Ortho-type polygonal serpentine from Shimotake, Izumimachi, Yatsushiro city, Kumamoto Prefecture

Abstract

In this study, we researched the mineralogical properties of ortho-type PS at Shimotake. Shimotake is the most ortho-type polygonal serpentine rich locality in Kyushu Kurosegawa belt. Ortho-type polygonal serpentine occurs as yellowish green vein between foliate serpentinites. The vein was chemically homogeneous, with minor Al (0.03-0.05 apfu) and Fe (0.05-0.12 apfu) components. The host serpentinite was more Al rich than the vein, which had bastite textures. The diameter of ortho-type PS was 200-300 nm, with 15 sectors.