Blueschists and related metamorphic rocks along the Tayuan-Xiguitu Fault in Inner Mongolia, NE China

Abstract

The blueschists and the related metamophic rocks along the Tayuan-Xiguitu fault, between the Ergun block and the Xing`an block have been found since 1990s. Recent our field work survey revealed that the blusechists occur with basic schists, pelitic schists and siliceous schists. The blueschists consist mainly of chlorite, epidote, amphibole, the peak metamorphic stage: epidote-blueschists facies is characterized by the sodic-amphibole, epidote, albite, phengite and hematite. The basic schists consist mainly of amphibole, epidote, plagioclase and clinopyroxene. The constituent minerals (Hbl + Pl + Ep + Qtz +Cpx) are stable at the peak metamorphic stage of epidote-amphibolite facies.