• karst
  • 1) A German rendering of a Serbo-Croat term referring to the terrain created by limestone solution and characterized by a virtual absence of surface drainage, a series of surface hollows, depressions and fissures, collapse structures, and an extensive subterranean drainage network. 2) A type of topography that is formed on limestone, gypsum, and other rocks by dissolution, and that is characterized by sinkholes, caves, and underground drainage. Etymology: German, from the Yugoslavian territory Krs; type locality, a limestone plateau in the Dinaric Alps of northwestern Yugoslavia and northeastern Italy.
Abstract from DBPedia
    Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. However, in regions where the dissolved bedrock is covered (perhaps by debris) or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground. The study of paleokarst (buried karst in the stratigraphic column) is important in petroleum geology because as much as 50% of the world's hydrocarbon reserves are hosted in carbonate rock, and much of this is found in porous karst systems.

    カルスト地形(独: Karst)とは、石灰岩などの水に溶解しやすい岩石で構成された大地が雨水、地表水、土壌水、地下水などによって侵食(主として溶食)されてできた地形(鍾乳洞などの地下地形を含む)である。化学的には、空気中の二酸化炭素を消費する自然現象である。 広義には、クロアチアのプリトヴィツェ湖群国立公園や中国の九寨溝、トルコのパムッカレ、アメリカのイエローストーン国立公園などの、大量の石灰分を溶解した地下水や温・熱水から石灰華が大規模に再沈殿して作り出される地形も、カルスト地形に含まれる。これらの場合、基盤地質が石灰岩であるとは限らず、化学的には空気中に二酸化炭素を放出する。 また、石灰岩やチョーク(白亜)、泥灰岩、白雲岩(ドロマイト)などの炭酸塩岩以外にも、蒸発岩類(石膏岩、岩塩など)には溶食性の地形が大規模に形成されることがあり、カルスト地形に含められる。空気中の二酸化炭素量の増減には関係しない。

    (Source: http://dbpedia.org/resource/Karst)