The History

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The New Rambler mine is a classic supergene enriched deposit that was capped by a porous spongy limonite and jaspilite gossan overlying a 75-foot thick oxidized zone. The oxidized zone included copper carbonates and oxides with dendrites and nuggets of native copper and some copper sulfides. These grade down from 75 to 100 feet into the supergene zone with platinum-bearing covellite and chalcocite (McCallum and others, 1975). Below 100 feet, supergene assemblages graded into primary mineralized rock with quartz-pyrite-chalcopyrite veins and minor sperrylite. The association of epigenetic platinum and palladium in the shear zones suggests the ore was remobilized from a hidden, as yet undiscovered, platinum reef at depth (McCallum and Orback, 1968), or laterally.

The mine sporadically operated from 1900 to 1918. Operations terminated after a fire destroyed the mine buildings. After the fire, the mine manager estimated probable reserves at 7,000 tons of 7 to 8% Cu, 0.25 opt Pt, with some gold and silver. Total metal production was reported at 1,753,924 pounds of Cu, 171.35 ounces of Au, 7,346 ounces of Ag, 170.16 ounces of Pt, and 451.4 ounces of Pd (Needham, 1942). Silver Lake Resources (1985) estimated platinum-group metal production was more on the order of 16,870 ounces of Pd and 910 ounces of Pt. In addition to platinum and palladium, iridium was also detected. According to Knight (1902) a composite sample of dump material from the mine yielded 0.06 opt Pt, 0.04 opt Ir, 0.04 opt Pd, 0.10 opt Ag, and a trace Au. Much of the platinum was incorporated in the copper ore. Two assays reported by Knight (1902) included: (1) an assay of copper minerals which yielded 0.10 to 0.70 opt Pt, and (2) seven carloads of covellite ore that contained 0.40 to 1.4 opt Pt.