雷琼新生代断陷盆地构造特征及其演化

雷琼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。雷琼新生代断陷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 Byolution of the Lei-Qiong Cenozoic Graben Basin

The structures of the Lei-Qiong (the abbreviation for Leizhou Peninsulaand North Hainan) Graben Basin are principally controlled by the three sets offractures trending ENE, NW and NE. The activities of each set of these frac-tures varied in the different periods during the Cenozoic era. Through analyzing the isopach maps of different stages in the Cenozoic, theauthors have discussed the characteristics of the Lei-Qiong Graben Basin and thetectonic migration, development and space-time transformation of the secondarystructures within it. According to the calculation of the thickness of the stra-tigraphic profiles, the subsidence, the subsidence-rate and the stretching factorsat different stages, as well as the stretching of the basin have been estimated. The tectonic evolution of the Lei-Qiong Graben Basin can be divided intofive stages which are closely related with the spreading of the South China Seaand the deep-seated materials movement, as well as the mutual action of theIndia-Australian Plate and the Philippines Plate.