Abstract:

The East China Sea is situated in a huge subsidence area of the first subsi-dence zone in the Neocathaysian.It is confined to latitudinal tectonic zones of Nanling in the south and Qingling in the north, and composed of two huge Cenozoic NNE-trending basins.The East China Sea can be divided into the Neocathaysian and the latitudinaltectonic systems and a NW-trending structure.Among them, the Neocathaysian system is the dominant one.while the origin and development of both theeastern and western basins of the East China Sea are controlled by the firststage positive structure of the Neocathaysian system and the Nanling and Qing-ling latitudinal tectonic zones.The main characteristics of the Neocathaysian system are as follows:On theplane, first-and second-stage structures are arranged in a distinct arc form and"S" shape, the third-and fourth-stage structures are arranged in a type.Onthe profile, the uplifts and depressions are appearent.On the histrory of the development of the Cenozoic in this area, the age of the strata, the magmatic rocks, the tectonic movements became younger, and the strength of the move-ments tended to enhancement from the east to the west.This indicates that themovement of the Neocathaysian has become more intensive in recent times.In the tectonic stress field of the East China Sea,the lateral push-compressiveforce from the Pacific Ocean can not be Neglected except dominant torsion and N-S trending secondary compressive stress.This has been proved by a series ofthrust faults faces the west from the Xihu sag and western Taiwan.The tectonic model of the East China Sea shelf basin is Paleogene rift-Miocene depression-Pliocene-Quaternary regional subsidence.The influence of NWW-SEE compressive stress of the Neocathaysian system changed from weakto strong and then weak again,leading to a conversion process of rift to depres-sion.The tectonic model of the Okinawa Trongh Basin has been in a riftingcondition ever since the middle-late Miocene.With the increase of the NWW-SEE compressive stress of the Neocathaysian, the rift is further developing.