Bulk X-ray random diffraction patterns using the polished thin sections of ordinary chondrites: the thermal and shock metamorphism

Abstract

Ordinary chondrites consisting of the chemical group (H, L, and LL) have experienced various degrees of thermal and shock metamorphism. Random X-ray diffraction patterns for ordinary chondrites were obtained using in-plane rotation of polished thin section, mainly focusing on olivine, low-Ca clinopyroxene, and low-Ca orthopyroxene. Then the four patterns were clearly recognized: weak shock equilibrated, weak shock unequilibrated, strong shock equilibrated, and shock melted.