A solutional cave, solution cave, or karst cave is a cave usually formed in a soluble rock like limestone (Calcium carbonate, with chemical formula CaCO3). It is the most frequently occurring type of cave. It can also form in other rocks, including chalk, dolomite, marble, Evaporite, and gypsum.
Process
Bedrock is dissolved by
carbonic acid in rainwater,
groundwater, or
Humic substance acids from decaying vegetation, that seeps through bedding planes,
Geological fault, joints, and the like. Over time, the surface terrain breaks up into clints separated by grikes and punctuated by
Sinkhole into which streams may disappear, crevices expand as the walls are dissolved to become caves or cave system. These may turn into large caverns or
dolines when the roof collapses.
The portions of a solutional cave that are below the water table or the local level of the groundwater are flooded.
Limestone caves
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
,
,
,
,
,
calcite rafts, and
stalagnate. These secondary mineral deposits in caves are called "
".
Carbonic acid dissolution
Limestone dissolves under the action of rainwater and groundwater charged with H2CO3 (carbonic acid) and naturally occurring . The dissolution process produces a distinctive landform known as "karst", characterized by and underground drainage. Solutional caves in this landform—topography are often called karst caves.
Sulfuric acid dissolution
Lechuguilla Cave in New Mexico and nearby are now believed to be examples of another type of solutional cave. They were formed by H2S (hydrogen sulfide) gas rising from below, where reservoirs of petroleum give off sulfurous fumes. This gas mixes with ground water and forms H2SO4 (sulfuric acid). The acid then dissolves the limestone from below, rather than from above, by acidic water percolating to the surface.
Examples
Australia
Malaysia
-
List of caves in Malaysia
Taiwan
-
Black Dwarf Cave, Pingtung County
United States
-
Jewel Cave National Monument, South Dakota
-
Mammoth Cave National Park, Kentucky
-
Russell Cave National Monument, Alabama
-
Wind Cave National Park, South Dakota
-
Oregon Caves National Monument and Preserve, Oregon
-
Cumberland Caverns, Tennessee
Vietnam
-
Hang Sơn Đoòng, Quảng Bình Province
Germany
-
König-Otto-Tropfsteinhöhle
Sources
External links
