Karst

"Karst" redirects here. For other uses, see Karst (disambiguation).

File:Kravice Trebižat river BiH.jpg

The Kravice waterfall on the Trebižat river in Bosnia and Herzegovina has karst geology.

A karst landscape in Minerve, Hérault, France.

The karst hills of The Burren on the west coast of Ireland

Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite.

Due to subterranean drainage, there may be very limited surface water, even to the absence of all rivers and lakes. Many karst regions display distinctive surface features, with sinkholes or dolines being the most common. However, distinctive karst surface features may be completely absent where the soluble rock is mantled, such as by glacial debris, or confined by a superimposed non-soluble rock strata. Some karst regions include thousands of caves, even though evidence of caves that are big enough for human exploration is not a required characteristic of karst.

Various karst landforms have been found on all continents except Antarctica (see below: Notable karst areas).

Background

Karst topography is characterized by subterranean limestone caverns, carved by groundwater.The geographer Jovan Cvijić (1865–1927) was born in western Serbia and studied widely in the Dinaric Kras region. His publication of Das Karstphänomen (1893) established that rock dissolution was the key process and that it created most types of dolines, "the diagnostic karst landforms". The Dinaric Kras thus became the type area for dissolutional landforms and aquifers; the regional name kras, Germanicised as "karst", is now applied to modern and paleo-dissolutional phenomena worldwide. Cvijić related the complex behaviour of karstic aquifers to development of solutional conduit networks and linked it to a cycle of landform evolution. After Cvijić, two main kinds of karstic areas exist: holokarst i.e. karst developed at whole as it is Dinaric region along eastern Adriatic coast comprises deep in the inland of Balkan Peninsula and merokarst developed imperfectly with some karstic forms as it is in eastern Serbia. He is recognized as "the father of karst geomorphology".

Different terms for karst topography exist in other languages—for example, yanrong in Chinese and tsingy in Malagasy. The international community has settled on karst, the German name for Kras, a region in Slovenia partially extending into Italy, where it is called "Carso" and where the first scientific research of a karst topography was made. The name has an Indo-European origin (from karra meaning "stone"), and in antiquity it was called "Carusardius" in Latin. The Slovene form grast is attested since 1177, and the Croatian kras since 1230.. "Krš" - "Krsh" meaning in Serbo-Croatian "barren land" which is typical feature in the Northern Dinaric limestone mountains could also be a origin to the word Karst.

Chemistry

Karst lake (Doberdò del Lago, Italy), from underground water springing into a depression. This lake has no surface inlet or outlet.

Karst landforms are generally the result of mildly acidic water acting on soluble bedrock such as limestone or dolostone. The carbonic acid that causes these features is formed as rain passes through the atmosphere picking up CO₂, which dissolves in the water. Once the rain reaches the ground, it may pass through soil that may provide further CO₂ to form a weak carbonic acid solution: H₂O + CO₂ → H₂CO₃ (the acid). Recent studies of sulfates, in karst waters, suggests sulfuric acid and hydrosulfuric acid may also play an important role in karst formation.

This mildly acidic water begins to dissolve the surface along fractures or bedding planes in the limestone bedrock. Over time, these fractures enlarge as the bedrock continues to dissolve. Openings in the rock increase in size, and an underground drainage system begins to develop, allowing more water to pass through the area, and accelerating the formation of underground karst features.

Somewhat less common than this limestone karst is gypsum karst, where the solubility of the mineral gypsum provides many similar structures to the dissolution and redeposition of calcium carbonate.

Morphology

Limestone pavement in Dent de Crolles, France

The karstification of a landscape may result in a variety of large or small scale features both on the surface and beneath. On exposed surfaces, small features may include flutes, runnels, clints and grikes, collectively called karren or lapiez. Medium-sized surface features may include sinkholes or cenotes (closed basins), vertical shafts, foibe (inverted funnel shaped sinkholes), disappearing streams, and reappearing springs. Large-scale features may include limestone pavements, poljes and blind valleys. Mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers, or haystack/eggbox landscapes. Beneath the surface, complex underground drainage systems (such as karst aquifers) and extensive caves and cavern systems may form.

The Witch's Finger stalagmite in Carlsbad Caverns, USA

Erosion along limestone shores, notably in the tropics, produces karst topography that includes a sharp makatea surface above the normal reach of the sea and undercuts that are mostly the result of biological activity or bioerosion at or a little above mean sea level. Some of the most dramatic of these formations can be seen in Thailand's Phangnga Bay and Halong Bay in Vietnam.

Calcium carbonate dissolved into water may precipitate out where the water discharges some of its dissolved carbon dioxide. Rivers which emerge from springs may produce tufa terraces, consisting of layers of calcite deposited over extended periods of time. In caves, a variety of features collectively called speleothems are formed by deposition of calcium carbonate and other dissolved minerals.

Hydrology

A karst spring in the Jura mountains near Ouhans in eastern France at the source of the river Loue

Farming in karst areas must take into account the lack of surface water. The soils may be fertile enough, and rainfall may be adequate, but rainwater quickly moves through the crevices into the ground, sometimes leaving the surface soil parched between rains.

A karst fenster is where an underground stream emerges onto the surface between layers of rock, cascades some feet, and then disappears back down, often into a sinkhole. Rivers in karst areas may disappear underground a number of times and spring up again in different places, usually under a different name (like Ljubljanica, the river of seven names). An example of this is the Popo Agie River in Fremont County, Wyoming. At a site simply named "The Sinks" in Sinks Canyon State Park, the river flows into a cave in a formation known as the Madison Limestone, and then rises again a half-mile down the canyon in a placid pool. A Turlach is a unique type of seasonal lake found in Irish karst areas which are formed through the annual welling-up of water from the underground water system.

Water supplies from wells in karst topography may be unsafe, as the water may have run unimpeded from a sinkhole in a cattle pasture, through a cave and to the well, bypassing the normal filtering that occurs in a porous aquifer. Karst formations are cavernous and therefore have high rates of permeability, resulting in reduced opportunity for contaminants to be filtered out.

Groundwater in karst areas is just as easily polluted as surface streams. Sinkholes have often been used as farmstead or community trash dumps. Overloaded or malfunctioning septic tanks in karst landscapes may dump raw sewage directly into underground channels.

The karst topography itself also poses difficulties for human inhabitants. Sinkholes can develop gradually as surface openings enlarge, but quite often progressive erosion is unseen and the roof of an underground cavern suddenly collapses. Such events have swallowed homes, cattle, cars, and farm machinery.

The Driftless Area National Wildlife Refuge in Iowa protects Discus macclintocki, a species of ice age snail surviving in air chilled by flowing over buried karst ice formations.

Pseudokarst

Pseudokarsts are similar in form or appearance to karst features, but are created by different mechanisms. Examples include lava caves and granite tors—for example, Labertouche Cave in Victoria, Australia and paleocollapse features.

Notable karst areas

Africa Madagascar Anjajavy Forest, western Madagascar Ankarana Reserve, Madagascar Madagascar dry deciduous forests, western Madagascar Tsingy de Bemaraha Strict Nature Reserve, Madagascar Asia Phong Nha Cave in Phong Nha-Ke Bang, Vietnam China Area around Guilin and Yangshuo Jiuzhaigou and Huanglong National Park, (UNESCO World Heritage Site) South China Karst, World Heritage Site Stone Forest Zhangjiajie National Forest park, forming part of the Wulingyuan scenic area, World Heritage Site Georgia Arabika Massif (including Voronya Cave—the world's deepest cave), Abkhazia, Georgia Indonesia Bantimurung, Indonesia Gunung Sewu, Indonesia Israel Ofra region, Israel Japan Akiyoshi Plateau, Japan Atetsudai and Taishakudai Plateaus, Japan Shikoku Karst, Japan Hiraodai Plateau, Japan Okinoerabujima Island and other islets of Nansei Islands, Japan Laos Vang Vieng, Laos Lebanon Dunnieh mountains, North Lebanon Jeita Grotto, Lebanon Parts of Mount Lebanon Malaysia Gunung Mulu National Park, Malaysia Kilim Karst Geoforest Park, Langkawi, Malaysia Kinta Valley, Perak, Malaysia Perlis State Park, Perlis, Malaysia Batu Caves, Selangor, Malaysia Philippines South Korea Gangwon-do (South Korea), South Korea Northwestern North Chungcheong Province, South Korea Thailand Krabi region, Thailand Phangnga Bay Area, southern Thailand Doi Nang Non, northern Thailand Taiwan Kenting National Park, Taiwan Turkey Taseli plateau, Turkey Vietnam Halong Bay, Vietnam Phong Nha-Ke Bang, Vietnam Tam Coc - Bich Dong in Ninh Binh Province, Vietnam Europe Albania Bisa area in Eastern Albania Austria Eastern region of the Northern Limestone Alps in the provinces of Salzburg, Upper Austria, Styria, and Lower Austria, forming huge limestone plateaus such as Steinernes Meer, Hagengebirge, Tennengebirge, Dachstein, Totes Gebirge, Hochschwab, Rax, and Schneeberg. Area around Graz, Styria. Bosnia and Herzegovina Karst poljas (Bosnian: kraška polja) Popovo polje in Herzegovina region of Bosnia and Herzegovina Livanjsko polje (405 km2), near Livno in Bosnia (region) of Bosnia and Herzegovina Nevesinjsko polje, near Nevesinje in Herzegovina region of Bosnia and Herzegovina Gatačko polje, near Gacko in Herzegovina region of Bosnia and Herzegovina Glamočko polje, near Glamoč in Bosnia (region) of Bosnia and Herzegovina Duvanjsko polje, near Duvno in Bosnia (region) of Bosnia and Herzegovina Mostarsko polje, near Mostar in Herzegovina region of Bosnia and Herzegovina Kupreško Polje, near Kupres in Bosnia (region) of Bosnia and Herzegovina Vjetrenica (which means "wind cave" or "blowhole"), largest and most important cave Neretva river Trebisnjica river Bulgaria Central Rhodope karst (including Trigrad Gorge), Bulgaria Devnya Valley, Varna Province, Bulgaria Dragoman marsh, Bulgaria Karlukovo Karst Geocomplex Croatia Regions of Dalmatia (including Zagora), Lika (Plitvice Lakes National Park), Gorski kotar, Kvarner and the islands in Croatia Czech Republic Moravian Karst, Czech Republic Bohemian Karst, Czech Republic England White Peak of the Peak District, around Matlock, Castleton (including Thor's Cave) Mendip Hills including Cheddar Gorge Yorkshire Dales including the Gaping Gill and Ease Gill systems Forest of Dean including the Clearwell Caves and Mines Estonia Tuhala karst area, Estonia France Ares de l'Anie, in the southernmost part of Barétous valley, southwest France Causses of the southern Massif Central, France Germany Hönnetal at Balve Swabian Alb region in the federal state of Baden-Wuerttemberg Hungary Region of the Mecsek Mountains Bükk, a plateau in northeastern Hungary Bakony-hills in Transdanubien Budai-hills, thermal karst area Aggtelek karst and the largest cave in Hungary Ireland Burren in County Clare Italy Murge, in Apulia and Basilicata, southern Carso (Template:Lang-sl), a plateau in southwestern Slovenia and northeastern Italy Malta Wied iż-Żurrieq and Dingli, West Montenegro Dinaric Alps region

Poland Kraków-Częstochowa Upland (Jura Krakowsko-Częstochowska) Holy Cross Mountains (Góry Świętokrzyskie) with the Jaskinia Raj (Raj Cave) Tatra Mountains including the Jaskinia Wielka Śnieżna (Great Snowy Cave)— the longest cave in Poland Romania Apuseni Mountains, Romania Serbia Dinaric Alps region merokarst of eastern Serbia Scotland Assynt, southeast Skye and near Kentallen in Scotland, United Kingdom Slovakia Slovak Paradise, Slovak Karst and Muránska planina, Slovakia Slovenia Region of Inner Carniola, Goriška, Upper Carniola and Lower Carniola Kras (German: Karst), a plateau in southwestern Slovenia and northeastern Italy Spain El Torcal (Antequera - Spain) Picos de Europa and Basque mountains, northern Spain Larra-Belagua, Navarre, northern Spain Cadí mountain range, Spain Garraf Natural Park area, Spain Ciudad Encantada in the Cuenca province, Castilla-La Mancha El Torcal de Antequera nature preserve, southern Spain Switzerland Karst and Caves of Switzerland 7,900 square kilometres (3,100 sq mi), 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 (750 mi). Ukraine Podolia and Bukovina regions in the northeastern edge of the Carpathian Mountains. Includes some of the largest gypsum karst 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. Wales Southern region of the Brecon Beacons National Park, Wales, United Kingdom North America Canada Marble Canyon, British Columbia Monkman Provincial Park, British Columbia Northern Vancouver Island, British Columbia Niagara Escarpment, Ontario Port au Port Peninsula, Newfoundland Nahanni region in the Northwest Territories Wood Buffalo National Park in Alberta and the Northwest Territories Avon Peninsula, Nova Scotia St-Jude, Quebec Mexico Cenotes of the Yucatán Peninsula Sótanos of the Sierra Gorda, Querétaro Cacahuamilpa grottos Guerrero United States Bluegrass region of Kentucky Carlsbad Caverns National Park, New Mexico Central Pennsylvania Cumberland Plateau in Middle Tennessee Deschutes River basin, Oregon Driftless Area of southwest Wisconsin, southeast Minnesota, northeast Iowa and northwest Illinois Peneplain areas of central Minnesota and western Wisconsin (forming the 10,000 lakes of Minnesota) Florida peninsula. Germany Valley Karst Area, West Virginia Grassy Cove Karst Area, Tennessee Great Valley of Appalachia (Huntsville, Alabama to Howe Caverns, central New York) Greenbrier River watershed in West Virginia Illinois Caverns State Natural Area and Illinois Sinkhole Plain in Monroe County, Illinois Kamas Ranch and Alabaster Cavern area of Oklahoma Kosciusko Island, southeastern Alaska Lehman Caves located within Great Basin National Park in eastern Nevada Mammoth Cave in central Kentucky Texas Canyon in Arizona Mitchell Plain and uplands of southern Indiana Ozark Plateau of Missouri and Arkansas Presque Isle County near and around Rogers City in northern Michigan Ricks Spring in northeast Utah Shenandoah Valley, Virginia Swago Karst Area, West Virginia Texas Canyon, Cochise County, Arizona Texas Hill Country, Texas and its northern extensions, including the Palo Pinto Mountains Yosemite area, California Central America and the Caribbean Belize Eastern foothills of Maya Mountains including parts of the Cockscomb Basin Wildlife Sanctuary, Belize Great Blue Hole near the center of Lighthouse Reef, Belize Cuba Mogotes in Viñales Valley Dominican Republic Los Haitises National Park Jamaica Cockpit Country region Puerto Rico Karst forest, Puerto Rico (see Geography of Puerto Rico) Mountains of northwestern Puerto Rico (see Geography of Puerto Rico) Oceania Australia Cutta Cutta Caves National Park and Kintore Caves Conservation Park, Katherine, Northern Territory Leeuwin-Naturaliste National Park, near Margaret River, south west Western Australia Northern Swan Coastal Plain, Perth, Western Australia Naracoorte Caves National Park, South Australia Jenolan Caves, New South Wales Wombeyan Caves, New South Wales Mole Creek Karst National Park, Tasmania Nullarbor Plain, South Australia and Western Australia New Zealand Takaka Hill, South Island Waitomo, Oparara regions Papua New Guinea Nakanai Mountains, East New Britain South America Madre de Dios Island and Guarello Island (the world's southernmost limestone mine), Magallanes, Chile

Notable pseudokarst areas

North America

Belize

• Great Blue Hole near the center of Lighthouse Reef, Belize

United States

• Arroyo Tapiado in Anza-Borrego Desert State Park. Over two-dozen mud caves are found in this desert area east of San Diego, California.

See also

• Glaciokarst
• Thermokarst
• Speleology
• Subterranean river
• List of landforms

References

• Jennings, J.N., Karst Geomorphology, 2nd ed., Blackwell, 1985, ISBN 0631140328
• Sweeting, M.M., Karst Landforms, Macmillan, 1973, ISBN 023103623X

External links

• Speleogenesis Network, a communication platform for physical speleology and karst science research
• Speleogenesis and Karst Aquifers - a large glossary of Karst related terms.
• Acta Carsologica - research papers and reviews in all the fields related to karst.
• SERA Karst Task Force - a non-profit resource organization dedicated to karst conservation and the clean up of cave and karst features.
• CDK Citizens of the Karst - Citizens of the Karst, a non profit NGO dedicated to the protection of the Puerto Rican Karst (English site available)