Zonal arrangement of ore minerals in the environs of the River Kinu, Tochigi Prefecture, Japan

Abstract

The environs of the River Kinu, Tochigi Prefecture, consist mainly of the Miocene green tuff formation which were intruded by quartz porphyry, rhyolite and andesite. In this district many copper deposits are developed, and as the result of experiment on mineral assemblage and texture of the ore, it is concluded that the ores show zonal arrangement forming high temperature cubanite zone, intermediate zone, and low temperature bismuthinite zone.