安达曼海海域盆地构造及其演化特征研究

Study on tectonic and evolution characteristics of basins in Andaman Sea

何文刚 梅廉夫 朱光辉 杨松岭 胡志伟 肖述光 邹玉涛1,

中国地质大学（武汉）构造与油气资源教育部重点实验室，湖北 武汉 430074 中国地质大学（武汉）资源学院，湖北 武汉 430074 中海石油研究中心，北京 100027

MOE Key Laboratory of Tectonics and Petroleum Resources, China University of Geosciences，Wuhan 430074, China Faculty of Resources, China University of Geosciences, Wuhan 430074, China Research Center, CNOOC, Beijing 100027, China

安达曼海海域盆地的构造及沉积演化历史研究，包括发育构造、应力场特征、沉积充填序列和物源分析。通过建立区域主干剖面和断裂体系，结合区域构造演化历史，利用地质、地球物理、地球化学资料综合研究了安达曼海海域盆地构造及其演化特征。安达曼海海域盆地经历了裂陷前的断陷期、同裂陷期，以及晚中新世以来继承性的张扭改造，盆地内部发育有早期正断层，这些正断层是早期盆地扩张作用形成的，实皆断裂对区域断裂发育具有重要的影响作用；后期发育的断裂、褶皱，跟实皆断裂活动及印度板块向NNE方向俯冲作用的方向有关；区域内底辟构造发育，有增生楔复合介质底辟、岛弧岩浆底辟及弧后走滑断裂诱发的泥底辟，其中增生楔复合介质底辟是缅甸海域汇聚型大陆边缘特有的底辟构造。特殊的地理位置决定了其独特的构造应力场和盆地构造演化特征，深入研究安达曼海域盆地的研究构造演化特征，将有利于对汇聚型大陆边缘油气的勘探，及对板块构造发展研究起一定指导作用。

The study on deposition and structural development history of the basins in Andaman Sea involved tectonic patterns, tectonic stress field features, deposition sequence and source provenance analysis. Through building up the important cross-section and faults system, combining with the regional tectonic evolution and using the geological, geophysical and geochemistry data, this paper analyzed the tectonic evolution characteristics of the basins in Andaman Sea. The basins in Andaman Sea have experienced pre-rifting, syn-rifting and inherit compression-shear transformation since Late Miocene. The early-period normal faults which were formed during the early stage of the pre-rifting were developed in the basin. The regional fractures were greatly influenced by Sagaing fault. The developed faults and folds in the late period were related to the direction of Sagaing fault and Indian Plate subduction from NNE. The basins in Andaman Sea have many diapiric structures, including accretionary wedge mixing medium diaper, magmatic arc diapir and mud diapir caused by back-arc striking-slip fault. Among them, the accretionary wedge mixing medium diapir is a special diapiric structure in the convergent continental margin of Burma sea. Special geographic position decides its individual tectonic stress field and the geotectonic evolution of basin. Intensive study on the basins in Andaman Sea will be in favor of exploring the oil and gas of convergent continental margin and play an instructive role in the development of plate tectonics.