On the genesis of barite associated with volcanogenic massive sulphides, Fukazawa mine, Hokuroku district, Japan.

Abstract

Chemical and textural evidence from Fukazawa indicates that the baryte-sulphur was probably derived directly from sea-water sulphate. A mechanism of an ascending Ba-rich hydrothermal fluid mixing with sea-water is proposed, support being given by the oxidation of pyrite to hematite, and by the Sr characteristics of the Ba. The bed was later affected by hydrothermal solutions, so equilibrium dynamics cannot be applied to the bulk system.-R.E.S.