The Gold Deposits of Pinson Mining Company: A Review of the Geology and Mining History through 1999, Humboldt County, Nevada
Colin D. Mclachlan, Eric M. Struhsacker, Warren F. Thompson, 2000. "The Gold Deposits of Pinson Mining Company: A Review of the Geology and Mining History through 1999, Humboldt County, Nevada", Part I. Contrasting Styles of Intrusion-Associated Hydrothermal Systems: Part II. Geology & Gold Deposits of the Getchell Region, John H. Dilles, Mark D. Barton, David A. Johnson, John M. Proffett, Marco T. Einaudi, Elizabeth Jones Crafford
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Open-pit mining by Pinson Mining Company from 1980 through 1999 yielded a total of 33,750 kg (1,085,105 oz) gold. Oxide ores were mined from sedimentary rock-hosted gold deposits at three locations along the Getchell trend in Humboldt County, Nevada.
Most Pinson Mining Company gold production (30,709 kg or 987,348 oz) came from the several deposits of the Pinson mine, located 35 km (21.7 mi) northeast of Golconda. These ores were extracted from carbonates and argillites of the Upper Cambrian to Upper Ordovician Comus formation. The deposits exhibit both strati-graphic and structural control and lie along several structural orientations. Silicification, decalcification, argillization, and fracture-controlled iron oxidation are the principal alteration types associated with these deposits.
The Preble mine, located 14.8 km (9.2 mi) northeast of Golconda produced 2,807 kg (90,249 oz) of gold. Ore was mined from interbedded carbonaceous shales, calcareous shales, and silty limestones of the middle member of the Lower Cambrian to Lower Ordovician Preble formation. Mineralization is localized within a broad northeast-striking, southeast-dipping shear zone locally flanked by massive limestone beds. Silicification, phyl-losilicate alteration, and iron oxidation are spatially associated with gold.
The Kramer Hill mine, located 3.2 km (2 mi) south of Golconda yielded 234 kg (7,508 oz) of gold. Most of this ore was mined from shattered, interbedded phyllitic shales and impure quartzites of the Twin Canyon member of the Precambrian to Cambrian Osgood Mountain quartzite within the hanging wall of a north-northeast-striking, west-dipping normal fault. Argillization, silicification, and fracture-controlled oxidation are the most evident types of alteration.
Gold in the three mines is very fine grained, typically <5 microns in size. Gold mineralization is associated with anomalous Hg, As, Sb, and Tl.