The age of a karst depression zone located in Langshi Subterranean River, Guilin

摘要

The emergent point of the Langshi Subterranean River is in a karst depression zone which is located in the east strand of Lijiang River, Yangshuo County, Guilin City. Langshi Subterranean River is a typical single channel subterranean river system which discharges into Lijiang River at Langshi Village. In this paper, the geological structure is analyzed. Using hydrogeochemistry and MAPGIS spatial analysis measures,the karst depression zone is ascertained to have an age of 2.56 Ma. Strontium element techniques are used in the study to check this conclusion, and give an age of 2.59 Ma. Those all show that the karst depression zone of Langshi Subterranean River had been formed during the Pliocene-Quaternary periods. This conclusion provides a theoretical reference to the historical study of the Langshi subterranean river.