Geochemical exploration for antimony in southeastern Alaska

Abstract

Preliminary geochemical prospecting by the Geological Survey was carried out in 1952 in muskeg-covered ground at Caamano Point, Cleveland Peninsula, Alaska, in an effort to delimit areas of stibnite concentrations. It was conducted to aid, if possible, a prospecting project of the Defense Minerals Exploration. Samples were collected from soil and decomposed limestone-and-schist bedrock at depths ranging from 18 inches to 60 inches, by means of a pipe with an interior plunger. Initial sampling was followed by detailed sampling of the areas where the antimony content of the soils consistently averaged more than 300 ppm. These Areas of major soil concentrations were prospected by surface trenching and percussion drilling to depths of 20 feet which proved the existence of stibnite ore. Next a shaft and drifts made in the most favorable area proved disseminated stibnite ore to depths of 60 feet. This geochemical work of soil sampling to indicate hidden ore bodies in a typical Alaskan muskeg area is believed to be the first application in Alaska of such techniques in active ore exploration. The results show the economic feasibility of such exploration as a first step in extending the known boundaries of mineralized areas, and in directing initial exploration toward the most favorable areas of near-surface ore bodies. Data are presented to help establish values of soil content of antimony that may be considered as normal in this type of geologic terrain.