Sedimentary environments of the Maotai Formation in Guizhou

The Upper Cretaceous Maotai Formation strata are widespread in Guizhou except the Chishui region, with a maximum outcropped area of 25 km² around the Yuqing region and a residual thickness of about 1440 m along the Rongjiang River. There is a unconformity between the Maotai Formation and underlying Qingbaikouan Xiajiang Group/Danzhou Group-Jurassic strata. Although commonly cropped out along the faults,the Maotai Formation strata are not controlled by the associated faults. Instead,they represent red fluvial-lacustrine molasse formations deposited above the unleveled surfaces in the intracontinental intermontane basins under the xerothermic climatic conditions from the Yanshanian movement onwards.