Geochemistry and zircon SHRIMP U-Pb dating of granitoids from the west segment of the North Qaidam

作     者：Joseph L.WOODEN Paul T.ROBINSON Frank K.MAZDAB Chris MATTINSON 

作者机构：Department of Earth and Environmental Sciences Stanford University Department of Earth Sciences Dalhousie University 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2009年第52卷第11期

页      面：1771-1790页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：Supported by National Natural Science Foundation of China (Grant Nos. 40472034, 40672049) China Geological Survey Projects (Grant Nos. 1212010611803, 1212010711816) 

主　　题：granitoid zircon SHRIMP U-Pb dating North Qaidam 

摘      要：Granitoid intrusives such as Saishitenshan, Tuanyushan, Aolaohe and Sanchagou occur widely in the western segment of North Qaidam. All these bodies trend NW, roughly parallel to the regional structure. Zircon SHRIMP dating for these granites show that they range in age from Ordovician to Permian; 465.4±3.5 Ma for Saishitenshan, 469.7±4.6 Ma and 443.5±3.6 Ma for Tuanyushan, 372.1±2.6 Ma for Aolaohe, and 271.2±1.5 Ma and 259.9±1.2 Ma for Sanchagou. Both the Tuanyshan and Aolaohe plutons record two distinct intrusive events. Geochemically, the early Paleozoic granites have an island arc or active continental margin affinity, and their protolith may have been Mesoproterozoic oceanic crust derived from depleted mantle. The protolith of the late Paleozoic granites may have been Mesoproterozoic lower crust from the root of an island arc with the magmas reflecting a mixture of mantle and crustal material.