FORMING MECHANISM OF SLOPE-BREAK AND ITS CONTROL ON SYN-DEPOSITIONAL FAULT AND DEPOSITION IN HALFGRABEN SAG—A CASE STUDY OF THE NANGYANG SAG, THE NANXIANG BASIN

The slope-break zone is a pivotal zone of depositional physiognomy.The listric normal faults in the south of Nanyang Sag glide on lumpy surface and result in the gentle wrenches of cap formation in the north,serving as the boundary between depositional regions.Syn-depositional faults and sedimentary facies changes mainly take place here.Certain slope-break zone types indicate the activities and distributions of syn-depositional faults and control sediment dispersal and sand body accumulation.During different stages of basin evolution,syn-depositional faults and sedimentary facies belts control the gene-ration of different traps.