The Characteristics of Fracture and Mineralization of the Toyoha Mine

Abstract

Deposits of the Toyoha Mine are composed of many fissure-filling veins. Main ore minerals are galena, sphalerite, pyrite and manganese minerals. Fissures and. mineralizations of these veins are classified into two stages, the early and later ones. There are two kinds of fissures in the early stage. One of them occurs along the E_W trend sheared zone and the other is tension cracks of NW_SE trend. The minerals of early stage mineralization are quartz, galena, sphalerite and pyrite. The later stage veins are composed of the combination of fissures with NW_SE and E_W trends. Ore minerals of the later mineralization are abundant manganese minerals, coarse-graimed galena and sphalerite with minor silver minerals, pyrrhotite, stibnite, chalcopyrite and barite.