雷琼新生代断陷盆地构造特征及其演化

雷琼新生代断陷盆地构造主要受走向北东东、北西和北东3组断裂控制,新生代不同时期各组断裂活动程度不同。在编制新生代不同阶段的地层等厚度图的基础上,讨论了雷琼断陷盆地及其内部次级构造在时空上的迁移、发展和转化特征;根据地层厚度反演,估算了盆地的下降幅度和不同阶段的下降速率、拉张因子以及拉张量。盆地的构造演化可分为5个阶段,且与南海扩张、深部物质运动以及印澳板块、菲律宾海板块的相互作用在成因上有密切联系。

The Tectonics and Evolution of the Leiqiong Cenozoic Graben Basin

The structures of the Leiqiong (the abbreviation for Leizhou Peninsula and North Hainan) Graben Basin are principally controlled by the three sets of fractures trending ENE, NW and NE. The activities of each set of these fractures varied in the different periods during the Cenozoic era. Through analyzing the isopaeh maps of different stages in the Cenozoic, the authors have discussed the characteristics of the Leiqiong Graben Basin and the tectonic migration, development and spacetime transformation of the secondary structures within it. According to the calculation of the thickness of the stratigraphic profiles ,the subsidence,the subsidence-rate and the stretching factors at different stages ,as well as the stretching of the basin have been estimated. The tectonic evolution of the Leiqiong Graben Basin can be divided into five stages which are closely related with the spreading of the South China Sea and the deep-seated materials movement, as well as the mutual action of the India-Australian Plate and the Philippines Plate.