Abstract:
Abstract:The Meso-Cenozoic basins along the Yangtze River in Anhui Province are located at the southern margin of the Dabie orogen. They are overlapped basins formed by compression and then by extension. These basins are ideal sites for the study of the coupling between the uplift of the Dabie orogen and the subsidence of the basins in the middle-lower Yangtze River region. In the Early Mesozoic, the Dabie Mountains area is a collisional orogen between the South and North China continental blocks. The South China continental crust was subducted to great depths and underwent ultrahigh-pressure metamorphism. Then the ultrahigh-pressure metamorphic rocks were exhumed progressively to the surface. The depressions along the Yangtze River is of foreland basin nature, which are filled with Late Triassic-Middle Jurassic molasses. In the Late Mesozoic, in the wholesale extensional setting in eastern China, the Dabie metamorphic belt was entirely exhumed and was in a regime of metamorphic core complex. On the other hand, the depressions along the Yangtze River is of rift basin nature, which are filled by Late Jurassic to Early Cretaceous and Late Cretaceous to Paleocene red clastic sequences. These clastic sequences were formed as a result of the coupling of isostatic uplift and extensional rifting.