Participants On This Publication
Organisms In This Publication
Geochimica et Cosmochimica Acta, 1984      Arsenic and antimony in geothermal waters of Yellowstone National Park, Wyoming, USA
Robert E. Stauffer and John M. Thompson
Geochimica et Cosmochimica Acta, 1984

A total of 268 thermal spring samples were analyzed for total soluble As using reduced molybdenum-blue; 27 of these samples were also analyzed for total Sb using name atomic absorption spectrometry. At Yellowstone the Cl/As atomic ratio is nearly constant among neutral-alkaline springs with Cl > 100 mgL-1, and within restricted geographic areas, indicating no differential effects of adiabatic vs. conductive cooling on arsenic. The Cl/As ratio increases with silica and decreases with decreasing Cl/ ΣC03; the latter relationship is best exemplified for springs along the extensively sampled SE-NW trend within the Lone Star-Upper-Midway Basin region. The relationship between Cl/As and Cl/ΣC03 at Yellowstone suggests a possible rock leaching rather than magmatic origin for much of the Park's total As flux. Condensed vapor springs are tow in both As and Cl. Very high Cl/As ratios (>1000) are associated exclusively with highly diluted (Cl < 100 mgL-1) mixed springs in the Norris and Shoshone Basins and in the Upper White Creek and Firehole Lake areas of Lower Basin. The high ratios are associated with acidity and/or oxygen and iron; they indicate precipitation of As following massive dilution of the As-bearing high-Cl parent water.

Yellowstone Sb ranged from 0.009 at Mammoth to 0.166 mgL-1 at Joseph's Coat Spring. Within basins, the Cl/Sb ratio increases as the Cl/ΣC03 ratio decreases, in marked contrast to As. Mixed springs also have elevated Cl/Sb ratios. WHITE (1967) and WEISSBERG (1969) previously reported stibnite (Sb2S3), but not orpiment (As2S3), precipitating in the near surface zone of alkaline geothermal systems.

NOTE: the article text supplied here is for educational purposes only.
*Don't have Adobe Reader? Get the latest version.

NOTE: Some versions of Adobe Reader have problems with Google Chrome. Either resize the browser to view the paper or enable the Chrome internal PDF viewer by entering chrome://plugins in your address bar and clicking enable for the Chrome PDF Viewer plugin.