南海半封闭边缘海碳酸盐台地兴衰史

南海发育了广泛的碳酸盐台地，具有分布面积广和时空变化大的特点。南海碳酸盐台地的生命演化史总体上经历了萌生期、扩展期、繁盛期、淹没期和残留期等演化阶段。根据近年来国内外关于南海地质地球物理研究进展，发现南海碳酸盐台地是伴随着华南陆缘张裂、陆海巨变而萌生，台地基底往往发育在两个共轭陆缘伸展地块的伸展断块构造高地。随着大陆岩石圈进一步伸展、减薄和地幔剥露等过程，台地经历了晚渐新世末至早中新世初的萌生，到中中新世的勃发。此外，张裂和扩张期的岩浆构造也成为台地发育的重要控制因素，比如构造沉降提供了台地生长的可容纳空间，构造掀斜作用、断裂作用和前陆盆地前沿挤压褶皱的迁移控制了台地各单元厚度、沉积相和地震反射终止特征在横向上的变化，构造控制的相对海平面控制了不同级序生物礁碳酸盐台地的沉积旋回，而晚中新世构造作用导致半封闭边缘海的形成和大量碳酸盐台地淹没。最后，10.5Ma半封闭边缘海的形成，造成南海海盆古海洋环境的巨大变化，限制了台地的广泛发育，仅残留了数量少、面积小的现代孤立碳酸盐台地。

Vicissitude of Cenozoic carbonate platforms in the South China Sea:Sedimentation in semi-closed marginal seas

Cenozoic carbonate platforms are widely distributed in the South China Sea. They are characterized by large thickness and strong spatio-temporal variations. This study summarized most of the recently published findings on the geological and geophysical features of the South China Sea. It is found that all these carbonate platforms have experienced a progressive evolution from initiation, extension, flourishing, drowning and relict stages. Most of them are drowned in Late Cenozoic, and often called drowned carbonate platforms by some researchers. The carbonate platforms are unique in the South China Sea and contain rich information on tectonic evolution. The development of carbonate platforms follows the rifting process. They are usually initiated on the high shoulders of a faulted block at the conjugated rifting margin in Eocene and Early Oligocene. By rifting, thinning, and mantle exhumation of the South China Sea margin, the carbonate platforms has kept growing as NE-SW direction ridges, and flourished till Late Early Miocene. Tectonic subsidence provided accommodation space for platform growth. Tectonic tilt, faulting and migration of compressive folds in the front of foreland basins controlled the distribution of thickness and lateral variation in seismic reflection features. Tectonic induced relative sea level change controlled the sedimentary cycles of carbonate platforms in different orders. Furthermore, the rapid subsidence in Late Miocene and the formation of the semi-closed marginal sea caused the drowning of most carbonate platforms. Only a few carbonate platforms might leave behind as isolated platforms with limited distribution and small scale up to present.