南海北部中生代构造格局与盆地发育特征

Mesozoic tectonic framework and basin distribution characteristics of northern margin of South China Sea

华南板块整个构造发展史是一个大陆地壳逐步增生、地壳结构不断复杂化的过程。南海北部陆缘中生代构造演化亦是这一构造演化过程的一部分,其构造格局主要受区域基底断裂分隔,具有南北分带、东西分块的展布特征。南海北部中生代沉积盆地主要发育在粤中—粤东沉降带和东沙—高雄陆缘沉降带。东沙—高雄陆缘沉降带是南海北部海域最主要的中生代盆地发育区带,发育了潮汕、高雄和笔架3个中生代陆缘盆地,总体呈北东向展布,总面积约6.7×104km2;在这3个盆地中发育了巨厚的上三叠统—白垩系地层,具有良好的油气基础地质条件,是未来南海北部海域中生界油气勘查的有利区带。

During the tectonic history of the South China Plate, continental crust gradually accreted and crustal structure became more and more complicated. In the northern margin of the South China Sea, tectonic framework was separated by regional basement faults and was characterized by a north-south zoning and west-east blocking distribution during Mesozoic. The major Mesozoic sedimentary basins in the northern margin of the South China Sea were located at the centeral- eastern Guangdong subsiding belt and the Dongsha- GaoXiong continental margin subsiding belt. In the Dongsha-Gaoxiong continental margin subsiding belt, there were three Mesozoic continental margin basins including the Chaoshan Basin, the Gaoxiong Basin and the Bijia Basin, and their total area was about 6.7x 104 km2. The Upper Triassic and Cretaceous strata were deposited with giant thickness in these basins and had good oil and gas geological conditions. The Dongsha-Gaoxiong continental margin subsiding belt is a favorable zone for the Mesozoic petroleum exploration in the future.