The palaeogeographic research indicate that the palaeogeographic outline of the study area recorded the evolution from a sedimentary basin in which the shallow - water carbonate platform sediments and deep - water terrigenous clastic submarine fan developed from southeast to northwest and northeast during the late triassic through a submarine sheet - like model composed of deep - water sandy turbidite and fine - grained turbidite during the early jurassic to a terrigenous clastic barrier coast during the middle and late jurassic and finally to the coal - bearing delta sediments during the late cretaceous 古地理分析表明，研究区晚三叠世古地理轮廓是一个从东南向西北和东北方向由浅水碳酸盐台地及深水陆层海底扇沉积共同发育的沉积盆地；早中侏罗世，演变成为一个由深水砂质浊积岩和细屑浊积岩组成的水下席状体沉积；进入中晚侏罗世，其古地理表现为一个陆屑浅海有障壁海岸；到了晚白垩世，研究区表现为以含煤沉积为特征的三角洲相沉积。
