Abstract
The Bonanza King mine lies on the east slope of the Humboldt Range, and in an area of folded and faulted Triassic volcanics.The ore body is a sulphide quartz vein carrying gold and silver, associated with fractures in a diabasic dike.Primary minerals are quartz, pyrite, tetrahedrite (argentiferous), galena, sphalerite, chalcopyrite and native gold. Secondary enrichment appears to have yielded covellite, chalcocite, stephanite, and argentite. After deposition of most of the quartz and sulphides, reopening of the fracture permitted the deposition of additional quartz, together with tourmaline and some more sulphides. The solutions are thought to have come from a neighboring granodiorite stock, and the deposits are regarded as mesothermal or possibly hypothermal.
