Circular 27—PARAGENESIS OF THE ORES OF THE PALOMAS (HERMOSA) DISTRICT, SOUTHWESTERN, New mexico

By Henry L. Jicha, 1954, 21 pp.

Low temperature lead-zinc-silver mineralization of Tertiary age characterizes the Palomas mining district in the western part of Sierra County, in southwestern New Mexico. The ore occurs in fissure veins and relpacement bodies in Paleozoic limestones and dolomitic limestones. Structural control of ore deposition has been exerted by fractures or shaly horizons. The principal hypogene minerals are galena, sphalerite, chalcopyrite, and argentite. Supergene minerals include covellite, native silver, limonite, carbonates of lead, zinc, and copper, silver halides. and a littel vanadinite, descloizite, and pyromorphite.

Talc, which occurs both as vein filling and in wall-rock alteration, is thought to have been formed by the action of silica-bearing hypogene solutions.