摘要
对西藏措勤惩香错地区林子宗群典中组火山岩进行了岩石地球化学和LA-ICP-MS锆石U-Pb定年测试,2件样品(流纹岩、英安岩)LA-ICP-MS锆石U-Pb年龄分别为(65.58±0.33)Ma、(58.83±0.41)Ma,代表了该火山岩的形成年龄,时代为古新世。岩石地球化学特征显示为钙碱性,富集大离子亲石元素Rb、Th、Pb,亏损高场强元素Nb、Ta等,反映了弧火山岩的特征,说明该时期新特提斯洋仍处于俯冲消减阶段。
The petrogeochemistry and LA-ICP-MS zircon U-Pb dating results of the Dianzhong Formation volcanic rocks in Linzizong Group,Cuoqin and Chengxiangcuo area,Xizang Province were studied.The LA-ICP-MS zircon U-Pb ages of the two samples(rhyolite and dacite)are(65.58±0.33)Ma and(58.83±0.41)Ma,respectively,representing the formation age of the volcanic rocks in the Paleocene.The geochemical characteristics of the rocks show that they are calc-alkaline,enriched in large ion lithophile Rb,Th,Pb,and depleted in high field strength Nb,Ta,etc.,which reflects the characteristics of arc-volcanic rocks,indicating that the New Tethyan Ocean was still in subduction stage during this period.
作者
江庆源
Jiang Qingyuan(Southeastern Geology Party of Fujian Province,Quanzhou,362021)
出处
《福建地质》
2023年第1期1-11,共11页
Geology of Fujian
基金
冈底斯-喜马拉雅铜矿资源基地调查项目“西藏1∶5万惩香错地区4幅区调”。
