Solutional cave

A solutional cave or karst cave is a cave usually formed in the soluble rock limestone. It is the most frequently occurring type of cave. It can also form in other rocks, including chalk, dolomite, marble, salt beds, and gypsum.

Bedrock is dissolved by natural acid in groundwater that seeps through bedding-planes, faults, joints and so on. Over geological epochs these openings expand as the walls are dissolved to become caves or cave systems.

The portions of a solutional cave that are below the water table or the local level of the groundwater will be flooded.

The largest and most abundant solutional caves are located in limestone. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation. These include flowstones, stalactites, stalagmites, helictites, soda straws, calcite rafts and columns. These secondary mineral deposits in caves are called speleothems.

Limestone dissolves under the action of rainwater and groundwater charged with H₂CO₃ (carbonic acid) and naturally occurring organic acids. The dissolution process produces a distinctive landform known as karst, characterized by sinkholes, and underground drainage. Solutional caves in this landform—topography are often called karst caves.

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