Podiform Chromite Occurrences in the Caribou Mountain and Lower Kanuti River Areas, Central Alaska. Part 1. Reconnaissance Investigations

摘要

The Bureau of Mines sampled surface exposures of podiform chromite in the Caribou Mountain-Melozitna ultramafic belt in the Kokrines-Hodzana Highlands, central Alaska. The belt comprises six complexes of which the three closest to the pipeline corridor were investigated. Concentrations of chromite disseminated in dunite host rock make up mineralized intervals ranging in thickness from less than an inch to 5 ft and in grade from 3 to 23 pct chromium. The largest occurrence has an exposed strike length of 80 ft. Bulk surface samples were collected from 10 of these exposures, and benefication tests on the samples produced concentrates of metallurgical, refractory, and subindustrial grades. Part I--this report--describes the fieldwork.