The discovery, petrology and geochronology of the retrograde eclogite in Jiangshan-Shaoxing suture zone

Abstract: This paper reports retrograde eclogite that occurs in lanticular form in Xikou area of Jiangshan-Shaoxing suture zone. The retrograde eclogite consists of the mineral assemblage of amphibole+garnet+clinopyroxene+plagioclase+quartz. A clear ‘white-eye' structure is well developed, garnet is rimmed with symplectitic plagioclase, and clinopyroxene is surrounded by symplektic plagioclase and amphibole. Zircon U-Pb dating by LA-ICP-MS shows that the peak metamorphic age is （451+8/-18）Ma. Exposures of retrograde eclogites in the Jiangshan—Shaoxing suture zone provide new insight for the collisional process between the Cathaysia block and the Yangtze block.