Senior Hydrogeochemist
U.S. Geological Survey
Boulder, CO
Our project integrates field work, analytical work, laboratory studies, thermodynamic property evaluation, and modeling applications into the interpretation of water-rock interactions in surface and ground waters with an emphasis on trace elements. A major objective of the project is to develop, test, evaluate, and apply analytical and modeling techniques to the interpretation of trace element and redox geochemistry in natural waters. We have a fully equipped analytical laboratory for determining major ions, trace elements, and redox species in water. Our field studies emphasize mined and unmined environments where oxidative weathering of sulfide minerals forms acid waters, deep crystalline-rock environments that might host radioactive waste, and geothermal environments. Field sites have included the Leviathan mine, CA, Iron Mountain mines, CA, the Summitville mine, CO, the Upper Animas Basin, CO, the Crystal mine, MT, the Boulder Creek watershed, CO, Fairbanks, AK, the Mojave Desert, CA, the Questa mine, NM, the Stripa mine, Sweden, the Osamu Utsumi mine, Brazil, the Morro do Ferro site, Brazil, and Yellowstone National Park.
Bibliography
- Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming
Environmental Microbiology, 2009
- Thioarsenates in Geothermal Waters of Yellowstone National Park: Determination, Preservation, and Geochemical Importance
Environmental Science & Technology, 2007
- Speciation of volatile arsenic at geothermal features in Yellowstone National Park
Geochimica et Cosmochimica Acta, 2006
- Mercury in water and biomass of microbial communities in hot springs of Yellowstone National Park, USA
Applied Geochemistry, 2006
- Ground Water to Surface Water: Chemistry of Thermal Outflows in Yellowstone National Park
Geothermal Biology and Geochemistry in YNP [TBI Text!], 2005
- Water-Chemistry Data for Selected Hot Springs, Geysers, and Streams in Yellowstone National Park, Wyoming, 2001-2002
U.S. Geological Survey Open-File Report, 2004
- Oxidation reactions for reduced Fe, As, and S in thermal outflows of Yellowstone National Park: biotic or abiotic?
Water-Rock Interaction, Wanty & Seal II (eds) [Text], 2004
- Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. III. An anion-exchange resin technique for sampling and preservation of sulfoxyanions in natural waters
Geochemical Transactions, 2003
- Geothermal Arsenic: The source, transport and fate of arsenic in geothermal systems
Arsenic In Ground Water [Text], 2003
- Water-Chemistry Data for Selected Springs, Geysers, and Streams in Yellowstone National Park, Wyoming, 1999-2000
U.S. Geological Survey Open-File Report, 2002
- Water-Chemistry and On-Site Sulfur-Speciation Data for Selected Springs in Yellowstone National Park, Wyoming, 1996-1998
U.S. Geological Survey Open-File Report, 2001
- Sulfur geochemistry of hydrothermal waters in Yellowstone National Park, Wyoming, USA. II. Formation and decomposition of thiosulfate and polythionate in Cinder Pool
Journal of Volcanology and Geothermal Research, 2000
- Chemical Analyses of Hot Springs, Pools, Geysers, and Surface Waters from Yellowstone National Park, Wyoming, and Vicinity, 1974-1975
U.S. Geological Survey Open-File Report, 1998
- Water-Chemistry and On-Site Sulfur-Speciation Data for Selected Springs in Yellowstone National Park, Wyoming, 1994-1995
U.S. Geological Survey Open-File Report, 1998
- Sulfur redox chemistry and the origin of thiosulfate in hydrothermal waters of Yellowstone National Park
Water-Rock Interaction, Arehart & Hulston (eds) [Text], 1998
- Sulfur geochemistry of hydrothermal waters in Yellowstone National Park: I. The origin of thiosulfate in hot spring waters
Geochimica et Cosmochimica Acta, 1998
- Fluorite solubility equilibria in selected geothermal waters
Geochimica et Cosmochimica Acta, 1977