Economic Geology Professor, Associate Department Head & Undergraduate Advisor Current Research Interests The application of conventional and laser microprobe stable isotope techniques for economic geology studies is my main area of research interest. I have also recently become involved in some very interesting geobiological and paloeclimatic studies in the past several years thanks to a number of collaborative studies undertaken with other UGA faculty and graduate students. Education Education: B.A., Colgate University, 1980 M.S., University of South Florida, 1983 Ph.D., University of Wisconsin, 1990 Research Research Areas: Economic Geology Geochemistry Research Interests: Main Areas of Interest The application of conventional and laser microprobe stable isotope techniques for economic geology studies is my main area of research interest. I have also recently become involved in some very interesting geobiological and paloeclimatic studies in the past several years thanks to a number of collaborative studies undertaken with other UGA faculty and graduate students. We have an outstanding stable isotope facility here in Athens, with the ability to extract and analyze silicate oxygen (soon via a new laser system), carbonate carbon and oxygen, sulfide/sulfate sulfur, and mineral/water H/D isotopes for geologic studies. The stable isotope lab is also equipped with a laser microsampler for in-situ analysis of sulfide sulfur and carbonate carbon and oxygen isotope ratios. The original (ancient) system that I constructed when I arrived in 1991 has now been replaced with a state of the art computer controlled sampling system connected to a continuous flow inlet that was designed and constructed by Dr. Kristen Leckrone during her stay here as an NSF postdoc. Since I arrived in Athens in 1991, my students have worked on the following research projects: Sandra Bezenek, Frank Lieth, Mustapha Kane: Dalnegorsk borosilicate skarn deposit, Far East Russia Three students (Sandra Bezenek M.S. 1996, Frank Lieth M.S. 1996, Mustapha Kane Ph.D. 1996) worked on projects on theDalnegorsk borosilicate skarn deposit, Far East Russia. These studies focused on both the regional scale geology of the central Primorye region from a metallogenic standpoint, as well as geochemical studies of the Dalnegorsk deposit itself. This deposit is the largest borosilicate skarn in the world, supplying over 80% of Russia's boron, and is also the largest wollastonite deposit in the world. We were able to determine the time-integrated history of the fluid system as it evolved from an initial magmatic-dominated system to a meteoric-dominated system with time. The fluid history was complex, however, with multiple cyclic intrusions causing the fluid composition to vary with time from magmatic- to meteoric-dominated regimes several times. This work involved field work in Russia as well as subsequent lab work here in Athens and at Oak Ridge National Lab using the SIMS housed there. This project, the results of which were published in GEOLOGY in 2001, was a cooperative study sanctioned by a formal agreement between the Far East Geological Institute of the Russian Academy of Science and the University of Georgia. At left is a photo of the Primorye coast at Rudnaya Pristan, approximately 30 km east of Dalnegorsk. Greg Vaughan: Seafloor Hydrothermal Vents (Blacksmokers), East Pacific Rise Graduate student Greg Vaughan (M.S. 1995) worked on seafloor hydrothermal vents (blacksmokers) from several East Pacific Rise vent sites. Greg had the unique opportunity of getting some dive time on the ALVIN submersible at the 9-10º N site, where very recent volcanic activity (zero age) gave scientists the chance to see a submarine hydrothermal system born. Greg's research focused on the variation of sulfur isotope ratios within individual chimney walls. This work documented variable fluid compositions in these ephemeral vent sites, and has led to a better understanding of mid-ocean ridge hydrothermal fluid flow. He used the laser microprobe here in Athens for this work. The photo at left shows the blacksmoker chimney collected at the 21º N site that Greg concentrated on in his thesis. It is one of the largest chimney structures collected to date from a mid-ocean ridge site, and it currently resides here in Athens. Greg also did a substantial amount of work on improving the standardization procedure used for laser ablation stable isotope ratio measurement, and the results of that work was published in American Mineralogist in 1996. U.S. Mineral Deposits Between 1995 and 2002 a number of students worked on mineral deposits here in the U.S. Langdon Mitchell Langdon Mitchell (M.S. 1996) worked on the Viceroy Gold Castle Mountain adularia-sericite epithermal gold deposit in California. This system is unusual in the sense that it appears to be directly spatially related to and contemporaneous with the 15 my Linder Peak volcanic package that it’s hosted in. These adularia-sericite systems almost always form distal to volcanic centers and 1-2 my after the cessation of volcanism, so Langdon's thesis is an important study that proves to be the exception to the rule from an ore deposit model standpoint. The top left photo is an aerial shot of the Castle Mountain property , and clearly shows the widespread, argillically-altered zone surrounding the centrally located pits representing the zone of focused fluid flow and gold mineralization. The results of Langdon’s work were published in a GSN Ore Deposits of the Cordillera volume in 1996. Grant Eager Grant Eager (M.S. 1998) focused on the Kennecott Ridgeway gold deposit in South Carolina. We led an SEG-sponsored fieldtrip here from the 1995 national GSA meeting, and many of the participants were hard pressed to say what sort of deposit Ridgeway was initially as it is now so structually deformed. Grant found that the sulfur isotope signature of the pyrite that is ubiquitous throughout the deposit is strongly suggestive of formation in a submarine hot-spring environment. These data, coupled with a number of critical field observations, will hopefully put the shear-zone vs. hot-spring debate to rest. The top left photograph shows a piece of high grade ore (upper, cm scale) and a photomicrograph (lower, field of view is 4.6 mm) of the same material which shows the strongly developed cleavage. Julia Rosdeutscher Julia Rosdeutscher (M.S. 1999) did her thesis on the Pikes Peak Mining Co. Grassy Valley gold deposit in Colorado. This deposit is hosted just outside the phonolitic breccias that comprise much of the diatreme in the middle of the Cripple Creek district (see lower left photo for a map of the district, including Grassy Valley), which is a famous and long-term gold producer. Julie was able to show that although the deposit is not hosted within the diatreme proper, it was still dominated by magmatic rather than meteorically derived fluids. Christian Schrader and Berkley Tracy Students Christian Schrader and Berkley Tracy completed their Masters projects in 2001 working on a large porphyry system in Alaska. We spent about a month during the summer of 1998 at Lake Iliamna, Alaska, working on core samples from thePebble Cu-Au porphyry deposit. Cominco American Exploration funded this project. Christian worked on the geochronology and geochemistry of the multiple intrusive phases extant within the area, while Berkley focused on a combined fluid inclusion/barometry/structure problem that involved a significant amount of three dimensional modeling. It's a huge deposit, and both of these projects could easily have been expanded into Ph.D. dissertations. The photo at the left shows Christian and Berkley stylingon the back of the Iliamna Lake Lodges' 900 HP jet boat that took us for a run up the Newhalen River that runs into Lake Iliamna. Fred Andrus: Stable Isotope Geochemistry and Oxygen Isotope Profiles Graduate student Fred Andrus completed his M.S. under the direction of Dr. Betsy Reitz (UGA Anthropology) working on the stable isotope geochemistry of oysters and clams from the Georgia coast and his Ph.D. under my direction, and is solely responsible for dragging me kicking and screaming into the archeological and climatological realm. Now a professor at the University of Alabama, Fred made some major breakthroughs, and in particular his work that has shown that sea surface temperature (SST) and El Nino is clearly recorded inoxygen isotope profiles in Peruvian sea catfish otoliths (aragonite "earstones" in fish) collected during the 1997-1998 ENSO event. Otoliths from the same species of catfish excavated from archaeological sites in northern Peru show that SST's were warmer prior to 5000 BP than today. The results of this research are now published in Science, Paleoceanography, and the Journal of Archeological Science. The photo at left shows Fred at the Ostra site south of Trujillo near the Santa river in Peru. Chris Kelson: Intrusion and Mineralization in Battle Mountain District, Nevade Chris Kelson worked with PlacerDome USA on an investigation of the Hilltop mine and surrounding areas in the Battle Mountain district, Nevada. He completed his Ph.D. in 2006 and is now an assistant professor at SUNY-Potsdam. Chris’ research focused on the timing of intrusion and mineralization in the Hilltop district. Chris spent several summers in Nevada working on the numerous mines and prospects in the district, and a great deal of time here in Athens doing stable isotope, fluid inclusion, and age dating on a huge suite of samples. The figure shows some of the nice sulfosalt-rich material Chris worked on from the Betty O’Neal mine, one of the many interesting mineralized areas within the Hilltop district. The results of this research have already been published in a GSN Ore Deposits of the Cordillera volume, and are now in submission to Economic Geology. Elizabeth Hollingsworth: Fluid Flow Systems in the Uzon Caldera, Kamchatka Elizabeth Hollingsworth just completed her M.S. working on elucidating the nature of the fluid flow system in the Uzon caldera, Kamchatka. This project is an NSF funded study to evaluate the relationships between hydrothermal fluid flow and microbiological consortia that live in hot spring systems. Elizabeth spent a field season in the caldera collected a large suite of water, sediment, and rock samples, and subsequently collected a large amount of sulfur isotope data from those samples. She was able to constrain quite nicely the origin, migration, and ultimate fate of sulfur as it released from the magma chamber beneath the caldera, migrated upward, and then interacted in a myriad of ways at the surface, including becoming available to numerous microbial organisms. This work is now in submission at the Journal of Volcanology and Geothermal Research. The photo shows Elizabeth and colleagues working in the East Thermal Field, with Mt. Uzon in the background. Elizabeth just completed her first tour as a geologist working at the Green’s Creek massive sulfide mine in southeast Alaska, and is currently mushing dogs for tourists in Chena Hot Springs near Fairbanks. All these students have done outstanding jobs and have gone on to a variety of careers in academia and industry. In the process of doing their research they became quite savvy at doing a host of different things, and I have benefited more than they know from all wonderful things they have learned. I am now beginning a year long formal Study in a Second Discipline program here at UGA, during which time I hope to morph somewhat into a geobiologist, while retaining my ore deposit roots. We will continue our Kamchatka hot spring work, with exciting new projects on the horizon focused on nitrogen and sulfur cycling in hot springs, as well as the biogeographic distribution of various microbial consortia within active caldera settings. Selected Publications Selected Publications: Peer-Reviewed Journals and Volumes Andrus, C.F.T., Hodgins, G.W.L., Sandweiss, D.H., and Crowe, D.E., 2005, Molluscan radiocarbon as a proxy for El Niño-related upwelling variation in Peru,in Isotopic and Elemental Tracers of Late Quaternary Climate Change, Surge, D. and Mora, G, eds., Geol. Soc. Amer. Spec. Pub., v.395, p. 13-19 (Invited). Kelson, C.R., Crowe, D.E., and Stein, H.J., 2005, Geochronology and geochemistry of the Hilltop, Lewis, and Bullion mining districts and surrounding area, Battle Mountain-Eureka trend, Nevada in Rhoden, H.N., Steininger, R.C., and Vikre, P.G., eds., Geological Society of Nevada Symposium 2005: Windows to the World, Reno, NV., 18 p. Andrus, C.F.T. and Crowe, D.E., in press, Determination of season of capture of hard clams from six sites on St. Catherine’s Island using incremental stable oxygen isotope analysis; Anthropological Papers Amer. Mus. Natural History (Invited). Railsback, L.B., Holland, S.M., Hunter, D.M., Jordan, E.M., Diaz, J.R., and Crowe, D.E., 2003, Controls on geochemical expression of subaerial exposure in Ordovician limestones from the Nashville Dome, Tennessee, U.S.A.; Jour. Sed. Res. v. 73, p. 790-805. Andrus, C.F.T., Crowe, D.E. and Romanek, C.S., 2002, Oxygen isotope record of the 1997-1998 El Niño in Peruvian sea catfish (Galeichthys peruvianus) otoliths; Paleoceanography, v.17, DOI:10.1029/2001PA000652. Andrus, C.F.T., Crowe, D.E., Sandweiss, D.H., Reitz, E.J., and Romanek, C.S., 2002, Otolith δ18O record of mid-Holocene sea surface temperature in Peru; Science, v. 295, p. 1508-1511. Andrus, C.F.T. and Crowe, D.E. 2002, Alteration of otolith aragonite: Effects of Prehistoric cooking methods on otolith chemistry; Jour. Archaeological Sci., v. 29, p. 291-299. Crowe, D.E., Riciputi, L.R., Bezenek, S.R., and Ignatiev, A.I., 2001, Oxygen isotope and trace element zoning in hydrothermal garnets: Windows into large-scale fluid flow behavior; Geology, v. 29, p. 479-482. Andrus, C.F.T. and Crowe, D.E., 2000, Geochemical analysis of Crassostrea virginica as a means of determining season of capture; Jour. Archeological Sci., v. 27, p. 33-42. Bierlein, F.P. and Crowe, D.E., 2000, Phanerozoic orogenic lode gold deposits, inHagemann, S.G. and Brown, P.E., eds., Gold in 2000; Soc. Econ. Geol. Reviews in Economic Geology, v. 13, p. 103-139. Thomas, R.C., Romanek, C.S., Coughlin, D.P., and Crowe, D.E., 1999, Treatment of acid mine drainage using anaerobic constructed treatment wetlands: Predicting longevity with substrate neutralization potential, in Goldsack, D., Belzile, N., Yearwood, P., and Hall, G.J., eds., Sudbury '99 Mining and the Environment, vol. 2; Sudbury Environmental, Sudbury, Canada, p. 449-458. Shanks, W.C., III, Crowe, D.E., and Johnson, C., 1998, Sulfur isotope analyses using the laser microprobe, in McKibben, M.A., Shanks, W.C., III, and Ridley, W.I., eds., Applications of Microanalytical Techniques to Understanding Mineralizing Processes; Soc. Econ. Geol. Reviews in Econ. Geol., v. 7, p. 141 - 153. Puchner, C.P., Smith, G.M., Flanders, R.W., Crowe, D.E., and McIntyre, S.C., 1998, Bedrock geology of the Ruby/Poorman mining district, Alaska; Alaska Dept. of Natural Resources, DGGS, no. 98-11, 12 p. and 3 color maps. Crowe, D.E., Mitchell, T.L., and Capps, R.C.,1996, Geology and stable isotope geochemistry of the Jumbo South Au deposit, California: Evidence for magmatic and meteoric fluid mixing, in Coyner, A.R., and Fahey, P.L., eds., Geology and Ore Deposits of the American Cordillera: Geol. Soc. of Nevada Symposium Proceedings, Reno/Sparks, Nevada, April 1995, p. 891-907. Crowe, D.E. and Vaughan, R.G., 1996, Improved standardization techniques for laser microprobe δ34SCDT determination: Amer. Mineral., v. 81, p. 187-193. Miller, J.S., Glazner, A.F., and Crowe, D.E., 1996, Upper Cretaceous muscovite-garnet granites in the central and western Mojave desert, California and their relation to the crustal structure of the continental margin; Geology, v. 24, p. 335-338. Saunders, J.A., Cook, R.B., Thomas, R.C., and Crowe, D.E., 1996, Coprecipitation of trace metals in biogenic pyrite: Implications for enhanced intrinsic bioremediation, in Bottrell, S.H., ed., Proceedings of the 4thInternational Symposium on the Geochemistry of the Earth's Surface, p. 470-474. Crowe, D.E., 1995, Geology and geochemistry of gold deposits of the Carolina Slate Belt, South Carolina, in Crowe, D.E., ed., Gold Deposits of the Carolina Slate Belt; Society of Economic Geologists Fieldtrip Guidebook series, v. 24, p. 1-20. Crowe, D.E., 1995, ed., Gold Deposits of the Carolina Slate Belt; Society of Economic Geologists Fieldtrip Guidebook Series, v. 24, 172 p. Crowe, D.E., 1994, Preservation of original hydrothermal δ34S values in greenschist to upper amphibolite volcanogenic massive sulfide deposits; Geology, v. 22, p. 873-876. Crowe, D.E., Nelson, S.W., Brown, P.E., Valley, J.W. and Shanks, W.C., III,1993, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound region, southcentral Alaska: Reply; Econ. Geol., v.88, p. 1285-1288. Crowe, D.E. and Valley, J.W., 1992, Laser microprobe study of sulfur isotope variation in a seafloor hydrothermal spire, Axial Seamount, Juan de Fuca Ridge, eastern Pacific (Invited): Chem. Geol. (Isotope Geosci.), v. 101, p. 63-70. Crowe, D.E., Nelson, S.W., Brown, P.E., Valley, J.W. and Shanks, W.C., III, 1992, Geology and geochemistry of volcanogenic massive sulfide deposits and related igneous rocks, Prince William Sound region, southcentral Alaska: Econ. Geol., v.87, p. 1722-1746. Crowe, D.E., Millholland, M. and Brown, P.E., 1991, Precious and base metal mineralization associated with high salinity hydrothermal fluids in the Mt. Estelle pluton, southcentral Alaska: Econ. Geol., v.86, p. 1103-1109. Crowe, D.E., Shanks, W.C., and Valley, J.W., 1991, Laser microprobe investigation of the Rua Cove deposit, Prince William Sound, Alaska; in Good, E.E., Slack, J.F. and Kotra, R.K., eds., U.S. Geol. Survey Circ., no.1062, p. 13-14. Crowe, D.E., Valley, J.W., and Baker, K.L., 1990, Micro-analysis of sulfur-isotope ratios and zonation by laser microprobe; Geochim. Cosmochim. Acta, v. 54, p. 2075-2092. Crowe, D.E., 1990, Geochemistry of volcanogenic massive sulfide and high-grade Au granite-hosted ore deposits, southern Alaska, and, Development and application of laser microprobe techniques for analysis of sulfur, carbon and oxygen isotope ratios; Ph.D. thesis, University of Wisconsin, Madison, WI, 209 p. Crowe, D.E. and Davis, R.A., Jr., 1985, North Bunces Key: A recently formed emergent barrier island. in R.A. Davis, Hine, A.C. and Belknap, D.F. (eds.), Geology of the Barrier Island and Marsh-Dominated Coasts, west-central Florida. Geol. Soc. Amer. Guidebook, 119p (Invited). Abstracts Crowe, D.E., Jordan, T.R., Baker, M.S., and Schroeder, P.A., 2006, Mapping the distribution of alteration minerals in an active geothermal setting using satellite-based spectral reflectance: An example from the Uzon Caldera, Kamchatka, Far East Russia: Geol. Soc. Amer. Abstr. with Prog., v. 38, no. 7, p. 565. Kelson, C.R., Crowe, D.E., and Stein, H.J., 2005, Geochronology and geochemistry of the Hilltop, Lewis, and Bullion mining districts, Battle Mountain - Eureka trend, Nevada: Geol. Soc. Amer. Abstr. with Prog., v. 37, no. 7, p. 314. Purdin, B., Railsback, L.B., Holland, S.M., and Crowe, D.E., 2005, Significance of δ13C, δ18O, and strontium content in the identification of surfaces of subaerial exposure in Ordovician limestones of the Nashville Dome, Tennessee, U.S.A., Geol. Soc. Amer. Abstr. with Prog., v.37, no. 7, p. 356. Purdin, B., Railsback, L.B., Holland, S.M., and Crowe, D.E., 2005, Significance and variation in δ13C and δ18O across surfaces of subaerial exposure in Ordovician limestones of the Nashville Dome, Tennessee, Geol. Soc. Amer. Abstr. with Prog., v. 37, no. 2, p. 11. Kelson, C.R., Crowe, D.E., and Stein, H.J., 2005, Geochronology and geochemical study of part of the Battle Mountain - Eureka trend, Nevada: Geochim. Cosmochim. Acta, v. 69, no. 10S, A567. Crowe, D.E., and Karpov, G.A., 2004, Geologic Setting of the Uzon Caldera, Kamchatka, Far East Russia, Geol. Soc. Amer. Abstr. with Prog., v. 36, p. 432. Hollingsworth, E.R., Crowe, D.E., and Romanek, C.S., 2004, Hydrothermal alteration facies in the Uzon Caldera, Kamchatka, Far East Russia, Geol. Soc. Amer. Abstr. with Progr., v. 36, p. 432. Jones, C.A., Crowe, D.E., and Romanek, C.S., 2004, Geothermal fluid source determination in the Uzon Caldera, Kamchatka, Russia, Geol. Soc. Amer. Abstr. with Progr., v. 36, p. 432. Kelson, C.R., and Crowe, D.E., 2004, Origin and significance of melnikovite pyrite from the Hilltop gold deposit, Nevada, Geol. Soc. Amer. Abstr. with Progr., v. 36, p. 354. Kyle, J., Schroeder, P., Crowe, D.E., and Romanek, C., 2004, Evidence for biomineralization and preservation of microorganisms in siliceous sinter deposits from the Uzon Caldera, Kamchatka, Russia, Geol. Soc. Amer. Abstr. with Progr., v. 36, p. 474. Romanek, C.S., Crowe, D.E., Kyle, J., and Schroeder, P.A., 2004, Chemical and stable isotopic composition of microbial mats from hot springs of Uzon Caldera, Kamchatka, Geol. Soc. Amer. Abstr. with Progr., v. 36, p. 474. Heim, N.A., Layou, K.M., Railsback, L.B., Holland, S.M., Cox, J.E., and Crowe, D.E., 2004, Geochemical evidence of subaerial exposure at parasequence boundaries in upper Ordovician limestones from the Nashville Dome, Tennessee, U.S.A., Geol. Soc. Amer. Abstr. with Progr., v. 36, p. 76. Andrus, C. Fred T., Hodgins, Gregory, and Crowe, D. E. 2002, Molluscan radiocarbon as a proxy for El Niño-related upwelling variation in Peru. Geol. Soc. Amer. Abstr. with Progr., v. 140, p. 12. Andrus, C.F.T., Crowe, D.E., and Sandweiss, D.H., 2001, Development and application of otoliths as paleoclimate proxies (Invited); American Geophysical Union - Fall, Eos 80: F575. Andrus, C.F.T., Crowe, D.E., and Sandweiss, D.H., 2000, Anthropogenic induration of sediments at the terminal Pleistocene Peruvian site Quebrada Jaguay; Geol. Soc. Amer. Abstr. with Prog., v. 32, p. A276. Andrus, C. F. T., Crowe, D.E., and Sandweiss, D. H., 2000, Climate change and subsistence strategy in mid-Holocene Peru: Geochemical evidence of ENSO variation; Soc. Amer. Archaeology Prog., v. 65, p. 30. Tracy, B., Crowe, D.E., and Turner, K., 2000, Geology and ore fluid geochemistry of the Pebble Cu-Au porphyry deposit, southwest Alaska: Microthermometric clues to buried structure, in Bucci, L.A. and Mair, J.L., eds., Gold in 2000 Extended Abstract volume, Centre for Global Metallogeny, Perth, Australia, p.69-73. Andrus, C.F.T., Crowe, D.E., and Sandweiss, D.H., 1999, Geochemical evidence of mid-Holocene ENSO variation derived from otoliths; Am. Geophys. Union, Prog. and Abstr., v. 80, p. F575. Andrus, C. F. T., and Crowe, D.E., 1999, Geochemical determination of Hard Clam season of capture from five sites on St. Catherine's Island, Georgia;. Southeastern Archae. Conf. Bull., v. 42, p. 18-19. Hagemann, S.G., Bateman, R., Crowe, D.E., and Veilreicher, R.M., 1999, In situ sulfur isotope composition of pyrites from the Fimiston- and Oryoa-style gold lodes in the Golden Mile camp, Kalgoorlie; Implications for sulfur source(s) and depositional processes; Geol. Soc. Amer. Abstr. with Prog., v. 31, p. 32. Leckrone, K.J., and Crowe, D.E., 1999, In situ isotopic analysis of sulfide minerals by UV laser-GC-iRMS; Am. Geophys. Union, Prog. and Abstr. Swanson, S.E., Maloof, T.L., Crowe, D.E., Riciputi, L.R., and Hochella, M.F., Jr., 1999, Oxygen isotope analysis of olivine from the Blue Ridge of western North Carolina and Georgia, Geol. Soc. Amer. Abstr. with Prog., v. 31, p. A225. Thomas, R.C., Romanek, C.S., and Crowe, D.E., 1999, Remediation of acid-sulfate runoff using a modified constructed-wetland technology: Field demonstration from a coal storage pile; 19th International Geochemical Exploration Symposium, Vancouver BC., p. 99-100. Thomas, R.C., Romanek C.S., Coughlin, D.P., and Crowe, D.E., 1999, Treatment of acid mine drainage using anaerobic constructed treatment wetlands: Predicting longevity with substrate neutralization potential, Mining and the Environment II Conference Proceedings, Centre in Mining and Mining Environment Research, Sudbury Ontario, p. 449-458. Andrus, C.F.T., Crowe, D.E., and Sandweiss, D.H., 1998, Mid-Holocene El Niño variation recorded in otoliths from Preceramic Peru; Geol. Soc. Amer. Abstr. with Prog., v. 30, p. A-16. Andrus, C.F.T., Crowe, D.E., and Sandweiss, D.H., 1998, Laser microprobe isotopic analysis of otoliths: New methods and applications from Mid-Holocene Peru; 8th Int. Council Archaeozoology, Victoria, B.C., August 23-29, p. 40. Leckrone, K.J., Ricci, M.P., and Crowe, D.E., 1998, An algorithm for the calculation of sulfur and oxygen isotope ratios based on the mass spectrum of sulfur dioxide; Geol. Soc. Amer. Abstr. with Prog., v. 30, p. A-80. Rosdeutscher, J.A., Crowe, D.E., and Harris, T.D., 1998, Characterization of distal gold mineralization and alteration in the Cripple Creek District, Colorado; Geol. Soc. Amer. Abstr. with Prog., v. 30, p. A-301. Eager, W.G., Crowe, D.E., and Mitchell, T.L., 1997, Geology and stable isotope geochemistry of the Ridgeway North pit deposit, Ridgeway, South Carolina: Evidence for a syngenetic origin: Geol. Soc. Amer. Abstr. with Prog., v. 29, no. 3, p. 15. Schroeder, P.A., Crowe, D.E., and Melear, N.D., 1997, Stable carbon isotope signatures preserved in authigenic minerals from a forested granitic regolith; Panola Mt., Georgia; Geol. Soc. Amer. Abstr. with Prog., v. 29, p. 363. Thomas, R., Saunders, J.A., and Crowe, D.E., 1997, Trace element fixation via biogenic pyrite formation: A study of the Uphapee Creek pyritized logs: Geol. Soc. Amer. Abstr. with Prog., v. 29, no. 3, p. 74. Saunders, J.A., and Crowe, D.E., 1996, Retardation of boiling and the genesis of shallow bonanza epithermal gold deposits: Evidence from the Sleeper Deposit, Nevada; Geol. Soc. Amer. Abstr. with Prog., v. 28, p. A94. Roden, M. R., Kamola, D., Holland, S., Crowe, D.E., and Fleisher, C., 1996, Punctuated equilibrium: The case for thematic and extended field trips during a six week field school; Geol. Soc. Amer. Abstr. with Prog., v. 28, p. A328. Ivanov, V.V., Ignatiev, A.V., and Crowe, D.E., 1995, Stable isotope studies of hydrothermal gold deposits in the North-West Pacific: Sources of carbon and oxygen and implications for the mineralization processes; Proc. 8th Int. Symp. on Water-Rock Interactions, Vladivostok, Russia, August 15-19, 1995, A.A. Balkema, Rotterdam. Bezenek, S.R., Crowe, D.E., and Riciputi, L.R., 1995, Evidence of protracted growth history of skarn garnet using SIMS oxygen isotope, trace element and rare earth element data; Geol. Soc. Amer. Abstr. with Prog., v. 27, p. A-67. Lieth, F.G. and Crowe, D.E., 1995, Oxygen isotope study of the Dalnegorsk borosilicate skarn, Far East Russia; Geol. Soc. Amer. Abstr. with Prog., v. 27, p. A-377. Crowe, D.E., Mitchell, T.L., and Capps, R.C., 1995, Geology and stable isotope geochemistry of the Jumbo South Au deposit, California: Evidence for magmatic and meteoric fluid mixing; Geological Society of Nevada, symposium on Geology and Ore deposits of the Cordillera, April 8-12 Reno, Nevada. Saunders, J., Thomas, R.C., Cook, R., and Crowe, D.E., 1995, Mineralogy, geochemistry and textures of natural iron sulfides formed by sulfate-reducing bacteria; 5th V.M. Goldschmidt Conference on Geochemistry, May 24-26, Penn State Univ. Crowe, D.E., and Vaughan, R.G., 1994, Advances in the SO2 laser microprobe technique: Development of a new standardization method; Am. Geophys. Union, Prog. and Abstr., v. 75, p. 695 . Vaughan, R.G., and Crowe, D.E., 1994, Sulfur isotope zonation within 21°N hydrothermal conduits: Laser microprobe data; Am. Geophys. Union, Prog. and Abstr., v. 75, p. 315 . Crowe, D.E., and Ignatiev, A.I., 1993, Geology and geochemistry of the Dalnegorsk borosilicate skarn deposit, Far East Russia; Geol. Soc. Amer. Abstr. with Prog., v. 25, p. A403. Kane, M. and Crowe, D.E., 1993, Geobarometry and geothermometry of Sn-W greisen systems and associated igneous rocks, Sikhote-Alin region, Far East Russia; Geol. Soc. Amer. Abstr. with Prog., v. 25, p. A402. Mitchell, T.L., and Crowe, D.E., 1993, Stable isotope geochemistry of the Jumbo South Au deposit, California; Geol. Soc. Amer. Abstr. with Prog., v. 25, p. A163. Crowe, D.E., Valley, J.W., and Shanks, W.C.,III, 1993, Preservation of original hydrothermal δ34S values in greenschist and amphibolite massive sulfide deposits: Laser microprobe data (Invited): Europ. Union Geosci., Terra Abstr., v. 5, p. 369. Crowe, D.E., Valley, J.W., and Shanks, W.C., III, 1992, Laser microprobe evidence for preservation of initial δ34S values in amphibolite grade massive sulfide deposits: Thermometric Implications; Am. Geophys. Union, Prog. and Abstr., v. 73, p. 626. Valley, J.W., Baumgartner, L.P., Crowe, D.E., Eiler, J.E., Elsenheimer, D., Kohn, M.J., and Spicuzza, M., 1992, Stable isotope thermometry, speedometry, and hygrometry (Invited); Geol. Soc. Amer. Abstr. with Prog., v. 24, p. A172 Crowe, D.E., and Shanks, W.C., III, 1992, Laser microprobe δ34S study of recent and ancient volcanogenic massive sulfide deposits (Invited): 3rd V.M. Goldschmidt Conference, May 8-10, Reston, VA, p. A23-A24. Crowe, D.E., and Shanks, W.C., III, 1991, Laser microprobe δ34S study of coexisting sulfide pairs: Seeing through metamorphism. Am. Geophys. Union, Prog. and Abstr., v. 72, p. 292. Crowe, D.E. and Valley, J.W., 1991, Laser microprobe study of sulfur isotope variation in a seafloor hydrothermal spire, Axial Seamount, Juan de Fuca Ridge, eastern Pacific (Invited): Terra Abstr., v. 3, p. 3. Crowe, D.E., Millholland, M.A., and Brown, P.E., 1990, High-grade gold mineralization associated with high salinity hydrothermal fluids, Mt. Estelle pluton, central Alaska Range. Geol. Soc. Amer. Abstr. with Prog., v. 22, p. A41. Crowe, D.E., Valley, J.W., Scott, S., and Hannington, M., 1990, Sulfur isotope variation in a seafloor hydrothermal chimney, Juan de Fuca Ridge: Laser microprobe data. Geol. Soc. Amer. Abstr. with Prog., v. 22, p. A160. Crowe, D.E., Valley, J.W., Scott, S. and Hannington, M., 1990, Laser microprobe investigation of sulfur isotope variation in a seafloor hydrothermal spire, Axial Seamount, Juan de Fuca Ridge. Seventh Intl. Conf. Geochron., Cosmochron. and Isotope Geol., Canberra, v. 27, p. 22. Valley, J.W., Elsenheimer, D., Komor, S., Baker, K., and Crowe, D.E., 1990, Laser microprobe and conventional BrF5 δ18O analyses of Siljan granite: A comparison. Seventh Intl. Conf. Geochron., Cosmochron. and Isotope Geol., Canberra, v. 27, p. 104. Crowe, D.E., Valley, J.W. and Baker, K.L., 1989, Laser microprobe analysis of sulfur isotope ratios. Geol. Soc. Amer. Abstr. with Prog., v. 21, p. A12. Valley, J.W., Crowe, D.E. and Baker, K.L., 1989, Stable isotope analysis by laser microprobe (Invited). Geol. Soc. Amer. Abstr. with Prog., v. 21, p. A172. Crowe, D.E., Brown, P.E. and Valley, J.W., 1988, Reinterpretation of volcanic- and sediment-hosted massive sulfide deposits, Prince William Sound, Alaska: Stable isotope evidence. Geol. Soc. Amer. Abstr. with Prog., v. 20, p. A141. Crowe, D.E., Nelson, S.W., Brown, P.E., Valley, J.W. and Shanks, W.C., III, 1988, Stable isotope and fluid inclusion investigation of massive sulfide deposits, Orca and Valdez Groups, Alaska. Geol. Soc. Amer. Abstr. with Prog., v. 20, p. 153.
