BASIN PROTOTYPE OF THE CENOZOIC CHANGJIANG DEPRESSION IN THE EAST CHINA SEA SHELF BASIN

The interpretation of seismic profiles for Cenozoic structures of the Changjiang Depression in the East China Sea Shelf Basin was carried out.It suggests that many Cenozoic tectonic movements occur in this depression.The Oujiang movement happened in late Paleocene is especially important to the formation of the present geometry of the depression.Data show that inversed anticlines and horsts are very significant for trapping,migration and preservation of oil and gas in the Changjiang Depression,and T30 is a critical time for the formation of the present geometry.The technique of balanced sections is used for reconstruction of the prototype basin.It is concluded that the Changjiang Depression was a pull-apart basin in Paleocene with the long axis in EW direction.The faults in NE direction played most important role in the formation of the basin after the time of T12.