Mineralization Ages of Some Epithermal Gold-Silver Vein-type Deposits in the Central Kitami Mining District of the Kitami Metallogenic Province, Hokkaido, Japan

Abstract

The mineralization ages of some epithermal gold-silver vein-type deposits in the Kitami metallogenic province, Hokkaido, Japan have been studied based on the K-Ar dating on the vein adularia and quartz mixtures. The Kohnomai mineralization took place in Middle Miocene time (12.9•}0.4 Ma). On the other hand, the gold-silver mineralization in the Ikutahara-Rubeshibe area occurred in Late Miocene to Early Pliocene time (Ryuo mine: 7.7•}0.2 Ma; Shakinzawa mine: 7.4•}0.2 Ma; Muka mine: 6.6•}0.2 Ma; Saroma mine: 5.3•}0.5 Ma).