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) Hydrogen isotope study of the Babbitt Cu-Ni Deposit, Duluth Complex, Minnesota.
Taib, Nur Iskandar (M.Sc) 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) Genesis of sediment-hosted copper mineralization in south central Kansas: sulfide- sulfur/organic carbon associations and sulfur isotope systematics.
Johnson, Timothy Whipple (M.Sc) Oxygen isotope analysis of quartz, kaolin, smectite, and silver phosphate by CO2-laser microprobe.
Lee, Insung (Ph.D) Petrologic and geochemical studies of the Spruce Road Cu-Ni deposit, Duluth Complex, Minnesota.
McCoy, Megan E. (M.Sc) Oxide stockpile assessment, Golden Sunlight Mine, Whitehall, MT. [Montana].
Park, Young-Rok, (Ph.D) 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.
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.
2013-14 Graduate Student Supervision
- Anne Ayre PhD
- Matt Lilley PhD
- Eric Stifter MS
- Valentina Taranovic PhD
- Brad Thomas MS
Li, C., Thakurta, J. and Ripley, EM (2012) Low-Ca contents and kink-banded textures are not unique to mantle olivine: evidence from the Duke Island Complex, Alaska. Mineralogy and Petrology, v. 104, p. 147-153. DOI.
Li G, Li C, Ripley EM, Kamo S, Su S (2012) Geochronology, petrology and geochemistry of the Nanlinshan and Banpo mafic-ultramafic intrusions: implications for subduction initiation in the eastern Palaeo-Tethys. Contributions to Mineralogy and Petrology 164, 773–788.
Li C, Tao Y, Qi L, and Ripley EM (2012) Controls on PGE fractionation in the Emeishan picrites and basalts: constraints from integrated lithophile-siderophile elements and Sr-Nd isotopes. Geochimica et Cosmochimica Acta 90, 12–32.
Ding X, Ripley EM, Shirey SB, and Li C, (2012) Os, Nd, O and S isotope constraints on country rock contamination in the conduit related Eagle Cu-Ni-(PGE) deposit, Midcontinent Rift System, Upper Michigan. Geochimica et Cosmochimica Acta 89, 10–30.
Ding X, Ripley EM, and Li C (2012) PGE Geochemistry of the Eagle magmatic sulfide deposit, upper Michigan: Constraints on ore genesis in a dynamic magma conduit. Mineralium Deposita 47, 89-104.
Ripley, EM and Li, C. (2013) Sulfide saturation in mafic magmas: Is external Sulfur required for magmatic Ni-Cu-(PGE) ore genesis? Economic Geology 108, 45-58.
Li C, Ripley EM, Thakurta J, Stifter EC, and Qi L (2013) Variations of olivine Fo-Ni contents and highly chalcophile element abundances in arc ultramafic cumulates, southern Alaska. Chemical Geology 351, 15–28.
Peng R, Zhai Y, Li C, and Ripley EM (2013) The Erbutu Ni-Cu deposit in the Central Asian Orogenic Belt: a Permian magmatic sulfide deposit related to boninitic magmatism in an arc setting. Economic Geology 108, 1879–1888.
Thakurta, J, Ripley, EM, and Li, C (in press) Platinum group element geochemistry of sulfide-rich horizons in the Ural-Alaskan type ultramafic complex of Duke Island, southeastern Alaska. Economic Geology.
Stifter, EC, Ripley , EM, Li, C (in press) Silicate melt removal and sulfide liquid retention in ultramafic rocks of the Duke Island Complex, Southeastern Alaska. Mineralogy and Petrology.
Donoghue, K.A., Ripley, EM, and Li, C. (2014) Sulfur isotope and mineralogical studies of Ni-Cu sulfide mineralization in the Bovine Igneous Complex (BIC Intrusion), Baraga Basin, Northern Michigan. Economic Geology 109, 325-341.
Ripley, EM (2014) Ni - Cu - PGE mineralization in the Partridge River, South Kawishiwi and Eagle Intrusions; A Review of Contrasting Styles of Sulfide -Rich Occurrences in the Midcontinent Rift System. Economic Geology 109, 309-324.
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.
- Member of the Advisory Committees for the International Nickel Symposiun, Guiyang, China, 2012.
- International Workshop on Magmatic Ore Deposits, Bangalore, India
- 2014 International Platinum Symposium, Ekaterinburg, Russia
- Chair for CODMUR; Commission on ore deposits in mafic and ultramafic rocks
- Current member National Science Foundation Petrology and Geochemistry Panel
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