Paleo-karst landforms on top of limestone of the Maokou Formation in the west of the Upper Yangtze platform and its geological significance

Abstract：The Middle Permian Maokou Formation is generally overlain by the Late Permian Emeishan basalts in eastern Yunnan and western Guizhou in the west of the Yangtze platform. It has long been taken for granted that there are no sedimentary breaks or erosion between the Maokou Formation and Emeishan basalts. On the basis of the field investigation and indoor integrated study, the authors present various evidence of the paleo-karst landforms on top of the Maokou Formation, including rugged ancient erosion surfaces, uvalas, dolines or holes, cone karst, tower karst and caves, as well as cave fillings and red soils on the ancient erosion surfaces, and suggest that paleo-karst landforms have great significance in the geological development in an area，which represent a crustal uplift. The systematic study of the paleo-karst not only enriches the content of the study of paleo-karst in China, but also affirms the existence of the Dongwu movement in Yunnan, and also provides important evidence for the activity of the Emeishan mantle plume.