Analysis of the physiographic stages of the development and evolution process of karst geomorphology in Guilin, China

This paper analyzes the development and evolution process of karst geomorphology in Guilin from the perspective of physiognomy.In order to provide scientific basis for studying the development and evolution law of karst geomorphology and exploring the protection, utilization and sustainable development of karst geomorphology.Through examining the spatial distribution characteristics of strata and landforms within the area, as well as the changes to geomorphic forces(hydrological systems), and integrating factors such as the area's tectonic development history and the changes in lithofacies paleogeographic environments, we can analyze the stages of Guilin's geomorphological development and evolution.The research indicates that: ①From the Middle Triassic to the Late Cretaceous, the rise and fall of the Earth's crust caused marine transgressions and regressions, which established the material foundation and fundamental framework for the development of the modern karst landforms in the study area.②From the Paleocene to the Pliocene, the development of inland basins due to faulting and subsidence provided the topographical conditions necessary for the development of hydrodynamic forces in modern karst landforms.③In the end of the Oligocene, the fault block structure in southern Guangxi became significantly pronounced, strengthening the ability of the region's southward flowing water systems to erode and trace their paths upstream, thereby connecting the water systems of Yangshuo and Guilin(leading to the formation of the Lijiang River).This resulted in the shaping of Guilin's modern karst landform landscape under the influence of these hydrological effects.Therefore, based on the geological evolution history, changes in external forces(hydrological systems), and geomorphological characteristics of the area, the development and evolution of Guilin's karst geomorphology can be categorized into three geologic periods: the Maoershan period, the Mountain Basin period, and the Lijiang period.