Fluid inclusion study of the Kaneuchi tungsten deposit, Kyoto Prefecture.

Abstract

The ore deposits of the Kaneuchi mine are wolframite and scheelite bearing quartz veins occurring in slate, sandstone and chert of Permian period. Filling temperature and salinity of fluid inclusions in quartz and some scheelite were measured with the heating-cooling stage and compressing-heating stage investigated by HAYAKAWA and NAMBU (1973, 1978). Leakage of fluid from the inclusions in the case of brittle samples were prevented by the use of the compressing-heating stage.
Filling temperature of primary inclusions of quartz is similar to that of scheelite. Thus quartz can be useful to estimate temperature and salinity condition of the mineralization. The filling temperature of quartz varies from 200 to 300°C and is positively correlated with the salinity (Fig.5). CO₂-bearing inclusions are not uncommon. Both filling temperature and salinity of the primary inclusions increase from west to east in the vein swarm indicating the ore solution flowed out from east, which supports the hidden granitic cusp proposed by IMAI et al. (1972) in that area.