CHARACTERISTICS AND EVOLUTIONS OF GEOLOGIC STRUCTURES IN THE TAIWAN STRAIT BASIN

After the analysis of the regional geologic background in which the Taiwan Strait basin was formed, we considered the basin to be in the same formation settings as the East China Sea and South China Sea basins when studying the regional evolutional stages and characteristics of the Taiwan Strait. The study results showed that the southeastern coastal areas of China (covering the East China Sea coast and the northern continental margin of the South China Sea and with the Taiwan Strait basin as the center) were in a unified margin-sea tectonic background in Paleocene-Eocene. Since late Eocene, however, the northern continental margin of the South China Sea began to evolve differently from the Taiwan Strait and the East China Sea. The former gradually evolved into the passive continental margin, and the latter continued their evolutional processes since Paleocene-Eocene and went into four orderly distributed rifts and corresponding arc systems from Paleocene to late Miocene. The Taiwan Strait basin has had two specific foreland basin experiences, respectively occurring during late Oligocene-early Miocene and from late Miocene to present, and the second one was much intensive than the first.