【摘要】 海南五指山地区出露大面积花岗片麻岩,且广泛发育NW向定向变形构造,表明经历了明显的动力变形变质作用;4个花岗片麻岩样品的LA-ICP-MS锆石U-Pb年代学测试数据表明它们形成于263～269 Ma,代表了中二叠世的一次重要地质构造热事件。结合前人研究成果认为,海南五指山地区263～269 Ma花岗片麻岩可能形成于华南与印支块体的碰撞拼合作用。这也暗示华南与印支的碰撞拼合可能始于263～269 Ma。更多还原

【Abstract】 Better understanding on the formation and evolution of the convergence of the South China with Indochina Blocks had been restricted by the lack of precise geochronological data.Syntectonic granitic gneisses with NW-trending gneissic foliations are widely distributed in Wuzhishan area,Hainan Island.LA-ICP-MS zircon U-Pb dating of four samples yielded crystallization ages of 263–269 Ma,representing a key thermal-tectonic event in the Middle Permian.Combined with previous work,our dating results for the Wuzhishan orthogneiss suggest the Wuzihshan syntectonic granitic gneisses were derived from the convergence of the South China with Indochina Blocks.This age(263–269 Ma) might represent the initial time of the collision between the South China and Indochina Blocks.更多还原