Dept of Earth & Environmental Sciences
Centre for Environmental and Information Technology (EIT)
200 University Ave. W
Waterloo, Ontario, Canada N2L 3G1
Phone: (519) 888-4567
D. Kirk Nordstrom
U.S. Geological Survey, Boulder CO
Yellowstone's Contaminated Waters: Chemistry and Transport of As, Hg, H2S and F
Reception to follow in the Earth Sciences Museum.
Enivironmental Information and Technology (EIT) Building Foyer
For the last 17 years we have been quantifying the speciation and transport of major and trace constituents in Yellowstone's geothermal features. The elements As, Li, B, Hg, H2S, and F are distinctive chemical signatures of hydrothermal activity. Oxidation of As and H2S occurs rapidly in hot spring overflows with substantial changes in speciation. Microbial oxidation converts arsenic to arsenate and independently of pH and temperature whereas H2S volatilizes as a function of pH and oxidizes to thiosulfate abiotically. Mercury volatilizes with predicted isotopic fractionation. Fluoride stays in solution and, along with arsenic, is transported without attenuation into the main rivers that flow out of the Park. The lack of arsenic attenuation is attributed to the high silica concentrations that reduce sorption capacity of fluvial sediments.
200 University Ave West
Waterloo, ON N2L 3G1