Abstract:
A high pressure metamorphic (HP) belt is exposed from west to east with a length of about 500 km in central Qiangtang, northern Qinghai-Tibet Plateau. Eclogite presence has been reported in Pianshishan area in the middle of the belt. In this paper, we report another eclogite outcrop at Gangmacuo area in the western of this HP belt. The eclogite in Gangmacuo area occurs as lens or blocks and consists of garnet, omphacite, phengite and amphibole. Peak temperature of 427~472℃ and pressure of ~2.3GPa were obtained based on the geothermobarometer. The discovery of Gangmacuo eclogite further supports that a suture zone should exist in this area, which is very important for interpreting the evolution of Qinghai-Tibet Plateau and Tethys Ocean.