GEOLOGIC EVOLUTION AND TECTONIC STYLES IN THE SOUTH YELLOW SEA BASIN

The South Yellow Sea Basin, based on the pre-Nanhua metamorphic basement of the Lower Yangtze platform, is a polycycle basin with a sandwich-type construction. The geologic evolution of the basin can be divided into three stages:the Nanhua-early and middle Triassic marine basin stage, the late Cretaceous-Paleogene graben fault basin stage and the Neogene-Quaternary depression basin stage. There are various tectonic styles controlled by multiple-period tectonic reformation and different regional stress fields. On the new seismic profiles, we can recognize four kinds of tectonic styles (extension structure, compression structure, inversion structure and diapir structure). The first three structures are due to hori-zontal motion of the crust and the last is due to vertical motion of the crust.