Spatial distribution characteristics and the geomorphological evolution process of the Jiudongtian cave system in Guizhou Province

The study of cave distribution characteristics and geomorphological evolution provide a solid basis for can aid of the development of scientific activities and tourism of cave. In order to understand the distribution of the large scale bead-like skylights in the cave system of Jiudongtian Scenic spot, in situ investigations have been made to the discover the scale, shape, development direction and distribution elevation of karst caves in this area. Then the spatial distribution characteristics and geomorphological evolution process of the cave system are discussed by combining the idea of “from the present to infer the ancient” in geography with the Geographic Information system (GIS). The results show that the strata of the Jiudongtian cave system are dominated by Permian Maokou formation, of which the development is controlled by fault and hydrological conditions. The karst caves are mostly in NE and NW directions, largely consistent with the regional structure. Affected by Quaternary intermittent motions of uplifting and erosion datum plane, the caves are mostly distributed at at elevations of 1，170 m, 1，220 m and 1，310 m, which are similar to that of the ancient river courses in the area. The evolution of this cave system and geomorphology experienced three major stages， (1) Youcai river current and Dinazhai dry valley formation, (2) Ladder cliff current and Zhangjiazhai dry valley formation, (3) Jiudongtian volute current and Datianqiao dry valley formation, resulting in a typical karst pattern of skylight caves, bright and dark currents and ancient river courses coexisting in the Jiudongtian scenic spot.