鄂尔多斯盆地三叠纪延长期湖水分布特征及演化规律

利用Fisher图解求取了延长期可容空间变化，结合露头、岩芯、测井等资料在延长组内识别出了6期三级湖泛层（Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ），并对其进行了识别和对比。在此基础上，研究了与湖泛层Ⅲ、Ⅳ、Ⅴ、Ⅵ相对应的长7、长4+5、长3、长2的湖水分布特征及整体演化规律。最后，通过各期湖泛层沉积厚度中心分布特征探讨了延长湖盆沉积洼陷的分布和演化问题，认为延长湖除长7存在一个大的沉积洼陷外，其它各期是多个沉积洼陷同时存在的、且其沉积洼陷整体逐渐向东北部迁移的坳陷型湖盆。

The Lake Distribution and Evolution Law of the Ordos Basin,in Triassic Yanchang Period

Fisher diagram used to get the Yanchang period accommodation changes, combining the data of outcrop, core and logging in Yanchang group, we identified six period (Ⅰ,Ⅱ,Ⅲ,Ⅳ,Ⅴ,Ⅵ) third degree flooding layers, and compared them. On this basis, we further studied the lake distribution and overall evolution of the flooding layers, Ⅲ,Ⅳ,Ⅴand Ⅵ, which are corresponding to Chang7, Chang4+5, Chang3 and Chang2 section. Finally through each flooding layer deposition center distribution characteristics, we discussed that the distribution and evolution issues of Yanchang lake basin's sedimentary depression, and believed that the Yanchang lake besides the Chang7 existed a big sedimentary depression, also there were more than one sedimentary depressions in other period, and the sedimentary depressions overall move to the north east.