REVieWS IN EConomiC Geology Volume 12 APPLICATION OF RADIOGENIC ISOTOPES TO ORE DEPOSIT RESEARCH AND EXPLORATION CONTENTS Pb Isotopes, Ore Deposits, and R.M. Tosdal, J.L. Wooden, and R.M. Bouse Metallogenic Terranes Re-Os Isotope Geochemistry of Magmatic D.D. Lambert, J.G. Foster, L.R. Frick, and E.M. Ripley Sulfide Ore Systems Metallogenesis in Continental Margins: J. Ruiz and R. Mathur Re-Os Evidence from Porphyry Copper Deposits in Chile 40Ar/39Ar Geochronology of Supergene Processes in Ore Deposits P.M. Vasconcelos Integrative Geochronology of Ore Deposits: J.T. Chesley New Insights into the Duration and Timing of Hydrothermal Circulation Isotopic Dating of Diamonds D.G. Pearson and S.B. Shirey In Situ Analysis of Radiogenic Isotopes with Emphasis on R.A. Stern Ion Microprobe Techniques and Applications Editors D.D. Lambert and P.E. Brown SOCIETY OF ECONOMIC GEOLOGISTS, INC. Society of Economic Geologists, Inc. Reviews in Economic Geology, Vol. 12 Application of Radiogenic Isotopes to Ore Deposit Research and Exploration D.D. Lambert and P.E. Brown, Editors Additional copies of this publication can be obtained from Society of Economic Geologists, Inc. 7811 Shaffer Parkway Littleton, CO 80127 www.segweb.org ISBN: 978-1-629495-70-5 The Authors: Robin M. Bouse D. Graham Pearson Paulo Vasconcelos U.S. Geological Survey Department of Geological Sciences Department of Earth Sciences 345 Middlefield Road Durham University University of Queensland Menlo Park, CA 94025 South Road Brisbane, QLD 4072 USA Durham DH1 3LE Australia Telephone: 650.329.4448 U.K. Telephone: 61.7.3365.2297 Email: [email protected] Telephone: 44.191.374.4701 Email: Email: [email protected] [email protected] John Chesley Department of Geosciences Edward M. Ripley Joseph L. Wooden University of Arizona Department of Geological Sciences U.S. Geological Survey Tucson, AZ 85721 Indiana University 345 Middlefield Road USA Bloomington, IN 47405-5101 Menlo Park, CA 94025 Telephone: 520.621.6024 USA USA Email: [email protected] Telephone: 812.855.5581 Telephone: 650.725.9237 Email: [email protected] Email: [email protected] Jeffrey G. Foster BHP Minerals Discovery Joaquin Ruiz 40 McDougall Street Department of Geosciences Brisbane, QLD 4064 University of Arizona Australia Tucson, AZ 85721 Telephone: 61.7.3278.5733 USA Email: [email protected] Telephone: 520.621.6024 Email: [email protected] Louise R. Frick Victorian Institute of Earth and Steven B. Shirey Planetary Sciences Department of Terrestrial Magnetism Department of Earth Science Carnegie Institution of Washington Monash University 5241 Broad Branch Road, N.W. Melbourne, VIC 3168 Washington, D.C. 20015 Australia USA Telephone: 61.3.9905.4893 Telephone: 202.686.4370 Email: Email: [email protected] [email protected] Richard A. Stern David D. Lambert J.C. Roddick Ion Microprobe Victorian Institute of Earth and Laboratory Planetary Sciences Geological Survey of Canada Department of Earth Science 601 Booth St. Monash University Ottawa, ON K1A 0E8 Melbourne, VIC 3168 Canada Australia Telephone: 613.995.8935 Telephone: 61.3.9905.5767 Email: [email protected] Email: [email protected] Richard M. Tosdal Mineral Deposit Research Unit Ryan Mathur Department of Earth and Ocean Department of Geosciences Sciences University of Arizona University of British Columbia Tucson, AZ 85721 Vancouver, BC V6T 1Z4 USA Canada Telephone: 520.621.6024 Telephone: 604.822.6136 Email: [email protected] Email: [email protected] ii PREFACE The concept for Reviews in Economic Geology: Application included is one chapter devoted to the isotopic dating of di- of Radiogenic Isotopes to Ore Deposit Research and Exploration amonds. This study has profound implications for diamond grew out of discussions between scientists at several cen- genesis, the longevity of portions of the Earth’s upper man- ters for ore deposit studies in the United States, Canada, tle, and diamond exploration strategies in Archean cratonic and Australia. We recognized that there was a need for a settings. book that illustrates the diverse applications of radiogenic We sincerely hope that this volume makes members of isotope geochemistry in the mineral exploration arena. the economic geology community more aware of the The purpose of this volume and of the Society of Eco- broad field of radiogenic isotope geochemistry and the nomic Geologists short course is to provide economic geol- potential applications to their own research and explo- ogists, and the students of economic geology, with the fun- ration problems. The volume editors/short course con- damentals of the most commonly used radiogenic isotope venors and SEG editors are indebted to all of the authors systems and up-to-date information on applications of these for their efforts in the production of the short course and important tools to understanding ore-forming processes. the resulting volume. The editors would especially like to The volume covers the fundamentals of the more tradi- thank Lisa Laird of SEG for her extreme patience during tional (Pb, Rb-Sr, Sm-Nd) as well as the more exotic (Re-Os) the final stages of production of this Reviews volume. isotope systems in both magmatic and hydrothermal min- eral deposits. Unique new applications of Ar-Ar geochronol- David D. Lambert ogy in understanding supergene processes are also pre- Joaquin Ruiz sented, as are the latest in situ U-Pb geochronology techniques using SHRIMP microbeam technology. Finally, iii BIOGRAPHIES ROBIN M. BOUSE received her BS degree from Duke DAVID D. LAMBERT received his PhD degree in geo- University and an MS degree from the University of Rhode chemistry from the Colorado School of Mines in 1982. He Island. In 1995, she received a PhD from the University of has worked for the Branch of Isotope Geology (U.S. Geo- Arizona. As a doctoral candidate, Bouse studied ore de- logical Survey) in Denver; Texas Christian University in posits and isotope geochemistry, with emphasis on por- Fort Worth; and the Department of Terrestrial Magnetism phyry copper deposits in Arizona. She is interested in the at Carnegie Institution of Washington in Washington, origin of metals in ore deposits and their use, fate, and D.C. In 1990, he joined the Department of Earth Sciences transport in the environment. Since 1994, Bouse has been at Monash University (Melbourne, Australia), where he with the USGS Water Resources Division in Menlo Park, leads the Ore Genesis Research Group. The prime focus California, where she has concentrated on isotope geo- of this group is the study of igneous processes that are chemistry and its application to tracing sources of metals recorded in ultramafic-mafic intrusions, mantle xenoliths, in the environment. komatiite and flood basalt successions, ultrapotassic rocks, and granite porphyry system—in particular, those JOHN T. CHESLEY began his career in exploration with processes that concentrated strategic mineral resources of a BSc degree in geology from Oregon State University. He chromium, nickel, copper, gold, the platinum-group ele- received his MSc degree from OSU in 1986 and spent the ments, and diamonds. His research and teaching is cen- next two years helping set up the 40Ar/39Ar facility at the tered on the role of lithospheric geodynamics in the pet- U.S. Geological Survey in Denver. A continuing interest in rogenesis of giant ore deposits and in new applications of ore deposits led to his completion of a PhD degree at the trace element and radiogenic isotope geochemistry in University of Michigan in 1993. Chesley’s thesis was enti- tracing elemental pathways in magmatic and hydrother- tled, “Geochronology of Hydrothermal Ore Deposits.” For mal systems. He is a Fellow of the Society of Economic Ge- this, he used Sm-Nd in fluorite for direct dating of ore de- ologists and a member of the American Geophysical posits; he was the first person to do so. In conjunction with Union, Geochemical Society, and the Geological Societies other researchers at the University of Michigan and the of America and Australia. University of Arizona, Chesley has shown the importance of directly dating ore deposits and the application of mul- D. GRAHAM PEARSON is a graduate of the Royal School tiple isotopic dating methods toward understanding the of Mines, Imperial College, London. He completed a PhD overall lifetime of hydrothermal systems. He has worked at Leeds University in 1989, studying graphitised dia- with the U-Pb, Ar-Ar, Rb-Sr, Sm-Nd and Re-Os systems. monds in the Beni Bousera peridotite massif, north Mo- Currently he is a Research Associate at the University of rocco. He then undertook postdoctoral work at the De- Arizona, where he helped set up the Re-Os facility and partment of Terrestrial Magnetism (DTM), Carnegie continues his research on the geochronology of ore de- Institution of Washington, applying the Re-Os isotope sys- posits. His research horizons have broadened to include tem to dating mantle xenoliths in kimberlites. This work the timing of formation of Archean cratons, crust/mantle continued back in the UK, where he established an Re-Os interaction, Himalayan tectonics, and Sr in groundwater. isotope laboratory at the Open University. Moving to Durham in 1995, as a lecturer, he began applying the LOUISE R. FRICK graduated with a PhD in geochemistry Re-Os isotope system to dating diamond inclusions, col- from Monash University in 1999. As a graduate student, laborating with Steve Shirey and Rick Carlson at DTM. she spent three months as a predoctoral fellow at the De- Current research is focused on diamond genesis, plat- partment of Terrestrial Magnetism at Carnegie Institution inum-group-element geochemistry and applications of of Washington in Washington, D.C. Her specialty is the ap- Re-Os isotopes to Earth sciences, among other things.