CHARACTERISTICS OF THE FAULT SYSTEM IN THE NORTHERN SOUTH YELLOW SEA BASIN AND ITS FORMING MECHANISM

The fault system of the northern South Yellow Sea Basin and the uplifting and depression pattern of the basin suggest a clear dextral twist movement. The fault system can be classified into three levels:basin-controlling fault, sag-controlling fault and derived fault within a sag. There are three types of sag in the basin:single-faulted graben, oblique double-faulted rift and parallel double-faulted rift. The original inverse thrust faults nearly in EW direction, was formed in the Indosinian stage, and the Qianliyan fault in NE and its derived faults formed later in the Yanshan Himalayan period. All of the faults jointly controlled the distribution pattern of the fault system and the uplift-depression of the northern South Yellow Sea Basin.