Luota,a perfect karst synclinal catchment basin, is situated in a karst mountainous area in the west of Hunan, near Hubei, Sichuan and Guizhou provinces. Carbonate rocks of Permian-Lower Triassic, 881.4-1159.5 meters thick,are distributed in the basin, which can be divided into three karstic suites and six karstic horizons.The fault structures are mainly of two sets trending NE and NW, which control the development of the caves. It is suggested that in addition to the corrcding action of water that ...