Karst topography is a geological formation shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite, but also in gypsum.[1] It has also been documented for weathering-resistant rocks, such as quartzite, given the right conditions.[2] This is an incomplete list of the major karst landscape areas of the world.
Shaanxi tiankeng cluster, discovered in 2016, it is one of the largest in the world comprising forty-nine sinkholes and more than fifty funnels ranging from 50–100 metres in diameter.
The Abisko-Torneträsk area in northern Sweden contains several cave systems developed on carbonate stata of the Caledonidenappes.
Switzerland
7,900 square kilometres (3,100sqmi), or 19% of the surface of Switzerland, is karst, within this area lies the majority of the 7,500 currently known Swiss caves, with an accumulated passage length of more than 1,200 kilometres (750mi).[citation needed]
Ukraine
Podolia and Bukovina regions in the northeastern edge of the Carpathian Mountains which includes some of the largest gypsum caves in the world, including the Optymistychna Cave, which is over 200,000 meters in length, making it the longest cave in Eurasia, the third longest in the world, and the longest gypsum cave in the world.[citation needed]
Castleton, Karst hydrology By Christian Leibundgut, John Gunn, Alain Dassargues, International Association of Hydrological Sciences, 1998, ISBN1-901502-40-6, accessed June 2009.