A former surface and underground Zn-Pb-Ag-Fluorspar-Mn-Mo mine located in the SE¼ sec. 11 & the SW¼ sec. 12, T4S, R23W, about 1 mile SE of the Red Cloud Mine, 36 miles from Dome, 4 miles NW of the Colorado River, at about 750 feet of altitude, on patented (private) land. Patented during the 1880's. Owned at times, or in part, by the Black Rock Mining & Reduction Co.; Penn Metals, Inc.; Riley & Holmes; and, Mr. C.E. Batton (1933).

Mineralization is the Black Rock vein that has an immense outcrop (about 200 feet wide). The ore zone is 609.6 meters long with a depth to bottom of 82.3 meters, strikes N65W and dips 40NE. Ore is zinc carbonate and argentiferous lead carbonate, oxide and sulfate and local residual galena, in irregular, cellular masses in a gangue of manganese and iron-stained calcite, together with less amounts of silicified breccia, vuggy quartz and fine-grained fluorite, in lensing ore shoots in Cretaceous or Tertiary schist and hornfels, intruded and metamorphosed by granodiorite. The vein occurs within a fault zone that strikes N65ºW. & dips 40ºNE. and can be traced on surface for more than 600 feet. Several quartz-fluorite stringers occur near and parallel to the large vein, and are cut by branching veinlets of later calcite. For some 50 feet on each side of the main vein, the schist shows pronounced silicification, chloritization and carbonitization.

The prevailing rock on this claim is schist, which, in the southeastern portion, underlies the Tertiary volcanic series. This schist consists of fine-grained quartz and sericitized feldspar, alternating with bands of partly chloritized biotite. It weathers to blocky, moderately fissile, dark gray surfaces. On this claim its principal lamination strikes NW and dips steeply NE. Complex faulting and fracturing have affected this schist.

This is one of the earliest discoveries and patented in 1880. A shaft at 100 feet deep (1881), later deepened to 420 feet before 1884, and more than 900 feet of drifts and tunnels, adit and pit operations produced rich Pb-Ag ore from 1883 to 1887 but the amount is unknown. In 1941 additional production of 1,300 tons of ore averaging about 5.3% Pb, 1.7 oz. Ag/T and minor Cu and Au occurred. The dump was retreated in 1948-1949 together with other dumps.

Other Databases

GeoNames ID:	5285615
Link to USGS MRDS:	10027198
Link to USGS MRDS:	10113536

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References