西昆仑康西瓦北侧蒙古包—普守—带早古生代花岗岩锆石SHRIMP U-Pb测年

Zircon SHRIMP U-Pb dating of Early paleozoic granite in the Menggubao-Pushou area on the northern side of Kangxiwar,West Kunlun

依据1:25万康西瓦幅区域地质调查成果,重点对西昆仑康西瓦北侧蒙古包—普守一带早古生代花岗岩的岩石学、岩石地球化学及同位素年代学进行了综合研究。岩石学和地球化学特征表明,该花岗岩为高钾钙碱性花岗岩类,锆石SHRIMP U-Pb年龄为443.1 Ma±2.3Ma和430.7Ma±2,6Ma,形成时代为晚奥陶世—早志留世。该成果的获得,为进一步系统地研究蒙古包—普守早古生代蛇绿混杂岩带及与其配套的早古生代花岗岩提供了直接的时代证据,为进一步深入地研究西昆仑造山带的地质构造演化提供了新的实际资料。

According to the results of regional geological survey of the 1：250000 Kangxiwar Sheet, an integrated petrological, geochemical and isotope chronological study was conducted on the Early Paleozoic granite in the Menggubao-Pushou area on the northern side of Kangxiwar, West Kunlun. Petrological and geochemical characteristics show that the granite belongs to calc-alkaline granitoids and has zircon SHRIMP U-Pb ages of 443.1±2.3 and 430.7±2.6 Ma, indicating a Late Ordovician- Early Silurian age for its formation. The results provide direct age evidence for a further detailed and systematic study of the Early Paleozoic Menggubao-Pushou ophiolitic melange zone and Early Paleozoic granite and furnish new actual material for the further and intensive study of the tectonic evolution of the West Kunlun orogenic belt.