Antimony and other metal anomalies south of Stibnite, Valley County, Idaho

Abstract

Results of geochetnical investigations south of Stibnite, Valley County, Idaho, shov that the distribution of Sb, As, Au, Zn, Ag, and MO in mull ash and of Hg in soil forms a highly anomalous area which is more than 1,5 km long and 1 km vide along the trace of the Meadow Creek fault, a major northstriking fault zone. In the report area the Meadow Creek fault is covered by deposits of Quaternary glacial debris ranging in thickness from several meters to more than 30 meters. Two other highly anomalous areas-one of Au t Zn t and Hg, and one of Zn, Ag, Up, and MO -correlate x<7ith silicified granodiorite along the trace of the Meadow Creek fault. These anomalies are not related to known ore deposits and merit further investigation.The enrichment of metals in mull ash in the area of thick glacial debris suggests that the metals migrate from bedrock unvard through the glacial debris, are taken up by the forest vegetation, and are concentrated in the mull as the litter fron the vegetation decays. The findings indicate that mull is the most useful geochemical sampling medium in the stibnite area because the bedrock is deeply buried beneath deposits of transported material such as colluvium or glacial debris.

Analytical results, sample locality map, geochemical maps, and histograms for samples from the Stibnite Mill tailings pond, Stibnite, Valley County, Idaho

“…During the early 1970s the USGS conducted a geochemical study in an area just south of Stibnite (Curtin and King, 1974). The purpose of the study was to test and compare the usefullness of various sample media, including rocks, soils, mull, and assorted vegetation types, in an area that was considered to have potential for mineral deposits concealed by glacial debris and alluvium.…”