Edward M. Ripley
Professor of Geological Sciences
- Ph.D., 1976, Pennsylvania State University
- M.S., 1973, University of Minnesota
- B.S., 1971, Illinois State University
My research interests include the genesis of metallic ore deposits and the application of stable isotopic geochemistry to petrologic problems. Primary research goals center on the understanding of both igneous and hydrothermal processes that control the concentration of metals in a variety of geologic settings. Techniques employed in this research program include field mapping, transmitted and reflected light microscopy, fluid inclusion microthermometry, major and trace element analyses, stable isotopic measurements, a variety of microbeam analytical techniques, and thermodynamic/kinetic modeling. Examples of research currently in progress include studies of the genesis of copper, nickel and platinum group elements in mafic igneous rocks of the Duluth Complex and Voisey's Bay deposit, Jinchuan deposit, Stillwater Complex, Duke Island Complex, and the Bushveld Complex, hydrothermal flow systems associated with continental rift zones, experimental studies of metal solubility in mafic magmas, and hydrothermal beryllium mineralization in rhyolitic volcanic rocks. Specific topics of concern include the relative roles of fractional crystallization and assimilation of country rocks in the formation of immiscible sulfide melt, the origin of hydrothermal fluids involved in the sub-solidus redistribution of platinum, palladium and gold, and both magmatic and meteoric waters in hydrothermal beryllium mineralization. Additional projects concern sulfur isotopic fractionation in ore systems, stable and radiogenic isotopic systematics of melt-country rock interaction, and metal enrichment in organic-bearing sediments. In 2003, I became part of the new NASA Astrobiology Institute, headquartered in the IUB Department of Geological Sciences. We are conducting a variety of experiments that deal with sulfur isotopic fractionation, including isotopic effects related to radiolytic oxidation processes.
At the undergraduate level I teach courses in Petrology (G418), Economic Geology (G416), and on occasion, Fuel and Mineral Resources (G316) and Earth Resources (G161). My graduate level courses include Isotopic Systematics (G690), Magmatic and Hydrothermal Geochemistry (G690), Metallic Ore Deposits (G616), and Geochemical Exploration (G617).
Recent Research Projects
Graduate Student Theses
Butler, Brian Keith (M.Sc., 1989) Hydrogen isotope study of the Babbitt Cu-Ni Deposit, Duluth Complex, Minnesota.
Taib, Nur Iskandar (M.Sc., 1989) A carbon isotope study of the Babbitt Cu-Ni Deposit, Duluth Complex, northeastern Minnesota: the devolatilization of graphitic-carbon bearing metasediments and the resulting contamination of the magma.
Branam, Tracy D. (M.Sc., 1991) Genesis of sediment-hosted copper mineralization in south central Kansas: sulfide- sulfur/organic carbon associations and sulfur isotope systematics.
Johnson, Timothy Whipple (M.Sc., 1994) Oxygen isotope analysis of quartz, kaolin, smectite, and silver phosphate by CO2-laser microprobe
Lee, Insung (Ph.D., 1994) Petrologic and geochemical studies of the Spruce Road Cu-Ni deposit, Duluth Complex, Minnesota
McCoy, Megan E. (M.Sc., 1997) Oxide stockpile assessment, Golden Sunlight Mine, Whitehall, MT. [Montana]
Park, Young-Rok, Ph.D., 1998, Stable isotopic studies of hydrothermal systems located above and below the Duluth Complex, Midcontinent Rift System, Minnesota
Nur Iskandar Taib, 2001, Open system magmatism and the emplacement of the Partridge River Intrusion, Duluth Complex, Minnesota
Tim Johnson, 2001, Oxygen isotopic fractionation in CO2 laser microprobes: Testing the metal-oxide - metal fluoride chemical and isotopic exchange hypothesis
Student Theses in Progress
Mariga, Jeffrey (Ph.D.) Oxygen isotopic studies of the Voisey's Bay Ni-Cu-Co deposit, Labrador
Shafer, Paula (Ph.D.) Mineralogic and isotopic studies of PGE mineralization at the Birch Lake deposit, Duluth Complex, Minnesota
Thakurta, Joyashish (Ph.D.) Mineralogic and isotopic studies of the Duke Island ultramafic complex, Alaska
Sarkar, Arindam (Ph.D.) Mineralogic and isotopic studies of the Uitkomst and Kabanga Cu-Ni deposits, South Africa, and Our Lady of the Lake Complex, Montana
Matthews, Wesley (M.S.) Oxygen isotopic studies of a pegmatite near the contact of the Harney Peak Granite and pelitic country rocks, Black Hills, South Dakota
Li C, Ripley EM, Naldrett AJ (2009) A new genetic model for the giant Ni-Cu-PGE sulfide deposits associated with the Siberian flood basalts. Economoc Geology 104, 201-301.
Li C, Ripley EM, Naldrett AJ, Schmitt AK, Moore CH (2009) Magmatic anhydrite-sulfide assemblages in the plumbing system of the Siberian Traps. Geology 37, 259-262.
Zhang M, Kamo S, Li C, Hu P, Ripley EM (2009) Precise U-Pb zircon-baddeleyite age of the Jinchuan sulfide ore-bearing ultramafic intrusion, western China. Mineralium Deposita (in press)
Thakurta J, Ripley EM, Li C (2009) Oxygen isotopic variability associated with multiple stages of serpentinization, Duke Island Complex, southeastern Alaska. Geochim. Cosmochim. Acta 73, 6298-6312.
Li C, Ripley EM (2009) Sulfur contents at sulfide-liquid or anhydrite saturation in silicate melts: empirical equations and example applications. Economic Geology 104, 405-412.
Sarkar A, Brophy JG, Ripley EM, Li C, Kamo S (2009) Geochemical and isotopic studies of the Lady of the Lake Intrusion and associated Tobacco Root Batholith: Constraints on the genetic relation between Cretaceous mafic and silicic magmatism in southwestern Montana. Lithos (in press)
Ripley EM (2009) Magmatic sulfide mineralization in Alaskan-type complexes. In Li C and Ripley EM (eds) New Developments in Magmatic Ni-Cu and PGE Deposits, 219-228.
Ripley EM , Li C (2009) Ni-Cu-PGE mineralization associated with the Proterozoic Midcontinent Rift System, USA. In Li C and Ripley EM (eds) New Developments in Magmatic Ni-Cu and PGE Deposits, 180-191.
Naldrett AJ, Li C, Ripley EM (2009) Anorthosite-related Ni-Cu-Co deposits: Examples from Labrador, Canada. In Li C and Ripley EM (eds) New Developments in Magmatic Ni-Cu and PGE Deposits, 192-218.
Pang KN, Li C, Zhou M-F, Ripley EM (2009) Compositional variations of olivine, clinopyroxene, plagioclase and apatite in the Panzhihua Fe-Ti-V ore-bearing intrusion, SW China: Constraints on petrogenesis and oregenesis. Lithos 110, 199-214
Ripley EM, Li C, Moore CH, Schmitt AK (2009) Micro-scale S isotope studies of the Kharaelakh intrusion, Noril’sk region, Siberia: Constraints on the genesis of coexisting anhydrite and sulfide minerals. Geochim. Cosmochim. Acta
I serve on several Departmental committees, and am a reviewer for several national and international journals, Associate Editor of Geochimica et Cosmochimica Acta, and am a proposal reviewer for NSF, PRF, Australian Research Council, and Canadian Research Council.
Stable Isotope Research Facility at Indiana University (SIRF-Indiana)
Scanning Electron Microscope
Analytical facilities for major and trace element analyses (ICP and AA)
Transmitted and reflected light microscopy, with digital photography