Petrology, mineralogy and pTt path for the eclogite from central Qiangtang, northern Tibet, China

The eclogite from central Qiangtang is located in the central part of Longmucuo–Shuanghu suture zone in Pianshishan area of Gumu Town, Gerze County. Major minerals of eclogite include garnet, omphacite, phengite, rutile and amphibole, and their sorrounding rocks are garnet phengite schist and blueschist. Garnet phengite schist is mainly composed by garnet, phengite and quartz, and blueschist is mainly composed by garnet, amphibolite and phengite. Petrology and mineralogy data suggest that the eclogite has experienced three stages of metamorphism. Stage Ⅰ: Peak eclogite metamorphism featured by Grt + Omp + Phen + Rt, the p-T conditions of the eclogite are 500 °C and ~ 2.3 GPa. Stage Ⅱ: Epidote-amphibolite facies metamorphism is characterized by assemblages of Bar + Ab + Ep of later stage alteration on the early eclogite minerals. Stage Ⅲ: Green schist facies metamorphism is featured by fibrous actinolites. The evolution of eclogite is an evidence of the subduction of Paleo-Tethys and collision between Gondwana and Laurasia in the Northern Tibetan plateau.