On the Hydrothermal Mineral Veins Developed in the Takinoue Geothermal Area, Northeast Honshu, Japan

Abstract

In order to clarify the hydrothermal structure in the Takinoue Geothermal Area, Iwate Pref., Northeast Honshu, Japan, 415 hydrothermal veins developed in the area are examined. These veins are classified into five systems:NNW-SSE to NW-SE strike and moderate dip system (NW-moderate dip system), NW-SE strike and steep dip system (NW-steep dip system), NE-SW to E-W strike and steep dip system (NE to E-W system) and horizontal system. The latter two fracture systems, which are the youngest, consist of quartz, calcite, aragonite, prehnite, K-feldspar, wairakite, yugawaralite, laumontite, analcime, stilbite, pyrite, marcasite and kaolinite. On the basis of their occurrence and distribution, eight mineral zones are established, that is, prehnite zone, wairakite zone, K-feldspar zone, yugawaralite zone, laumontite zone, stilbite zone, analcime zone and calcite zone.The minerals