Additional Product Info - Society of Economic Geologists

GUIDEBOOK SERIES
Volume 43
Climax and Henderson Porphyry
Molybdenum Deposits and
The Leadville District, Colorado
Prepared for the Society of Economic Geologists Field Trip
September 25-27, 2014
Field Trip Leaders
R.J. Stegen and T.B. Thompson
SOCIETY OF ECONOMIC GEOLOGISTS, INC.
GUIDEBOOK SERIES
OF THE
SOCIETY OF ECONOMIC GEOLOGISTS, INC.
Guidebook 43
Print
ISSN 1547-3090
ISBN 978-1-629490-46-5
CD-ROM
ISSN 1547-3104
ISBN 978-1-629490-47-2
Online
ISSN 2374-6955
ISBN 978-1-629494-80-7
Digital version (on CD-ROM or as a pdf file) available from
Society of Economic Geologists, Inc.
7811 Shaffer Parkway
Littleton, Colorado 80127
Tel. 1.720.981.7882
Fax: 1.720.981.7874
Bookstore: www.segweb.org/store
Publication date: September 2014
(Revised)
CONTENTS
Preface
Ralph J. Stegen and Tommy B. Thompson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii
Road Log
To the Henderson Mine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
To Climax, Colorado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
To Leadville, Colorado. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Climax Porphyry Molybdenum Deposit, Colorado: A Summary [Reprint]
James R. Shannon, Eric P. Nelson, and Richard P. Smith. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
An Abbreviated History of the Leadville Mining District, Colorado
Tommy B. Thompson. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
The Black Cloud Story [Reprint]
Douglas M. Smith, Jr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
Post-Production History of the Black Cloud Mine, Leadville District, Colorado
Tommy B. Thompson. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .63
Geology and the Origin of Ore Deposits in the Leadville District, Colorado:
Part I. Geologic Studies of Orebodies and Wall Rocks [Reprint]
Tommy B. Thompson and Greg B. Arehart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67*
Geology and the Origin of Ore Deposits in the Leadville District, Colorado:
Part II. Oxygen, Hydrogen, Carbon, Sulfur, and Lead Isotope Data and
Development of a Genetic Model [Reprint]
Tommy B. Thompson and David W. Beaty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93*
*Guidebook 43 page numbers (in the format Page XX) are included for convenience; original publication
numbers have been retained in these papers as well.
Additional reprints relevant to these field trips are listed on the reverse and included on the CD-ROM that
accompanies this field trip guide. All except two of the papers were published by the Society of Economic
Geologists (SEG).
The American Institute of Mining, Metallurgical, and Petroleum Engineers has granted permission for the
reprinting of Wallace et al. (1968) from the Graton-Sales volume. The Geological Society of America has
granted permission for the reprinting of Shannon et al. (1982) from its journal, Geology.
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Reprinted Papers Included on the CD-ROM
Carten, R.B., Geraghty, E.P., Walker, B.M., and Shannon, J.R., 1988, Cyclic development of
igneous features and their relationship to high-temperature hydrothermal features in the
Henderson porphyry molybdenum deposit, Colorado: Economic Geology, v. 83, p. 266–
296.
Seedorff, E, and Einaudi, M., 2004, Henderson porphyry molybdenum system, Colorado: I.
Sequence and abundance of hydrothermal mineral assemblages, flow paths of evolving
fluids, and evolutionary style: Economic Geology, v. 99, p. 3–37.
Seedorff, E., and Einaudi, M., 2004, Henderson porphyry molybdenum system, Colorado: II.
Decoupling of introduction and deposition of metals during geochemical evolution of
hydrothermal fluids: Economic Geology, v. 99, p. 39–72.
Shannon, J.R., Walker, B.M., Carten, R.B., and Geraghty, E.P., 1982, Unidirectional
solidification textures and their significance in determining relative ages of intrusions at
the Henderson mine, Colorado: Geology, v. 10, p. 293–297.
Wallace, S.R., 1991, Model development: Porphyry molybdenum deposits: Economic Geology,
Monograph 8, p. 207–224.
——1995, The Climax-type molybdenite deposits: What they are, where they are, and why they
are [Presidential Address]: Economic Geology, v. 90, p. 1359–1380.
Wallace, S.R., Muncaster, N.K., Jonson, D.C., MacKenzie, W.B., Bookstrom, A.A., and Surface,
V.E., 1968, Multiple intrusion and mineralization at Climax, Colorado, in Ridge, J. D.,
ed., Ore deposits of the United States 1933–1967: New York, American Institute of
Mining, Metallurgical, and Petroleum Engineers, p. 603–640.
Wallace, S.R., MacKenzie, W.B., Blair, R.G., and Muncaster, N.K., 1978, Geology of the Urad
and Henderson molybdenite deposits, Clear Creek County, Colorado, with a section on a
comparison of these deposits with those at Climax, Colorado: Economic Geology, v. 73,
p. 325–368.
White, W.H., Bookstrom, A.A., Kamilli, R.J., Ganster, M.W., Smith, R.P., Ranta, D.E., and
Steininger, R.C., 1981, Character and origin of Climax-type molybdenum deposits:
Economic Geology 75th Anniversary Volume, p. 270–316.
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PREFACE
The Climax and Henderson porphyry Mo and Leadville district carbonate-hosted manto
deposits are within the Colorado Mineral Belt, a mineralized belt that contains the most
productive porphyry molybdenum and some of the largest base- and precious-metal manto
deposits in the world. Since the discovery of molybdenum-bearing stockwork veinlets at Climax
in 1879, the Urad orebody in 1914, and Henderson in 1964, collectively these mines have
produced over 2.9 billion pounds of Mo. In late 2009, Henderson produced its billionth pound of
molybdenum and in 2012 Climax commissioned a new concentrator and is now producing ore
from an open pit. Significant published reserves remain and for both Climax and Henderson that
total 1 billion pounds of molybdenum metal. The Leadville district is noted for its long history of
production having produced 3.1 million ounces of gold, 260 million ounces of silver and
significant base metals since its discovery in 1860, research on carbonate-hosted Ag-Zn-Pb-(Au)
deposits, and the founding of the Guggenheim mining fortune, including the formation of
ASARCO, Inc. SEG Monograph 7 reported on much of the research on the Colorado Mineral
Belt manto systems.
The Climax and Henderson porphyry molybdenum deposits are genetically associated
with Tertiary rhyolitic and granitic stocks. They are complex igneous hydrothermal systems
characterized by multiple intrusive and mineralizing events with average ore grades greater than
0.2% Mo. The orebodies are Mo stockwork veinlets that form dome-shaped masses centered on
an intrusive stock.
The Leadville veins and mantos were formed by magmatic-hydrothermal fluids
associated with the central intrusive body, the Breece Hill composite stock. Thermal and metal
zoning have been documented in SEG Monograph 7. Stable isotopic data from fluids and orealteration minerals have been utilized to develop the model of ore formation.
This guidebook provides copies of the key previously published papers of Climax,
Henderson and Leadville districts. This is a departure from the traditional SEG. Guidebook
format in that it does not contain new papers of the deposits. With the exception of the two
Economic Geology papers by Seedorff published in 2004, very little geologic study has been
performed of these deposits for the last 20 years. This is largely due to mine closures and
depressed Mo metal prices. It is planned that with the recent stability in the price of Mo and the
re-opening of the Climax mine, that mine geology programs and new research will lead to further
understanding of these important deposits. In addition to the professional papers, road logs from
Denver to Henderson, Climax and Leadville are included.
RALPH J. STEGEN
TOMMY B. THOMPSON
Field Trip Leaders
Editor’s note: SEG Guidebook 43 includes some materials previously published in Guidebooks 2
(on Leadville) and 38 (Henderson and Climax) and Economic Geology Monograph 7 (Leadville),
along with two short papers on the Leadville mining district and a combined road log. The current
field trip guidebook has been revised from 2013, with an updated Preface and Road Log that
reflects a departure point from Keystone, Colorado, venue for the SEG 2014 Conference.
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