STATE OF LITHOSPHERE BENEATH THE NORTH CHINA CRATON BEFORE THE MESOZOIC LITHOSPHERIC DISRUPTION:A SUGGESTION
ZHAI Mingguo(CAS Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)
In recent years,the extent and cause of Mesozoic lithospheric disruption beneath the NCC have been discussed extensively.However,some geological sketch maps in the published papers showing the state of lithosphere beneath the North China Craton(NCC)before the Mesozoic lithospheric disruption are not reasonable,which ignore multi-stage tectonic evolution process of the North China Craton.Author,here,would like emphasize following points:(1)The NCC is one of the oldest cratons in the world,which has complicated tectonic history with 3.8Ga continental rocks.(2)The NCC experienced multi-stage cratonization.It fundamentally formed at the end of Archean,and ultimately completed cratonization at Paleoproterozoic of 1.9～1.85Ga.(3)The NCC came upon the stage of platform regime since 1.8Ga,marked by Proterozoic continental rift and Phanerozoic sedimentary basin within craton.(4)A Mesozoic tectonic inversion occurred in eastern North China with a large-scale lithospheric thinning beneath the sub-continent.Therefore,the state of the NCC before the disruption is a multi-stage evolving lithosphere,other than a 2.5Ga craton or a 1.9～1.85Ga craton.