The first member of Huoshiling Formation in Changling Fault Depression has well-developed fan delta and lacustrine facies. The fan delta facies include delta plain with braided and interdistributary channels, and delta front with various subfacies like underwater channels and bars. The lacustrine facies consist of semi-deep and deep subfacies. Sand bodies are mainly found in Huo-Ⅱ and Huo-Ⅲ sand groups, followed by Huo-Ⅰ and Huo-Ⅳ sand groups.