Force poster abstracts_20.11.13
Transcription
Force poster abstracts_20.11.13
Biostratigraphy, Geochemistry and Paleoenvironment of Brucebyen Beds,basal Tyrellfjellet Member, Svalbard Felix Gradstein1, Vladimir Davydov2, Carl Dons3, Jon Halvard Pedersen3 & Judith Hannah4 1 University of Oslo, Norway University of Boise, ID, USA 3 Lundin Norway As 4 Colorado State U., Colorado, USA 2 Three Svalbard limestone localities were sampled for biostratigraphy, paleoenvironment and organic maturation of the Brucebyen Beds, a potential Barents Sea petroleum source rock. At both the Kapitol and Tyrellfjellet localities on Svalbard the Brucebyen Beds belong in the Schwagerina robusta-Ultradaixina bosbytauensis fusulinid zone of latest Gzhelian age, latest Carboniferous and 300- 298.9 Ma In both localities samples with the fusulinid microfossils appear to be in place, and there is no indication of abraded or fragmented specimens due to re-sedimentation. At the same time, the microfossil specimens are severely compressed during early diagenesis, as many specimens have post mortality damage or are crushed and broken. It appears that this shallow-water limestone was very porous and permeable during sedimentation and early diagenesis, allowing organics to easily migrate in the sample space. A shale sample from Kapitol is oil and gas prone, and of low thermal maturity (TOC of 5.6%, HI of 292 mgHC/g TOC and Tmax 434 C0). Gas chromatography analysis of a shale extract suggest a marine, dys-oxic sedimentary environment (pristane/phytane 1.7). Vitrinite reflectance of 0.6%Ro, calculated from aromatic compounds, indicates a maximum burial of around 3.5 km (early oil window). In the Kolosseum locality the bluish Brucebyen limestone belongs in the Sphaeroschwagerina vulgaris –S. fusiformis fusulinid zone of earliest Asselian Age, earliest Permian; 298.9 - 296 Ma. Samples are coarse, poorly sorted grainstone; some shells are abraded and crushed before the diagenesis. The meteoritic cementation was very early. Hence, organics had less possibility to migrate in than in the latest Gzehlian samples of the other two localities. Deposition of all samples was most likely initiated high in the photic zone in the warmest waters above storm-weather wave base and possibly above fair-weather wave base. A global warming trend at the Carboniferous-Permian boundary allowed migration of tropical fusulinids northwards. Managing biostratigraphic data with StrataBugs v2.0 John Athersuch, Paul Britton & Rosa Townsend StrataData Ltd, 17 The Bothy, Ottershaw Park, Surrey UK – KT16 0QG, info@stratadata.co.uk Since the time of William Smith, biostratigraphy has been a key technique for calibrating the stratigraphic record. Advanced computational methods enable huge datasets, typically from industry wellbore samples, to be systematically gathered, organised and manipulated. StrataBugs is the industry-leading tool for the implementation of such procedures, allowing users to probe the stratigraphic record at an ever finer resolution. In StrataBugs, schemes and dictionaries, including a taxonomic database, stratigraphic schemes and event composite standards, underpin all stratigraphic data. This encourages consistency and standardisation throughout the database and enables events to be correlated between stratigraphic sections. Raw biostratigraphic data is easily entered using a variety of methods, including an on-screen picklist or a touch-screen device. Microscope images can be referenced and stored in the database. Interpretation of well data is an iterative process which makes full use of the raw data and supporting schemes. A set of preconfigured interactive charts gives a graphic snapshot of the well or outcrop section. Data entry is facilitated by a ‘scheme picklist’, and many of the data types can be edited directly from the charts – e.g. drag-and-drop interval boundaries. An interactive graphic correlation tool facilitates definition of the age-depth profile (line of correlation), including drag-and-drop nodes for its construction and refinement. Other charts can display biostratigraphic data on age or TVD scales. A typical workflow might be: enter the raw occurrence data, display the distribution chart and pick events directly from it, use these well events together with an event composite standard to define the age-depth profile. From this you can generate a preliminary list of biozones, which can be viewed and refined using the chart, alongside other supporting data. Foraminiferal assemblages from Lower Jurassic transgressive mudstones of the southwestern Barents Sea Silvia Hess1, Jenö Nagy1, Gitte Vestergaard Laursen2 & Bas van de Schootbrugge3 1 Department of Geosciences, University of Oslo, Norway; 2 Statoil ASA, Stavanger, Norway 3 Department of Geosciences, University of Frankfurt, Germany Lower Jurassic sediments of the southwestern Barents Sea compose the Kapp Toscana Group composed of sandstones, mudstones and shales deposited in shallow shelf to coastal plain environments. Intervals of the Nordmela and Stø formations were sampled from cores of two commercial wells (7119/12-1 and 7119/12-2) drilled in the Hammerfest Basin (south-western Barents Sea). Foraminiferal assemblages were analyzed and integrated with sedimentological data to assess depositional conditions, transgressive-regressive developments and stratigraphic relations of the delta-influenced, marginal marine succession forming the upper part of the paralic Kapp Toscana Group. Foraminiferal assemblages occurred exclusively in transgressive mudstone intervals of the Stø Formation in well 7119/12-1. High-energy marginal marine and offshore sandstones, and freshwater deposits were barren of foraminifera. All foraminiferal assemblages contain only agglutinated taxa with high dominance of Ammodiscus and Trochammina. Species diversity is extremely low (Fisher α < 5). These features and analogies to modern faunas indicate restricted environmental conditions with low salinity as the main restricting factor in strongly delta-influenced waters. The three mudstone horizons of the Stø Formation represent marine transgressions. Their foraminiferal content reveals Pliensbachian-Toarcian affinities. These transgressive mudstones are considered as local developments of the global Pliensbachian-Toarcian transgressions and associated major faunal changes. In addition to the age relationships suggested by the foraminiferal assemblages, this consideration is based on the transgressive nature of these mudstone horizons, their slightly increased TOC content and a negative δ13C-isotope excursion which is characteristic for the Toarcian Oceanic Anoxic Event. Our results show that foraminiferal assemblages can be used to recognize paleoenvironmental changes in paralic environments. They clearly indicate regional transgressive events in shallow water deposits which could serve as key horizons for basin-wide correlation. Planed foraminiferal analyses combined with detailed carbon isotope data can contribute significantly to delineate the stratigraphy of this, until now, poorly dated succession. Interactive Biostratigraphy of the North Sea Rebecca Bobick1, Felix Gradstein2, James Ogg1 & Dirk Munsterman3 1 Purdue University, Indiana, USA 2 University of Oslo, Norway 3 NO, Utrecht, The Netherlands We have produced an extensive and user-friendly stratigraphy dataset for the North Sea ranging from Triassic through Cenozoic using Time Scale Creator; a visualization program that allows users to interactively view all types of Earth history data. The North Sea fossil suites consist of dinoflagellate cysts, pollen-spores and foraminifers. All data was scaled to the standard international geologic time scale 2012. The information for each individual fossil range, biozone and regional lithologic facies is readily accessible. The 2000+ data points also include over 300 images of the fossils that appear on the user-generated and selected charts for quick identification and larger versions within mouseover popup windows in the on-line version of the user selected charts. The pop-ups also contain external links to more information for the fossils (e.g. the Dinoflaj compilation and Grzybowski Foundation taxonomy) and time calibration information from international GTS2012. The Time Scale Creator visualization system itself has options for user customization, such as selecting the time intervals, vertical scale and specific fossil of geochem or geomagnetic columns to view. By allowing easy accessibility and providing a user-friendly interface and specific columns to view this program may aid in education, consolidation of research products and offshore biostratigraphy in the North Sea. Stratigraphic Guide to the Rogaland Group,Norwegian North Sea Harald Brunstad1, Felix Gradstein2,Jan Erik Lie1, Øyvind Hammer2, Dirk Munsterman3, Gabi Ogg4 & Michelle Hollerbach5 1 Lundin Petroleum AS Norway, NO-1366 Lysaker, Norway. Geology Museum, University of Oslo, NO-0318 Oslo, Norway. 3 TNO, P.O. Box 80015, NL-3508 TA Utrecht, The Netherlands. 4 1224 N Salisbury St, West Lafayette, IN 47906, USA. 5 Senergy AS, Strandkaien 2, NO-4004 Stavanger, Norway. 2 This guide provides a major revision and update of the lithostratigraphy of the Rogaland Group for the Norwegian North Sea. An abundance of recent well and seismic data sheds new light on lithology, biostratigraphy, provenance, geographic distribution and terminology of all Rogaland rock units, used widely in the search for oil and gas. While finer siliciclastic units largely remain as previously defined, previous sandstone/siltstone formations and one (reworked) chalky unit are now re-defined. These lithostratigraphic units are local sediment bodies of a lithology different from the surrounding and embracing formation. Hence, these lithostratigraphic units are members in the formal stratigraphical hierarchy. With the new definitions and re-definitions the Rogaland Group now consists of four formations and 15 members, which span the stratigraphic interval from lower Paleocene to lower Eocene. The revisions concerning the sandstone bodies are of four different types: Re-definition from formations to members; re-definition of lithological criteria; introduction of members long used already offshore England and Denmark; definition of new members. For those practicing geologists not familiar with historic precedence, an important ‘sine qua non’ in (litho-) stratigraphy, it should be pointed out that 8 out of 15 members discussed here have been predefined in literature dealing with the UK and Danish sectors of the North Sea. The present study thus updates the Norwegian lithostratigraphic bulletins of the nineteen eighties for its offshore area. Each unit has a detailed biostratigraphy and age section also. The internet site www.nhm2.uio.no/norlex provides an interactive digital version of this study, with links to well data, biozonations and core archives. Carnian palynology from a shallow stratigraphic core from the Sentralbanken High, Barents Sea Holen L. 1, Mangerud, G. 1, Paterson, N.W. 1, Lundschien, B.A. 2, Throndsen, I. 3 & Miljeteig, K.I. 1 1 Department of Earth Science, University of Bergen, Allégaten 41, N-5007 Bergen, Norway, 2Norwegian Petroleum Directorate, P.O. Box 600, 4003 Stavanger, Norway 3 Applied PetroleumTechnology AS (APTEC), P.O. Box 123, 2027 Kjeller, Norway During the Triassic Period, a major embayment formed on the northern coast of the Pangea Supercontinent in what is now the Barents Sea. During the Late Triassic this embayment was gradually filled by sediment derived mainly from the erosion of the recently uplifted Uralian Mountains. These sediments formed a huge prograding delta which gradually converted into a paralic platform. Very little data are available from the Northern Barents Sea; however, several stratigraphic cores drilled by the Norwegian Petroleum Directorate in the area offer a unique insight into the Late Triassic stratigraphy and paleogeography of the region. The present study forms a master’s thesis in palynology of a shallow core, 7533/3-U-7, drilled through the Snadd Formation from the Sentralbanken High in the Northern Barents Sea. This study constitutes part of a broader palynostratigraphic investigation of the Middle to Late Triassic of the Barents Sea currently being undertaken at the University of Bergen. From core logging, the preliminary interpretation indicates a mid to upper delta plain depositional environment. The main aims of the thesis are to date the core and evaluate the paleoenvironments represented by utilising palynological and palynofacies analyses. By combining palynostratigraphic and palynofacies data it is hoped that any marine incursions will be recognised and dated, thereby enhancing our current understanding of the Late Triassic paleogeography of the Barents Sea. Together with documentation of the recorded palynomorphs, a preliminary correlation to published sections on Svalbard and to the shallow core 7830/3-U-1 drilled offshore Kong Karls Land will be presented. Carnian palynology from a shallow stratigraphic core offshore Kong Karls land, Barents Sea Miljeteig, K.I. 1, Mangerud, G. 1, Paterson, N.W. 1, Lundschien, B.A. 2, Throndsen, I. 3 & Holen L. 1 1 Department of Earth Science, University of Bergen, Allégaten 41, N-5007 Bergen, Norway, 2Norwegian Petroleum Directorate, P.O. Box 600, 4003 Stavanger, Norway 3 Applied PetroleumTechnology AS (APTEC), P.O. Box 123, 2027 Kjeller, Norway During the Triassic Period a major embayment formed on the northern coast of the Pangaea Supercontinent in what is now the Barents Sea. During the Late Triassic this sea was gradually filled by sediment derived mainly from the erosion of the recently uplifted Uralian Mountains. These sediments formed a huge prograding delta which gradually converted into a paralic platform. Very little data are available from the Northern Barents Sea; however, several stratigraphic cores drilled by the Norwegian Petroleum Directorate in the area offer a unique insight into the Late Triassic stratigraphy and paleogeography of the region. The present study forms a master’s thesis in palynology of a shallow core, 7830/3-U-1, drilled through the Snadd Formation, equivalent to the Tschermarkfjellet and De Geerdalen Formations, from offshore Kong Karls Land in the Northern Barents Sea. This study constitutes part of a broader palynostratigraphic investigation of the Middle to Late Triassic of the Barents Sea currently being undertaken at the University of Bergen. From core logging, the preliminary interpretation indicates a range from prodelta, to delta front and interdistributary bay depositional environments. The main aims of the thesis are to date the core and evaluate the paleoenvironments represented by utilising palynological and palynofacies analyses. By combining palynostratigraphic and palynofacies data it is hoped that any marine incursions will be recognised and dated, thereby enhancing our current understanding of the Late Triassic paleogeography of the Barents Sea. Together with documentation of the recorded palynomorphs, a preliminary correlation to published sections on Svalbard and to the shallow core 7533/3-U-7 drilled on the Sentralbanken High will be presented. A new, formal palynozonation for the Triassic succession of the Barents Sea area - a solid correlative tool for the Norwegian Arctic Mangerud, Gunn1, Jorunn Os Vigran2, Atle Mørk2,3 Peter A. Hochuli4 & David Worsley5 1 Department of Earth Science, University of Bergen, Allégaten 41, N-5007 Bergen, Norway, 2 Sintef Petroleum Research, 3 NO-7465 Trondheim, Norway, Department of Geology and Mineral Resources Engineering, NTNU, NO-7465 Trondheim, Norway 4Palaeontological Institute and Museum, University Zürich, Karl Schmid-Str. 4, CH-8006 Zurich, 5 Switzerland, Fergestadsveien 11, N-3475 Sætre, Norway. The Norwegian Barents Shelf with Svalbard forming its exposed north-western corner reveals an almost complete Triassic sedimentary record when combining outcrops with stratigraphic cores and explorations wells. Dating and reliable correlation tools are essential in exploration, and palynological studies from these sections have been carried out resulting in the definition of fifteen palynological Composite Assemblage zones (CAz). Calibrations with ammonoids recovered from Lower and Middle Triassic deposits cored on the Svalis Dome, the Bjarmeland Platform, in Finnmark East and in the Nordkapp Basin permit exact dating of the co-appearing palynological assemblages and confident correlation with the ammonoid-dated sections on Svalbard. Shallow cores from Sentralbanken and off Kong Karls Land add valuable knowledge of the Late Triassic and the variable depositional environments and breaks in deposition during the Carnian and Norian. Important data are added based on exploration wells. At the Triassic-Jurassic transition on Svalbard, where Lower Jurassic deposits directly overlie Norian beds, we demonstrate that reworked Late Triassic palynomorphs dominate. In exploration wells further to the southeast, Rhaetian strata represent the youngest Triassic deposits in the area. Seven composite assemblage zones have been defined for the lower Triassic. These include the Uvaesporites imperialis, Reduviasporonites chalastus, Proprisporites pocockii, Maculatisporites spp., Naumovaspora striata, Pechorosporites disertus and Jerseyiaspora punctispinosa CAz. These appear to have a variable west-east presence on Svalbard. Four composite assemblage zones have been defined for the Middle Triassic. These include the Anapiculatisporites spiniger, Triadispora obscura, Protodiploxypinus decus, and the Echinitosporites iliacoides CAz and are present in most measured sections on Spitsbergen. On Bjørnøya there is a major stratigraphic break above Smithian beds where the oldest Middle Triassic is represented by the Ladinian E. iliacoides CAz. Four Composite Assemblage zones have been defined for the Late Triassic. These include the Aulisporites astigmosus, Rhaetogonyaulax spp., Limbosporites lundbladii and Quadraeculina anellaformis CAz. However, in most localities on Svalbard only the Carnian A. astigmosus CAz is recognised. The present study represents a comprehensive compilation of palynology from the Triassic succession of the Norwegian Arctic. There is still a huge potential for further detailed work of the palynoassemblages and their application in palaeoenvironmental as well as stratigraphic interpretations and reconstructions. The results will be presented in the book: J. O. Vigran, G. Mangerud, A. Mørk, D. Worsley, P. A. Hochuli. 2013: Palynology and geology of the Triassic succession of Svalbard and the Barents Sea. Norwegian Geological Survey, Special Publication. Integrated biostratigraphy and foraminiferal biofacies from a Late Cretaceous fan system in the Vøring Basin Eiichi Setoyama1*, Wiesława Radmacher2, Michael A. Kaminski1,3, Jarosław Tyszka2 1 Earth Sciences Department, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia *E-mail: setoyama@kfupm.edu.sa 2 Polish Academy of Sciences, Institute of Geological Sciences, Cracow Research Centre, BioGeoLab, ul. Senacka 1, 31-002, Kraków, Poland 3 Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK Foraminifera and dinoflagellate cysts from the Upper Cretaceous on the Nyk High, the Vøring Basin were analysed in order to document their biostratigraphic ranges and to analyse foraminiferal biofacies of different fan sub-environments previously proposed based on ichnofossils by Knaust (2009). The studied core samples from well 6707/10-1 includes the Tumler Member of the Kvitonos Formation, the Spekkhogger Member of the Nise Formation and the Hvithval Member of the Springer Formation. The foraminiferal assemblages are composed exclusively of deep-water agglutinated taxa and generally diversified. Foraminiferal species with biostratigraphic values were, however, not recorded. The assemblages show some similarity to those described from the Fenestrella belli Zone of Gradstein et al. (1999) in their completely agglutinated nature and the presence of species of Gerochammina. The dinocyst assemblages are also diversified, and more reliable dating of the studied interval was provided based on bioevents of dinocysts that can be correlated to ones reported from the southwestern Barents Sea, the North Sea and Greenland. Those include the last occurrences of Heterosphaeridium cf. difficile and Odontochitina spp and the presence of pollen, Wodehouseia spinata. The whole interval is estimated to be of Santonian–Maastrichtian age. The relatively high diversity of foraminiferal assemblages with abundant tubular forms support the middle–upper bathyal palaeobathymetric estimation previously made for the northwest Vøring Basin by Gradstein et al. (1999). The comparison of assemblages from different subenvironments of a fan system shows that the species diversity and relative abundance of morphogroups are inconsistent due to small numbers of specimens in the inner to middle fan assemblages. Deep infaunal forms may be more common in this subenvironment, but the abundance is so low that this observation should be treated carefully. In contrast, the abundance and diversity of the assemblages from the overbank, fringe and basin plain subenvironments are relatively high, and their morphogroup composition is also comparable to each other where the assemblage size is large. The presence of bottom water currents, possibly in the form of a western boundary current, is suggested based on the abundant occurrence of tubular forms in the overbank, fringe, and basin plain subenvironments. References Gradstein, F.M., Kaminski, M.A., Agterberg, F.P., 1999. Biostratigraphy and paleoceanography of the Cretaceous seaway between Norway and Greenland. Earth Science Reviews 46, 27–98. Knaust, D., 2009. Characterisation of a Campanian deep-sea fan system in the Norwegian Sea by means of ichnofabrics. Marine and Petroleum Geology 26, 1199–1211. Setoyama, E., Radmacher, W., Kaminski, M.A., Tyszka, J., 2013. Foraminiferal and palynological biostratigraphy and biofacies from a Santonian–Campanian submarine fan system in the Vøring Basin (offshore Norway). Marine and Petroleum Geology 43, 396–408.