Late Mesozoic magmatism in the Jiaodong Peninsula,East China:Implications for crust-mantle interactions and lithospheric thinning of the eastern North China Craton  

作　　者：Yayun Liang Xuefei Liu Qingfei Wang Rui Zhao Yao Ma 

机构地区：[1]School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing,100083,China [2]State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Beijing),Beijing,100083,China

出　　处：《Geoscience Frontiers》2020年第3期895-914,共20页地学前缘（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.41230311 and 41802077);the Fundamental Research Funds for the Central Universities(Grant No.53200759380);the China Postdoctoral Science Foundation(Grant No.2018M631538)。

摘　　要：A section from the Linglong gold deposit on the northwestern Jiaodong Peninsula,East China,containing Late Mesozoic magmatic rocks from mafic and intermediate dikes and felsic intrusions,was chosen to investigate the lithospheric evolution of the eastern North China Craton(NCC).Zircon U-Pb data showed that low-Mg adakitic monzogranites and granodiorite intrusions were emplaced during the Late Jurassic(~145 Ma) and late Early Cretaceous(112-107 Ma),respectively;high-Mg adakitic diorite and mafic dikes were also emplaced during the Early Cretaceous at^139 Ma and ~118 Ma,and 125-145 Ma and 115-120 Ma,respectively.The geochemical data,including whole-rock major and trace element compositions and Sr-Nd-Pb isotopes,imply that the mafic dikes originated from the partial melting of a lithospheric mantle metasomatised through hydrous fluids from a subducted oceanic slab.Low-Mg adakitic monzogranites and granodiorite intrusions originated from the partial melting of the thickened lower crust of the NCC,while high-Mg adakitic diorite dikes originated from the mixing of mafic and felsic melts.Late Mesozoic magmatism showed that lithosphere-derived melts showed a similar source depth and that crust-derived felsic melts originated from the continuously thickened lower crust of the Jiaodong Peninsula from the Late Jurassic to Early Cretaceous.We infer that the lower crust of the eastern NCC was thickened through compression and subduction of the Palaeo-Pacific plate beneath the NCC during the Middle Jurassic.Slab rollback of the plate from ~160 Ma resulted in lithospheric thinning and accompanied Late Mesozoic magmatism.

关 键 词：Late MESOZOIC MAGMATISM LITHOSPHERIC thinning Jiaodong PENINSULA Eastern North China CRATON 

分 类 号：P588.11[天文地球—岩石学]