Formation of Two Types of Tiankeng
Karst scientists classified tiankeng into two types: the collapsed tiankeng and the eroded tiankeng. As research went deeper, scientists found that eroded tiankeng were actually also formed by land surface collapses. The illustrations show how these two types of tiankeng were formed.
Illustrations/ Liu Chuntian Under groun d River Grand Cave Appea srs Land Surfac e Collpa ses Formation of Collapsed Tiankeng
Doline transforms into a cave
Land sufrace collpases and a tiankeng appears
Cave is connected with the ground through a shaft
Doline collpases and expands
Formation of a doline