New Mexico Mineral Symposium — Abstracts

The Kingston district has historically been a producer of base and precious metals, and its enriched lead-zinc-silver deposits have produced phenomenal near-surface oxidized silver ores in the past. The area was extremely active in Tertiary time, typified by an early period of major north-south faulting, followed by intrusion and extrusion of shallow intermediate to acidic porphyritic rocks. Finally, there was regional silicification and minor fracturing followed by ore emplacement.

Mineralization on Carbonate Creek is of a type apparently unique in the area. Argentite (acanthite) float, reportedly in masses up to 200 pounds, was found in Silver Gulch in the early 1880's. Although 80,000 ounces were produced from float alone, extensive developement failed to reveal the source of the large masses.

The source area of the argentite is in highly altered limestones adjacent to an andesite body, which is also altered in places. Work by the authors using geochemical and other methods has revealed the presence of argentite unevenly distributed within a "replacement" deposit in several members of the Lake Valley limestone. This bed consists almost entirely of fine¬grined silica and varying amounts of argentite, almost to the exclusion other minerals. Minor native gold with high silver content fills cavities and seems to be the last mineral deposited. The deposit is interesting in, that it appears to be the top of an epithermal system.