EuroSpeleo 2016

Evolution and Characteristics of Jinfoshan Cave Systems in Chongqing, China

Oral|Mr Jing Zhang

Abstract

Jinfoshan is a karst table mountain that has been separated from the surrounding Yunnan-Guizhou-Chonqing plateau by deep fluvial dissection. A series of ancient and enormous cave systems with active streams are located at the top of Jinfo Mountain at 1,800-2,100m a.s.l., perhaps the highest elevation of any known extensive horizontal trunk cave passage on Earth. The cave systems total over 25km in length, with passages 20-120m wide and 10-18m high. They include Gufo Cave and Xiannv Cave along the northern slope, and Lingguan Cave, Yanzi Cave, and Jinfo Cave along the western slope. Large-scale trunk passages formed during the early stage are mixed with maze passages formed during the middle stage and vadose shafts formed during the most recent stage to create a highly complex system. The top layer of clastic sediments in Jinfo Cave has been dated to 5.7Ma, implying Neogene (5-20Ma) deposition for cemented sediments found in upper levels of the system. This is the oldest measured age for a cave in Asia. Together with the historical remains of large-scale nitrate extraction found in the cave system, this vividly demonstrates the whole process of the development, degradation and disappearance of the subterranean streams in Jinfoshan.