The Ore Deposits and the Recent Exploration in the Kishu Mine

Abstract

The Kishu mine, where the output of copper ore is about 27, 000 tons a month, is situated in the southern part of Mie Prefecture. The rocks around the main area of the mine consist of sandstones and shales of the Miyai group which is of middle Miocene age. The fissures in which ore deposits were are divided into three groups, namely, N-S, NW-SE and E-W group in their strike. On the other hand, four stages of mineralization in the main district can be recognized. They are Cu-Py, Pb-Zn, Au-Ag and calcite stages. The first is the most important. In the northern area, the Yunokuchi and the Hakko district, ore shoots were formed in the C member (medium sandstone) of the Itaya formation that belongs to the Miyai group, generally extending along bedding planes. The recent exploration in the southern area, the Kiyadani and the Josen district gave us some information on the shape of ore shoot of another type. The ore shoots of this type occur more vertically to the bedding planes.