台湾海峡盆地的地质构造特征及演化

CHARACTERISTICS AND EVOLUTIONS OF GEOLOGIC STRUCTURES IN THE TAIWAN STRAIT BASIN

分析了台湾海峡盆地形成的区域地质背景,将其纳入东海和南海盆地形成的框架内考虑,研究其区域演化阶段和盆地演化特征。结果表明,以台湾海峡盆地为中心的包括南海北部陆缘和东海在内的中国东南沿海地区在古新世—始新世期间处于统一的边缘海盆构造背景之下,而自晚始新世起,南海北部大陆边缘与其北部的台湾海峡地区、东海逐渐走上了不同的演化道路,前者向非典型的被动大陆边缘演变,而后者则继续其自古新世—始新世以来的演化进程,形成了自古新世至晚中新世间的4个有序分布的裂陷盆地群和相应的盆间弧体系。台湾海峡盆地有两次独特的前陆盆地经历,分别发生于晚渐新世—早中新世和晚中新世末至今,并且以第二次前陆最为强烈。

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.