The timing and tectonic implications for the North Huaiyang synclinoria

The timing and tectonic implications for the North Huaiyang synclinoria are explored on the basis of the principles of basin-range coupling,and the comparison is made for the sedimentary and tectonic features in the North Huaiyang and Huainan reqions.during the Carboniferous and Late Triassic in southern North China.There are many striking similarities in the morphology of folded structures,trace orientation and mineral elongation lineation orientation for the North Huaihang synclinoria,Huainan synclinoria and "Xuzhou-Suzhou arc".It can be indirectly inferred that the North Huaiyang synclinoria were formed during the Middle and late Triassic.The uplift of the Dabie landmass may be attributed to the "tectonic extrusion" during the continental return,thus resulting in the formation of the tectonicallyaccretedcomplexes composed of metamorphic rocks of different types and grades.