Abstract:

Lower Yangtze Region is situated in front of Qingling-Dabie Orogenic Belt.Its structural activities had been controlled by strike-slip faults since Ladinian Stage of Middle Triassic.Within the limit of strike-slip faults at its south and north margins,the Lower Yangtze Landmass appeared as a wedge that was narrow in the southwest part and wide in the northeast part in Late Mesozoic.Late Cretaceous basin group distributed regularly in the wedge.Basins in southwest part are in long-narrow strip-form of small scales stretching NE-NNE,foot-hill facies and alluvial-pluvial fan facies of oxidation condition devloped well;in the northeast part,Subei Basin is in planar form stretching E-W with lacustrine deposits formed under reduction condition;basins in the central part are sinistral oblique arranged striking NNE direction,their sedimentary facies and depositional environment are between those of the above mentioned two kinds.The results of geologic survey suggest that the evolution and distribution of fault structures,sedimentary and igneous rocks within this area show corresponding regularities with the above mentioned ones.This indicates that,in Late Mesozoic,the Lower Yangtze wedge landmass fled towards northeast with the southwest part to be compressional zone,the northeast part to be extensional zone,and the central part to be transitional zone,just like Anatotian tectonic escape system formed in Cenozoic in Turkey.