Mechanism of the Mineralization in the Southern Part of Shiretoko Peninsula, Hokkaido

Abstract

The authors have been engaged in the exploration of black ore deposits (Kuroko) in the southern part of Shiretoko peninsula, Hokkaido, since May 1950.
In this paper, the ore deposits in this area are mainly reported. The general geology will be described in another paper in the near future.
The important ore deposits in this area are black ore and sulphur. This paper is concerned only with the black ore deposits.
The black ore deposits of the Nemuro, Rubeshu, Kunbetsu, Sakimui and Rikushibetsu mines have been explored. Those of the Shibetsu, Toa and Shinutoro mines are under exploration.
The southern part of Shiretoko peninsula consists of Neogene Tertiary and Quarternary rocks. The igneous rocks are generally divided by age into two groups, Neogene Tertiary and Quarternary. The Neogene Tertiary rocks are associated with the hinge zone of eastern Shiretoko, while the Quarternary rocks are associated with the Shiretoko central anticlinal structure.
The authors believe, the black ore deposits were formed as the post actions of the acidic igneous activities along the hinge zone.
The forms of each ore deposit in this area are characterized according to the types of associated igneous activities and geological structures. That is one of the key principles on which exploration of the ore deposits is based.