Abstract

The Mercur Mine is located 35 mi (by air) southwest of Salt Lake City in the Oquirrh Mountains of north-central Utah.

The district, primarily a producer of gold, was originally organized in 1870 around a silver discovery.

Gold production occurred during 1891 through 1918 and again in 1932 through 1942. Getty Mineral Resources Company optioned the property from Gold Standard, Inc., in 1973 and brought the mine into production in 1983 at a rate of 3,000 t/day of ore.

The gold mineralization at Mercur occurs in altered carbonaceous silty limestone rocks of Mississippian age. Disseminations of micron-size gold forms discontinuous stratabound ore bodies within a 240-ft zone of favorable lithology.

Decalcification of the host rocks and deposition of quartz, kaolinite, and sericite are the main alteration features. Incomplete hydrothermal oxidation of the deposit has left both oxidized and unoxidized rocks containing gold mineralization. In the unoxidized rocks the gold is associated with pyrite, marcasite, realgar, orpiment and carbonaceous material. In the oxidized zones it occurs with quartz and calcite.