New Mexico Geological Society Annual Spring Meeting — Abstracts

The Kingston Mining district is located on the east flank of the flack Range, approximately 50 miles east of Silver City. The district produced more than six million oz. of Ag prior to 1904. The majority of the mineralization occurs tetween two major N-NW trending faults which define the eastern structural margin of the Emory Cauldron. A crude zonation occurs in the district, mines to the south and west have atundant copper, while mines to the east and north have abundant Manganese. The Black Colt mine is located in the Mn-rich zone. At the Black Colt the primary mineralization occurs along ESE-WNW trending fissure veins with related replacement deposits in the Fusselman Dolomite. Pods of massive sulfide, containing pyrite-alabandite-sphalerite-galena-minor acanthite and chalcopyrite (oldest-youngest) occur in a barren quartz vein. Pyrite-sphalerite-galena (oldest-youngest) occur in a rhodochrosite, calcite-quartz gangue in the adjacent replacement deposits. Two types of sphalerite have teen distinguished, a dark marmatitic sphalerite with abundant chalcopyrite blebs and a brown resinous sphalerite lacking the chalcopyrite. Fluid inclusion homogenization temperatures for the brown sphalerite range from 307° to 332°C while the quartz temperatures range from 187° to 351°C. Limited sulfur isotope analyses suggest disequilibrium during deposition.