Abstract: Tectonic Evolution of the Pearl River Mouth Basin, Northern South China Sea

Zuyi Zhou, Robert John Wittington

A collision took place along the south China margin in the early Mesozoic between the south China block and the South China Sea block, which includes Hainan Island, Xisha, Zhongsha, Reed Bank, northern Palawan, and Borneo. The formation and evolution of the Pearl River Mouth basin were the results of the drifting of these continental fragments away from south China since the late Mesozoic. Three stages of evolution are identified. (1) Early Rifting Stage (Late Cretaceous-early Paleocene): The drifting of Borneo resulted in the development of a series of northeast-southwest normal faults and the formation of main subbasins and the intervening uplifts. (2) Late Rifting Stage (late Paleocene-middle Oligocene): The northeast faults were overprinted by the east-northeast-west-southwest and east-west normal faults as a consequence of the drifting of other continental fragments. (3) Post Rifting Stage (late Oligocene-present): This stage saw the rejuvenation of the east-west faults and the formation of grabens, normal faults, and tilted block in correspondence to the spreading along 18°N in the Central basin of the South China Sea. The three stages show distinguishable characteristics in volcanic activities, sediment fills, and structural styles and are related to regional tectonic developments such as the cessation of westward subduction of the Kula plate, the collision between the Indian and the Qinghai-Tibetan plates, and the subduction of the proto South China Sea under Borneo.

AAPG Search and Discovery Article #90982©1994 AAPG International Conference and Exhibition, Kuala Lumpur, Malaysia, August 21-24, 1994