 foot interval of the Deadwood Formation inflated by 137 feet of igneous intrusions. There is a strong correlation between gold and arsenic, and a weak correlation of gold with silver and tellurium. Silver tellurides are also locally present, evident from the correlation of silver and tellurium. Analysis of thin sections discloses that at least two different stages of pyrite emplacement occurred. The first generation is anhedral and disseminated throughout the rock with local alteration to limonite. Higher gold grades are associated with the second generation of pyrite which is euhedral and occurs along veins of quartz ± K-feldspar ± calcite, indicative of potassic alteration. The geochemical and petrographic data support the essential influence of the Tertiary magmas on fluid source and mobilization and source of metals. 19-10 BTH 22 Nolan, Wyatt C. [171896] ROCK GLACIER AGES IN THE SAWATCH RANGE, COLORADO NOLAN, Wyatt C. and BRUGGER, Keith A., Geology Discipline, University of Minnesota, Morris, 600 E. 4th Street, Morris, MN 56267, nolan096@umn.edu We measured the thalli diameters of the 50 largest lichens (Rhizocarpon, subgenus Rhizocarpon) on 15 individual lobes of 7 rock glaciers or rock glacier complexes in the Swatch Range of central Colorado. The relative age of each lobe was characterized by the mean of the five largest lichens measured. Means varied from about 70 to 140 cm, with 12 of the 15 clustering around 125 cm. Some variation in lichen size can be attributed to differences in boulder lithologies, however these variations appear to be more evident in the total sample populations and less so in the means of the five largest lichens. Absolute ages of rock glacier lobes were assigned using a calibrated lichen growth curve developed by Benedict (1993) in the nearby Front Range. Lichen ages are interpreted as intervals of cooler (periglacial) climate and subsequent rock glacier activity. The ages thus determined range from 1760 to 4050 yr BP; the mean age of the 12 lobes is 3080 ± 350 yr BP. The latter interval is identical to one identified by Refsnider and Brugger (2007) in the study area and is correlative to an interval of cooling documented by other proxies of Late Holocene climate within the region. 19-11 BTH 23 Leithauser, Eric [171902] HOLOCENE PALEOSOL RADIOCARBON AGES AND SOD TABLE MORPHOLOGY IN THE WHITE RIVER BADLANDS REVEAL EROSION RATES OF 1-4 CM/YR, OR MORE, IN THE LAST 800 YEARS LEITHAUSER, Eric1, BURKHART, Patrick1, and BALDAUF, Paul2, (1) Geography, Geology, and Environment, Slippery Rock University, 335 ATS, Slippery Rock, PA 16057, ejl6320@ sru.edu, (2) Division of Math, Science, and Technology, Nova Southeastern University, 3301 College Avenue, Fort Lauderdale, FL 33314 Sod table morphology, coupled to radiocarbon dating of the bulk humate fractions of paleosols, help portray the sedimentary dynamic of the White River Badlands during the late Holocene. Throughout the interval from approximately 3,500 to 800 RCYBP, erosion of the Badlands ‘castles’ built pediments, within which the Oligocene Brule Formation widely exists as the bedrock root. During the last millennium, these pediments have been incised, leaving sod tables as vestiges of the pediments. The Holocene fans capping the pediments contain between one and six visible paleosols, from which we measured radiocarbon dates. The uppermost paleosol constrains the maximum age for the onset of incision because the burial required to create a relict soil requires that the pediment remains attached to the eroding highlands. Indeed, dissection of the pediment into sod tables ends fluvial-colluvial deposition upon the sod table. Erosion rates can be determined by surveying the maximum depth of the incised channel between two sod tables, as well as the width of that intervening arroyo. In this manner, the calculated erosion rates represent a minimum, in accord with the uppermost paleosol constraining the maximum age for onset of incision. We report two locations, where rates of stream incision and lateral retreat of ravine walls were calculated. For the pediment present along the northern fringe of Norbeck Ridge, we calculated a minimum incision rate of 0.8 cm/yr, and a minimum rate of lateral retreat of arroyo wall equaling 1.9 cm/yr. From the pediment adjacent to the ‘castles’ located to the east of the Loop Rd by the Fossil Trail exhibit, the minimum incision rate is 0.8 cm/yr and the minimum rate of lateral retreat of the arroyo wall is 4.9 cm/yr. These rates reveal very rapid erosion during the last millenium. The larger quandary concerning the geomorphic evolution of Holocene pediments and sod tables in the White River Badlands, however, lies in determining the environmental circumstance initiating incision of the pediments, which commenced sometime around 900 to 600 years ago. 19-12 BTH 24 Testin, Jason James [171903] ANALYSIS OF DENTITION MORPHOLOGY OF ALLOSAURUS FRAGILIS (THERAPODA: AVETHEROPODA): IMPLICATIONS ON TAXONOMIC UTILIZATION OF ISOLATED SHED TEETH FROM LARGE BODIED THEROPODS TESTIN, Jason James, Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57702, jason.testin@ mines.sdsmt.edu Dental morphology and its significance to theropod (Dinosauria: Saurischia) taxonomy is poorly understood among vertebrate paleontologists. Dentition morphology is closely linked to feeding; changes in dental morphology could provide a basis for adaptations linked to utilization of new feeding niches. Due to this relationship, it is possible that paleontologists could rely on preservation of dentition in the fossil record to aid in the understanding of theropod evolution. Isolated theropod teeth are fairly widespread in dinosaur-bearing deposits, unfortunately a significant majority of these isolated teeth are shed during hunting or scavenging and lack any root structures. To date there is little quantitative data to assign isolated crowns to distinctive theropod taxa. Detailed measurements will be taken form Allosaurus along with Tyrannosaurus, Carcharodontosaurus, Spinosaurus, Ceratosaurus, Torvosaurus, and Acrocanthosaurus. Variables to be measured will include crown base length, crown base width, crown height, and apical length along with a series of morphologically relevant ratios and angles, including the crown base ratio, crown height ratio and the crown angle. Counts will be taken to determine the average number of denticles on the mesial and distal carinae of each tooth. The measurements and counts taken will be complied into a database of morphological standards that can be used to identify shed teeth found in rocks of the Late Jurassic age Morrison Formation. Owing to enamel’s property as the hardest biological substance known, isolated teeth are commonly found among dinosaurian assemblages. In several instances shed teeth have been used to extend pre-existing paleobiographical ranges. A study based solely on isolated dentition must be viewed critically, such identifications are based on an assumption of phylogenic affinity and results are approximations of those gained from using in-situ dentition of know taxonomy. It is there for the goal of this project to discuss in detail the dentition of a single theropod, Allosaurus fragilis and create a database of dentition values from A. fragilis and other large theropods. The emphasis will be placed on in-situ dentition, and the use of morphologic standards in the taxonomic identification of isolated teeth. 19-13 BTH 25 Trumbull, Con B. [171904] NEW ICHNOTAXA FROM THE MOWRY SHALE OF WYOMING MAY BE VERTEBRATE IN ORIGIN TRUMBULL, Con B. and CONNELY, Melissa V., Earth Science, Casper College, 125 College Dr, Casper, WY 82601, con_trumbull@blm.gov Outcrops of the Mowry Shale (Lower Cretaceous) of Casper, Kaycee, and Greybull, Wyoming contain a diverse fossil assemblage of marine life including; reptiles, fish scales, and ammonites 2010 GSA Rocky Mountain Section Meeting 41 SESSION NO. 19 and other mollusks. Recent studies indicate that trace fossils can be added to the diversity of fossil evidence, which allows researchers to study the behavior patterns of the above taxa. Due to the fissile nature of the Mowry Shale, large scale trace fossils are difficult to collect. However, well preserved tracks and traces can be found under the bentonite beds, which are mined throughout Wyoming. A research project was recently funded by the NSF EPSCoR program to investigate reports of various sites that may contain these little known trace fossils. The sites studied are areas that have been uncovered by bentonite mine activity through the cooperation of the mining companies, landowners, and the BLM. Results from this study suggest that many of these traces are vertebrate in origin and represent new ichnotaxa. 19-14 BTH 26 Korf, Jason J. [171907] SCANNING ELECTRON MICROSCOPY AND ELECTRON MICROSCOPY OF BONE FRAGMENTS FROM A CAMARASAURUS (DINOSAURIA, SAUROPODA) FEMUR KORF, Jason J., Geology, South Dakota School of Mines and Technology, Rapid City, SD 57701, jraptor52@hotmail.com A fragment of bone from a Camarasaurus sp. (Dinosauria, Sauropoda) femur was obtained in the Little Houston Quarry near Sundance, Wyoming in the Morrison Formation (Upper Jurassic). The goal of the project was to locate and identify microstructures, if possible within the bone and possibly determine diagenetic effects on the bone. During operations the general settings was for the SEM to be on VP mode for the vacuum to help prevent charging, and the current was high. The acceleration voltage was set at 20 kV, and the SEM was set at 30.00 µm. Chemical compositions of the bone and clay particles were taken using backscatter. The clay particles showed that the major components that comprised the clay were silica, aluminum, calcium, carbon, and oxygen. While the bone showed spikes at calcium K alpha and beta, oxygen, carbon, and aluminum. SEM scans also showed grooves and canals, which may possibly be microbial destruction to the bone. Upon further investigation using electron microscopy showed possible growth rings are observable in the femur. 19-15 BTH 27 Olinger, Danielle [170386] PETROLOGIC ANALYSIS AND ECONOMIC STUDY OF SKARNS IN THE KORAMAZ AREA, ÇELEBI, KIRIKKALE PROVINCE, CENTRAL TURKEY OLINGER, Danielle, Spring, TX 77379, danielle.olinger@gmail.com Several Fe-skarn deposits have been found in the Ҫelebi district of central Turkey. Geologic mapping of the Koramaz area, Ҫelebi, Kirikkale Province, central Turkey indicates that the area has potential to host an Fe-skarn deposit. Analysis of the skarn minerals using SEM and optical techniques revealed andradite garnet, hedenbergite pyroxene, and magnetite occurrences that provided further support of this hypothesis. Chloro-potassic-ferri-magnesiotarmite, an amphibole, was identified within some of the exoskarns and reflects the composition of the hydrothermal fluid that contributed to the formation of skarns in the Koramaz area. This species is an accepted amphibole by the International Mineralogical Association but there is little reference in the literature to the nature of its occurrence. Native bismuth, identified in the same exoskarn samples, is not uncommon in Fe, Ag, Au, and Pb-Zn skarn deposits around the world though its occurrence in the Koramaz area skarns was not identified in earlier studies. The Ҫelebi granitoid samples are geochemically analogous to the primitive granitoids in the district. The low-Fe and high-K geochemistry bring into question whether the granitoid could produce Fe-skarn deposits. Exploration for Fe-skarn deposits should continue and focus on areas underlain by the garnet-epidote-quartz exoskarn, because other studies of the district have shown that this exoskarn can contain massive magnetite deposits. Definition of the boundaries of the intrusion and geochemical characterization of the pristine granitoid would contribute to the understanding of the skarn deposit potential in the Koramaz area. SESSION NO. 20, 1:20 PM Thursday, 22 April 2010 T6. Recent Advances in Understanding the Geologic History of the White River Badlands II Rushmore Plaza Civic Center, Alpine Room 20-1 1:20 PM Terry, Dennis O. [171736] LATERAL CHANGES IN PALEOSOLS, SEDIMENTOLOGY, AND VERTEBRATE TAPHONOMY WITHIN THE OLIGOCENE SCENIC MEMBER OF THE BRULE FORMATION, BADLANDS NATIONAL PARK, SD TERRY, Dennis O. Jr1, FACTOR, Lewis1, MCCOY, Matt2, and METZGER, Christine A.3, (1) Earth and Environmental Science, Temple University, 326 Beury Hall, 1901 N. 13th St, Philadelphia, PA 19122, doterry@temple.edu, (2) Hull & Associates, Inc, 4770 Duke Drive, Suite 300, Mason, OH 45040, (3) Environmental Science, Whittier College, 13406 Philadelphia Street, P.O. Box 634, Whittier, CA 90608 The Oligocene Scenic Member of the Brule Formation is composed of ca. 50 m of fossiliferous fluvial and eolian deposits that change laterally from southwest to northeast across the North Unit of Badlands National Park. Lateral changes are manifested as differences in facies architecture, paleosols, and vertebrate taphonomy. Throughout the study area the base of the Scenic Member is marked by an unconformable contact with hummocky, greenish gray mudstones of the underlying Eocene Chadron Formation. At the extreme southwest part of this transect, at the north end of Sheep Mountain Table, fluvial deposits are composed of thin overbank mudstones superimposed by weakly developed paleosols and numerous channel sandstones with large width to depth ratios. Vertebrate fossils occur as isolated elements, with the exception of numerous complete tortoise shells. Just to the northeast of Scenic, overbank facies become dominant, but occasional large channels are found. Channels toward the base of the unit are finer grained and lack a coarse bedload, with the exception of bone fragments. Paleosols range from very weak to weakly developed depending on the proximity to channels. Fossils are very well preserved, commonly as articulated to associated remains within defined zones. Farther to the northeast within Conata Basin, overbank mudstones are dominant, and paleosols become better developed. Fossils occur as isolated elements and occasional articulated remains, but also as discrete high density bonebed accumulations within former oxbows. The lateral change in fluvial facies and associated paleosols is likely due to asymmetric basin development with the northeast end of the study area experiencing less frequent depositional events due to its proximity to the Sage Arch and Sage Fault, whereas the southwest end was more frequently flooded. In addition to lateral changes, vertical changes in paleosols morphology are noted in the Dillon Pass area as paleotopography 42 2010 GSA Abstracts with Programs on the underlying Chadron Formation was infilled, resulting in a change from paleosols affected by hydromorphy to well drained paleosols higher in the section. 20-2 1:40 PM Kennedy, Raymond [171757] LOCAL VARIABILITY IN EARLY OLIGOCENE PALEOSOLS AS A RESULT OF ANCIENT SOIL CATENARY RELATIONSHIPS, BRULE FORMATION, TOADSTOOL PARK, NEBRASKA KENNEDY, Raymond and TERRY, Dennis O. Jr, Earth and Environmental Science, Temple University, 326 Beury Hall, 1901 N. 13th St, Philadelphia, PA 19122, tub66397@temple.edu Paleopedology is often employed in paleoenvironmental reconstruction since the features of paleosols are affected by changes in climate, ecology, topography, and lithology over time. These changes cause very small-scale lateral variations in the morphology and apparent development of paleosols and influence the degree to which certain soil features are preserved in the rock record. When making claims about the past using paleosols, care must be taken to ensure that as many of the soil forming factors as possible are understood. While climates and biomes have certain breadth that allows for local variations to be essentially ignored, and the lithology of an area is usually still present as the medium of soil preservation, topographic relief can vary over local scales, and can contribute greatly to the development of soils. Paleo-geomorphological relationships were investigated along a paleovalley sequence in the Early Oligocene Orella Member of the Brule Formation in the White River Group of Toadstool Park, NE. A series of three separate, but laterally contiguous, soil profiles exhibit variation in the type and degree of apparent pedogenesis. Changes in the presence, abundance, and size of multiple soil features such as root traces, soil structure, and slickensides were observed over a distance of ~350 meters. The effect of paleotopographic control on pedogenesis along this paleovalley tends to follow general trends according to the physiographic relationship of soils to one another along modern hill-slopes. The processes of erosion, deposition, and the through flow of water change in a predictable way along landscapes, which are indicated by changes in slope, and back-and-forth transitions from convexity to concavity. Further geochemical analysis should reflect the processes driven by geomorphology. Soils forming on different landscape positions, even though they are adjacent to one another, develop strikingly different morphologies, and without knowledge of their topographic association these soils would be interpreted as having formed under vastly different environmental factors. Reconstruction of the paleoenvironment in and around the Eocene-Oligocene Boundary has significant implications for the temporal and spatial evolution of paleoecology at this time. 20-3 2:00 PM Griffis, Neil [171644] VERTICAL CHANGES IN PALEOSOL MORPHOLOGY WITHIN THE WHITE RIVER SEQUENCE AT FLAGSTAFF RIM, WYOMING: IMPLICATIONS FOR PALEOCLIMATIC CHANGE LEADING UP TO THE EOCENE-OLIGOCENE TRANSITION GRIFFIS, Neil and TERRY, Dennis O. Jr, Earth and Environmental Science, Temple University, 326 Beury Hall, 1901 N. 13th St, Philadelphia, PA 19122, tub85959@temple.edu Flagstaff Rim near Casper, WY preserves the most complete late Eocene section of the White River Sequence, approximately ~214 m compared to the ~35 m of section preserved at Toadstool Geologic Park, in northwest NE. While the Rim does not span the Eocene-Oligocene boundary it may hold clues to climatic perturbations. Some studies suggest that climate change across the Eocene-Oligocene boundary occurred in steps, possibly throughout the late Eocene. In this study 6 paleosol profiles were collected and analyzed above and below dated volcanic ashes at Flagstaff Rim. The lowermost paleosol is composed of red mudstone with clay filled and grayish green reduced root traces. The sediments within this profile are similar to those of the Interior Paleosol Series of the Chamberlin Pass Formation in South Dakota and Nebraska. This paleosol is smectite rich, and formed in a moist, oxidizing environment. Overlying this section is the lithologic equivalent of the Peanut Peak Member of northwest Nebraska. The sediments in this section are more olive yellow/beige in color and weather into hummocks. The paleosols within the Peanut Peak equivalent contain both clay filled and crystalline roots; there is also less smectite in this section than in the underlying Chamberlin Pass equivalent. Overlying the Peanut Peak equivalent is the lithologic equivalent of the Big Cottonwood Creek Member. These paleosols are cemented by calcite and preserve calcite filled root traces. The increase in glass, pumice fragments, calcium carbonate, and a decrease in smectite all suggest that this soil formed either in a drier environment or that there was an increase in sedimentation rates. Changes in the resistance to modern weathering have also been noted in Flagstaff Rim. The exposures at the base of the Rim weather into large hummocks, whereas up section the sediments are more cliff forming. This same change in weathering has been noted at Toadstool Geologic Park, NE and has previously been interpreted as a change in climate, and/or also as an increase in sedimentation rates, suggesting that either may be at work during the late Eocene at Flagstaff Rim, WY. 20-4 2:20 PM Burkhart, Patrick [171932] OVERVIEW OF FINDINGS FROM A DECADE OF RESEARCH EXAMINING THE HOLOCENE SOD TABLES IN THE WHITE RIVER BADLANDS BURKHART, Patrick, Geography, Geology, and the Environment, Slippery Rock University, Slippery Rock, PA 16057, patrick.burkhart@sru.edu, LIVINGSTON, Jack, Geography, Geology and the Environment, Slippery Rock Univ, Slippery Rock, PA 16057, and MICKLE, Katherine, Art, Slippery Rock University, Slippery Rock, PA 16057 In the Badlands, the sod tables remaining from incision of Holocene pediments are perforated with pseudokarst. Observation of these voids triggered our scrutiny of sod tables. Initially, we surveyed the relief of sod tables from the adjacent washes in an attempt to group sod tables into geomorphic clusters, as river terraces are often categorized. This effort was stymied by the rugged topography, so we commenced study of paleosols within the sod tables, with hopes of identifying marker beds to allow correlation. To date, however, no paleosol has proven useful as a marker bed. Meanwhile, we have collected 25 radiocarbon dates from paleosols, which offer the opportunity for inferences concerning geomorphic processes during the past 3,600 years. The dates cluster during intervals of fan stability and pedogenesis, including ~900, 1100-1300, 1700-1900, 2300-2400, and ~3600 radiocarbon years bp. These intervals of soil development on alluvial-colluvial silts compare well with those reported for eolian deposits within the same region. The age of the uppermost paleosol also provides a maximum age for onset of the incision that dissected the pediments into sod tables. Furthermore, with initiation of the incision known, minimum erosion rates of down-cutting equal 0.8 cm/yr, while rates of lateral retreat of arroyo walls equal 2-5 cm/yr, or more, during the last millennium. In addition to examining these paleosols, we have developed a classification for pseudokarst throughout the region, as well as postulating upon the hydrologic conditions contributing to such morphogenesis. Lastly, we have refined a host of pedagogical approaches to undergraduate research that have involved about four dozen undergraduates logging one thousand field days, who we collectively call the Badlands Working Group at Slippery Rock University of Pennsylvania. We employ a peer-mentoring model, where alumni return to guide novices. Interdisciplinary inquiry is another hallmark, including an amalgam of art and science. Our 2008 expedition yielded an art gallery exhibition entitled Where Art Meets Science: Synergy on the Landscape, which received highly favorable reviews. We intend to con- SESSION NO. 21 tinue this inquiry to explain Holocene landscape evolution, while preparing materials that better convey the story of the Badlands to the general public. 20-5 2:40 PM Yamnitsky, Steven J. [171854] CHARACTERIZATION OF THE INCEPTISOLS IN HOLOCENE SOD TABLES, BADLANDS NP, SD YAMNITSKY, Steven J. IV, Butler, PA 16002, sjy0411@sru.edu, MARTIN, Tyler Q., Warren, PA 16365, LIVINGSTON, Jack, Geography, Geology and the Environment, Slippery Rock Univ, Slippery Rock, PA 16057, and BURKHART, Patrick A., Geography/Geology, Slippery Rock University, Slippery Rock, PA 16057 We characterize the paleosols present in the sod tables, which are incised into late Holocene pediments, as inceptisols. Herein we describe these paleosols and their geomorphic context. The field setting lies upon the upper prairie, immediately north of Norbeck Pass, between mile posts nine and ten on the Loop Rd., easily accessible from the Fossil Trail parking lot. Sod tables are remnants of pediments, which have been incised and are bounded by arroyo walls, and typically exhibit a graded, sod-covered, flat top, of a few meters relief. Paleosols, or buried relict soils, are characterized by field description of soil profiles and a suite of ensuing laboratory analyses. Observations of grain size support a fining-distally progression from the bedrock source, Oligocene Brule ‘castles’, fining from sandy-silt to silt. The color of organic-rich paleosol horizons are typified by Munsell 10yr 5/3, while inorganic horizons are Munsell 7.5 yr 4/3 to 10yr 5/3. Paleosol horizon structure within the studied sod tables was classified as angular-blocky to crumb. The results of a TOC (total organic carbon) analysis reveal a LOI (loss on ignition) of 4.2% within horizon Ab from CT-01-08. The underlying and overlying horizons (C and 2C respectively) reveal a LOI of 1.5% and 3.6%, justifying the results to proceed with radiocarbon dating. Similar trends in results were also found for CT-03-08. We have previously published radiocarbon dates from bulk humate fractions of paleosols in the age range of 530 and 1280 RCYBP from this locale. We have found that the LOI should exceed 3.6% to yield successful radiocarbon dates. The intervals of soil formation we have recorded for alluvial pediments are synchronous with those reported on forming upon Aeolian sediments in the Badlands. SESSION NO. 21, 1:20 PM Thursday, 22 April 2010 T13. Western South Dakota Hydrology Conference III “Surface-Water Quality” Rushmore Plaza Civic Center, Ponderosa Room 21-1 1:20 PM Snyder, Patrick L. [171753] SOUTH DAKOTA SURFACE WATER QUALITY STANDARDS AND MONITORING SNYDER, Patrick L., South Dakota Dept. of Environment and Natural Resources, Joe Foss Building, 523 East Capitol, Pierre, SD 57501, patrick.snyder@state.sd.us The basis for South Dakota’s Surface Water Quality Standards originated in 1967 when the Water Quality Standards for Surface Waters Of South Dakota were adopted by the South Dakota Committee on Water Pollution. These standards were developed by Floyd L. Matthews for the state in response to the 1965 Federal Water Quality Act. While there have been modifications to these original standards over the years, the basics of assigning designated beneficial uses and adopting criteria to protect those uses are familiar to anyone working with the present surface water quality standards. Issued by the Board of Water Management, the Surface Water Quality Standards are reviewed every three years as required by the federal Clean Water Act. The Surface Water Quality Program of the Department of Environment and Natural Resources is responsible for administering the Surface Water Quality Standards. The Program’s responsibilities also include the permitting and monitoring of municipal and industrial discharges, establishing surface water quality criteria, and monitoring the surface waters of the state. Another program in the DENR, the Watershed Protection Program, also conducts surface water monitoring. DENR conducts ambient water quality monitoring of streams and lakes, monitoring to develop Total Maximum Daily Loads, Use Attainability Analyses, Fish Flesh Analyses, and monitoring for specific projects. These special projects include pre-construction monitoring for the proposed Hyperion oil refinery and proposed Powertech uranium mining project and monitoring to determine impacts from past uranium mining. 21-2 1:40 PM Foreman, Cory S. [171863] TOTAL MAXIMUM DAILY LOAD DEVELOPMENT FOR THE LOWER CHEYENNE RIVER WATERSHED FOREMAN, Cory S., Manager, Water and Geologic Characterization, RESPEC, P.O. Box 725, Rapid City, SD 57709, Cory.Foreman@respec.com, KENNER, Scott J., Civil & Environmental Engineering, South Dakota School of Mines and Technology, 501 East St Joseph St, Rapid City, SD 57701, and TROELSTRUP, Nels H., Department of Biology and Microbiology, South Dakota State Univesity, P.O. Box 2207B, South Dakota State University, Brookings, SD 57007 The Cheyenne River in western South Dakota is currently listed as impaired for total suspended solids (TSS) and fecal coliform bacteria. A Total Maximum Daily Load (TMDL) assessment project for the Cheyenne River Watershed in western South Dakota was initiated in the spring of 2007. The focus area of this project was the Cheyenne River Watershed below Angostura Reservoir, near Hot Springs, South Dakota, to the mouth of the river where it meets Oahe Reservoir. A major emphasis of the TMDL project was to identify contributing areas of sediment loadings to the Cheyenne River and to evaluate natural background, while linking sediment loading to stream health. This was accomplished through four main tasks: design and implementation of a detailed water-quality monitoring plan; development of a watershed model using the program Hydrologic Simulation Program Fortran (HSPF), collection and analysis of benthic macroinvertbrate biological data, and collection and analysis of stream physical habitat data. The Cheyenne River has a large natural loading of sediment, largely originating from the badlands region of western South Dakota. The Cheyenne River has four distinct reaches. The first reach, from Angostura Dam to Cedar Creek near Redshirt Table, has relatively low loading for both TSS and fecal coliforms. The second reach, from Cedar Creek to near Wasta, is a transition reach in water quality for both TSS and fecal coliforms, where loading increases dramatically. The third reach, from Wasta to the confluence of the Belle Fourche River, has a shift in stream morphology and sediment transport processes. The final reach, from the Belle Fourche River to the mouth, has consistent increases in both TSS and fecal coliform loading. Biologic condition, based on Index of Biotic Integrity (IBI) scores calculated from benthic macroinvertebrate data, increases upstream to downstream, with the highest IBI scores occurring in the lowest reaches of the Cheyenne River. 21-3 2:00 PM Love, Jason T. [171710] DEVELOPING A BACTERIA TOTAL MAXIMUM DAILY LOAD FOR THE BIG SIOUX RIVER LOVE, Jason T., Vice President, RESPEC Water & Natural Resources, RESPEC, PO Box 725, Rapid City, SD 57709-0725, Jason.Love@respec.com, OSWALD, Jared K., Manager, Watershed Planning and Implementation, RESPEC, PO Box 725, Rapid City, SD 577090725, and FOREMAN, Cory S., Manager, Water and Geologic Characterization, RESPEC, P.O. Box 725, Rapid City, SD 57709 A bacteria total maximum daily load (TMDL) assessment is being completed on four reaches of the Big Sioux River from Dell Rapids to Brandon, South Dakota. The project area is unique in that it encompasses a mixture of rich agricultural land as well as the densely populated area within and surrounding the city of Sioux Falls, a Phase I National Pollutant Discharge Elimination System (NPDES) community. The assessment is being completed in three phases: planning, monitoring, and TMDL development. During the planning phase, available water-quality and quantity data, along with relevant background watershed data, were compiled to gain a basic understanding of the impairment, waterbodies, and watershed characteristics affecting impairment. The subsequent monitoring phase involves implementing an adaptive monitoring plan that fills in any gaps in the historical data as identified in Phase I. The final phase of the project will require calibrating and validating a watershed model application, using the data gathered in the first two phases, to develop the TMDL document and identify best management practice (BMP) scenarios that will bring the Big Sioux River into compliance with water-quality standards. The challenge of the project is to separate the impact the city of Sioux Falls is having on the overall bacteria loading from that originating outside the city limits. Furthermore, quantification of the relative loadings from each of the land uses within the city (industrial, commercial, residential) and below existing BMPs need to be assessed to understand the effectiveness of the city’s current stormwater treatment capability and properly prioritize future BMP implementation. Implementing BMPs within an NPDES community is different than those for a nonpoint sourcedriven load in that adoption is regulated rather than voluntary, making the accurate quantification of the water-quality impacts and associated BMP recommendations imperative. This presentation will focus primarily on the results obtained from Phase I and Phase II and briefly outline the approach and progress to date on Phase III. 21-4 2:20 PM Stone, James [171673] MERCURY TMDL DEVELOPMENT FOR SOUTH DAKOTA STONE, James1, STETLER, Larry2, MCCUTCHEON, Cindie1, BETEMARIAM, Hailemelekot3, and CHIPPS, Steve4, (1) Dept of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, james.stone@sdsmt.edu, (2) Dept Geology and Geological Engineering, South Dakota School Mines and Technology, Rapid City, SD 57701-3901, (3) Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, (4) Dept of Wildlife and Fisheries Sciences, South Dakota State University, Brookings, SD 57007 Currently nine lakes and impoundments within South Dakota are EPA 303(d) listed as mercury impaired waterbodies due to occurrence of fish tissue concentrations exceeding 1.0 mg/kg total mercury. In cooperation with the South Dakota Department of Environment and Natural Resources (SD-DENR), a series of interdisciplinary monitoring and assessment studies commenced in 2008 to understand mercury loading and cycling behavior within South Dakota air and watersheds, with the goal of collecting data to complete a total maximum daily loading (TMDL) criterion for mercury impaired waterbodies in South Dakota. Comparisons between historical water quality and mercury fish tissue concentrations were screened and analyzed using binary logistic regression, Akaike’s Information Criterion, and stepwise logistic regression methodology. Correlations were strongest between northern pike and walleye mercury tissue concentrations and water column alkalinity, total solids, and phosphorous concentrations, and suggest productivity and consequential eutrophication are the predominant indicators of fish tissue mercury susceptibility for aquatic conditions common in South Dakota. Eleven sediment cores collected at both advisory and non-advisory lakes and impoundments were analyzed for total mercury, iron, phosphorous, sulfur, sulfate, carbon, and water content, and quantitatively dated using Pb210 and Cs137 radiodating to estimate historical mercury fluxes. Strong correlations exist between sulfate reduction and sediment mercury, suggesting predominant pathway of methyl mercury formation and aquatic uptake is due to sulfate reducing bacteria activity within mercury advisory lakes. Advisory lakes sediment mercury concentrations range from 13 to 310 mg/kg, with the highest concentrations generally found within the top 10cm sediment depth. Nine bulk atmospheric mercury deposition monitors were deployed throughout South Dakota, Nebraska, North Dakota, and Wyoming, and a strong positive correlation exists between local atmospheric mercury deposition and mercury fish tissue occurrences. Results from these studies provide the basis of future mercury TMDL development for South Dakota lakes and impoundments. 21-5 2:40 PM Baker, Kevin K. [171607] MONITORING STORM-WATER QUALITY IN THE ARROWHEAD DRAINAGE BASIN, RAPID CITY, SD 2008-2009 BAKER, Kevin K.1, STAMM, John2, and KENNER, Scott J.1, (1) Civil & Environmental Engineering, South Dakota School of Mines and Technology, 501 East St Joseph St, Rapid City, SD 57701, kkbaker@usgs.gov, (2) U.S. Geological Survey, 1608 Mountain View Road, Rapid City, SD 57702 The City of Rapid City, South Dakota, has implemented programs to improve storm-water quality in response to the “Phase II Final Rule” issued by the U.S. Environmental Protection Agency. Applicable State of South Dakota guidelines for beneficial uses on Rapid Creek include a maximum total suspended solids (TSS) concentration of 53 mg/L in any one sample and a maximum fecal coliform concentration of 400 colony forming units (CFU)/100 mL in any one sample. To better understand urban stormwater runoff in the Rapid City area, the U.S. Geological Survey, in cooperation with the city of Rapid City, began storm-water monitoring in 2008 in the Arrowhead drainage basin (a tributary to Rapid Creek), which contains a mix of residential communities, forest and rangeland, construction sites, and many septic systems. Previous sampling efforts had indicated high concentrations of fecal coliform and suspended sediment in this basin. Two automatic water-quality sampling stations were installed within Arrowhead basin, one in July 2008 at the center of the basin and a second in July 2009 upstream from the confluence with Rapid Creek. The stations performed automated sampling during storm events and continuous monitoring of stage, along with air and water temperature. Precipitation data were collected at the first site. Thirteen storms were sampled during the spring, summer, and early fall months of 2008 and 2009. Storms ranged from long-duration, low-intensity storms to short-duration, high-intensity thunderstorms. Event mean concentrations (EMCs) averaged over the basin for the storm 2010 GSA Rocky Mountain Section Meeting 43 SESSION NO. 21 events were: 355 mg/L for TSS; 16800 CFU/100 mL for fecal coliform; and 2200 most probable number/100 mL for E. coli. EMCs of TSS ranged from 9 to 1900 mg/L, and fecal coliform counts ranged from 24 to 154,000 CFU/100 mL. E. coli to fecal coliform ratios ranged from 0.19 to 1.08 across the basin indicating that E. coli may be a major component of fecal coliform counts. Spatial patterns of the data indicate that TSS concentrations increase throughout the center of the basin then decrease through golf courses in the lower part of the basin to the outlet. Fecal coliforms increase throughout the basin to the outlet with no noticeable effect of surface conditions on the fecal coliform concentrations. 21-6 3:20 PM Upadhayay, Sikchya [171964] DIDYMOSPHENIA GEMINATA STUDY IN RAPID CREEK, SOUTH DAKOTA UPADHAYAY, Sikchya, ABESSA, Mebratu, and SUNDARESHWAR, P.V., Atmospheric Sciences, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, Sikchya.Upadhayay@mines.sdsmt.edu Rapid Creek is a spring fed perennial oligotrophic cold water stream that rises in southwestern South Dakota, in the Black Hills National Forest in the Black Hills in Pennington County (Carter et. al., 2002). In 2002, a massive algal bloom was observed in Rapid Creek. This bloom was due to excessive growth of a diatom Didymosphenia geminata. Algal blooms are typically associated with nutrient rich waters, often attributed to anthropogenic activities that pollute surface waters. It is paradoxical that D. geminata blooms under conditions where nutrient availability can be apparently growth limiting. Nutrient analyses on Rapid Creek confirm low concentration of dissolved nutrients. Yet the algal mats harbor relatively higher nutrient concentrations. While the surface water nutrient concentrations do not vary significantly over a 6 mile stretch of the Rapid Creek, D. geminata blooms are spotty. Observations show these stations differ in stream velocity, which may be an important factor in regulating the bloom of D. geminata in this stream. This paper presents how nutrients availability and stream flow rate at different sites contribute to the growth of D. geminata. References Carter J. M., Williamson J. S., Teller R. W. (2002): ‘The 1972 Black Hills-Rapid City Flood Revisited’, USGS Fact Sheet FS-037–02. 21-7 3:40 PM Betemariam, Hailemelekot [171612] SEDIMENT MERCURY BEHAVIOR IN SOUTH DAKOTA LAKES AND IMPOUNDMENTS BETEMARIAM, Hailemelekot1, STONE, James2, STETLER, Larry3, MCCUTCHEON, Cindie2, CHIPPS, Steve4, DESUTTER, Thomas5, PENN, Michael6, and URBAN, Noel7, (1) Dept of Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, Hailemelekot.Betemariam@Mines.sdsmt.edu, (2) Dept of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701, (3) Dept of Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701-3901, (4) Dept of Wildlife and Fisheries Sciences, South Dakota State University, Brookings, SD 57007, (5) Soil Science, North Dakota State University, Fargo, ND 58105, (6) Dept of Civil Engineering, University of Wisconsin-Platteville, Platteville, WI 53818, (7) Dept of Civil and Environmental Engineering, Michigan Tech, Houghton, MI 49931 Currently seven lakes and impoundments within South Dakota are EPA 303(d) listed as mercury impaired water bodies where mercury fish tissue concentrations have exceeded 1.0 mg/kg total mercury. The objectives of this study were to quantify the extent of sediment mercury within a subset of South Dakota water bodies, and to establish sediment and watershed relations responsible for biogeochemical methyl-mercury production and eventual accumulation by fish. Sediment cores were collected from eleven water bodies throughout South Dakota based upon current mercury fish advisory status and lake depth, and analyzed for total mercury, a suite of total metals, water content, total carbon and nitrogen concentration, and radiometric dating. Sediment profiles collected at four mercury advisory lakes contained low total sulfur (< 6 mg/g), moderate total iron (20-35 mg/g) and high total mercury (60-200 ng/g) compared to non mercury advisory lakes . The presence of low sulfur (< 6 mg/L) within advisory lake sediments suggest much of the available sulfur was mobilized through biological sulfate reduction-related processes, and appears responsible to increased methyl-mercury production. High sulfur sediment concentrations favor the formation of sulphides that are effective mercury complexants, thus rendering mercury unavailable for methylation. On-going radiometric dating analyses (Pb210 and Cs137) will provide estimates of historical watershed mercury fluxes entrapped within lake sediments. Mercury non-advisory lake watersheds generally contained higher percentage of wetlands compared to advisory lakes, suggesting that wetlands appear to be effective scavengers or sinks of mercury and effectively reduce mercury transport into the lakes. Catchment area to lake area ratios (CA: LA) correlated positively with organic solids and mercury lake loading. The extent of watershed grasslands correlated positively with sediment mercury, while cultivated land exhibited a negative correlation, suggesting that land use appears to influence mercury watershed behavior. Findings from this study provide a better understanding of mercury behavior within watersheds and sediments of South Dakota lakes and impoundments. Thursday, 22 April 2010 T13. Western South Dakota Hydrology Conference IV “Ground-Water Quality and Hydrology” Rushmore Plaza Civic Center, Rushmore G 1:20 PM Betemariam, Hailemelekot [172071] ARSENIC CONTAMINATION IN THE MOUNT RUSHMORE AREA AND PROPOSED REMOVAL TECHNIQUES BETEMARIAM, Hailemelekot1, DAVIS, Arden D.1, DIXON, David2, and HANSEN, Marion2, (1) Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, Hailemelekot. Betemariam@Mines.sdsmt.edu, (2) Department of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701 Naturally occurring arsenic has been detected in several wells in the area near Mount Rushmore, in the Black Hills of South Dakota. The geology of Mount Rushmore area includes Precambrian granitic and metamorphic rocks. The main aquifers are fractured schist, alluvium and colluvium. Arsenopyrite is a major contributor of arsenic to groundwater in the area. The U.S. Environmental 44 2010 GSA Abstracts with Programs 22-2 1:40 PM Salvatore, Michelle [171935] PRELIMINARY REPORT: ISOLATION AND DETECTION OF FILTERABLE CONTAMINANTS IN DRINKING WATER, PINE RIDGE RESERVATION, SOUTH DAKOTA SALVATORE, Michelle1, LAGARRY, Hannan E.1, LEE, Patrick1, and ONE FEATHER, Leola2, (1) Department of Math, Science, & Technology, Oglala Lakota College, 490 Three Mile Creek Road, Kyle, SD 57752, msalvatore@olc.edu, (2) PO Box 12, Wounded Knee, SD 57794 Based on a study by the USGS and unpublished data, toxic heavy metals, principally arsenic and uranium, are known to contaminate ground water on the Pine Ridge Reservation. Based on untested, anecdotal evidence, these contaminants are linked to increased prevalence of diabeteslike symptoms, skin damage, problems with circulatory problems, and various kinds of cancer near Wanblee, South Dakota and along American Horse Creek. Arsenic levels in excess of the MCL were documented in the USGS study. In order to better understand the levels and distributions of toxic heavy metal contaminants, we sampled water from: 1) private wells in Wounded Knee, Kyle, Porcupine, Red Water, American Horse, Pine Ridge, and Oglala, 2) a community spring in Potato Creek, 3) rural (piped-in) water in Rockyford, and 4) faucet water in Red Water. In all cases, water was sampled directly from its point of access. A total of 13 water samples were tested for arsenic and analyzed on the atomic absorption mass spectrometer at the Oglala Lakota College Center for Science and Technology using EPA Method 3051a. Method 3051a consists of microwave extraction designed to mimic conventional extraction methods using heated nitric or nitric and hydrochloric acids. Our analysis revealed arsenic levels ranging from 4.3 ppb (Porcupine well) to 19.95 ppb (Potato Creek spring). In addition to Potato Creek, highest concentrations of arsenic were recorded at Kyle (10.44 & 10.92 ppb), American Horse (11.78 ppb), Wounded Knee (11.78 ppb), and Red Water (15.95 & 17.95 ppb). Based on these data, Oglala Lakota College and the University of Illinois CAMPWS are seeking funding to experiment with low-cost devices that filter arsenic from drinking water. At Oglala Lakota College we have ongoing research that aims to identify all potential contaminants in surface water and groundwatert water supplies, their sources, and their distributions across the Pine Ridge Reservation. This research was funded by NSF Model Institutes for Excellence Phases I &II, NSF Tribal Colleges and Universities Program Phases I & II, and the NASA-SEMAA program at Oglala Lakota College, and the University of Illinois CAMPWS. 22-3 2:00 PM Davis, Arden D. [171853] GROUND-WATER VULNERABILITY OF THE KARSTIC MADISON AQUIFER IN THE EASTERN BLACK HILLS DAVIS, Arden D., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, arden.davis@sdsmt.edu, LISENBEE, Alvis L., Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995, and MILLER, Scott L., ExxonMobil Exploration Company, 233 Benmar Drive, Houston, TX 77060 The karstic Madison aquifer is western South Dakota’s major subsurface reservoir. It is the primary water source for the City of Rapid City and several other communities in the eastern Black Hills. As a result of karst development, the Madison aquifer is extremely heterogeneous and anisotropic. It varies in thickness between 60 and 155 meters in the Rapid City area because of paleotopographic relief from erosion during late Mississippian time. Field mapping indicates that ground-water flow paths are influenced by fractures, joints, faults, folds, stratigraphic variations, and a Laramide-age, graben-like structural depression in the Rapid City area. The Madison aquifer is highly sensitive and vulnerable to contamination because of extremely fast ground-water velocities and little filtering of contaminants. Parts of the recharge area that are believed to display the greatest vulnerability contain sinkholes, disappearing streams, and other karst features, along with highways and concentrations of on-site wastewater systems in areas of residential and urban development. Current vulnerability mapping involves modifications of methods such as DRASTIC and KARSTIC. This vulnerability mapping is part of an effort involving nine contiguous 1:24,000scale quadrangles in the Rapid City area. 22-4 SESSION NO. 22, 1:20 PM 22-1 Protection Agency’s maximum contaminant level (MCL) for arsenic is 10 parts per billion (ppb). Some individual wells in the area do not meet this criterion, and samples from the water supply at Mount Rushmore National Memorial have shown arsenic concentrations of about 13 ppb. Many treatment technologies have been tested for removal of arsenic from drinking water. Limestonebased methods are environmentally friendly and offer the advantage of low disposal costs of the waste product. Recent research funded by the U.S. Geological Survey has involved removal of arsenic from water with crushed Minnekahta Limestone. In this work, limestone removed 63% to 96% of arsenic from water. The limestone waste currently is being tested for thermal stability. If the method passes the test, the limestone waste could be used as a raw material for the manufacturing of cement. In related work, water was sampled from a city well in Keystone, two miles from Mount Rushmore. The results showed an average of 91.6% arsenic removal, and the final arsenic concentration was 0.006 mg/L, lower than the MCL. Further research is underway to encapsulate the limestone waste in concrete as aggregate, thereby minimizing the disposal cost. 2:20 PM Saxton, Samantha L. [171790] THE BLACK HILLS ATLAS OF AQUIFER SUSCEPTIBILITY AND VULNERABILITY SAXTON, Samantha L., BROWN, Rachel A., SCHNEIDER, John M., and PRICE, Maribeth H., Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, samantha.saxton@ mines.sdsmt.edu The West Dakota Water Development District has been funding a number of small projects to determine aquifer susceptibility and vulnerability in 7.5-minute quadrangles near Rapid City, South Dakota. Several students have been working on these quads for the past 6-7 years, generating a variety of formats and procedures, and to date the resulting maps have not been generally available except as thesis plates. We are designing an atlas of consistently produced and formatted aquifer maps for the quadrangles that will be distributed online through the new GeoPDF format adopted by the United States Geological Survey. A GeoPDF is similar to a standard PDF file readable with Adobe Reader, but it contains map layers that can be turned on and off individually to provide an interactive map environment for the user to view, zoom in/out, and print the map. A free toolbar download can be installed in Adobe Reader to implement additional functions within the GeoPDF. The maps are being produced in a Geographic Information System (GIS) environment, and a consistent framework for the underlying GIS databases is being developed alongside consistent GIS analysis parameters and techniques. All data will have complete metadata documentation. A series of maps including aquifer susceptibility, aquifer vulnerability, structure contour and depth to formation are generated for each quadrangle. Additionally, a series of larger compilations will be made available such as a strip map showing the structural contours for Blackhawk, Rapid City West, and Rockerville quadrangles. This work has also included the collection and organization of domestic water well production figures and related data for use in GIS analyses. The maps will made available and distributed to the public online at http://aquifers.sdsmt.edu. SESSION NO. 23 22-5 2:40 PM Valder, Joshua F. [172073] END-MEMBER MIXING ANALYSIS APPLIED TO THE KARSTIC MADISON AQUIFER USING WATER CHEMISTRY IN THE SOUTHERN BLACK HILLS, SOUTH DAKOTA VALDER, Joshua F.1, LONG, Andrew J.1, DAVIS, Arden D.2, and KENNER, Scott J.3, (1) U.S. Geological Survey, 1608 Mountain View Rd, Rapid City, SD 57702, jvalder@usgs.gov, (2) Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, (3) Civil & Environmental Engineering, South Dakota School of Mines and Technology, 501 East St Joseph St, Rapid City, SD 57701 The U.S. Geological Survey and the National Park Service are studying the Madison aquifer in Wind Cave National Park in the southern Black Hills of South Dakota. The purpose of the study is to better understand complex groundwater flow through the karstic Madison aquifer in and around Wind Cave National Park and to estimate source-water areas for different sample locations based on water chemistry. Samples collected from 19 locations in 2007 were analyzed for major ions, nitrate, and stable isotopes. To identify recharge areas or other source waters for the study area, an end-member mixing model utilizing principal component analysis is used to estimate the water chemistry of probable source waters, or end-members. End-member chemistries are estimated using two different methods. The first method assumes that none of the samples necessarily represents any specific end-member. The second method determines which samples most likely represent end-members through statistical evaluation. Possible end-members include source water from local outcrop recharge, recharge on the outcrop on the western side of the Black Hills, and regional groundwater flow from west of the Black Hills. The mixing proportions of these endmembers are estimated for several sampling sites. Results of this study can be applied to better characterize groundwater flow through the complex karst environment and can provide insight about which areas are more important to protect from contamination in relation to a particular well or spring in the southern Black Hills. 22-6 3:20 PM Long, Andrew J. [171623] TEMPERATURE: A USEFUL TRACER FOR SEPARATING CONDUIT AND DIFFUSE FLOW IN THE KARSTIC MADISON AQUIFER LONG, Andrew J., U.S. Geological Survey, 1608 Mountain View Rd, Rapid City, SD 57702, ajlong@usgs.gov and GILCREASE, Patrick C., Department of Chemical and Biological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701 Continuous water temperature data can be recorded at high precision and low cost for wells, springs, and streams. Groundwater temperature is affected by heat exchange with aquifer material, which is affected by the geothermal gradient, and thus temperature is a tracer that may require numerical heat transport-modeling in groundwater. This type of model was applied to the carbonate karst Madison aquifer in the Black Hills of South Dakota, which contains pipe-like openings called conduits into which water from sinking streams enter to recharge the aquifer. The model accounted for several variables including the heat exchange between aquifer rocks and groundwater, variable groundwater velocity in the conduit, conduit roughness and turbulence, the geothermal gradient, and a proportionality constant weighted by the rate of sinking streamflow to quantify the relative fractions of conduit and diffuse flow. The model was applied to 7 months of continuous temperature measurements for the well, which withdraws fast-moving groundwater from a conduit as well as slow-moving diffuse flow from smaller pore spaces. Temperature fluctuations of the sinking stream water are heavily damped by contact with conduit walls at nearly constant temperature, which results in near equilibrium between rock and water temperatures inside the conduit. Similarly, the model was insensitive to temperature changes in the sinking stream. Results of the simulation indicated that within the well’s capture zone, groundwater in the conduit generally is about 0.5°C cooler than diffuse flow as a result of prior contact with conduit walls upgradient from the well and closer to the land surface than small pore spaces within the well’s capture zone. Thus it was possible to estimate from model calibration that the conduit-flow fraction to the well was in the range of 2-31% of total flow depending on the recharge rate, and that simulated conduit velocity was in the range of 44-353 m/d, which is consistent with velocities determined from previous dye tracing results. Temperature fluctuations for the well with periods ranging from 0.5 to 1.5 days could not be simulated but probably resulted from rapid changes in the mixture of conduit and diffuse flow, which may have resulted from factors such as pumping of proximal wells or earth tides. 22-7 3:40 PM Mergenthal, Daniel [171906] EFFECTS OF HOMESTAKE MINE WORKINGS ON SUBSURFACE AND SURFACE HYDROLOGY MERGENTHAL, Daniel and STETLER, Larry, Dept Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701-3901, mergenwulf@hotmail.com A study has been initiated as part of the Deep Underground Science and Engineering Laboratory site Environmental Impact Statement to gain understanding of subsurface and surface hydrological effects from groundwater pumping. Groundwater elevation in the early 1900’s was closely associated with Whitewood Creek, approximately 300 feet below the current Ross and Yates headframes. After pumping water for nearly a century the mine was closed and for five years, water flowed into the mine, ultimately filling to bottom 3621 feet. Since August 2008, renewed pumping has lowered the water table to ~5300 feet. It is currently unknown how the long-term pumping, the five-year hiatus, and renewed pumping has affected the groundwater flow, cone of depression, and the surface hydrology in the vicinity of the workings. This project will include assessment of the cone of depression, potential inflow from Whitewood Creek, and environmental effects of increased flow in Whitewood Creek. Historical and new data will be used to build groundwater models showing the cone of depression. These data will be augmented using water quality data from inside the mine and Whitewood Creek. Results will be utilized in the EIS to provide recommendations on methods to ensure environmental degradation to surface water does not occur as a result of installation and operation of DUSEL. SESSION NO. 23, 8:00 AM Friday, 23 April 2010 Hydrogeology Rushmore Plaza Civic Center, Ponderosa Room 23-1 8:00 AM Garcia, Patricia K. [171825] HYDROGEOLOGY OF A SHIELD VOLCANO IN THE TRANS-MEXICAN VOLCANIC BELT GARCIA, Patricia K., SCHOENROCK, Jared K., EMERMAN, Steven H., BRADFORD, Joel A., ANDERSON, Ryan B., KEMP, Tracy L., DURAND, James P., PALMER, Mallory A., and BUNDS, Michael P., Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, mntbkrgrl@hotmail.com Tamaula, a village of 400 residents in Guanajuato, Mexico, is one of many poor communities living on extinct shield volcanoes within the Trans-Mexican Volcanic Belt without sufficient sources of potable water. Prior to the summer of 2009, the residents of Tamaula relied on two muddy reservoirs, several rooftop catchment systems, six springs yielding only 120 L/d for the most productive spring, and 4000 L of water per week delivered by the municipality of Irapuato. In August 2009 a site for a 50-m-deep well was chosen based on a dream. The resulting well yields 50 L/s, making it as productive as the most productive wells in the valley surrounding the volcano and completely transforming the life of the village. The objective of this study is to determine why this particular well site was so successful and whether the current well production is sustainable so that the knowledge can be used to aid similar poor communities on shield volcanoes. Twelve springs were located on the volcano and water samples were collected from the springs, reservoirs and well. Electrical conductivity, pH and temperature were measured on site. Concentrations of As, Fe, Cu, Ni, Co, Mn, Zn, Cr and F were measured with a spectrophotometer. The size of the aquifers will be estimated by applying cluster analysis to the spring and well chemistry. A comparison of spring locations with fracture traces seen on aerial photos shows that two springs lie along a shorter fracture trace, while 11 springs lie along a longer fracture trace that includes the well site. Slug tests were carried out during several stages of the drilling. The slug test results will be combined with description of the rock chips collected every meter of drilling to determine the probable thickness of the aquifer. The discharge from the well and the resulting long-term change in head are being monitored by the local high school students so that the sustainability of the well can be determined. Results will be reported at the meeting. 23-2 8:20 AM Emerman, Steven H. [171677] ARSENIC CONTAMINATION OF GROUNDWATER IN KATHMANDU VALLEY, NEPAL, AS A CONSEQUENCE OF RAPID EROSION EMERMAN, Steven H.1, PRASAI, Tista2, ANDERSON, Ryan B.1, and PALMER, Mallory A.1, (1) Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, StevenE@uvu.edu, (2) Nepal Academy of Science and Technology, Kathmandu, Nepal Elevated levels of As in groundwater in the flood plain of the Ganges River in Bangladesh, West Bengal (India) and the Terai (southern Nepal) have been well-documented over the past decade. The objective of this study was to measure As and the transition elements normally associated with As in Kathmandu Valley in Nepal, a heavily populated tectonic valley in the upper reaches of the Ganges River system. Water samples were collected from six shallow tubewells (depth < 50 m), eight deep tubewells and 13 dug wells and stone spouts. Electrical conductivity, temperature and pH were measured on-site and concentrations of As, Fe, Cu, Ni, Co, Mn, Zn and Cr were measured with a spectrophotometer. Five tubewells and four dug wells had As levels exceeding the Nepal Interim Standard (As = 0.05 mg/L). The maximum As level was As = 2.07 mg/L in the deep tubewell of Paropkhar Maternity Hospital. There was no statistically significant clustering of As levels either with depth or horizontal location. Arsenic was uncorrelated with either Fe (R2 = 0.096), Mn (R2 = 0.0004) or any combination of transition elements (R2 < 0.083), which is inconsistent with both the reduction-dissolution and the sulfide oxidation models for As release. The geometric mean As level of groundwater (As = 0.015 mg/L) was indistinguishable from the geometric mean As level of surface water (As = 0.013 mg/L) obtained from 48 river samples from Kathmandu Valley in a previous study. Although the rivers of Kathmandu Valley are heavily polluted, the geometric mean of surface water As is indistinguishable from the geometric mean of surface water As (As = 0.010 mg/L) found in 102 river samples throughout central Nepal outside of Kathmandu Valley. We are suggesting that elevated groundwater As results not from subsurface redox conditions or from direct human activity, but from losing streams with elevated As, which is a consequence of rapid erosion caused by a combination of monsoon climate, rapid tectonic uplift and deforestation. Other recent studies have reached different conclusions by studying a different set of wells and not comparing groundwater with surface water. It is crucial that a common database be created for all studies of groundwater quality in Kathmandu Valley and that this study be repeated in other tectonic valleys in the upper reaches of the Ganges River system. 23-3 8:40 AM Gilmore, Adam Matthew [170649] ENHANCED MEASUREMENTS OF CHROMOPHORIC DISSOLVED ORGANIC MATTER (CDOM) FOR WATER QUALITY ANALYSIS USING A NEW SIMULTANEOUS ABSORBANCE AND FLUORESCENCE INSTRUMENT GILMORE, Adam Matthew1, CORY, Rose M.2, and OWEIMRIN, Michael1, (1) Molecular Microanalysis, HORIBA Scientific, 3880 Park Avenue, Edison, NJ 08822, adam.gilmore@ jobinyvon.com, (2) Environmental Sciences and Engineering, University of North Carolina Chapel Hill, 160 Rosenau Hall CB 7431, Chapel Hill, NC 27599-7431 Water quality, with respect to suspended particles and dissolved organic and inorganic compounds, is now recognized as one of the top global environmental concerns. Contemporary research indicates fluorescence spectral analyses coupled with UV-VIS absorbance assays have the potential, especially when combined and coordinated, to facilitate rapid, robust quantification of a wide range of compounds, including interactions among them. Fluorescence excitationemission matrices (EEMs) collected over the UV-VIS region provide a wealth of information on chromophoric dissolved organic matter (CDOM). Analysis of the EEMs using conventional and multivariate techniques, including primarily parallel factor analysis (PARAFAC), provides information about many types of CDOM relevant to carbon cycling and pollution of fresh, marine and drinking water sources. Of critical concern also are the CDOM interactions with, and optical activities of, dissolved inorganic compounds. Many of the inorganic compounds and oxygen demand parameters can be analyzed with a wide range of UV-VIS absorbance assays. The instrument is designed and optimized for high UV throughput and low stray light performance. The sampling optics are optimized for both fluorescence and absorbance detection with the same sample. 2010 GSA Rocky Mountain Section Meeting 45 SESSION NO. 23 Both EEM and absorbance measurements implement NIST traceable instrument correction and calibration routines. The fluorescence detection utilizes a high dynamic range CCD coupled to a high-resolution spectrograph while absorbance utilizes diode based detection with a high dynamic range and extremely low-stray light specifications. The CDOM analysis is facilitated by a transfer of the data and model information with the PARAFAC routine. The EEM analysis software package facilitates coordinated correction of and correlation with the absorbance spectral data to quantify fluorescence reabsorption in the sample. The absorbance software also facilitates a wide range of UV-VIS assays with standard water quality kits as well as providing information on turbidity. In conclusion, the instrument is generally applicable to both water quality research and analytical laboratories as well as a wide number of other applications utilizing EEM and or absorbance methodology. 23-4 9:00 AM Schoenrock, Jared K. [171963] VOLCANOSTRATIGRAPHIC AND HYDROGEOLOGIC STUDY TO SITE A WELL IN BASIGORABO, SIERRA TARAHUMARA, MEXICO SCHOENROCK, Jared K., ROBERTSON, Scott A., WITT, Dallin, BUNDS, Michael P., EMERMAN, Steven H., and BRADFORD, Joel, Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, Pier49sf@gmail.com Many Tarahumaran villages near Creel, Chihuahua, Mexico, lack sufficient potable water. The Jesuit Mission in Creel, Chihuahua, Mexico, has been drilling wells in villages near Creel but many of the wells are unproductive. The villages are situated in the Sierra Madre Occidental volcanic field, which is one of the largest ignimbrite provinces in the world, yet has mostly been mapped only at the reconnaissance level and virtually no work has been done on its hydrogeology. Utah Valley University students and faculty conducted field work in October 2009 as part of an ongoing hydrogeologic study to aid the Mission’s well-drilling program. The focus of the research presented here is the volcanostratigraphy and fracturing near the village of Basigorabo, which has requested a well. Prior to our work, the area around Basigorabo had only been mapped as undifferentiated 29 Ma Divisadero Tuff. Our work shows Basigorabo sits on a plateau at 2408 m elevation that is underlain by a flat – lying, strongly welded and flattened crystal-rich tuff that is the base of a major cooling unit. The base of the welded tuff is at approximately 2390 m elevation, and it is underlain by another cooling unit that contains moderately welded pumice-rich tuff with minimal flattening at its top, grading downwards into tuff with moderately flattened pumice at 2347 m. The base of this flat-lying unit is not locally exposed. The tuffs in the area contain very low matrix permeability and fractures are necessary for a viable aquifer. The welded tuff at the base of the upper cooling unit is moderately fractured along a stream that follows a lineament visible in aerial photographs. Four fracture sets were measured near the stream; the dominant set has a density of 14 fractures per 4 m and is oriented parallel to the lineament (123/85 SW). Fracture density decreases rapidly to 1 fracture per 4 m 100 m from the lineament. The less welded tuff in the upper portion of the lower cooling unit contains no visible fractures. The strongly welded tuff along the lineament may form a viable aquifer if it is sufficiently thick. Our results also suggest that where strongly welded tuffs within the Divisadero Tuff are cut by fracture zones they are potential aquifers, whereas the less welded, upper portions of cooling units are unlikely to host fractured aquifers. 23-5 9:20 AM Anderson, Ryan B. [171685] ARSENIC AND OTHER HEAVY METALS IN THE SUN KOSHI AND SAPTA KOSHI RIVERS, EASTERN NEPAL ANDERSON, Ryan B.1, EMERMAN, Steven H.1, BHANDARI, Sushmita2, BHATTARAI, Roshan R.2, PALMER, Mallory A.1, BHATTARAI, Tara N.2, and BUNDS, Michael P.1, (1) Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, zb_ryan@hotmail.com, (2) Department of Geology, Tri-Chandra Multiple Campus, Tribhuvan University, Ghantaghar, Kathmandu, Nepal Elevated levels of groundwater As have been well-documented in the flood plain of the Ganges River in Bangladesh, West Bengal (India) and the Terai (Indo-Gangetic Plain of southern Nepal). The dominant paradigm for the presence of elevated As is that the reducing conditions in the thick sedimentary package cause release of As from sediment into groundwater. This paradigm has no role for recharge of groundwater by arsenic-enriched rivers and, in fact, fluvial arsenic has been found to be very low in Bangladesh and West Bengal. However, previous studies by the authors have found elevated fluvial arsenic in many tributaries of the Ganges River system in Nepal, upstream of West Bengal and Bangladesh. The objective of this study was to determine where in the Ganges River system arsenic precipitates or becomes adsorbed onto sediments in order to gain insight into the arsenic cycle in South Asia. The objective was accomplished by rafting the Sun Koshi River to the Sapta Koshi River across eastern Nepal from Dolalghat to the Sapta Koshi Barrage at the Indian border (total length of 219 km), and collecting water samples twice daily or whenever a major tributary was crossed, and collecting sediment samples daily for a total of 27 water samples and 11 sediment samples. Electrical conductivity, pH, and temperature were measured on site. The Hach DR-2700 Spectrophotometer was used to measure As and the transition elements that are normally associated with arsenic (Fe, Cu, Mn, Zn, Ni, Co, Cr). Of water samples collected upstream of the confluence of the Sun Koshi with the Sapta Koshi (upstream of the Indo-Gangetic Plain), 45% showed As levels exceeding the WHO standard (As = 0.01 mg/L), which is consistent with previous work that showed 53% of fluvial samples from Nepal outside of the Higher Himalayan Zone exceeding the WHO standard. Water samples collected from the Sapta Koshi River within the Indo-Gangetic Plain uniformly showed no detectable As, suggesting that As is precipitated or adsorbed onto sediment in Nepal at the boundary between the Siwalik Hills and the Indo-Gangetic Plain. Sediment samples will be analyzed for mobile (adsorbed) As by extracting As with 1 M HCl. Further results will be reported at the meeting. 23-6 9:40 AM Mead, Jack [172056] WATER PRODUCTION FROM FRACTURED PRECAMBRIAN CRYSTALLINE AQUIFERS, CENTRAL BLACK HILLS, SOUTH DAKOTA MEAD, Jack1, TUFFOUR, M.1, TOTH, Natalie1, ANDERSON, Fred J.2, DAVIS, Arden1, and LISENBEE, Alvis L.1, (1) Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995, jack.mead@mines.sdsmt.edu, (2) North Dakota Geological Survey, 600 East Boulevard Avenue, Bismarck, ND 58505 Water wells for home and commercial use in the central Black Hills (specifically the Hill City, Mt. Rushmore, Pactola Dam and Silver City Quadrangles) are chiefly drilled in Precambrian phyllite, schist, metagraywacke, metabasalt and granite with lesser production from alluvial aquifers. Fracture porosity (faults and joints) in differing quadrangles in the crystalline rocks yield flows averaging 17 to 32 gallons per minute (gpm) in varying quadrangles at the time of initial well completion, but vary from one-half to 350 gpm. Granite and metagraywacke averages vary from 19 to 27 gpm whereas schist and phyllite averages vary from 1 to 23 gpm. Wells deeper than 300 feet rarely produce more than one to two gpm, but in exceptional cases yield greater than 100 gpm: average well depths vary from 141 to 215 feet and average static water levels from 35 to 45 ft. 46 2010 GSA Abstracts with Programs Drill logs compiled by commercial drillers indicate production from fractured quartz bodies averaging 16 gpm: Vertical quartz “veins” (1-2 feet wide by 3-10 high) are noted in surface exposures as are iron-stained fractures (indicative of groundwater flow) in the metamorphic country rock. Trends of subvertical fracture sets in the Pactola Dam Quadrangle vary from location to location, but NE and/or NW trends are most common. Such orientations likely lend anisotropy to the aquifer and have an effect on ground water flow paths, as might several major NNW-trending faults. 23-7 10:20 AM Kemp, Tracy L. [171680] GROUNDWATER RECHARGE BY GLACIAL LAKES IN THE WASATCH RANGE AND UINTA MOUNTAINS, UTAH KEMP, Tracy L., ANDERSON, Ryan B., EMERMAN, Steven H., and VAN WAGONER, Marc E., Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, trc_kempy7@hotmail.com The conventional wisdom has long been that groundwater in Salt Lake and Utah Valleys is recharged by losing streams from the Wasatch Range. However, recent work using noble gases has shown that much of the groundwater in Salt Lake and Utah Valleys follows subterranean flow paths from the Wasatch Range. The objective of this study was to calculate the groundwater recharge by individual glacial lakes in the Wasatch Range and Uinta Mountains by measuring the input and output stream discharges, estimating lake evaporation from the difference between lake and input stream electrical conductivities, and measuring the lake level between two visits roughly two weeks apart. In the Wasatch Range, groundwater recharge was calculated for Lake Blanche, Lake Florence, White Pine Lake, Lower Red Pine Lake, Upper Red Pine Lake and Silver Lake as 7.9 × 104 m3/month, 4.5 × 103 m3/month, 7.4 × 104 m3/month, 5.7 × 105 m3/month, 4.7 × 105 m3/ month, and 7.0 × 105 m3/month, respectively, while Lake Lillian had a groundwater discharge of 4.7 × 104 m3/month. In the Uinta Mountains groundwater recharge was calculated for Amethyst Lake, McPheeter Lake and BR-24 Lake as 3.3 × 106 m3/month, 2.1 × 104 m3/month, and 2.07 × 104 m3/month, respectively, while Ryder Lake had a groundwater discharge of 6.6 × 103 m3/month. The Wasatch Range lakes studied had a net groundwater recharge of 1.9 × 106 m3/month. These lakes included about half the glacial lake surface area of the Wasatch Range, implying a total groundwater recharge of 3.8 × 106 m3/month, which is consistent with Manning and Solomon’s (2003) range of (1.7 – 3.9) × 106 m3/month based on noble gases. We are suggesting that almost all of the groundwater recharge from the Wasatch Range occurs through the glacial lakes. Moreover, very little of this groundwater recharge enters streams on the Wasatch Range (local flow), but nearly all appears as groundwater in Salt Lake and Utah Valleys (regional flow). Further research will include estimating each lake area’s drainage basin and annual precipitation for comparison with estimates of groundwater recharge, as well as more precise estimates of total glacial lake surface area and groundwater recharge. Further results will be reported at the meeting. 23-8 10:40 AM Garcia, Patricia K. [171864] USE OF AQUEOUS CHEMISTRY OF SPRINGS TO DELINEATE AQUIFERS IN THE SIERRA TARAHUMARA, CHIHUAHUA, MEXICO NELSON HADLEY, Janae, THAYNE, Michael, GARCIA, Patricia K., EMERMAN, Steven H., VAN WAGONER, Marc E., BUNDS, Michael P., and BRADFORD, Joel A., Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, mntbkrgrl@hotmail.com This research is part of an ongoing hydrologic survey of the Sierra Tarahumara volcanic tuff region near the village of Creel, Chihuahua, Mexico, which is being carried out in cooperation with the Tarahumara Children’s Hospital. The hospital drills water wells for the Tarahumara Indians at a cost of approximately $5000 per well, all of which must be raised through charity. However, many wells have yielded water for less than a week. The objective of this study is to provide guidelines for predicting the sustainability of a well through the use of aqueous chemistry to delineate the extent of the aquifers, and stream hydrographs to determine the recharge rate of aquifers. In October 2009, Utah Valley University students and faculty collected 75 water samples from 24 developed springs, 33 undeveloped springs, 11 streams, 2 producing wells, and 5 cisterns. This greatly expanded the data set of 26 samples collected from six developed springs, eight streams, 11 wells and one cistern by UVU in October 2008. The 75 additional water samples were tested for temperature, electrical conductivity and pH on site. Concentrations of As, the transition elements normally associated with As (Fe, Cu, Ni, Co, Mn, Zn, Cr) and F were measured with a Hach DR-2700 Spectrophotometer. Near the “Educación y Patria” school in Creel, stream discharge and stage were measured and a stream rating curve was created. Students and teachers were taught to measure stream stage, and are taking measurements at the stream on a daily basis. Groundwater recharge will be calculated using the seasonal recession method. Cluster analysis is being used to group springs and wells with similar chemical characteristics. Spatial autocorrelation methods will then be used to determine the spatial extent of clusters of springs and wells with similar chemistry. Results will be reported at the meeting. SESSION NO. 24, 8:00 AM Friday, 23 April 2010 T2. Structural and Tectonic Evolution of the Proterozoic Trans-Hudson–Archean Wyoming Province Boundary Rushmore Plaza Civic Center, Alpine Room 24-1 8:00 AM Dahl, Peter S. [171705] MORE EVIDENCE THAT THE BLACK HILLS DOMAIN WAS ORIGINALLY PART OF THE ARCHEAN WYOMING CRATON: OCCURRENCES OF 3.8-2.6 GA DETRITAL ZIRCONS IN 2.5-1.9 GA METASEDIMENTARY ROCKS DAHL, Peter S.1, HARK, Jessica S.1, FREI, Robert2, GHOSH, Amiya K.1, WHITEHOUSE, Martin J.3, and WOODEN, Joseph L.4, (1) Department of Geology, Kent State University, Kent, OH 44242, pdahl@kent.edu, (2) Institute of Geography and Geology, University of Copenhagen, Øster Voldgade 10, Copenhagen, DK-1350, Denmark, (3) Laboratory for Isotope Geology, Swedish Museum of Natural History, Stockholm, SE-104 05, Sweden, (4) U. S. Geol Survey, 345 Middlefield Road, MS977, Menlo Park, CA 94025 A longstanding question concerning the Archean Wyoming craton is whether the Black Hills domain has always comprised its eastern margin, as suggested by published Pb- and Sm-Ndisotopic tracer studies or, instead, was juxtaposed at 1.72-1.71 Ga along the Hartville-Rawhide SESSION NO. 24 fault, a prominent convergent shear zone of known age in SE Wyoming. This question is being addressed with ongoing U-Pb microchronometry of detrital magmatic zircons in Precambrian metasedimentary rocks from the Black Hills basement. Seven rocks representing diverse lithology, age, and location have been analyzed thus far, including: four 2.56-2.48 Ga conglomeratic quartzites (Boxelder Creek Formation, Nemo); two 2.01-1.89 Ga metapelites (Vanderlehr Formation, Bear Mtn.; unnamed schist, Crook Mtn.); and a 1.89 Ga phyllite (Montana Mine Formation, Rochford). U-Pb concordia plots of all the 207Pb/206Pb spot-dates, and relative probability plots of the >90% U-Pb concordant dates, indicate that the detritral-zircon populations range in age from 3.4-2.6 Ga in each rock analyzed, despite their wide 2.56-1.89 Ga range of depositional ages. Specifically, detrital zircons in: (1) the older rocks exhibit 9 apparent age populations between 3.45-2.59 Ga, with 2.67 and 3.32-3.10 Ga ages predominant in the 3 quartzites and a metaconglomerate, respectively; (2) the intermediate-age metapelites exhibit 8 such populations of 3.43-2.61 Ga age (3.37 Ga predominant), with an outlier at 3.83 Ga; and (3) the younger phyllite exhibits 8 populations of 3.41-2.55 Ga age (2.71-2.68 Ga predominant). As for potential detrital source(s), crustal ages ranging from ~3.9-2.5 Ga and ~2.9-2.5 Ga characterize the Wyoming and Superior cratons, respectively. Thus, a Wyoming source is more likely for 3.8-2.6 Ga zircons in the Black Hills, indicating also that this domain was contiguous with the craton at 2.56-1.89 Ga. Support for this hypothesis is provided by the cross-bedded quartzites, which independently point to westerly (i.e., Wyoming) sources. We suggest that the Black Hills domain was initially separated from the Wyoming craton during early Trans-Hudsonian back-arc rifting at 1.88 Ga (known ages of tholeiitic dikes) and then rejuxtaposed during terminal WyomingSuperior collision at 1.715-1.695 Ga (known timing-duration of Harney Peak granitic magmatism). 24-2 8:20 AM Hark, Jessica S. [171672] U-PB AGES OF ZIRCON, MONAZITE, AND XENOTIME IN THE HARNEY PEAK GRANITE, BLACK HILLS, SD: IMPLICATIONS FOR THE TIMING AND DURATION OF SYN- TO POSTOROGENIC MAGMATISM HARK, Jessica S.1, DAHL, Peter S.1, FREI, Robert2, GHOSH, Amiya K.1, WHITEHOUSE, Martin J.3, WOODEN, Joe4, and REDDEN, Jack A.5, (1) Department of Geology, Kent State University, Kent, OH 44242, jhark@kent.edu, (2) Institute of Geography and Geology, University of Copenhagen, Øster Voldgade 10, Copenhagen, DK-1350, Denmark, (3) Laboratory for Isotope Geology, Swedish Museum of Natural History, Stockholm, SE-104 05, Sweden, (4) USGS-Stanford Ion Microprobe Laboratory, Stanford University, Stanford, CA 94305, (5) Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, Rapid City, SD 57701-3995 The eastern margin of the Archean Wyoming craton (Black Hills, SD) records a complex history of Precambrian thermotectonism and magmatism associated with convergence, rifting, and supercontinent cycles. Establishing the timing and duration of the Harney Peak magmatic event would constrain events associated with the terminal Black Hills orogeny. Accordingly, uraniumbearing accessory minerals from western (A) and west-central (B) sample sites within the Harney Peak granite (HPG) have been spot-dated by U-Pb ion-microprobe methods. Magmatic zircon, monazite, and xenotime have yielded precise 207Pb/206Pb weighted-mean ages of 1716.8 ± 9.3 Ma (2σ, MSWD = 0.95, n = 5, location A); 1703.2 ± 2.2 Ma (2σ, MSWD = 2.1, n = 9, locations A and B); and 1695.9 ± 2.9 Ma (2σ, MSWD = 1.8, n = 6, location B), respectively. These ages are consistent with microtextural occurrences of monazite and xenotime as overgrowths on zircon. Also, diffusional Pb closure temperatures for these minerals exceed the known maximum temperatures of HPG magmatism. Therefore, we interpret our results as mineral-growth ages indicating that the southern Black Hills HPG event lasted for 23 +10 -12 Myr (or ~9-33 Myr), beginning at ~1715 Ma and ending at ~1695 Ma. This ~1715-1695 Ma interval of magmatism agrees with published ages of metamorphism, magmatism, and post-magmatic cooling in several ways. First, it neatly dovetails with local ~1750-1715 Ma 207Pb/206Pb ages of pre- to syn-HPG metamorphism and with ~1690-1300 Ma 40Ar/39Ar ages of post-HPG cooling. Second, it accounts for U-Pb magmatic ages of 1713 ± 10 Ma (monazite at Whitewood Peak) and 1718 ± 22 Ma (zircon at Crook Mountain) also evident in northern Black Hills granites. Third, the ~23 Myr interval of HPG magmatism inferred here agrees within error with a ~14 Myr interval documented for the Laramide Tuolumne granitoids (CA), suggesting that the general duration of culminating magmatism in collisional orogens is on the order of ~10-20 Myr. 24-3 8:40 AM Bauer, Robert L. 9:00 AM Allard, Stephen T. [171678] RETHINKING THE PROTEROZOIC ASSEMBLING OF THE NORTH-CENTRAL US ALLARD, Stephen T., Department of Geoscience, Winona State University, P.O. Box 5838, Winona, MN 55987, sallard@winona.edu The crystalline core of the Black Hills (BH) uplift exposes Precambrian rocks near the TransHudson Orogen (THO) where it is “truncated” by the Central Plains Orogen (CPO). Although this geometry is consistent with continental reconstructions interpreting the CPO as younger than the THO, structural orientations and age relationships identified in the BH support north-south compression prior to east-west suturing. This research investigates a basement-involved shearing event interpreted as final suturing of the Wyoming (WP) and Superior (SP) provinces and draws ties to similar-age deformation in the WP as far west as the Laramie Mountains. Proterozoic rocks in the east-central BH and Archean basement in the Little Elk Terrane, northeast BH, both contain NW-trending shear zones indicating east-side up, left-lateral transpression. In both study areas shear fabrics are coupled with folds oriented parallel to the shear fabric with hinge lines parallel to shear lineations. Reconnaissance work between field sites identified several locations with similar folds and shear fabrics supporting a connection between the two. Identification of a NW-striking shear zone with similar shear sense along the Archean-Proterozoic contact in the Bear Mtn Terrane, western BH, suggests the basement-involved shear event affected rocks along both eastern and western margins of the uplift. The structures described above postdate regional ENE-trending recumbent folds (ca. 1785) and subsequent NNW-trending upright folds and associate metamorphism (ca. 1750 Ma), and in the east-central BH predate intrusion of the post-tectonic Harney Peak Granite and associated metamorphism (ca. 1715 Ma). Timing for this event is similar to shearing in the Hartville Uplift, (ca. 1714) as well as post Cheyenne Belt (CB) deformation in the Eastern Laramie Mountains (ca. 1722). Therefore, I propose the Green Mountain Block, south of the CB in WY, extends eastward at least to the BH and was attached to the WP prior to the WP—SP suturing. 24-5 9:20 AM Nabelek, Peter [171697] TECTONIC IMPLICATIONS OF PALEOPROTEROZOIC MAFIC ROCKS IN THE BLACK HILLS, SOUTH DAKOTA NABELEK, Peter, Dept. of Geological Sciences, University of Missouri, Columbia, MO 65211, nabelekp@missouri.edu and VAN BOENING, Angela, Department of Geography and Geology, University of Nebraska-Omaha, Omaha, NE 68182 Metamorphosed mafic to intermediate intrusions and flows that occur in the Precambrian core of the Black Hills served to establish the tectonic settings of magmatism during the early Proterozoic history of the region. The rocks define at least two distinct tectonic settings of magmatism between 2480 and 1880 Ma. The 2.48 Ga Blue Draw intrusion, located on the eastern edge of the Precambrian core, has compositions ranging from gabbro to granodiorite. It is a calc-alkaline pluton with SiO2 from 51.8 to 60.5 wt.% and K2O >1 wt.%. REE patterns are slightly concave upward with LREE enrichment. The intrusion is also enriched in Ba, Rb, Th, and Zr. The geochemistry is typical of modern calc-alkaline rocks and is similar to the neighboring, 2.56 Ga Little Elk granitegneiss. These two intrusions indicate the presence of late Archean/early Proterozoic arc magmatism on the eastern margin of the Wyoming craton. The other mafic rocks occur within sequences of deep marine sediments. Published U–Pb zircon ages are between 2.01 and 1.88 Ga. In the Mt. Rushmore and Pactola Dam quadrangles and near Bear Mountain, these rocks have slightly depleted to enriched tholeiitic compositions with SiO2 ~50 wt.%, K2O generally <0.5 wt.%, and flat to slightly light-enriched REE patterns. The chemical characteristics of these two suites point to E-MORB-type magmatism that characterizes present-day plume-related magmatism at oceanic spreading centers. A mantle plume source is especially evident in the composition of mafic rocks in the Rochford district. They have LREEenriched patterns, have the highest TiO2 concentrations, typically >2.5 wt.%, and the lowest SiO2 concentrations, typically <50 wt.%. They also have the highest Nb/Yb and Ta/Yb ratios and are relatively depleted in Y. With the Bear Mountain and Rushmore–Pactola suites, the Rochford suite provides evidence for rifting of the crust over a mantle plume that has produced a submarine spreading center. This plume-related magmatism in the Black Hills was apparently coeval with 2.01 Ga basic magmatism in southeastern Wyoming and together these locations indicate an extended presence of a mantle plume under the eastern Wyoming craton at this time. The plume may have led to the break-up of the previously proposed paleocontinent Kenorland. [171946] MULTIPHASE PROTEROZOIC REWORKING OF THE SOUTHEASTERN MARGIN OF THE WYOMING ARCHEAN PROVINCE IN THE CENTRAL LARAMIE MOUNTAINS, WYOMING BAUER, Robert L., Geological Sciences, University of Missouri, 101 Geological Sciences Bldg, Columbia, MO 65211, bauerr@missouri.edu, TOMLIN, Kenneth, Missouri Department of Natural Resources, P.O. Box 176, Jefferson City, MO 65102-0176, and GOERGEN, Eric, Geological Sciences, Brown University, Geochemistry building room 030, Providence, RI 02912 Archean granitic gneiss and supracrustal rocks of the central Laramie Mountains, along the southeastern margin of the Wyoming Archean province, preserve a complex history of Paleoproterozoic and Mesoproterozoic reworking. Evidence for the timing of the deformation comes from deformation fabrics and features in ca. 2000 Ma mafic dikes of the Kennedy dike swarm that intruded the Archean rocks during rifting of the SE margin of the Wyoming province. Three major Proterozoic events are recorded in the dikes and their host Archean rocks, which are correlated here with the Trans-Hudson orogeny, the Medicine Bow orogeny (Cheyenne Belt suture), and the emplacement of the Laramie Anorthosite, respectively. Deformation associated with the events overprints Archean deformation, lumped as D1, and includes: 1) D2 - E-W shortening that produced upright, dominantly Z-symmetry folds and a southerly plunging L to LS fabric, 2) D3 - NW-SE shortening that reoriented and locally folded and crenulated the earlier fabrics and dikes, and 3) D4 - recumbent to open folding of earlier features along the northern and western margins of the Laramie Anorthosite complex (LAC). All three of the Proterozoic phases of deformation are superposed in interlayered gneiss and supracrustal rocks in the area north of the Elmers Rock greenstone belt (ERGB), and to the northwest of the Red Mountain syenite of the LAC. In this area, mafic dikes with a strong L2 fabric are folded by F3 folds, and contain an S3 crenulation foliation. The dikes and associated F3 folds are refolded across a broad F4 synform that formed above the northwestern margin of the Red Mountain syenite. Deformation fabric-porphyroblast relationships in pelitic schist in the ERGB indicate that each of the three events occurred at distinctly different metamorphic pressures. D2 deformation was accompanied by kyanite, D3 produced sillimanite and cordierite replacing staurolite, and D4 andalusite occurs in the contact zone of the LAC. 24-4 24-6 9:40 AM Jones, Daniel S. [171687] IS THE CHEYENNE BELT THE MAZATZAL DEFORMATION FRONT?: EVIDENCE FOR REACTIVATION OF THE CHEYENNE BELT AT ~1.65–1.63 GA JONES, Daniel S., Dept. Geology and Geophysics, Univ. of Wyoming, Laramie, WY 82071, dsjones@uwyo.edu, PREMO, Wayne R., U.S. Geol Survey, MS 980, P.O. Box 25046, Denver Federal Center, Denver, CO 80225, MAHAN, Kevin H., Geological Sciences, University of Colorado-Boulder, 2200 Colorado Ave, Boulder, CO 80309, and SNOKE, Arthur W., Dept. Geology and Geophysics, Univ of Wyoming, Laramie, WY 82071 Several lines of evidence suggest that the Cheyenne belt in the Sierra Madre, Wyoming, was reactivated by thrusting at ~1.65–1.63 Ga. New geologic mapping shows that the ~1.65–1.63-Ga pegmatitic white quartz monzonite (WQM), originally mapped as a small intrusive body of uncertain tectonic affinity actually pervasively intrudes the 1.78–1.75- Ga, high-grade Big Creek Gneiss. Foliation in the Big Creek Gneiss was folded during ~N–S shortening under upper amphibolitefacies conditions prior to intrusion of the WQM. SHRIMP analyses document widespread metamorphic zircon growth in the Big Creek Gneiss at ~1.63–1.60 Ga. WQM samples have εNd(1630 Ma) (+2.4 to -1.0) intermediate between the older rocks of the Big Creek Gneiss (+3.7 to -0.1,) and Barber Lake block (-2.2 to -6.2; Ball and Farmer, 2001). Electron-microprobe analyses of medium- to high-Y monazite growths, attributed to garnet breakdown, yield Th-U-total Pb dates of 1636–1614 Ma. These observations are consistent with contractional tectonism at or before ~1.63 Ga. In this model, thrusting of the Big Creek Gneiss over the Barber Lake block resulted in melting to produce the WQM, by tectonic thickening and/or strain heating. According to this new interpretation, the Big Creek Gneiss constituted the hanging wall in this contractional system and experienced synchronous folding and thrusting before the widespread emplacement of numerous bodies of pegmatitic WQM. These pegmatites and their associated silica-rich fluids resulted in widespread metamorphic zircon growth in the Big Creek Gneiss. Garnet became unstable at post-exhumation pressures and partially decomposed in the presence of added fluid, producing monazite growth in paragneiss. If correct, this contractional deformation constitutes a newly recognized period of Paleoproterozoic orogenesis in the region, following the ~1.75-Ga Medicine Bow orogeny (Chamberlain, 1998) and preceding ~1.60-Ga greenschist-facies cataclastic faulting (Duebendorfer et al., 2006). The simplest interpretation is that it represents foreland deformation associated with the Mazatzal orogeny. This interpretation, together with that of workers in the Lake Superior region (Holm et al., 1998), suggests reactivation along the length of the southern Archean-Proterozoic boundary in the late Paleoproterozoic. 2010 GSA Rocky Mountain Section Meeting 47 SESSION NO. 25 SESSION NO. 25, 10:20 AM Friday, 23 April 2010 T5. Laramide Tectonics and Stratigraphy of the Northern Rocky Mountains and Great Plains Rushmore Plaza Civic Center, Alpine Room 25-1 10:20 AM Erslev, Eric A. 25-4 [171791] MULTIPLE AGES AND ORIGINS OF EXTENSIONAL FRACTURES IN THE ROCKY MOUNTAINS ERSLEV, Eric A., Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, erslev@warnercnr.colostate.edu, GILLETT, Cyrus, BP America, Houston, TX 77079, THOMPSON, Ryan C., EnCana Oil & Gas (USA) Inc, Denver, CO 80202-5632, and ALLEN, Cody Lee, Department of Geosciences, Colorado State University, Fort Collins, CO 80523 Both shear (faults) and extensional (joints) fractures provide critical tests of tectonic hypotheses and solutions to industry problems related to reservoir anisotropy. Our industry-supported fracture studies show complex patterns indicating multiple fracture mechanisms and stages in the Rocky Mountains. Early NE- to E-striking, syn- to late-Laramide joints are typically partially to totally sealed with vein-fill mineralization. They strike sub-parallel to uni-directional Laramide compression directions defined by over 20,000 minor fault measurements, which indicate an average horizontal compression trending N67E-S67W. This orientation is nearly perpendicular to average Laramide basement-cored arch and secondary fold trends, indicating formation by splitting during thrustdominated Laramide deformation. Sets of younger, roughly NW-striking joints cut rocks as young as Miocene, and thus post-date Laramide deformation. Some NW-striking joint sets cross-cut Laramide folds, consistent with NE-SW post-Laramide regional extension. Associated post-Laramide normal and strike-slip faults show N-S to NE-SW extension, commonly reactivating pre-existing faults with oblique slip. Other joint sets parallel thrust-faulted arch margins, indicating localized post-Laramide back-sliding on Laramide master thrusts, especially those with more E-W strikes. Locally, these joints are consistent with current day stresses, paralleling modern SHmax from drilling-induced fractures and microseismic studies. Joints adjacent to folded arch margins and major river drainages are more difficult to understand. They may be generated by unfolding of continental lithosphere due to isostatic and erosional unloading. Continued research to define the patterns and mechanisms of jointing is needed to successfully predict subsurface permeability anisotropy in conventional and resource petroleum plays. 25-2 10:40 AM Cooper, Scott P. [171681] FRACTURE PATTERNS ASSOCIATED WITH LARAMIDE ANTICLINES COOPER, Scott P. and LORENZ, John C., Enhanced Oil Recovery Institute, University of Wyoming, 1000 E. University Ave, Department 4068, Laramie, WY 82071, scott@ fracturestudies.com Outcrop and core fracture data from formations that have been folded to different degrees above Laramide thrust structures in Wyoming suggests that idealized fracture models can be constructed but that local variations are common. Inherited F0 fracture patterns unrelated to folding are present in some structures. Fold-related extension fractures trend approximately normal (F1) and parallel (F2) to the axis of folding. Hinge-normal F1 extension fractures typically formed in response to horizontal stress prior to uplift and prior to the hinge-parallel F2 fractures that formed during folding. Areas on anticlines that were not significantly folded, i.e., relatively planar backlimbs, contain only the early, F1 fractures. This fracture set can strike oblique to the hinge in anticlines where the stress orientation that caused both folding and fracturing was oblique to the inherited basement structure that dictated the hinge trend of the anticline. Outcrop data from tightly folded structures; such as Beer Mug anticline, with a near-vertical forelimb, and backlimb dips up to 50 degrees, indicate that the entire exposed sedimentary package is cut by numerous intersecting fractures. Fractures of all three sets (F0, F1, and F2) were locally reactivated in both shear and extension as folding intensified. Some fractures also formed originally as shear fractures, FS. Small, complex thrust faults and shear fractures in the Alcova Limestone on the backlimb and in front of the forelimb record a horizontal compressive stress that exceeded the weight of the overburden. Knowledge of the actual fracture patterns were used to reconstruct tectonic evolution, and knowledge of likely fracture patterns can be used to model fluid flow. 25-3 11:00 AM Hamlin, Laura [171898] KINEMATIC ANALYSIS OF THE STRUCTURALLY COMPLEX, EASTERNMOST WIND RIVER BASIN USING FRACTURE CHARACTERIZATION AND 3D RESTORATION HAMLIN, Laura, Geology and Geophysics, University of Wyoming, 1000 University Ave, Laramie, WY 82071, rkennedy14@juno.com, ERSLEV, Eric A., Department of Geology and Geophysics, University of Wyoming, 705 Birky Place, Laramie, CO 82071, US Virgin Islands, and HENNINGS, Peter, ConocoPhillips The origin of the structures surrounding the eastern Wind River Basin has been problematic due to their diverse orientations. Current hypotheses explaining their diverse orientations include (1) single-stage NE- directed shortening with reactivation of some pre-existing weaknesses and (2) sequential multi-directional shortening. This study used 3D modeling and restoration with integrated fracture analysis on the southeastern margin of the Wind River Basin to determine the structural significance of these features. A better understanding of the kinematics of diversely oriented structures can be applied to improve predictions of hydrocarbon reservoir geometry and fracture characteristics in similar subsurface systems. Fracture analysis was conducted throughout the study area to characterize the Laramide and post-Laramide strain and then used to constrain stress evolution. Regional faults cutting preLaramide rocks are dominated by NW-SE striking thrust faults and E-W and NE-SW strike-slip faults, consistent with an ENE-trending regional Laramide compression. Similarly, ENE striking joint sets in pre-Laramide rocks are also consistent with regional Laramide compression. A regional NW-SE joint set occurs in most of the syn- and post-Laramide rocks. Uniform Laramide ENE-WSW shortening indicated by fracture data was successfully tested by palinspastic restoration of structures in the study area at the level of the crystalline/sediment interface. 3D restoration requires significant left-lateral slip between the southwest-verging Casper 48 2010 GSA Abstracts with Programs Arch and the east-verging Laramie Range along E-W faults bracketing Casper Mountain and the NE-SW striking Muddy Mountain fault. Also, the restoration shows a 1.5° counterclockwise rotation during NE-SW shortening of Casper Mountain during deformation. Observations during restoration of Casper Mountain suggest that it served as an accommodation block in a small transfer zone between Casper Arch and the Laramie Range during a single-stage of NE- directed shortening. Thus, this area at the intersection between Casper Arch and the Laramie Range is a transfer zone with oblique left-lateral convergence and compatible counterclockwise rotation of the Casper Mountain block. 11:20 AM Lisenbee, Alvis L. [171858] PRECAMBRIAN TEMPLATE FOR LARAMIDE STRUCTURES, EASTERN BLACK HILLS UPLIFT LISENBEE, Alvis L., Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995, alvis.lisenbee@sdsmt.edu The doubly plunging, NNW-trending Black Hills uplift is a broad arch, bound by two large monoclines on the west and a broad half dome on the east. Granite of the Wyoming Archean province underlies the western portion and the Late Proterozoic Trans-Hudson Province the east flank. Dominantly west-facing, second-order folds across the larger structure form monoclines on the west side and anticlines on the east. In the east-central portion of the uplift anticline-syncline pairs and rare east-vergent monoclines with structural relief to 300 m plunge SSE or E affecting the east-dipping panel of Phanerozoic strata. In the core of the uplift the SSE-trending “grain” of steeply dipping large faults, contacts, schistosity, and bedding of the Precambrian basement parallels strong aeromagnetic and gravity gradients. A similar geophysical pattern continues eastward in the area of Phanerozoic cover. Folds extending for many kilometers lie along some of the steepest geophysical gradients. Coincidence of Laramide fold trends with steep geophysical gradients and Precambrian structural grain imply a genetic relationship of Laramide structures over a Precambrian basement template. South of Rapid City, in areas interpreted from easterly trending geophysical anomalies to be underlain by granite plutons, east-trending, south-vergent monoclines form a linking pattern with SSE-plunging folds. An example exposed along Spring Creek shows a Precambrian fault zone reactivated by a Laramide fault. In other areas the Precambrian-Cambrian contact is folded. SESSION NO. 26, 8:00 AM Friday, 23 April 2010 Hydrogeology (Posters) Rushmore Plaza Civic Center, Rushmore H 26-1 BTH 1 Nichols, Christopher [171789] LIGHT DETECTION AND RANGING (LIDAR) USE TO DEVELOP AN ALTERNATE PROCEDURE TO CONDUCT FRACTURE ANALYSIS IN THE ROCHFORD QUADRANGLE, BLACK HILLS, SOUTH DAKOTA NICHOLS, Christopher and TERRY, Michael, Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, christopher.nichols@ mines.sdsmt.edu The past procedure for fracture analysis in the Black Hills of South Dakota has required the hand collection of numerous measurements along fracture surfaces within the area of study. Technological advances have afforded the opportunity to develop advanced methods for collecting fracture data in the Black Hills. Terrestrial light detection and ranging (LiDAR) has opened the digital and 3-dimensional realms to geologic measurement collection and analysis. The Rochford Quadrangle consists of metamorphosed Precambrian volcanic and sedimentary units. The age of these units is approximately 1.87-1.97 Ga and 2.2 Ga. These units have been folded and overturned creating steep foliations. While these orientations are well documented, a detailed fracture analysis has yet to be performed in this quadrangle. By applying the descriptive fracture analysis techniques developed by Anderson (2002) a fracture analysis has been completed by collecting hand measurements at several locations. The use of a Leica Geosystems HDS3000 LiDAR scanner is then implemented to scan outcrops and a geoprocessing model is developed to extract measurement data from the scan data. This data is compared to determine the accuracy and precision of the LiDAR method. Should the LiDAR method for collecting geologic measurements prove fruitful there are several advantageous reasons to adopt this method. Collecting the data with the LiDAR system will take about the same amount of time as collecting data by hand. An advantage is that after data collection the data can be stored for future use. This provides the ability to analyze the scans any time in the future. The scans can be looked at repetitively as needed without the need to go into the field if weather, time, or costs are a problem. Finally, if this method is adopted for all data collection then a database can be built containing Black Hills data for future use of continuing studies. 26-2 BTH 2 Witt, Dallin Christopher [171919] VOLCANOSTRATIGRAPHY OF THE DIVISADERO TUFF IN THE SIERRA TARAHUMARA NEAR ESCUELA SAN ELIAS, CHIHUAHUA, MEXICO WITT, Dallin Christopher1, SCHOENROCK, Jared K.2, BUNDS, Michael P.2, and ROBERTSON, Scott1, (1) Department of Earth Science, Utah Valley University, 800 W University Parkway, Orem, UT 84058, 10524277@uvlink.uvu.edu, (2) Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058 The Sierra Madre Occidental Volcanic Field in northwestern Mexico is one of the largest ignimbrite provinces in the world. The Jesuit Mission in Creel, Mexico has been drilling wells for Tarahumara Indian villages located on the volcanic field, but many of these wells have been unproductive. The wells sited by the mission were predominantly sited using water-witching techniques, such as dowsing rods. Previous work in the area consists only of reconnaissance mapping, in which the region was mapped as one undifferentiated 29 Ma Divisadero Tuff. Utah Valley University students and faculty traveled to Creel as part of an ongoing hydrogeologic study to aid the Mission’s well-drilling program. In order to determine which potential well sites may be productive, we mapped the volcanostratigraphy of the area around a productive well and spring near Escuela San Elias. The well is at 2460 m elevation and penetrates flat-lying, moderately welded and flattened tuff. The productive spring is at 2400 m elevation along fractures in strongly welded and flattened crystal-rich tuff. The strongly welded tuff grades upwards into the moderately welded tuff at the elevation of the well. Above the well, the tuff grades into moderately welded, slightly flattened tuff at a maximum elevation of 2498 m. We interpret the strata as a single cooling unit at least 98 m in thickness. The 50 m deep well reaches from the moderately welded central portion SESSION NO. 28 of the unit into the strongly welded base. Because the Divisadero tuff has very low matrix permeability, fracturing is considered to be a requirement for a viable aquifer. Fractures are abundant near the well, averaging over 9 fractures per meter, and the spring is located on highly fractured tuff. These observations suggest that zones of fracturing in and near the strongly welded bases of cooling units are viable locations for wells. observations made at multiple locations and at critical times also provide invaluable insights. Transparency tube estimates of suspended load are an appropriate technology for environmental monitoring and educational field exercises. 27-4 26-3 BTH 3 Thayne, Michael [171929] MAPPING OF SPRINGS TO DETERMINE FRACTURE PATHWAYS FOR GROUNDWATER IN THE SIERRA TARAHUMARA, CHIHUAHUA, MEXICO THAYNE, Michael, NELSON HADLEY, Janae, GARCIA, Patricia K., VAN WAGONER, Marc E., EMERMAN, Steven H., BUNDS, Michael P., and BRADFORD, Joel A., Department of Earth Science, Utah Valley University, 800 W. University Parkway, Orem, UT 84058, m_thayne@me.com The objective of this ongoing hydrologic survey is to improve the success rate of the Tarahumara Children’s Hospital when drilling wells for the Tarahumara Indians in the Sierra Tarahumara volcanic tuff region of Chihuahua, Mexico, near the village of Creel. Currently wells are sited only by “water witching,” each well requires about $5000 to be raised through charity, and about half the resulting wells are dry. In October 2009, Utah Valley University students and faculty mapped 24 developed springs, 33 undeveloped springs, two producing wells, and five dry wells. This greatly expanded the data set of six developed springs, eleven producing wells, and seven dry wells, collected by UVU students and faculty the previous year. Of the 30 mapped developed springs, nine are known to produce water year-round, while the remainder become dry by the end of the dry season (winter and spring). Using these data, a map was created using ArcGIS 9.3 to indicate regions of high and low groundwater potential. The primary data for the map are the locations of springs and producing wells, which define fracture pathways for groundwater, as well as locations of dry wells, which indicate the absence of fracture pathways. The fracture pathways defined by the springs and producing wells are well-correlated with the fracture traces as seen on aerial photographs. There do not seem to be additional fracture pathways defined by springs and producing wells that cannot be correlated with fracture traces. Sedimentation, Stratigraphy, and Geomorphology (Posters) Rushmore Plaza Civic Center, Rushmore H Miller, Matthew BTH 5 Fandrich, Joe W. [171745] [171667] AQUAVORTEX: A MODEL FOR THE FORMATION OF CERTAIN PIPE STRUCTURES NEAR THE PermoTriassic BOUNDARY IN SOUTHERN UTAH FANDRICH, Joe W., Department of Environmental and Physical Science, Mesa State College, 2415 Desert Meadows Court, Grand Junction, CO 81505, joefandrich@hotmail.com The sandstone/siltstone facies of the Hoskinnini Member of the Triassic Moenkopi Formation in southern Utah and northeastern Arizona contains a variety of exotic breccias, graded beds, soft-sediment deformation and clastic pipe structures interspersed within redbed sabkha deposits. Certain clastic megapipes in-filled from above and exhibiting evidence of rotation are described in this investigation. These pipes, associated breccias and soft-sediment deformation structures support an extreme and complex high energy event horizon situated between undisputed Triassic and Permian beds where the boundary disconformity represents an approximate hiatus of three million years. The western edge of the sabkha facies of the Hoskinnini Member appears to represent the western shoreline of Pangaea. It is proposed here that the unusual, vertically injected clastic megapipes were excavated and in-filled by massive water charged vortices generated by eastward onset tsunami originating in the late to end-Permian Panthalassa Sea. 27-3 BTH 6 Shurr, George W. [171696] TRANSPARENCY MEASUREMENTS IN A PRAIRIE STREAM--THE KANARANZI CREEK OF SOUTHWESTERN MINNESOTA AND NORTHWESTERN IOWA SHURR, George W., GeoShurr Resources, LLC, 1803 11 St, Ellsworth, MN 56129, george@geoshurr.com Transparency measurements are an inexpensive and efficient way to estimate suspended load in the field. Programs that use a transparency tube can be tailored to conditions in distinct stream reaches and mobilized in response to specific discharge events. During 2007, 2008, and 2009 more than 600 individual transparency measurements were made at eight separate locations distributed along a 15 mi (24 km) portion of Kanaranzi Creek. The resulting profiles illustrate an upstream increase in transparency consistent with an upstream decrease in suspended load. However, one particular profile has an anomalous upstream decrease in transparency that is the expression of a 2 in (5cm) rainfall event in the headwaters area. Similarly, discharge variations in response to the 2007 spring runoff and to more than ten individual rainfall events, are associated with transparency values that correlate with water level measurements. Numerical modeling and remote instrumentation are useful high tech tools for fluvial geomorphology. However, simple Structural Geology, Tectonics, and Petrology (Posters) Rushmore Plaza Civic Center, Rushmore H 28-1 EVIDENCE FOR EOLIAN DEPOSITION AND DUNE EVOLUTION IN TWO UNDESCRIBED SECTIONS OF THE UNKPAPA FORMATION, BLACK HILLS, SOUTH DAKOTA DARBYSHIRE, Jane and MILLER, Matthew, Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East St Joseph Street, Rapid City, SD 57701, matthew.miller@mines.sdsmt.edu The Jurassic Unkpapa Formation is reexamined in the Rapid City, South Dakota area to determine its paleoenvironment. Two previously undescribed sections are discussed and interpreted to be dune and interdune deposits. This claim is supported by the presence of pinstriping (wind ripples), fine laminae (adhesion ripples), wedge planar cross bedding, tabular planar cross bedding, and well sorted, subrounded to rounded quartz sands of a uniform composition; all of which are criteria of eolian deposits. This work supports previous interpretations that this unit represents an ancient eolian environment. Further scrutiny of bedding reveals tabular planar crossbeds underlying wedge planar crossbeds. These structures illustrate the process of transverse dunes grading directly into barchanoid ridge dunes during the process of dune evolution. 27-2 [171809] Friday, 23 April 2010 Friday, 23 April 2010 BTH 4 Straw, Byron M. SESSION NO. 28, 8:00 AM SESSION NO. 27, 8:00 AM 27-1 BTH 7 GLACIAL AND PERIGLACIAL DEPOSITS OF THE LAKE OF THE CLOUDS CIRQUE, NEVER SUMMER MOUNTAINS, COLORADO STRAW, Byron M. and HOPKINS, Kenneth D., Department of Earth Sciences, University of Northern Colorado, 501 20th Street, Box 100, Greeley, CO 80639, Byron.Straw@unco.edu Glacial and periglacial deposits within the Lake-of-the-Clouds cirque in the Never Summer Mountains of Colorado provide a record of late Quaternary climate change. Periglacial features include a large compound tongue-shaped rock glacier on the cirque floor, as well as several smaller lobate rock glaciers and protalus ramparts located around the perimeter of the cirque. Three closely spaced terminal moraines are located on the valley floor immediately downvalley from the terminus of the tongue-shaped rock glacier. The uppermost of the three moraines is partly overlapped by the lower lobe of the compound rock glacier, while the middle and lower moraines enclose small fens on their upstream sides. Rock-weathering and lichenometric data collected at 11 stations on the periglacial deposits record three episodes of periglacial activity in post-Altithermal time. The lower lobe of the large tongue-shaped rock glacier, which is clearly pre-Altithermal in age, is likely to be of glacigenic origin and probably formed as ice downwasted during retreat from the upper moraine. Soils on the three moraines have an A/Bw/Cox profile similar to Satanta Peak soil profiles found in the adjacent Front Range. A radiocarbon date of 11,595 14C yr BP obtained from basal sediment in a core taken from the fen behind the middle moraine provides a close minimum age for the moraine and suggests that deposition of the moraine may have been coeval with the European Younger Dryas event. A 23-cm-thick peat layer in the midsection of the same core yielded a radiocarbon date of 6200 14C yr BP, and reflects a period of warmer climate and a rise of treeline before renewed cooling and periglacial activity. BTH 8 Wall, Zackary S. [171384] TRACKING THE UPLIFT OF YELLOWSTONE’S THERMAL DOME IN SW MONTANA WALL, Zackary S.1, JOHNSON, Adam C.1, and SEARS, James2, (1) Geosciences Department, University of Montana, 32 Campus Drive #1296, Missoula, MT 59802-1296, zkwall@gmail.com, (2) Dept. of Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812-1296 Preliminary observations suggest that there is a significant height difference between Mioceneage river terraces in southwestern Montana and similar river terraces farther north. It is hypothesized that this dissimilarity is due to an increase in fluvial incision rates corresponding to surface uplift attributed to the Yellowstone thermal dome. Commonly, the terraces are overlain by Miocene Sixmile Creek Formation and cut underlying Miocene Renova Formation. This interface, known as the Renova unconformity, represents a nearly one million year gap spanning from 17.5 Ma to 16.8 Ma and provides a consistent reference surface throughout the field area for height measurement. Active normal faulting farther south has resulted in the location of the unconformity high up in mountains as well as at the bottom of gravel-filled grabens. Mapping the elevation of this surface with respect to current river elevations will provide a structure contour map of the millionyear-spanning unconformity. Because the surface to be mapped is dated to 17Ma, any structure recorded will have occurred in the past 17 million years. Also, the stratigraphy of the Sixmile Creek Formation further constrains the start of deformation in some areas to 4Ma. Tectonic reconstruction of the field area will be completed, thus measuring fault displacement. Total surface uplift and extension will be calculated as part of the reconstruction. An integral aspect of this investigation relies on gaining subsurface control of the Renova unconformity where it is buried deep beneath the surface. To this end, existing gravity-anomaly data will be analyzed and interpreted. Multiple theories concerning the origin and migration of the Yellowstone hotspot hinge on the shape and magnitude of its thermal dome. A systematic analysis of Miocene river terrace elevation has never been performed for the area surrounding Yellowstone. If successful, this investigation will serve as a quantitative test of existing Yellowstone uplift boundaries. 28-2 BTH 9 Tarbert, Kevin D. [171723] PRELIMINARY GEOCHEMISTRY OF SAMPLES FROM YELLOWSTONE NATIONAL PARK TARBERT, Kevin D., School of Earth and Environmental Science, Washington State University, P.O. Box 642812, Pullman, WA 99164-2812, ktarbert@gmail.com and LARSON, Peter B., School of Earth and Environmental Science, Washington State University, PO Box 642812, Washington State University, Pullman, WA 99164-2812 Precambrian terrains within Yellowstone National Park consist largely of granitic orthogneisses that underlie an area of approximately 250 km2 and are exposed in the northern portions of the park. Previous mapping by others has grouped these units as one, despite variations that exist in their mineralogy. Pb isotopic ratios for Lamar Canyon gneisses have yielded intrusive ages of 2625-2700 Ma, which coincide with igneous activity throughout the region in areas such as the Eastern Beartooth Mountains to the north. Exact ages for other units in the area have yet to be determined and relative timing relies on structural and contact relationships. Preliminary data from whole rock major chemical analyses of samples collected from Lamar Canyon (L.C.), Hellroring Creek (H.C.) and Slough Creek (S.C.) indicate covariations that display smooth trends suggestive of fractional crystallization while samples collected from the Yellowstone River Trail (Y.R.T.) area display dissimilar compositions. Plotting samples from each location on an AFM diagram indicate a tholeiitic trend with SiO2 values ranging from 53-73 wt%. Alumina saturation index values vary from peralkaline to peraluminous between samples from L.C. and S.C. but are consistently peraluminous for H.C. and Y.R.T. samples. Trace element plots indicate similarities between the L.C. and S.C. gneisses but little to no relationship with the H.C. or Y.R.T. gneisses. These initial results suggest that the H.C., L.C. and S.C. may have evolved from fractional crystallization of a single magma while the Y.R.T. originated from a separate source. However, trace element plots indicate differences between the H.C. samples and the L.C. and S.C. These may be the result of incorporation of different country rock during emplacement or a desperate emplacement altogether. 2010 GSA Rocky Mountain Section Meeting 49 SESSION NO. 28 28-3 BTH 10 Johnson, Adam Collier [171918] TESTING THE BULGE: USE OF NEOGENE BEDROCK PALEO-VALLEYS TO TEST MODELS OF THE YELLOWSTONE THERMAL DOME AND RELATED DEFORMATION JOHNSON, Adam Collier, Geosciences, University of Montana, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812, adam.johnson@umontana.edu, WALL, Zackary S., Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59802-1296, and SEARS, James, Dept. of Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812-1296 Anders et al, (1989) proposed that deformation from the migration of the Yellowstone hotspot has resulted in a parabolic distribution of outward propagating seismicity centered upon the axis of the Snake River Plain. Recently, Smith et al (2009) utilized geodetic measurements to seismically image the hotspot plume in order to constrain the geographic extent of the Yellowstone thermal deformation. The study delineated a ~400- km-wide and ~500-m-high topographic dome centered on the Yellowstone Plateau. Both hypotheses place southwest Montana within the region of Yellowstone deformation. South of Great Falls, MT, the upper Missouri River and its headwater tributaries, the Madison and Jefferson, flow through the region of deformation. The modern river valleys follow Miocene half grabens containing Cenozoic valley fill (Fields et al, 1985) and a midTertiary unconformity (Barnosky, 2008). The northern limit of the field area at Holter Lake, MT, has experienced very little tectonic activity. Strath terraces exposing the unconformity are typically ~80 meters above the adjacent Holocene floodplain. Moving south towards the Madison and Jefferson River valleys, the unconformity begins to gain elevation more rapidly than the current valley profile and is disrupted by increasing numbers of normal faults. Using the Mid Tertiary unconformity as a datum surface, this study will create a structural contour map in order to measure the uplift of southwest Montana in the periphery of the Yellowstone Hotspot. 28-4 BTH 11 Bauer, Robert L. [171815] LARAMIDE REACTIVATION OF THE CLEAR CREEK FAULT, SOUTHWEST WIND RIVER BASIN, WY: EFFECTS ON LARAMIDE FOLD GEOMETRIES ALWARD, William S. and BAUER, Robert L., Geological Sciences, University of Missouri, 101 Geological Sciences Bldg, Columbia, MO 65211, bauerr@missouri.edu The southwestern margin of the Wind River basin contains a series of southwest verging, left stepping en-echelon folds that fold Paleozoic and Mesozoic strata dipping off the uplifted Precambrian core of the Wind River Range. The southernmost, up-plunge extension of this Laramide fold sequence can be subdivided into two structurally distinct zones, one to the north of the ENE-trending Clear Creek fault (CCF) and a second to the south of the CCF. The northern zone contains Sheep Mountain anticline (ShMA), a SW vergent structure that plunges shallowly toward ~N15°W. This fold is similar in geometry and structural orientation to other Laramide folds that extend northward along the basin-margin fold trend. Folding of ShMA is interpreted to be controlled by a blind basement-involved thrust with a vertical throw of ~190 feet. Conversely, the southern structural zone includes fundamentally different fault and fold orientations and overall fault displacements. The southern zone contains the Schoettlin Mountain anticline (ScMA), which is a variably plunging, ENE-WSW trending, basement cored anticline that is bounded to the south by the Beaver Creek thrust (BCT). The complex fold geometry associated with this fold is interpreted to be the result of fault-related folding along the BCT. In contrast with the structural orientation of ShMA and other Laramide features of the area, both the ScMA and the BCT trend dominantly E-W. Furthermore, fault displacement to the south of the CCF along the BCT is substantially larger, with an estimated vertical throw of ~3,000 feet. The clear boundary between the two structural zones, the CCF, is a steep southerly dipping, ENE-WSW trending regional reverse fault with south-side-up displacement. However, the CCF extends well to the southwest of the study area and deforms the Precambrian core of the Wind River Range in the South Pass area (NW of highway 28), where the fault exhibits a south-side-down sense of offset. Due to the observed reversal in fault-offset sense between the two locations, the CCF is interpreted to be a pre-existing discontinuity, reactivated in Laramide time. We attribute the fundamental change in Laramide fault and fold orientations and overall fault displacements between the two structural zones to stress perturbations produced during reactivation of the CCF. 28-5 BTH 12 Tielke, Jacob A. [171926] EXAMINING THE PALEOSTRESSES RESPONSIBLE FOR THE BLACK HILLS UPLIFT THROUGH ANALYSIS OF CALCITE DEFORMATION TWINS USING ELECTRON BACKSCATTER DIFFRACTION TIELKE, Jacob A.1, TERRY, Michael P.1, and LISENBEE, Alvis L.2, (1) Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, jacob.tielke@mines.sdsmt.edu, (2) Department of Geology and Geological Engineering, South Dakota School Mines & Technology, 501 E Saint Joseph St, Rapid City, SD 57701-3995 To study the nature of the Laramide uplift in the Black Hills, South Dakota, a method is being developed to determine the orientations and magnitude of paleostresses from calcite deformation twins using electron backscatter diffraction. Compared to traditional methods for calcite deformation twin paleostress analyses, this method has the potential to produce more accurate results in less time. Under low pressure and temperature, calcite deformation twins form intracrystalline twin lamella on the {01-12} planes. Twinning occurs when the resolved shear stress acting along each {01-12} plane exceeds the yield stress value for twinning (~10 MPa). Combination of the relationships of crystallographic orientations and the yield stress value can be used to calculate a deviatoric stress tensor from deformed calcite crystals. Preliminary analyses from orientation image maps of deformed calcite crystals show misorientation angles of ~78 degrees between the host and twin lamella crystal lattices about the {01-12} planes. This angle is consistent with calcite deformation twinning and will be the foundation for development of the method. In order to place the project in a meaningful structural context, a detailed study was conducted in Wind Cave National Park, South Dakota. Fieldwork was carried out though the National Park Service and South Dakota Geological Survey during summer 2008 and summer 2009 and included 1:12,000 scale mapping of surface geology, recording structural data for analyses, and collecting samples for laboratory analyses. By integrating structural data with deformation twin data, the goal to constrain the orientation and magnitude of paleostresses that caused the Black Hills uplift. 50 2010 GSA Abstracts with Programs SESSION NO. 29, 8:00 AM Friday, 23 April 2010 T2. Structural and Tectonic Evolution of the Proterozoic Trans-Hudson–Archean Wyoming Province Boundary (Posters) Rushmore Plaza Civic Center, Rushmore H 29-1 BTH 13 McCormick, Kelli A. [171708] TERRANE MAP OF THE PRECAMBRIAN BASEMENT, SOUTH DAKOTA MCCORMICK, Kelli A., South Dakota Geological Survey, 2050 W. Main St, Suite 1, Rapid City, SD 57702, kelli.mccormick@state.sd.us The terrane map of the Precambrian basement presented here is based on a compilation of South Dakota well and test-hole data, the contour map of the Precambrian surface of South Dakota, existing geophysical data (magnetic and gravity data), previously published basement maps of South Dakota and surrounding states, and published radiometric dates. New interpretations from this study include the concept that the Wyoming boundary zone in and around South Dakota can be separated into three domains: the Cedar Creek domain, the Black Hills domain (only partially equivalent to the Black Hills domain defined by previous workers), and the Hartville domain. A new terrane, the Williston domain, is identified just east of the Cedar Creek domain. Finally, a new designation, southern Dakota domain, is proposed for terrane just north of the Yavapai suture. The southern Dakota domain encompasses the southern part of the state west of the Black Hills domain, including the region of low gravity in south-central South Dakota and the strong positive magnetic anomaly that penetrates the Superior boundary zone to the east. The southern Dakota domain is interpreted to be a magmatic terrane developed at the terminus of the southern Trans-Hudson orogen, composed mainly of volcanic centers and associated deposits and intrusions. This terrane is thought to have formed principally through modification of Trans-Hudson internides by the Yavapai orogeny. 29-2 BTH 14 Schmidt, Chris [171850] CHARACTERIZING A PROTEROZOIC LEUCOGRANITE WITHIN THE ARCHEAN LITTLE ELK TERRANE, BLACK HILLS S.D SCHMIDT, Chris and ALLARD, Stephen T., Department of Geoscience, Winona State University, P.O. Box 5838, Winona, MN 55987, crschmid9080@winona.edu The Little Elk Terrane (LET) is a window into the Archean basement in the NE margin of the Black Hills. Currently the Archean rocks are split into two units; the Little Elk Granite (LEG) and the Biotite-Feldspar Gneiss (BFG). Field mapping in the LET identified several small discontinuous bodies of post-tectonic leucogranite in both Archean units. This magmatism may be key to understanding the relationship between the LEG and BFG and the timing of shearing recognized across the LET. This research focused on two questions related to this leucogranite; 1) is there a structural element controlling granite locations, and 2) are all exposures of leucogranite from a single source or multiple sources. To answer these questions my research compared the host rock lithology and structural characteristics, and characterized the mineralogical variation for the granite at each granite location. The leucogranite cross-cuts both the BFG and LEG and commonly form sill-like bodies parallel to the NW-striking mylonitic fabric. In hinge areas where the fabric is folded to NE striking and overprinted by a younger NW-striking fabric, it is found intruding parallel to either or both. Therefore, the fabrics control the granite body’s shape, pre-existing structures do not control where in the LET the melt migrated and recrystallized. Thin section analysis of ten granite samples from across the LET compared mineralogic criteria to determine if a single source for the melt is possible. These included; 1) modal abundances for major minerals 2) plagioclase An content, and 3) accessory minerals. All samples contained similar amounts of quartz, and feldspars, but biotite showed minor variation in mode. Preliminary Anorthite content estimated using the Michel-Levy method are similar in all samples and at present no accessory minerals have been identified. Because biotite was scarce and disseminated in samples collected interior to melt bodies, and present as schlieren in samples collected proximal to the host rock, we interpret this variation a result of contamination by the host rock, not a source differences. Although not conclusive, we found no evidence to suggest more than one source for the melt. Therefore, we interpret a single post-tectonic intrusion for all the discontinuous bodies across both lithological units during a single melting event. 29-3 BTH 15 Chasten, Lindsay E. [171914] EPISODES OF MONAZITE GROWTH FROM THE HOMESTAKE IRON FORMATION, LEAD, SOUTH DAKOTA, U.S.A CHASTEN, Lindsay E. and TERRY, Michael P., Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, lindsay.chasten@ mines.sdsmt.edu Several generations of Proterozoic monazite from the Homestake Iron Formation in the Black Hills reveal different textures and correspond to distinct tectonometamorphic events. Monazite was investigated from samples taken across the Homestake mine, now the site of the Deep Underground Science and Engineering Laboratory (DUSEL), which represent a range of metamorphic conditions. Monazite was identified with petrographic and scanning electron microscopy, then X-ray chemical maps were generated, and the resulting identified domains were U-Th-Pb dated with the Ultrachron electron microprobe. Abundant grains are associated with ~1775 Ma Yavapai collision and the ~1750 Ma southern Trans-Hudson Orogen (THO) events. In one thin section, these ages occur in small grains with high-Y cores and low-Y rims, or large complex grains displaying irregular Th patterns. A reaction from allanite to monazite is preserved in garnet, yielding an age of 1757 ± 30 Ma. Another complex grain contains an older, ~1850 Ma high-Y core within a low-Y D2-age rim. Textures become well-zoned in Th and Y in monazite from another section, which also gives these D1 and D2 ages, along with a younger ~1670 Ma age. This age is repeated in another grain and may correspond to regional D5 deformation. Monazite from a lower-grade, more westerly sample contains such low-Th cores that are undatable at present, but some display zonation patterns within cores which may indicate more than one episode of growth. Thin, higher-Th rims allow dating and yield ~1300 and ~1200 Ma ages that are uniquely young for Black Hills monazite. These may be due to formation in the lower-temperature stability range of monazite that occurred during the slow cooling of the Black Hills. SESSION NO. 30 29-4 BTH 16 Matzek, Carl D. [171930] A QUANTITATIVE STUDY TO DIFFERENTIATE SIMILAR GNEISSES IN THE ARCHEAN LITTLE ELK TERRANE, BLACK HILLS, SOUTH DAKOTA MATZEK, Carl D., Geoscience, Winona State University, PO Box 5838, Winona, MN 55987, cdmatzek9471@winona.edu and ALLARD, Stephen T., Department of Geoscience, Winona State University, P.O. Box 5838, Winona, MN 55987 The Little Elk Terrane (LET) in the northeastern boundary of the Black Hills contains one of only two exposures of Archean basement rocks in the hills. Currently the LET is subdivided into three lithologic units that include two Archean-aged crystalline basement units and one Proterozoic-age metasedimentary unit. The Archean rock units include the Biotite Feldspar Gniess (BFG) and the Little Elk Granite (LEG). The LEG is a coarse-grained granite rich in feldspar and the BFG is a biotite gneiss with coarse-grained feldspar augen. Two criteria commonly used to distinguish the two are; coarser-grained feldspar in the LEG and greater abundance of biotite in the BFG. Recent mapping by WSU students in the LET raises concerns about the location of the previously mapped BFG-LEG contact. In some exposures mapped as LEG, the rocks are extensively sheared and appear very similar to the BFG due to grain-size reduction in the feldspar and an increase in biotite that occurred during shearing. This makes distinction of these two units very difficult in many outcrops. The goal of this project was to define quantitative criteria that will allow the classification of the two units in order to define better the contact location. Two independent methods were employed. The first will compare feldspar size by measuring individual grains with a millimeter scale and calculating the area using an ellipse formula. The second will look at variations in biotite abundance, and separation between biotite foliation. A size vs. frequency graph shows that BFG samples have grains smaller than 1.5 mm2 with greater than 30% biotite. LEG samples have grains larger than 5mm2, with a majority greater than 10mm2, and contain less than 20% biotite. Some data are transitional and plot between the BFG and LEG end members, with grain size decreasing corresponding with biotite percentage increasing. Additionally, one sample collected from a 30 cm wide shear band in an outcrop of irrefutable LEG is indistinguishable from the BFG using these criteria. We interpret these findings to suggest that the BFG may well be sheared LEG and the “transitional” samples demonstrate varying strain amounts between the typical LEG and BFG. 29-5 BTH 17 Jordan, Brennan T. [171959] GEOCHEMISTRY AND TECTONICS OF THE YATES UNIT OF THE POORMAN FORMATION (DUSEL BEDROCK) IN THE CONTEXT OF OTHER NORTHERN BLACK HILLS AMPHIBOLITES JORDAN, Brennan T., Department of Earth Sciences, University of South Dakota, 414 E. Clark Street, Vermillion, SD 57069, brennan.jordan@usd.edu and TERRY, Michael P., Department of Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701 The Early Proterozoic (~2012 Ma) Yates unit of the Poorman Formation is an amphibolite in the northern Black Hills, exposed near Lead, SD. The planned Deep Underground Science and Engineering Laboratory (DUSEL) will be constructed primarily in this unit. The geochemistry of a new suite of surface samples of the Yates unit is considered, from an igneous perspective, in the context of previous data from Homestake Mine drill core (from the 6800’ level), new surface samples from other northern Black Hills amphibolites, and data from an overlapping study to the south by Van Boening & Nabelek (2008: Precamb. Res. 167). The data was filtered to focus on samples whose normalized major element compositions resembled mafic lavas. Meeting imposed criteria were 11/18 Yates surface samples, 52/104 core samples, and 48/55 regional samples. Omitted samples have compositions reflecting metamorphic modification or cumulate, volcaniclastic, or sedimentary protoliths. The surface Yates unit suite has bulk compositions of primitive to moderately evolved (12.3-6.0 wt% MgO) tholeiitic basalts. The upper ~275 m of the core is geochemically similar with a broader compositional spectrum. The lower ~350 m of the core is compositionally distinct with higher TiO2 and P2O5. The surface Yates samples are slightly LREE-depleted and plot in the N-MORB fields of many tectonic discrimination diagrams (Nb-Zr-Y, Th/Yb-Nb/Yb, etc.). Based on fewer trace elements, the upper portion of the Yates core is broadly similar, but the lower Yates core is distinctly enriched in incompatible elements and plots in E-MORB to OIB fields on discrimination diagrams. Regionally, the upper Yates unit is more like N-MORB than any other Black Hills amphibolites. Possibly correlative samples to the south transition to E-MORB compositions. Amphibolites in the Rocheford, SD area are up to 130 m.y. younger and have an OIB affinity. The lower Yates unit may reflect an early phase of continental rifting, with or without mantle plume influence. The strong N-MORB signature of the upper Yates suggests a mature rift. Apparent spatial variations between correlative units could reflect rift architecture or a variation in plume influence, though temporal variation cannot be ruled out. The OIB signature of the younger Rochford rocks may reflect renewed rifting or plume interaction. 29-6 BTH 18 Terry, Michael [171968] KINEMATIC ANALYSIS OF STRUCTURAL FABRICS ASSOCIATED WITH BLACK HILLS OROGENY AND THEIR TECTONIC IMPLICATIONS FOR THE SOUTHEASTERN MARGIN OF THE WYOMING CRATON TERRY, Michael, Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, michael.terry@sdsmt.edu The Black Hills Orogeny (~1750-1795 Ma) produced the dominant NNW structural fabric in the Black Hills Precambrian core. The age of this fabric forming event is well constrained by monazite growth at ~ 1750 Ma. This event culminated in emplacement of the Harney Peak Granite that occurred from ~1715-1695 Ma. Careful structural analysis in four different areas including the Lead window, the Stratobowl area, Bear Mountain Dome, and Custer State Park allow the kinematic evolution to be better understood. Strain partition In the Lead window, show a progression of structures related to the Black Hills orogeny, including shallowly to moderately plunging, tight to isoclinal folds with associated NW striking east dipping axial planar foliation. These structures are locally overprinted by steeply east plunging fold and NNW striking axial planar foliation that is very steeply dipping associated with high strain zones. Regionally, these events have been referred to as D2 and D3 deformation events. Kinematic indicators including gash veins and fish structures show both east-side-up and left-lateral shear senses associated with D3. Spectacular examples of D3 high strain zones are observed in the Stratobowl area. These discrete shear zones crosscut D2 structures and have calculated offset of 80 meters. At Bear Mountain, microstructural studies indicate both top-to-the-north and west-side-up shear sense associated with doming or D4 structures in a shallowly east dipping foliation. In Custer state park on the SE margin of the Harney Peak Granite, deformed granite dikes indicate a top-to-the-NNW sense of shear. The kinematic observations when combined with known metamorphic conditions suggest a transpressional orogeny event that involved: 1) Dominantly left-lateral shearing associated with a shallow to moderately plunging stretch. 2) Increased shortening associated vertical stretch and the initiation of doming and decompression. 3) Continued left-lateral shearing and top-to-the-north over during granite and pegmatite intrusions. 29-7 BTH 19 Morton, Patrick [171917] CRYSTALLOGRAPHIC FABRICS OF QUARTZ IN THE ELLISON FORMATION: INSIGHTS ON DEFORMATION MECHANISMS AND METAMORPHIC CONDITIONS AT THE DEEP UNDERGROUND SCIENCE AND ENGINEERING LABORATORY (DUSEL) AT HOMESTAKE, SD MORTON, Patrick, Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, patrick.morton@mines.sdsmt.edu and TERRY, Michael, Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701 Quartz lattice preferred orientation (LPO) patterns have been used to study plastic deformation in the crust. Electron backscatter diffraction (EBSD) with the scanning electron microscope is a powerful method for measuring LPOs. The Homestake gold deposit in the Black Hills of South Dakota is hosted by a package of Proterozoic marine metasediments and metavolcanics, including the Homestake formation and superjacent Ellison formation. The surface trace of a garnet isograd intersects the deposit area on the western limb of the Lead Anticline. This isograd marks the transition zone from greenschist facies in the western anticlinorium to amphibolite facies in the east; the isograd and transition zone strike approximately N 20º W, have near vertical dips and parallel a major high-strain shear zone (left-lateral motion, east side up). Previous studies used garnet-biotite geothermometry and oxygen isotope data from samples across the deposit to define a steep (150 °C/km) metamorphic field gradient across the anticlinorium. We have obtained quantitative quartz LPO data from Ellison formation quartzites in order to relate LPOs to observed deformation and fabric overprinting relationships. Ten samples were taken along a 3 km W-E transect across the anticline. Samples were described as sericite-biotite-quartz phyllites/schists or as impure (e.g. biotite, muscovite, etc.) quartzites. Structural data describe NW to NE striking foliations with steep to moderately NE to SE dipping mineral aggregate lineations in the planes of foliation. Observations generally concur with previous descriptions of structural domains in the study area. Petrographic observations reveal complex microstructures that vary across the study area, reflecting original sedimentary textures and varying degrees of overprinting of deformation events. EBSD analyses of several samples have provided LPO patterns that may suggest deformation mechanisms consistent with metamorphic conditions described in previous studies, and may confirm the presence of a steep metamorphic field gradient across the anticline. SESSION NO. 30, 1:20 PM Friday, 23 April 2010 Sedimentation, Stratigraphy, and Geomorphology Rushmore Plaza Civic Center, Ponderosa Room 30-1 1:20 PM Balmat, Jennifer L. [171923] POST-LARAMIDE TECTONICS AND TECTOGENIC SEDIMENTATION IN THE BLACK HILLSPINE RIDGE REGION BALMAT, Jennifer L. and LEITE, Michael B., Physical and Life Sciences, Chadron State College, 1000 Main Street, Chadron, NE 69337, jebalm@eagles.csc.edu Preliminary mapping on the Pine Ridge near Chadron, Nebraska, indicates extensive normal faulting in Miocene-age rocks. Structural features also include small south-vergent thrusts. Previously unmapped probable upper Miocene-age cross-bedded feldspathic conglomerate and sandstones (maximum clast size 12 mm) are interpreted as tectogenic products of penecontemporaneous uplift. Crossbed dips indicate transport from the north, and angular coarse alkali feldspar clasts suggest a Black Hills origin. Rounded, finer-grained plagioclase (maximum clast size 0.5 mm) might have a different source, and are likely recycled. These lines of evidence suggest a tectonically active highland coincident with the conglomerate’s proximal source area. A proposed chronology is as follows: during the Oligocene northwestern Nebraska had been blanketed in thick volcaniclastic deposits of the White River Group. More tuffaceous and epiclastic sediments followed as mostly channel cut and fill deposits during the Miocene. The Whiteclay Gravel Beds (Ogallala Group), previously interpreted as fault-rupture fills of early Miocene age, indicate that uplift to the north began during the early Miocene. The conglomerate and faulted upper-Miocene rocks indicate that uplift continued into the late Miocene. Nearly all evidence of the contiguous Black Hills-Pine Ridge highland has been eroded by the structurally controlled White and Cheyenne rivers. Additional study of this area is needed to discover the evolving role of the Pine Ridge in the tectonics and paleogeography of the Rockies and Great Plains. 30-2 1:40 PM Rahn, Perry H. [171656] EARLY CENOZOIC DENUDATION OF THE BLACK HILLS RAHN, Perry H., Geology & Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, perry.rahn@sdsmt.edu The Black Hills was formed during the Laramide Orogeny. Uplift and erosion commenced at ~64 Ma and the landscape was eroded down to nearly the present topography by ~37 Ma. The denudation rate of the Black Hills during the early Cenozoic Era was determined by estimating the thickness of eroded rocks over this time interval. In the region of the Central Black Hills, ~2,463 m of rocks were eroded, including ~2,286 m of sedimentary strata and ~177 m of Precambrian rocks. The erosion started during the late Paleocene Epoch and lasted until the late Eocene Epoch, an interval of approximately 27 Ma. Thus the early Cenozoic denudation rate was ~0.0912 m/ka. This rate is nearly the same as the erosion rate for the early Laramide uplift determined by Lisenbee and DeWitt (1993), based primarily on stratigraphic relationships within sedimentary strata of the the Powder River Basin. A denudation model of the Black Hills uplift uses three units: MZ: ~1,836 m of Triassic to Paleocene shale and sandstone, PZ: ~450 m of Paleozoic carbonates, and P€: ~177 m of Precambrian metamorphic and igneous rocks. The relative erosion rates of the three units was estimated from the topographic relief of Black Hills drainage basins having lithologies similar to the three units, as well as rock strength and weathering characteristics. The three units have relative erosion rates of 1 : 0.311 : 0.253. Accordingly, the denudation chronology would be: ----- from 64 to 51.41 Ma, erosion of MZ, ----- from 51.41 to 41.80 Ma, erosion of PZ, ----- from 41.80 to 37 Ma, erosion of P€. The early Cenozoic denudation rate of the Black Hills is similar to the modern (albeit pre-dam) Mississippi River denudation rate, estimated at 0.096 m/ka. 2010 GSA Rocky Mountain Section Meeting 51 SESSION NO. 30 30-3 2:00 PM Wiles, Michael E. [171927] THE GEOLOGY OF JEWEL CAVE: NEW PIECES TO AN UNEXPECTED PUZZLE WILES, Michael E., Division of Resource Management, Jewel Cave National Monument, 11149 US Highway 16, Custer, SD 57730, Mike_Wiles@nps.gov Purpose Over the last 20 years, exploration and mapping of Jewel Cave, as well as geological mapping of the Jewel Cave Quadrangle, have documented several unexpected relationships between cave features and surface geology; and also within and between the Pahasapa Limestone and Minnelusa Formations themselves. This paper presents several of these observations in order to encourage further study. Results Geological mapping has identified six subunits within the Minnelusa: I) 40 feet of basal sandstone; II) 50 feet of thin-bedded limestone; III) 120 feet of sandstones; IV) 120 feet of dolomite with interbedded sandstones; V) 120 feet of medium-to-coarse grained sandstones, and VI) over 100 feet of brecciated sandstone layers. Unit thicknesses were constant throughout the quadrangle, allowing the mapping of subtle faults and folds. The folds express themselves in extensive dip-slope topography and exhibit a strong correlation between synclines and surface valleys. The most striking observation is the fact that Jewel Cave exists almost exclusively in limestone that is capped with the Minnelusa Formation. This relationship holds throughout the southern Black Hills to the point that, without exception, no cave over 200 feet in length is known to exist within uncapped limestone. Furthermore, there is no mappable paleotopographical relief within the quadrangle. Rather, evidence within Jewel Cave strongly suggested that “paleofill” developed contemporaneously with the development of the cave – after lithification of the basal Minnelusa sandstone. Finally, the only known natural entrance to Jewel Cave is located precisely at the crest of a broad anticline. General Conclusions There is a strong correlation between the passages of Jewel Cave and modern geological features. The evidence suggests that Jewel Cave formed as a result of the most recent processes that shaped the present-day stratigraphy, structure, and topography. There is virtually no evidence of a Mississippian paleokarst development. This gives pause for reevaluation of the origin of caves in the southern Black Hills. 30-6 3:00 PM Hartwick, Emily E. [170463] EOLIAN ARCHITECTURE OF SANDSTONE RESERVOIRS IN THE COVENANT FIELD, SEVIER COUNTY, UTAH HARTWICK, Emily E., Department of Geosciences, Western Michigan University, 1187 Rood Hall, 1903 W Michigan Ave, Kalamazoo, MI 49008, ehartwick@wolvgas.com The Lower Jurassic Navajo Sandstone and the sandstone of the Middle Jurassic White Throne Member of the Temple Cap Formation compose the primary reservoirs at Covenant Field in the central Utah thrust belt. Analysis of the stratigraphic and structural features identified from resistivity image logs along with core and standard electric logs permitted the definition of dune architecture and permeability anisotropy caused by crossbedding within the eolian reservoir units. Sandstone bodies are dominated by barchanoid dune types and commonly lack inter-dune deposits. Paleo-wind transport directions were calculated for the White Throne and Navajo sandstones. These directions are southwest and south-southeast, respectively, giving the two sandstones unique paleo-wind transport directions. Therefore, maximum permeability directions within each reservoir are different and must be considered for optimum well placement. Tri-axial permeability measurements indicate a horizontal to vertical permeability anisotropy ratio of 2.4 in the White Throne and 2.7 in the Navajo. The average width of individual dunes was estimated by examining the preserved dune set thicknesses in each sandstone. Average calculated dune widths for the White Throne and Navajo are 1,650 feet and 2,200 feet, respectively. Drainage ellipses were constructed using the paleo-wind transport directions, permeability anisotropy ratios, and estimated dune sizes. The validity of the drainage ellipses is supported by well interference identified from production data. Rocks previously known as the “Upper Navajo” at Covenant Field have recently been assigned to the White Throne Member of the Temple Cap Formation based on regional outcrop studies, subsurface correlations, palynology, and radiometric dating. This assignment is supported by comparing the calculated paleo-wind transport directions for the White Throne and Navajo sandstones at Covenant Field to measured Jurassic outcrop sections. The distinct lithologic and diagenetic attributes of each horizon also suggests they were deposited in different environments. SESSION NO. 31, 1:20 PM Friday, 23 April 2010 30-4 2:20 PM Anderson, Heidi [171842] ICE-PROXIMAL STRATIGRAPHY AND ACTIVE TECTONICS: AN EXAMPLE FROM SOUTHERN BOLIVIA ANDERSON, Heidi, Department of Geological Sciences, University of Idaho, PO Box 443022, Moscow, ID 83844, handerson@vandals.uidaho.edu, GRADER, George W. Jr, Department of Geological Sciences, University of Idaho, POBox 3352, Moscow, ID 83843, DI PASQUO, Mercedes, Consejo de Investigaciones Científicas y Tecnológicas (CONICET), Universidad de Buenos Aires, Departamento de Geología, Pabellón 2, Ciudad Universitaria, (C1428EHA), Buenos Aires, Argentina, and ISAACSON, Peter E., Department of Geological Sciences, University of Idaho, Moscow, ID 83844-3022 Late Carboniferous ice-proximal stratigraphy of the Peru-Bolivia master basin records a carbonate setting in the northwest yielding to tectonically- and glacially-influenced siliciclastics in the southeast. These sandstones and diamictites are the Macharetí and Mandiyutí groups of the Bolivian Subandes and southern Tarija Basin. Previous authors have suggested that these strata are the lateral facies equivalents of deltaic and marine Mississippian strata below Early Pennsylvanian to Permian carbonate ramps in central and northern Bolivia. Palynological analysis of diamictites and shales confirms a Pennsylvanian age for the glacial units. In the study area, the Macharetí and Mandiyutí groups consist of repeating successions of fluviodeltaic/marine? sands and glacial diamictites bound by significant unconformities. Each group can vary in thickness by orders of magnitude (0 to 1000m) confirming deposition of these units within paleovalleys. The more massive facies stacking patterns are difficult to trace laterally and are dissimilar to well dated cyclothemic carbonate sequences to the north. New stratigraphic sections show significant lateral changes and show problems with earlier mapping outside of type sections. Extreme lateral variability of both facies and thickness of the Macharetí and Mandiyutí groups (and underlying units) reflects primarily changes in tectonics and the growth and decline of glaciers; active loading, resedimentation and slumping on all scales additionally overprint these complex rocks. Only an active tectonically divided southern Peru-Bolivia Basin with a complex series of subbasins and paleovalleys might explain the observed stratal geometry, facies changes, and biostratigraphy. Questions of regional time-transgression, opening and closing of subbasins, and balance with laterally correlative and overlying fusulinid, conodont and ash-dated carbonates are under further study. 30-5 2:40 PM Santos, Joao [170756] ALLUVIAL TERRACES OF THE LOWER MONDEGO RIVER VALLEY: PRODUCT OF LATE QUATERNARY EUSTATIC AND CLIMATIC FLUCTUATIONS IN CENTRAL PORTUGAL SANTOS, Joao and CUNHA, Lucio, Geography, University of Coimbra, Faculdade de Letras da Universidade de Coimbra, Coimbra, 3004-530, Portugal, joaosantos123@yahoo.com With a drainage area of 6,772 km2 and a length of 220 km the Mondego river situated in westcentral Portugal is the largest Portuguese originating river. A set of slope deposits and two sets of alluvial terrace deposits are present on both margins of the lower Mondego river valley and have been identified, mapped, and sampled. Analysis of sedimentary units in gravel pits and road cut exposures present in these deposits revealed an interesting and complex late Quaternary alluvial history in this valley. The slope deposits are the oldest known Quaternary deposits and are located high above the oldest alluvial terraces. These deposits are composed mainly of massive sub-mature poorly sorted gravel units with Gmg and Gp lithofacies and with bi-modal grain size distributions. The highest and oldest alluvial terrace deposits present in the Mondego valley are composed of massive sub-mature poorly sorted gravel units with Gp and Gt lithofacies and with bi-modal grain size distributions. The lowest and youngest alluvial terrace deposits present in this valley are by far the most interesting sedimentary bodies. These are composed of massive sub-mature poorly sorted gravel units with a Gp lithofacie and with bi-modal grain size distributions overlaid by sub-mature moderate sorted and bedded sand units with Sp and Sr lithofacies and with unimodal grain size distributions. In some locations, an immature poorly sorted silt unit with an Fm lithofacie and a bi-modal grain size distribution overlies the sand units. Two sets of marine terrace deposits located on the northern and southern margins of the Mondego estuary are believed to be correlative in age with the two sets of alluvial terrace deposits. The present day alluvial sedimentology and stratigraphy of the lower Mondego river valley indicates that at least two cycles of aggradation and downcutting caused mainly by eustatic sea level and climatic fluctuations occurred during late Quaternary times. The alluvial lithofacies also show the presence of both braided and meandering channel environments during these two late Quaternary constructional cycles. 52 2010 GSA Abstracts with Programs Structural Geology, Tectonics, and Petrology Rushmore Plaza Civic Center, Alpine Room 31-1 1:20 PM Nabelek, Peter [171754] STRUCTURE OF THE NORTHERN GREAT PLAINS AND IMPLICATIONS FOR CONTINENTAL ASSEMBLY AND EVOLUTION SANDVOL, Eric1, NABELEK, Peter1, DUKE, Edward F.2, GAO, Stephen3, LIU, Kelley3, SNELSON, Catherine4, DAHL, Peter S.5, TERRY, Michael P.6, and MCCORMICK, Kelli A.7, (1) Geological Sciences, University of Missouri, 101 Geological Sciences Bldg, Columbia, MO 65211, nabelekp@missouri.edu, (2) Department of Geology and Geological Engineering, South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701-3995, (3) Geological Sciences and Engineering, Missouri University for Science and Technology, McNutt Hall, 1400 N. Bishop, Rolla, MO 65409, (4) Earth and Environmental Science, New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801, (5) Department of Geology, Kent State University, Kent, OH 44242, (6) Geology and Geological Engineering, South Dakota School of Mines & Technology, Rapid City, SD 57701, (7) South Dakota Geological Survey, 2050 W. Main St, Suite 1, Rapid City, SD 57702 Current understanding of the evolution of the North American plate in the northern Great Plains is constrained by basement outcrops on the Black Hills uplift combined with subsurface geologic, gravity, magnetic, heat flow, and very few seismic studies of the surrounding region. A Laramide arch, active ~64 – 40 Ma, extends from western Montana through the Black Hills uplift (structural relief ~ 2,000 m) and connects with the Chadron uplift of northwestern Nebraska. This trend crosses both the Wyoming/Trans-Hudson (WP/TH) and Trans-Hudson/Central Plains (TH-CP) province boundaries. A zone of small alkalic and calc-alkalic Laramide plutons (46-58 Ma) trend N.70oW across the Black Hills uplift possibly emplaced along an ancient basement fracture. Localization of the Laramide arch may lie along a transition from thin to thick lithosphere and reflect the surface manifestation of crustal shortening associated with deep-seated reverse faults. Understanding of the deep Proterozoic and Laramide structures requires remote sensing of the subsurface lithosphere beneath the Black Hills and surrounding regions New seismic stations from the USArray’s transportable array and the proposed FlexArray will help us to better understand the origin and tectonic evolution of the North American continental lithosphere, as well as the role of lithospheric roots and asthenospheric mantle flow in driving North American plate motion. In order to image lithospheric structure, we have begun to analyze the initial passive source seismic data from the transportable array stations recently deployed in and around the Black Hills. Shear wave splitting data provide information on the mantle anisotropy in this region and receiver functions on the nature of the crust across the Trans-Hudson collisional boundary. It is clear that a joint active and passive source seismic experiment and petrologic data designed to investigate inferred geologic structures that cross time boundaries at variable crustal and mantle depths are needed to understand the southern Trans-Hudson orogen and the later Laramide overprint. Such an experiment would allow us to image the transition from the primarily thin, actively-deforming lithosphere of the western U.S. to the stable, thick lithosphere beneath the Superior province. 31-2 1:40 PM Shah, Afroz A. [169023] PRESSURE-TEMPERATURE PATHS FROM FIAs, P-T PSEUDOSECTIONS AND ZONED GARNETS: SIGNIFICANCE AND POTENTIAL FOR ~1700 AND ~1400 MA DEFORMATION AND METAMORPHISM IN THE BIG THOMPSON REGION OF COLORADO ROCKIES, USA SHAH, Afroz A., School of Earth and Environmental Sciences, James Cook University, Campus, Townsville 4811 Australia, afroz.shah@jcu.edu.au A progression of FIAs (foliation intersection/inflection axes preserved within porphyroblasts) in the foothills of the Colorado Rocky Mountains reveals four periods of garnet and staurolite growth and two growth phases each of cordierite and andalusite. These minerals have grown in an overall prograde path, where growth of the garnet porphyroblast was always followed by the formation of staurolite, andalusite and cordierite phases in each FIA set. Inclusions of earlier minerals within the younger phases have supported the porphroblastic mineral sequence obtained through FIAs. Thermodynamic modelling in the MnNCKFMASH system reveals that this episodic growth SESSION NO. 31 occurred over a similar bulk compositional range and PT path. Multiple phases of growth by one reaction in these rocks strongly suggests that PT and X are not the only factors controlling the commencement and cessation of metamorphic reactions. The FIAs preserved by these porphyroblasts indicate that each stage of growth occurred during deformation and indicate that the local partitioning of deformation at the scale of a porphyroblast was the controlling factor on whether or not the reaction took place. In-situ dating of monazite grains preserved within porphyroblast from each FIA set has revealed that the first period of tectonism, occurred around 1759.7±9.8 Ma, recorded within the porphyroblasts of FIA set 1, where garnet nucleated at 540-550°C and 3.84.0 kbars. The intersection of Ca, Mn, and Fe isopleths in garnet cores for 3 samples, containing FIA set 1, set 2 (1759.7±9.8, 1721.0±6.4 Ma) and set 3 (1674±11 Ma), trending NE-SW, E-W and SE-NW respectively, indicate that these rocks never got above 4kbars throughout the Colorado Orogeny. They remained around the same depth until the onset of younger orogeny at 1415±16 Ma, when the pressure decreased slightly as porphyroblasts formed with inclusion trails preserving FIA set 4 and trending NNE-SSW. A slightly clockwise P-T path occurred for both orogenies. 31-3 2:00 PM Cross, William M. [171861] LUNAR REGOLITH SIMULANT MATERIAL CHARACTERIZATION CROSS, William M., Materials and Metallurgical Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph St, Rapid City, SD 57701, william.cross@sdsmt.edu The National Aeronautics and Space Administration (NASA) Constellation program has the objectives of advancing U.S. scientific, security, and economic interests through a robust space exploration program. Included in this are implementing a sustained and affordable human and robotic program to explore the solar system and beyond, and extending human presence across the solar system. Included in these objectives are a human return to the Moon by the year 2020, in preparation for human exploration of Mars and other destinations. To begin to accomplish these objectives, NASA needs materials that correctly simulate the properties of the lunar regolith, because the lunar regolith will be used in a variety of areas including construction, life support, propulsion and power. Unfortunately, few areas on Earth have mineral compositions even remotely close to those found on the Moon. One area that does have some mineralogical similarities to the lunar regolith is the Stillwater complex in Montana. The plagioclase at Stillwater is high in calcium similar to the Moon. The other main components, orthopyroxene and clinopyroxene, are also in the lunar regolith although the ratio of these pyroxenes is different in the regolith when compared to Stillwater. The work presented is the result of a NASA Exploration Systems Mission Directorate Faculty Fellowship grant to have senior design groups work on problems in conjunction with NASA technical experts to help solve problems important to NASA’s goals. In this work, the objective is to separate the plagioclase, orthopyroxene and clinopyroxene into relatively high-grade concentrates that can then be mixed-and-matched to produce lunar regolith simulants that can approximate nearly any area on the lunar surface. The main initial step in this process is the characterization of the minerals to understand their composition, liberation and ability to be separated. 31-4 2:20 PM Erslev, Eric [172051] IMAGING THE ROOTS OF ROCKY MOUNTAIN ARCHES: THE NSF-EarthScope BIGHORN PROJECT ERSLEV, Eric1, SHEEHAN, Anne2, ANDERSON, Megan3, SIDDOWAY, Christine3, MILLER, Kate C.4, and HARDER, Steven4, (1) Geosciences, Colorado State Univ, Fort Collins, CO 80523, erslev@cnr.colostate.edu, (2) Geological Sciences and CIRES, University of Colorado at Boulder, UCB 399, Boulder, CO 80309-0399, (3) Geology Dept, Colorado College, 14 E. Cache La Poudre St, Colorado Springs, CO 80903, (4) Geological Sciences, University of Texas at El Paso, El Paso, TX 79968-0555 The Bighorn Project is an integrated seismological and structural geology investigation to understand how basement-involved foreland arches form, how they are connected to plate tectonics, and what they reveal about the rheology of the continental lithosphere. Prior hypotheses for basement-involved arches include subcrustal shear and/or mantle hydration during shallow subduction and lithospheric buckling, crustal detachment, and/or domino-style lithospheric faulting during the end-loading of continental lithosphere. All of these hypotheses predict different lower crustal and Moho geometries beneath foreland arches. They will be tested by combining the near-surface geology of the optimally-exposed Bighorn Arch of northern Wyoming and southern Montana with new kinematic data and the results of the Bighorn Arch Seismic Experiment (BASE), an EarthScope Flexible Array experiment. Existing outcrop and industry subsurface data will be used to develop a 3D model of the upper crust. Data from minor faults, joints and fold geometries will be used to delineated the history of kinematic movements. The geometry of the deeper crust and uppermost mantle for the Bighorn Mountains and the adjoining Bighorn and Powder River basins will be determined by the integrated passive/active BASE experiment. During the summer of 2009, 35 broadband instruments were deployed to densify the EarthScope Transportable Array stations already in the region. They have already recorded several magnitude 7+ teleseismic events. This summer, this passive array will be supplemented by 200 short period seismometers and a several week deployment of 800 “Texan” instruments. In addition, an active refraction experiment involving 30+ shots recorded by 1600 “Texan” instruments will occur in late July. The combination of traditional geologic data with the results from the simultaneous inversion of active and passive seismological data will give a detailed structural crustal image of the Bighorn region at all levels of the crust. This will be combined with our kinematic data to define a complete 4D (3D space plus time) restorable lithospheric model of arch formation revealing the rheology of continental lithosphere and the mechanisms of basement-involved arch formation. 2010 GSA Rocky Mountain Section Meeting 53 Index of Authors How to use the indexing system: The first number (preceding the dash) represents the session number in which the paper will be presented. The second number (following the dash) indicates the presentation order of the paper within its session. Example: Cooper, Scott P. ….. 8-4* Find Session #8 in either the Abstracts volume or the Technical Session portion of the Program, and look at the fourth paper in the session. Page numbers are not listed in this index. Refer to session number and order of presentation to locate the author you are searching for. A Abbott, Marvin 12-4 Abessa, Mebratu 21-6 Adhikari, Narayan 2-5 Agenbroad, Larry 5-1, 19-8 Alexander, Jason 17-3* Allard, Stephen T. 24-4*, 29-2, 29-4 Allen, Cody Lee 25-1 Alward, William S. 28-4 Andersen, Allen 11-4* Anderson, Fred J. 4-2*, 23-6 Anderson, Heidi 30-4* Anderson, Megan 31-4 Anderson, Ryan B. 2-5, 23-1, 23-2, 23-5*, 23-7 Aurand, Katherine 15-10 Aurand, Katie 15-11 Azzolini, David C. 15-1, 17-2 B Baker, Kevin K. 21-5* Baldauf, Paul 19-11 Balmat, Jennifer L. 30-1* Barker, Paula 9-5 Bartling, Jamie 19-1* Bauer, Robert L. 24-3*, 28-4* Beasley, Barbara A. 11-2 Belile, Donald 14-2, 15-6 Benton, Rachel 13-1* Berdanier, Bruce 15-6 Betemariam, Hailemelekot 21-4, 21-7*, 22-1* Bhandari, Sushmita 23-5 Bhattarai, Roshan R. 23-5 Bhattarai, Tara N. 2-5, 23-5 Bishop, Nate 9-2 Boehlke, Adam R. 12-4 Borch, Thomas 15-2, 15-3 Bradford, Joel 23-4 Bradford, Joel A. 9-2, 19-3, 23-1, 23-8, 26-3 Bradshaw, Richard W. 11-6 Brave, Dylan 16-3* Breit, George N. 12-6 Breithaupt, Brent H. 5-2, 10-3*, 13-7 Brown, Rachel 10-6 Brown, Rachel A. 22-4 Brugger, Keith A. 19-10 Brunhart-Lupo, Maria 11-5* Bunds, Michael P. 2-5*, 9-2, 19-3, 23-1, 23-4, 23-5, 23-8, 26-2, 26-3 Bunkers, Matthew 14-9 Burkhart, Patrick 19-11, 20-4* Burkhart, Patrick A. 20-5 C Campbell-Stone, Erin 10-3 Cantorin, Maritza 1-4 Capehart, William 14-10* Carter, Janet M. 14-9 Cassle, Christopher F. 12-5* Chasten, Lindsay E. 29-3* Chipps, Steve 21-4, 21-7 Christensen, Tom 5-2 Clay, David 15-10, 15-11 Clay, Sharon 15-9, 15-11 Condon, Daniel 16-2 Connely, Melissa V. 19-13 Connors, Tim 11-1* Cooper, Scott P. 8-4*, 25-2* Cory, Rose M. 23-3 Cotter, James F.P. 19-6 Cowman, Tim 17-4 Cross, William M. 31-3* Cunha, Lucio 30-5 D Dahl, Peter S. 24-1*, 24-2, 31-1 Dannenbring, Scot E. 19-2* Darbyshire, Jane -1 Davis, Arden 23-6 Davis, Arden D. 3-5, 3-6, 22-1, 22-3*, 22-5 DeSutter, Thomas 21-7 Di Pasquo, Mercedes 30-4 Dinklage, William 9-2 Dixon, David 22-1 Dobson, Patrick F. 8-1 Dollarhide, Christopher 15-10, 15-11 Dreis, Erin 15-9* Driscoll, Dan 14-8 Driscoll, Daniel G. 14-7*, 14-9 Duke, Edward F. 31-1 Durand, James P. 23-1 E Egenhoff, Sven O. 12-2*, 12-5 Ellingson, William 3-10* Ellis, Geoffrey 12-4 Elsworth, Derek 3-8 Emerman, Steven H. 2-5, 19-3, 23-1, 23-2*, 23-4, 23-5, 23-7, 23-8, 26-3 Emsbo, Poul 12-6* Epstein, Jack 4-4*, 11-7* Erickson, Eli N. 17-6 Erslev, Eric 31-4* Erslev, Eric A. 25-1*, 25-3 Esker, Donald Anton 5-1* Evanoff, Emmett 13-8, 13-9* F Factor, Lewis 20-1 Fandrich, Joe W. -2* Felsman, Jason M. 1-1* Fischer, Anne 16-2 Fishman, Neil 12-4* Fishman, Neil S. 12-2 Foreman, Cory S. 15-8, 21-2*, 21-3 Foss, Scott E. 13-4* Frei, Robert 24-1, 24-2 Freifeld, Barry 3-8 Freifeld, Barry M. 8-1 Friberg, LaVerne M. 1-3, 10-4* G Gabel, Mark L. 7-1 Gaddie, Helene 13-11*, 15-6 Gallin, William N. 11-8* Gao, Stephen 31-1 Garcia, Patricia K. 23-1*, 23-8*, 26-3 Garraffa, Alfred 8-2 Gates, Ian 1-5 Geibel, Nicholas M. 15-1, 17-2 George, Graham N. 12-1 Ghosh, Amiya K. 24-1, 24-2 Gilcrease, Patrick C. 22-6 Gillett, Cyrus 25-1 Gilmore, Adam Matthew 23-3* Giraud, Gerald 14-2 Goergen, Eric 24-3 Goodman, Brian S. 4-5* Goodman, William M. 6-3 Grader, George W. Jr. 30-4 Grandstaff, David E. 11-2 Greenberg, Jeffrey K. 10-5 Griffis, Neil 20-3* I Isaacson, Peter E. 30-4 J Jarding, Lilias C. 15-5* Jetson, Melissa K. 19-4* Jinka, Ramith 15-10*, 15-11 Johnson, Adam C. 28-1 Johnson, Adam Collier 28-3* Johnson, Cari 11-8 Jones, Daniel S. 24-6* Jones, Tessa L. 3-6* Jordan, Brennan T. 29-5* K Karki, Kabita 2-5 Katzenstein, Kurt W. 9-1* Kemp, Tracy L. 23-1, 23-7* Kennedy, Raymond 20-2* Kenner, Scott J. 14-3*, 15-8, 21-2, 21-5, 22-5 Kenner, Seth 14-4* Korf, Jason J. 19-14* Kosmidis, Paul G. 16-1 Kowallis, Bart J. 11-6* Krumenacker, L.J. 13-6 Kuiper, Klaudia 16-2 H L Halfen, Alan F. 2-6 Hamer, Rayburn C. 3-11* Hamlin, Laura 25-3* Hanneman, Debra L. 16-4* Hansen, M.R. 15-6 Hansen, Marion 22-1 Harden, Tessa 14-7, 14-8* Harder, Steven 31-4 Hark, Jessica S. 24-1, 24-2* Harp, Michael T. 1-3* Hartman, J.H. 13-8* Hartwick, Emily E. 30-6* Harwood, Alison 14-6* Hasiotis, Stephen T. 2-1*, 2-6* Henebry, Geoffrey 14-10 Hennings, Peter 25-3 Hill, Ronald 12-3* Hladysz, Zbigniew J. 8-3* Holbrook, John 17-6 Holbrook, John M. 17-4 Holen, Steven 2-4 Holte, Sharon E. 19-8* Hopkins, Kenneth D. -4 Horns, Daniel 9-2 Howle, James 17-3 Hubbard, Stephen M. 1-5 LaGarry, Hannan E. 13-7, 13-10*, 13-11, 22-2 LaGarry, Leigh Anne 13-10 Lamothe, Paul 17-3 Larson, Darin 17-3 Larson, Lance 15-2*, 15-3, 15-4* Larson, Peter B. 28-2 Larter, Stephen R. 1-5 Le, Tuan 5-6 Lee, Patrick 22-2 Leite, Michael B. 13-7, 30-1 Leithauser, Eric 19-11* LeRoy, Janine 5-3 Liang, Kenneth 8-1 Linn, Thomas 5-3 Lisenbee, Alvis L. 3-4, 4-3, 8-4, 8-5, 10-1, 22-3, 23-6, 25-4*, 28-5 Liu, Kelley 31-1 Livingston, Jack 20-4, 20-5 Lomax, Dean R. 7-3 Long, Andrew J. 22-5, 22-6* Lorenz, John C. 25-2 Love, Jason T. 14-4, 21-3* Lowell, Robert 3-8 Lufkin, John L. 1-4* Lukens, William E. 11-2* Lundstrom, Scott 17-4* 2010 GSA Rocky Mountain Section Meeting 55 Lundstrom, Scott C. 17-5 Lupo, Christopher 15-9 M Maddox, Ashli 17-3 Mahan, Kevin 6-2 Mahan, Kevin H. 24-6 Mahan, Shannon A. 2-4*, 15-1, 17-2 Maher, Kate 3-8 Mailloux, Brian J. 3-8 Marcano, Norka 1-5 Marini, Brandon L. 5-3* Martin, James E. 2-3*, 17-1* Martin, Tyler Q. 20-5 Masciale, David M. 13-3* Matthews, Neffra A. 5-2*, 10-3, 13-7 Matzek, Carl D. 29-4* May, David W. 2-4 McCormick, Kelli A. 29-1*, 31-1 McCoy, Matt 20-1 McCutcheon, Cindie 21-4, 21-7 McGough, Jeffery 3-7 McKaskey, Jonathan 9-5 Mead, Jack 23-6* Mergenthal, Daniel 22-7* Metzger, Christine A. 20-1 Mickle, Katherine 20-4 Miller, Kate C. 31-4 Miller, Matthew -1* Miller, Scott L. 22-3 Minkler, Heidi R. 13-5* Minnick, Matthew 5-5* Mintz, Jason S. 16-1 Moore, Jason R. 13-6* Moreno-Ward, April DeAnn 17-6* Morlok, Brett A. 15-8* Morton, Patrick 9-5, 29-7* Moscati, Richard J. 17-5 Moshier, Stephen O. 10-5* Murray, Kyle Edward 5-6* Muxen, Andrew B. 3-7* N Nabelek, Peter 24-5*, 31-1* Neitzert, Kathleen M. 14-5* Nelson Hadley, Janae 23-8, 26-3 Nichols, Christopher 26-1* Noble, Tommy A. 5-2 Nolan, Wyatt C. 19-10* Norton, Parker II 14-3, 14-11* O O’Connor, Jim 14-8 O’Connor, Jim E. 14-7 Ohms, René E. 11-3 Oldenburg, Curtis M. 8-1 Olinger, Danielle 19-15* One Feather, Leola 22-2 Oswald, Jared K. 14-1, 21-3 Oweimrin, Michael 23-3 P Paces, James B. 17-4, 17-5* Pagnac, Darrin 2-2*, 19-8 Palmer, Mallory A. 2-5, 23-1, 23-2, 23-5 Parris, David C. 17-1 Paterson, Colin J. 3-9, 3-10, 3-11, 8-5, 19-9 Patruyo, David 1-5 Pauls, Kathryn N. 19-6 Paxton, Stanley T. 12-4 Pellowski, Christopher J. 4-3* Penn, Michael 21-7 Peters, Catherine A. 8-1* Pickering, Ingird J. 12-1 Pierson, M. Patrick 4-5 Pigati, Jeffrey S. 17-5 Pomarleau, Lacy 14-4 Popielak, Roman S. 3-3 Prasai, Tista 23-2 Pratt, Brian R. 12-1*, 12-7* Premo, Wayne R. 24-6 Price, Maribeth 5-3, 9-5 Price, Maribeth H. 8-2, 9-3, 22-4 Pushie, M. Jake 12-1 R Racay, Christopher A. 7-3* Rahn, Perry H. 30-2* Ramakrishnan, T.S. 8-1 Rasmussen, Donald L. 2-1 Rathbun, Kathryn 19-7* Redden, J.A. 9-4 Redden, Jack A. 24-2 Rempe, Norbert T. 3-1* Rey, Kevin 9-2 Robertson, Scott 19-3*, 26-2 Robertson, Scott A. 23-4 Rocha-Campos, A.C. 19-6 Roggenthen, W.M. 3-2*, 8-3 Rowe, Aryn M. 8-2* Rowe, Becci J. 7-1* Ryczek, Daniel 5-3 S Sahy, Diana 16-2* Salvatore, Michelle 22-2* Salve, Rohit 3-5 Samimi, Hadi 1-5* Sandvol, Eric 31-1 Santos, Joao 30-5* Saxton, Samantha 9-4* Saxton, Samantha L. 22-4* 56 2010 GSA Abstracts with Programs Schmidt, Chris 29-2* Schneider, John M. 6-3*, 22-4 Schoenrock, Jared K. 19-3, 23-1, 23-4*, 26-2 Schumaker, K.K. 13-8 Schwabe, Kathleen 19-5* Sears, James 1-2*, 28-1, 28-3 Secord, Ross 13-3 Sethi, Parvinder 10-2* Shah, Afroz A. 31-2* Sheehan, Anne 31-4 Shelton, Sally 10-6 Shelton, Sally Y. 7-1 Shurr, George W. -3* Siddoway, Christine 31-4 Smith Barnes, Connie K. 9-2* Smith, Barbara 14-3 Smith, Melissa 14-9* Snelson, Catherine 31-1 Snoke, Arthur W. 24-6 Snyder, Patrick L. 21-1* Sonnenthal, Eric 3-8* Spencer, Ronald J. 1-5 Stabinski, Eric 8-1 Stamm, John 14-7, 14-11, 21-5 Stamm, John F. 15-1*, 17-2*, 17-3 Stauffer, Phillip 14-10 Stetler, Larry 3-5*, 4-1*, 6-1, 15-2, 15-4, 21-4, 21-7, 22-7 Stinchcomb, Gary 16-1 Stoltenberg, Matthew B. 14-1* Stone, James 15-2, 15-3, 15-4, 15-9, 1511*, 21-4*, 21-7 Stone, James J. 15-10 Straw, Byron M. -4* Sundareshwar, P.V. 15-7*, 21-6 Sweeney, Mark 19-7 T Tarbert, Kevin D. 28-2* Terry, Dennis O. Jr. 11-2, 16-1*, 16-2, 201*, 20-2, 20-3 Terry, Michael 3-4*, 19-1, 26-1, 29-6*, 29-7 Terry, Michael P. 3-9, 3-10, 9-4, 19-4, 28-5, 29-3, 29-5, 31-1 Testin, Jason James 19-12* Thaler, Jacob A. 19-9* Thaler, Robert 15-10, 15-11 Thaler, Terry 9-3* Thayne, Michael 23-8, 26-3* Thompson, Ryan 18-1* Thompson, Ryan C. 25-1 Thomson, Olivia A. 19-6* Tielke, Jacob A. 28-5* Tinant, Charles Jason 14-2*, 15-6* Titus, Alan L. 5-2 Tolle, Charles R. 3-7 Tomlin, Kenneth 24-3 Toth, Natalie 10-6*, 23-6 Troelstrup, Nels H. 21-2 Troyer, Lyndsay 15-2, 15-3* Trumbull, Con B. 19-13* Tuffour, M. 23-6 Tuffour, Peprah 3-9*, 6-1* U Upadhayay, Sikchya 21-6* Urban, Noel 21-7 Uzunlar, Nuri 3-8, 8-4, 8-5*, 10-1* V Valder, Joshua F. 22-5* Van Beek, Jason K. 3-6 Van Boening, Angela 24-5 Van Wagoner, Marc E. 23-7, 23-8, 26-3 VanBeek, Jason 3-5, 19-1 VanWagoner, Marc E. 9-2 Vardiman, David M. 3-3 Verma, Sandeep 8-1 Volk, James 3-5 W Wahl, William R. 7-2* Wall, Zackary S. 28-1*, 28-3 Wang, Joe S. 3-6 Wang, Joseph S. 8-1 Ward, Dustin 6-2* Webb, David A. 5-4* Weber, Carolyn 8-2 Weiler, M.W. 13-8 Weinig, Walter 3-3* Welsh, Ed 13-2* Whitehouse, Martin J. 24-1, 24-2 Wideman, Charles J. 16-4 Wiles, Michael E. 11-3*, 30-3* Wilkins, W.J. 5-1 Wilson, Marcia 18-2* Witt, Dallin 23-4 Witt, Dallin Christopher 19-3, 26-2* Wooden, Joe 24-2 Wooden, Joseph L. 24-1 Woodward, Brenda 17-3 Wright, Christopher 14-10 Y Yamnitsky, Steven J. IV 20-5* Z Zaprowski, Brent J. 17-2 Zeitler, Joseph 9-5* Zhou, Wendy 5-5 Zwiebel, Jesse 13-7* Special Paper 461 Field Geology Education: Historical Perspectives and Modern Approaches Edited by Steven J. Whitmeyer, David W. Mogk, and Eric J. Pyle Field instruction has traditionally been at the core of the geoscience curriculum. The field experience has been integral to the professional development of future geoscientists, and is particularly important as it applies to student understanding of spatial, temporal, and complex relations in the Earth system. As important as field experiences have been to geosciences education and the training of geoscientists, the current situation calls for discipline-wide reflection of the role of field experiences in the geoscience curriculum in light of practical and logistical challenges, evolution in employment opportunities for geoscientists, and changing emphases in the geoscience curriculum. This volume seeks to broaden participation in field instruction by showcasing diverse approaches to teaching in the field across the many geodisciplines encompassed by GSA. R P RI C E B EM IC E • M 56 PR $ E• ME M SPE461, 356 p., ISBN 9780813724614, list price $80.00 BER GSA SALES AND SERVICE P.O. P O Box B 9914 140, 14 4 0, 0 B ou ould ld er, CO 803 lder 0 01-9 0301 01-914 9 140, 1400 U SA SA +1.303 0 .3577.1000, option 3 • toll-free +1.88 8 8.44 4 3 .4 47 4 2 • fa faxx +1.33 03 03.357.10771 Not Just Software. . . RockWare. For Over 27 Years. New Version ! RockWorks Academic Site License ® Stratigraphic/Lithologic Modeling • 2D and 3D striplogs • Cross-sections • Profiles • Fence diagrams • Contour maps and 3D surfaces • Solid models and isosurfaces • Relational database for storage of lithology, stratigraphy, geophysical, analytical, geotechnical, water levels, fracture data and more! Directional Analysis • Rose diagrams • Stereonets • Statistical analysis • Lineation mapping and gridding • Arrow maps • Slope and direction models • Strike and dip maps and more! Hydrochemistry Diagrams • Piper • Stiff diagrams and maps • Durov • Ion balance • TDS calculations and more! Gridding Tools • Contours • 3D surface diagrams • Several interpolation options • Grid math and grid filters • Boolean logic tools • Polynomial trend fitting Graphics /Imports/Exports • Customizable 2D and 3D visualization • Several import/export formats • Connectivity to ArcGIS All of these tools (and more!) are now available in an annual license for academic use: unlimited installations within a department for the same price as a single, standard license. $2,499 303.278.3534 • 800.775.6745 RockWare.com