湘鄂赣皖交界区的湖盆演化及其控制因素

受燕山期构造格局控制，湘鄂赣皖交界区的白垩-早第三纪湖盆呈近东西向和近南北向展布、第四纪湖盆继承这一格局发育，局部受到新构造运动改造，其中最重要的是北北东向的江汉-洞庭断陷；麻城-团风断裂控制了孝感断陷和梁子湖断陷，并使某些断陷湖演化为复成因湖。北西向断裂和鄂东南的掀斜对第四纪湖盆发育也有重要作用。在此基础上讨论了燕山运动的特征、北北东向断裂新生代活动的机制等问题。

LAKES BORDERING HUNAN,HUBEI,JIANGXI AND ANHUI PROVINCES:BASIN DEVELOPMENT AND CONTROL FACTORS

The lakes, scattering in the border area of Hunan, Hubei, Jiangxi and Anhui Provinces,are oriented to the W-E and approximately N-S directions, which might be controlled by theYanshanian tectonic framework, and the neotectonic rejuvenation of NNE-SSW as well asNW-SE fractures. Their evolutional history can be traced back to Cretaceous.Two tectonic units during Paleozoic and Early Mesozoic can be distinguished: the Jiangnan-Xuefeng Rise in the south and the Lower Yangtze Depression in the north. The sedimentary beds in the latter were folded violently in the Yanshanian orogenesis, which was responsible for the small fault basins along the W-E tensile fractures occurring in the crests of anticlines during Cretaceous-Eogene. There were four basin belts, named, in a northward order, the Puqi-Yangxin-Wangjiang, the south of Jiayu-Jinniu of Daye, the Wuchang-Echengand the Wuhan belts respectvely. The conjugate NNE and N(N)W fractures occurred in theregion of previously Jiangnan-Xuefeng Rise during the movement, which controlled the relatively large-scale Cretaceous-Eogene fault basins where some lakes formed, such as thePoyang and Dongting Lakes. The kinematic features of Yanshanian orogenesis there is obviously different from that in the southeast coast region of China, the latter being closely related to Jurassic Tethyan closure and followed collision and oblique convergence, which maycomprehend a kind of intra-continental orogenesis.The Quaternary basins might develop with inheriting the Yanshanian tectonic framework, only partially reformed by the neotectonics. The Jianghan-Dongting Block-Depressionmight be resulted from the rejuvenated NNE and NW fractures. The boundaries among thedepression's subunits and the distribution of modern lacustrine basins might imply the neotectonic activities. In addition,the rejuvenation of NNE as well as NW fractures might giverise to formation of the Xiaogan and Liangzihu Depressions. Owing to sinking of the Jianghan Depression, the southeast Hubei might be tilted eastwards,with the Lower Pleistoceneoccurring only in the border region of Hubei and Anhui Provinces, and no Quaternary lacustrine deposits in Puqi-Tongshan region. The sinistral tensile NNE fractures may, being related with the oblique collision (or shear orogenesis) between the Asian cotment and the LuzonArc, play the most important role in the neotectonics.Generally, these Holocene lacustrine basins may be in the stage of maturity. Only bystrengthening the water and soil conservation, and the environment protection, should therich resources in them be exploited rationally and more effectively.