Distribution of Guangxi karst rocky desertificationby palaeogeographic approach
Li Fei1 Yi Wenchao1，2 Yan Weiwei1
1 Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541004, Guangxi; 2 Graduate School, Guangxi Normal University, Guilin 541004, Guangxi
Abstract：Karst rocky desertification is a desertlike landscape generated in the carbonate rock area, which resulted from serious soil erosion as well as extensive exposure of bedrocks caused by rational human activities.The production of rocky desertification depends on both features of basement carbonate rock and its content of acid-insoluble residues.On the contrary，it seems difficult to identify the regularity in lithology and rocky desertification using traditional remote sensing.The origin of karst rocky desertification and partitioned rocky desertification of Guangxi into seven regions in light of distinct palaeogeographic bankground，including Guilin-Hezhou(Ⅰ），Liuzhou-Laibin（Ⅱ），Du′an-Mashan（Ⅲ），Pingguo Platform（Ⅳ），Jingxi Platform（Ⅴ），southern margin of Yangtze platform（Ⅵ） and Xilin-Leye-Lingyun（Ⅶ）.Karst rocky desertification is mainly formed in areas containing relatively stable platform-facies-environments.Moreover，intense rocky desertification largely corresponds to carbonate platform margin reef（or shoal）facies(such as Pingguo Platform，Jingxi Platform，southern margin of Yangtze Platform，etc.).Numerous and stable isolated carbonate platforms can provide such an opportunity to form karst rocky desertification.This work，combined with remote sensing interpretation and field investigation，can provide a new method for risk assessment and management according to local lithology which easily caused rocky desertification.
