白云凹陷构造演化史的研究对在白云凹陷开展油气勘探和深水沉积研究具有重要的意义。通过对断裂与沉积结构平面和剖面特点的分析,结合岩浆活动特点,文中提出白云凹陷是一个复式地堑,推测这种结构特点与凹陷下地壳的强烈韧性减薄和颈缩变形有关,表现为热岩石圈的伸展。其发育机制推测与白云凹陷位于构造转换带上有关,特殊的构造位置使白云凹陷成为强烈构造变形区,岩石圈地壳强烈减薄,伴随伸展过程和地幔上涌,脆性地壳或上地幔中部分熔融物质的出现导致岩石圈强度的急剧降低,在区域伸展应力场下以韧性流变方式减薄。岩浆在构造转换带下聚集并发育主岩浆房,由于白云凹陷南北边缘没有发育正断裂系统,岩浆主要沿垂直伸展的方向运移,因此在珠琼运动一幕和二幕南南东向伸展应力作用下,岩浆向白云凹陷的东部和西部运移至北西向基底深大断裂处,那里由于北西向断裂表现为左行张剪性质而成为压力较低的地区,从而成为岩浆上涌和侵位的地方。在岩浆聚集的地区,活动岩浆体附近的脆性变形被分散的韧性变形所取代,因此在凹陷的东北和西南两个角上,发育了张性和张剪性小断裂群,由于热岩石圈弹性较差,白云凹陷长期持续沉降。白云凹陷的断裂活动和沉积演化史还受到南海海盆扩张活动的影响。 The research on the tectonic evolution of Baiyun sag is of great significance to the research of oil and gas exploration and deepwater sedimentation in Baiyun sag. Based on the analysis of the characteristics of plane and section of faults and sedimentary structures and the characteristics of magmatism, Baiyun Sag is a double-graben. It is speculated that this structural feature is related to the strong ductility thinning and neck deformation of the lower crust, Hot lithosphere stretching. Its developmental mechanism is inferred to be related to the Baiyun sag which is located on the tectonic transition zone. The special tectonic position makes the Baiyun sag a strong tectonic deformation zone. The crust of the lithosphere is strongly thinned. Along with the extensional process and upwelling of the mantle, the crustal crust or upper mantle partially melts The appearance of matter led to a drastic reduction in lithosphere strength and thinning by ductile rheology in the region of extended stress fields. The magma aggregated and developed the main magma chamber under the structural transformation zone. Because no normal faulting system was developed along the northern and southern margins of the Baiyun Sag, the magma mainly migrated in the direction of vertical extensibility, and thus extended its stress in the Zhujuqiong and South-East directions , The magma migrates to the deep NW faults in the eastern and western parts of Baiyun sag, where it becomes the lower pressure area due to the left-lateral shearing and the northwesterly faults, and thus becomes magmatic upwelling and emplacement local. In the magmatic accumulation area, the brittle deformation near the active magma was replaced by the dispersed ductile deformation. Therefore, a small tensile and tensile shear fault group was developed in the two northeastern and southwestern corners of the depression. Because of the thermal lithospheric elasticity Poor, Baiyun Sag continued long-term settlement. The fault activity and sedimentary evolution in Baiyun Sag have also been affected by the expansion of the South China Sea basin.