中国板块构造对油气盆地演化和油气分布特征的控制

中国的板块构造演化表现为小陆块拼合、多旋回运动以及强烈的陆内构造变动等特征,使得中国的古生代盆地多为台内坳陷-断陷,陆缘盆地不发育,且多受改造,以至卷入造山带。中、新生代盆地则受板内构造影响,呈多期发展与改造特征,尤以前陆盆地发展独具中国特色。与国外典型的前陆盆地"二元"结构不同,中国的前陆盆地具"三元"结构特征。早期被动陆缘不发育,多以裂陷槽为特征;前陆盆地发育阶段多以陆相为主;晚期的强烈挤压叠加了巨厚的山前沉积。多旋回的构造运动和多期次的盆地叠加使中国的盆地多具叠合盆地的特征,影响到烃源岩的演化及油气的运移和分布。因此,中国的含油气系统多为复合油气系统。

Control of plate tectonics over evolution of petroliferous basins and characteristic of oil and gas distribution in China

Unique and complex geologic history created the characteristics of petroliferous basins in China. Plate tectonic evolution in China has been characterized by matching of microcontinents, multi-cyclic movements and intensive intracontinental tectonic events. As a result, the Paleozoic basins are mostly of intraplatform depressions and rifts; epicontinental basins are undeveloped, and most of which have been reformed and even involved in orogenic belts. The Meso-Cenozoic basins have been affected by intraplate tectonics and characterized by multiple phases of development and reformation, especially the foreland basins appear to have their own distinctive characteristics. The foreland basins in China have distinctive "ternary" architecture, which is different from the "binary" architecture of those foreland basins abroad. The early stage is characterized by taphrogenic troughs with undeveloped passive continental margins, and continental sediments have mainly been deposited during the development of foreland basins. The strong compression in later stage has resulted in the superimposition of very thick mountain front sediments. Multicyclic tectonic movements and multiple phases of basin superimposition have caused most of the basins in China to have the characteristics of superimposed basins, which have influenced the evolution of source rocks, and migration and distribution of oil and gas. Therefore, most of the petroleum systems in China are of composite types.