Kushikino Gold Mineralization in a Pliocene Volcanic Region, Kyushu, Japan

Abstract The Kushikino gold mine (Gold Park) is located 30 km northwest of Kagoshima city (Fig. 1) and historically has been the fourth largest gold mine in Japan. The mine was opened in 1660 by a lord of the Satsuma Province (a province in southern Kyushu during the Edo era) and development took place mainly on the Serigano vein group (Fig. 2) in the south central part of the area (Miyahisa and Wakabayashi, 1972). In the late Meiji era, 1905, Mitsui Mining and Smelting Co., Ltd. acquired the central part of the Kushikino area including the Kushikino no. 1 vein. In 1913, an all-slime cyanidation plant, the first of its kind in Japan at that time, began treating ore at a rate of 150 (t) per day. Since 1660 the mine has produced 55 t of gold and 497 t of silver, of which more than 80 percent was produced from the Kushikino no. 1 vein. Approximate average Au and Ag grades have been reported as 6.7 g/t and 61 g/t, respectively (MITI, 1979). In 1988, the Kushikino Gold Park was opened adjacent to the operating gold mine. In the park, the western part of the champion vein (Kushikino no. 1 vein) around the “New” inclined shaft (Shin-shako) can be seen in the adit (mine level 2L, 60 m above sea level), though the mining operation is no longer active. This article compiles previous studies and revises our understanding of the epithermal gold mineralization at the Kushikino deposit.