Exploration of the Ginzan Ore Deposit, Akita Prefecture

Abstract

In 1967, Nippon Mining Co. Ltd. commenced exploration in the west of the Lake Towada, and in 1968, a new Kuroko deposit was discovered. The deposit is located in the margin of the Namariyama basin, a small Miocene sedimentary basin between the Hokuroku and Hanawa major sedimentary basins where many Kuroko deposits occur.
The stratigraphical horizon of the Ginzan deposit, which is correlated with the upper part of the Nishikurosawa stage of Middle Miocene, is the same as the horizon of many Kuroko deposits in the Green Tuff region. Lithology of wall rocks, properties of ores, and nature of wall rock alteration are briefly described.