地质学报（英文版）2002，Vol.76Issue(1)：63-68,6.
Subduction of Continental Crust in the Early Palaeozoic North Qaidam Ultrahigh-Pressure Metamorphic Belt, NW China: Evidence from the Discovery of Coesite in the Belt
Subduction of Continental Crust in the Early Palaeozoic North Qaidam Ultrahigh-Pressure Metamorphic Belt, NW China: Evidence from the Discovery of Coesite in the Belt
摘要
Abstract
Coesite was discovered as inclusions in zircon separates from pelitic gneiss associated with a large eclogite body in the North Qaidam ultrahigh-pressure (UHP) terrane. Some graphite inclusions were also found. This finding suggested the occurrence of in-situ UHP metamorphism and that the terrane was most likely recrystallized at pressures below the diamond stability field. It supported other previous indirect UHP evidence, such as polycrystalline quartz inclusions in eclogitic garnet, quartz lamellae in omphacite and P-T estimates for both eclogite and garnet peridotite. The U-Pb and Sm-Nd ages of the North Qaidam eclogite indicated that subduction of continental crust occurred in the Early Palaeozoic, which probably recorded a collision between the Sino-Korean and Yangtze plates.关键词
UHP metamorphism/coesite/eclogite/Qinghai-Tibet plateau/North Qaidam MountainsKey words
UHP metamorphism/coesite/eclogite/Qinghai-Tibet plateau/North Qaidam Mountains分类
天文与地球科学引用本文复制引用
..Subduction of Continental Crust in the Early Palaeozoic North Qaidam Ultrahigh-Pressure Metamorphic Belt, NW China: Evidence from the Discovery of Coesite in the Belt[J].地质学报（英文版）,2002,76(1):63-68,6.基金项目
We are grateful to Shige Maruyama and his colleagues for the use of the laser Raman spectrum at the Institute of Tokyo Technology, to Louie Liou and Gary Ernst of Stanford University for useful discussions and to Joe Wooden for SHRIMP U-Pb dating. The res （）
