Collapse processes at the tiankengs of Xingwen

The karst of Xingwen, China, contains the Xiaoyanwan tiankeng, alongside the degraded tiankeng of Dayanwan and also the potential collapse chambers in the Zhucaojing cave system. These three sites appear to represent an evolutionary sequence, whereby a tiankeng develops from multiple cave collapses, and subsequently degrades to the profile of a large doline.