Geology of the Mercur Gold Camp, Utah

The gold deposits at Mercur, Utah, are typical epithermal deposits. Ore deposition probably occurred at depths of 1,000 feet or less with low temperatures ranging from 200 o + to 100 oC. The most prominent type of metasomatism associated with the gold deposits is silicificatlon accompanied by sericitizatlon. Sulfur isotopic data for the deposits have a mean value of of +7.9 permil and have a spread of values which correlate with sulfur isotopic data for hot spring deposits. Mercur is of interest structurally because of the occurrence of two breccea pipes believed to have originated as explosive events. Organic extraction and analysis by infrared spectroscopy of carbon-rich samples from Mercur, Utah, and Carlin and Getchell Mine, Nevada, show the presence of alkane and carbonyl groups. The carbon present in all three areas is believed to be the result of reduction of hydrocarbons to carbon by the chemical conditions that once existed in the hydrothermal areas.