The North China Craton(NCC)is the best example of an Archean craton that has lost its stability in the Late Mesozoic.Although the cratonic destruction is generally considered to have occurred in the Eastern Block and ...The North China Craton(NCC)is the best example of an Archean craton that has lost its stability in the Late Mesozoic.Although the cratonic destruction is generally considered to have occurred in the Eastern Block and reached a peak in the Early Cretaceous,the exact areal extent of cratonic destruction is debated,especially the southern and northern margin of the NCC.Here we report geochronology,geochemical and Hf isotopic data of the Late Mesozoic granitoids from Lushi polymetal mineralization area(LPMA)in the southern margin of NCC.These results provide new insights into the destruction in the southern margin of the NCC during the Late Mesozoic.Zircon U-Pb dating indicates that eight granitoids intruded in the Late Jurassic to Early Cretaceous(136.8–154.1 Ma),respectively.Geochemical signatures define these granitoids being A-type or I-type granite that formed in an extension setting.In addition,Hf isotopic compositions of zircons from these granitoids vary in a relatively large range,withεHf(t)values and TDM2 ages ranginge from-26.1 to+15.2 and 215 to 2849 Ma,respectively.The parental magmas were likely derived from diverse sources,including materials of the partial melting of ancient lower crust and mantle-derived mafic magmas in various proportions.Combining with previous studies on the contemporaneous magma-tectonic activities in circum of NCC,we suggest that the rim of NCC was already unstabilized from the Late Jurassic in the LPMA.The subduction of the Paleo-Pacific Plate was the main trigger to the destruction of the southern margin of NCC,which was responsible for the lithospheric extension and thinning,extensive magmatism and mineralization.展开更多
基金This work was financially supported by the National Key R&D Program of China(No.2016YFC0600109)the State Key Laboratory of Lithospheric Evolution,IGGCAS(No.SKL-Z201905)+1 种基金This work was also financially supported by the National Natural Science Foundation of China(No.41602099)the State Key Laboratory of Lithospheric Evolution,IGGCAS(No.SPECIAL201606).
文摘The North China Craton(NCC)is the best example of an Archean craton that has lost its stability in the Late Mesozoic.Although the cratonic destruction is generally considered to have occurred in the Eastern Block and reached a peak in the Early Cretaceous,the exact areal extent of cratonic destruction is debated,especially the southern and northern margin of the NCC.Here we report geochronology,geochemical and Hf isotopic data of the Late Mesozoic granitoids from Lushi polymetal mineralization area(LPMA)in the southern margin of NCC.These results provide new insights into the destruction in the southern margin of the NCC during the Late Mesozoic.Zircon U-Pb dating indicates that eight granitoids intruded in the Late Jurassic to Early Cretaceous(136.8–154.1 Ma),respectively.Geochemical signatures define these granitoids being A-type or I-type granite that formed in an extension setting.In addition,Hf isotopic compositions of zircons from these granitoids vary in a relatively large range,withεHf(t)values and TDM2 ages ranginge from-26.1 to+15.2 and 215 to 2849 Ma,respectively.The parental magmas were likely derived from diverse sources,including materials of the partial melting of ancient lower crust and mantle-derived mafic magmas in various proportions.Combining with previous studies on the contemporaneous magma-tectonic activities in circum of NCC,we suggest that the rim of NCC was already unstabilized from the Late Jurassic in the LPMA.The subduction of the Paleo-Pacific Plate was the main trigger to the destruction of the southern margin of NCC,which was responsible for the lithospheric extension and thinning,extensive magmatism and mineralization.
