洞庭盆地的第四纪构造活动

THE TECTOGENESIS IN THE QUATERNARY PERIOD OF THE DONGTING BASIN

依据第四系分统等厚度图,分析了洞庭盆地第四纪构造活动的演变。早更新世及晚更新世表现为盆地东西两侧对边掀斜,沉积中心呈近南北向伸延;中更新世及全新世,迎丰桥-北景港断裂两侧断块反向扭动掀斜,以致盆地西北角和东南角掀升,并形成与此主掀升部位相应的俯伏部位,其伸延方向与主掀升部位的掀斜方向垂直。

In this paper,by drawing up the isopach maps of series in the Quaternary system,analysed the evalution of the tectogenesis of each epoch in the Quaternary period of the Dongting Basin.In the Early Pleistocene and the Late Pleistocene,it showed opposite tilting in the east and the west,and the deposit laid down central block showed stretching to the south and the north;In the Middle Pleistocene and the Halocene because the fault blocks of thebilaterals of the Yingfeng bridge-Beijing port showed tangle-up tilting in the opposing direction,the northwest angle and the southeast angle of the basin showed tilting and it took a shape of prostrate part correspording to the major tilting part,its.stretching direction was vertical to the tilted direction of the major tilting part.