Zircon U-Pb geochronology,Hf isotopes,and geochemistry constraints on the age and tectonic affinity of the basement granitoids from the Qiongdongnan Basin,northern South China Sea

作     者：Lijun Mi Xiaoyin Tang Haizhang Yang Shuchun Yang Shuai Guo Lijun Mi;Xiaoyin Tang;Haizhang Yang;Shuchun Yang;Shuai Guo

作者机构：China National Offshore Oil Corporation(CNOOC)Research CenterBeijing 100028China Institute of GeomechanicsChinese Academy of Geological SciencesBeijing 100081China Key Laboratory of Paleomagnetism and Tectonic ReconstructionMinistry of Natural ResourcesBeijing 100081China Key Laboratory of Petroleum GeomechanicsChina Geological SurveyBeijing 100081China 

出 版 物：《Acta Oceanologica Sinica》 (海洋学报（英文版）)

年 卷 期：2023年第42卷第3期

页      面：19-30页

核心收录：

学科分类：070704[理学-海洋地质] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学] 

基　　金：The National Natural Science Foundation of China under contract No.42072181 

主　　题：Qiongdongnan Basin basement granitoids geochemistry U-Pb and Hf isotopes Paleo-Pacific Plate subduction 

摘      要：Studies in the northern South China Sea(SCS)basement remain important for understanding the evolution of the Southeast Asian continental *** to a thick cover of sediments and scarce borehole penetration,little is known about the age and tectonic affinity of this *** this study,an integrated study of zircon U-Pb geochronology,Hf isotopes,and whole-rock major and trace elements on seven basement granitoids from seven boreholes of Qiongdongnan Basin has been carried *** zircon U-Pb results for these granitoids present middle-late Permian((270.0±1.2)Ma;(253±3.4)Ma),middle to late Triassic((246.2±3.4)Ma;(239.3±0.96)Ma;(237.9±0.99)Ma;(228.9±1.0)Ma)and Late Cretaceous ages((120.6±0.6)Ma).New data from this study,in combination with the previous dataset,indicates that granitoid ages in northern SCS basement vary from 270 Ma to 70.5 Ma,with three age groups of 270–196 Ma,162–142 Ma,and 137–71 Ma,*** for the late Paleozoic-Mesozoic rocks in the basement of the northern SCS,a few old zircon grains with the age of(2708.1±17)Ma to(2166.6±19)Ma provide clues to the existence of the pre-Proterozoic *** geochemical signatures indicate that the middle Permian-early Cretaceous granitoids from the Qiongdongnan Basin are I-type granites formed in a volcanic arc environment,which were probably related to the subduction of the Paleo-Pacific Plate.