Karst

Karst is a landscape formed by the dissolution of soluble rock, chiefly limestone and dolomite, as rainwater absorbs carbon dioxide to form a weak carbonic acid that dissolves calcium carbonate over time. The process produces sinkholes, caves, and underground drainage networks in place of the surface streams found on non-soluble rock. Karst develops most strongly where dense, fractured carbonate rock meets moderate to heavy rainfall and a relatively low water table, and it appears across large regions of the world, including Australia's Nullarbor Plain, the Dinaric Alps of southeastern Europe, and the South China Karst of Guizhou, Guangxi, and Yunnan.