Subduction of the proto-Tethys ocean in the eastern segment of East Kunlun:A response to zircon U-Pb geochronology and geochemistry of Walega granitic rocks
In this study,we investigated the petrology,zircon U-Pb chronology,and geochemistry of Walega granitic rocks in the Gouli area to examine the tectonic evolution of the eastern section of the East Kunlun Mountains in the proto-Tethys ocean in the early Devonian.Monzogranite and granodiorite were the primary granitic rocks in the study area,with zircon U-Pb ages of 414.2±2.3 Ma and 416.9±5.3 Ma,respectively.Both were rich in silicon,alkalis,and aluminum,and were weakly peraluminous.They were also relatively rich in light rare earth elements and depleted in heavy rare earth elements.They generally had weakly negative europium anomalies,and were classified as Ⅰ-type granite.The results showed that the monzogranite and granodiorite from Walega were products of the partial melting of basic rocks in the lower crust.The comprehensive geological background of the region suggested that they were formed during the subduction of the proto-Tethys ocean,which had not completely closed in the East Kunlun region in 414 Ma.
East Kunlun orogenic beltproto-Tethys oceangranitic rockspetrogenesistectonic setting