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41-640: The river has a karst character . It receives much of its water through subterranean flow from the Reka River ( Slovenia ), but tracer studies have shown that other sinking rivers, Vipava , Soča , and Raša also contribute. From modelling results, the Timavo is believed to receive one third of its flow from the Reka and two-thirds of its flow from infiltration of precipitation into the Karst Plateau , and to

82-489: A 1918 publication, Cvijić proposed a cyclical model for karst landscape development. Karst hydrology emerged as a discipline in the late 1950s and the early 1960s in France. Previously, the activities of cave explorers, called speleologists , had been dismissed as more of a sport than a science and so the underground karst caves and their associated watercourses were, from a scientific perspective, understudied. Karst

123-613: A fellow of the Royal Society , London, introduced the word karst to European scholars in 1689 to describe the phenomenon of underground flows of rivers in his account of Lake Cerknica . Jovan Cvijić greatly advanced the knowledge of karst regions to the point where he became known as the "father of karst geomorphology". Primarily discussing the karst regions of the Balkans, Cvijić's 1893 publication Das Karstphänomen describes landforms such as karren, dolines and poljes . In

164-529: A lesser extent from the other sinking river sources. The Roman authors Livy , Strabo , and Virgil mention the river. Virgil wrote that nine streams emerge from a mountain to form the river. A Roman settlement near the sources was called Fons Timavi. An Italian passenger liner called the Timavo ran aground during the Second World War on the east coast of South Africa near Cape Vidal. The engine of

205-531: A major role in the formation of ancient Lechuguilla Cave in the US state of New Mexico and is presently active in the Frasassi Caves of Italy. The oxidation of sulfides leading to the formation of sulfuric acid can also be one of the corrosion factors in karst formation. As oxygen (O 2 )-rich surface waters seep into deep anoxic karst systems, they bring oxygen, which reacts with sulfide present in

246-440: A variety of spatial and temporal scales in karst regions, with the purpose of understanding karst aquifers and ecosystems, and the development of the surface and underground structure, so that the environment can be protected and human activities planned effectively. Dalmatian language Dalmatian or Dalmatic ( Italian : dalmatico ; Croatian : dalmatinski ) was a group of Romance varieties that developed along

287-529: A well in a fracture trace or intersection of fracture traces increases the likelihood to encounter good water production. Voids in karst aquifers can be large enough to cause destructive collapse or subsidence of the ground surface that can initiate a catastrophic release of contaminants. Groundwater flow rate in karst aquifers is much more rapid than in porous aquifers. For example, in the Barton Springs Edwards aquifer, dye traces measured

328-455: Is a topography formed from the dissolution of soluble carbonate rocks such as limestone and dolomite . It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. There is some evidence that karst may occur in more weathering -resistant rocks such as quartzite given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. In regions where

369-505: Is a UNESCO World Heritage Site. Many karst-related terms derive from South Slavic languages , entering scientific vocabulary through early research in the Western Balkan Dinaric Alpine karst. The study of the various aspects of karst regions is called karstology. This includes biological, chemical, ecological, geomorphological, hydrogeological, hydrological, political, socio-economical, and other processes over

410-562: Is a development of karst observed in geological history and preserved within the rock sequence, effectively a fossil karst. There are for example palaeokarst surfaces exposed within the Clydach Valley Subgroup of the Carboniferous Limestone sequence of South Wales which developed as sub-aerial weathering of recently formed limestones took place during periods of non-deposition within the early part of

451-538: Is a karst landscape which is developed beneath a cover of insoluble rocks. Typically this will involve a cover of sandstone overlying limestone strata undergoing solution. In the United Kingdom for example extensive doline fields have developed at Cefn yr Ystrad , Mynydd Llangatwg and Mynydd Llangynidr in South Wales across a cover of Twrch Sandstone which overlies concealed Carboniferous Limestone ,

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492-468: Is developed in areas where salt is undergoing solution underground. It can lead to surface depressions and collapses which present a geo-hazard. Karst areas tend to have unique types of forests. The karst terrain is difficult for humans to traverse, so that their ecosystems are often relatively undisturbed. The soil tends to have a high pH, which encourages growth of unusual species of orchids, palms, mangroves, and other plants. Paleokarst or palaeokarst

533-524: Is found in porous karst systems. The English word karst was borrowed from German Karst in the late 19th century, which entered German usage much earlier, to describe a number of geological, geomorphological, and hydrological features found within the range of the Dinaric Alps , stretching from the northeastern corner of Italy above the city of Trieste , across the Balkan peninsula along

574-636: Is frequently unseen until the roof of a cavern suddenly collapses. Such events have swallowed homes, cattle, cars, and farm machinery. In the United States, sudden collapse of such a cavern-sinkhole swallowed part of the collection of the National Corvette Museum in Bowling Green, Kentucky in 2014. The world's largest limestone karst is Australia's Nullarbor Plain . Slovenia has the world's highest risk of sinkholes, while

615-402: Is moderate to heavy. This contributes to rapid downward movement of groundwater, which promotes dissolution of the bedrock, whereas standing groundwater becomes saturated with carbonate minerals and ceases to dissolve the bedrock. The carbonic acid that causes karst features is formed as rain passes through Earth's atmosphere picking up carbon dioxide (CO 2 ), which readily dissolves in

656-428: Is most strongly developed in dense carbonate rock , such as limestone, that is thinly bedded and highly fractured . Karst is not typically well developed in chalk , because chalk is highly porous rather than dense, so the flow of groundwater is not concentrated along fractures. Karst is also most strongly developed where the water table is relatively low, such as in uplands with entrenched valleys , and where rainfall

697-601: The Republic of Ragusa , official business was conducted in Ragusan until approximately the end of the 15th century. In 1472 the Senate famously banned the use (without permission) of "Slavic" or "any language other than Ragusan or Italian" for conducting legal disputes. Another piece of evidence is a letter by Elio Lampridio Cerva (1463–1520) that mentions "I remember how, when I was a boy, old men would carry on legal business in

738-527: The Romance language that was called Ragusan". This was spoken in Krk ( Italian : Veglia , Dalmatian: Vikla ). It is documented from the 19th century, in large part thanks to the efforts of the linguist Matteo Bartoli and his informant Tuone Udaina . When they first met, Udaina had not spoken Vegliote in two decades and could only produce a sort of 'Dalmatianised' Venetian. As their interviews went on, he

779-577: The coast of Dalmatia . Over the centuries they were increasingly influenced, and then supplanted, by Croatian and Venetian . It has not been demonstrated that Dalmatian belonged to a larger branch of Romance or even that its varieties constituted a valid genetic grouping of their own. This was spoken in Dubrovnik ( Italian : Ragusa ). Various Ragusan words are known from local documents in Latin and Venetian. One such document, for instance, records

820-427: The coast of the eastern Adriatic to Kosovo and North Macedonia , where the massif of the Šar Mountains begins. The karst zone is at the northwesternmost section, described in early topographical research as a plateau between Italy and Slovenia . Languages preserving this form include Italian : Carso , German : Karst , and Albanian : karsti . In the local South Slavic languages , all variations of

861-450: The complexity of karst aquifers, and need to be supplemented with dye traces , measurement of spring discharges, and analysis of water chemistry. U.S. Geological Survey dye tracing has determined that conventional groundwater models that assume a uniform distribution of porosity are not applicable for karst aquifers. Linear alignment of surface features such as straight stream segments and sinkholes develop along fracture traces . Locating

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902-443: 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

943-557: The fissures. The enlarged fissures allow a larger quantity of water to enter which leads to a progressive enlargement of openings. Abundant small openings store a large quantity of water. The larger openings form a conduit system that drains the aquifer to springs. Characterization of karst aquifers requires field exploration to locate sinkholes, swallets , sinking streams , and springs in addition to studying geologic maps . Conventional hydrogeologic methods such as aquifer tests and potentiometric mapping are insufficient to characterize

984-466: The global demand for drinkable water. 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. The karst topography also poses peculiar difficulties for human inhabitants. Sinkholes can develop gradually as surface openings enlarge, but progressive erosion

1025-456: The karst groundwater flow rates from 0.5 to 7 miles per day (0.8 to 11.3 km/d). The rapid groundwater flow rates make karst aquifers much more sensitive to groundwater contamination than porous aquifers. Groundwater in karst areas is also just as easily polluted as surface streams, because Karst formations are cavernous and highly permeable, resulting in reduced opportunity for contaminant filtration. Well water may also be unsafe as

1066-562: The last-named locality having been declared a site of special scientific interest in respect of it. Kegelkarst is a type of tropical karst terrain with numerous cone-like hills, formed by cockpits, mogotes , and poljes and without strong fluvial erosion processes. This terrain is found in Cuba, Jamaica, Indonesia, Malaysia, the Philippines, Puerto Rico, southern China, Myanmar, Thailand, Laos and Vietnam. Salt karst (or 'halite karst')

1107-647: The most dramatic of these formations can be seen in Thailand 's Phangnga Bay and at 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. Interstratal karst

1148-709: The period. Sedimentation resumed and further limestone strata were deposited on an irregular karst surface, the cycle recurring several times in connection with fluctuating sea levels over prolonged periods. 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. Mud Caves are an example of pseudokarst. Karst formations have unique hydrology, resulting in many unusual features. A karst fenster (karst window) occurs when an underground stream emerges onto

1189-780: The river flows into a cave in a formation known as the Madison Limestone and then rises again 800 m ( 1 ⁄ 2  mi) down the canyon in a placid pool. A turlough 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. Main Article Aquifer#Karst Karst aquifers typically develop in limestone . Surface water containing natural carbonic acid moves down into small fissures in limestone. This carbonic acid gradually dissolves limestone thereby enlarging

1230-465: The sounds [j i y] , as in the word [tʃol] "arse" < * [kyl] < * [ˈkulu] < CULUM . It was once thought that Vegliote, like Romanian , showed the sound-change /kt/ > /pt/ , but the only example of this is /ˈwapto/ "eight" < OCTO , which was probably affected by analogy with /ˈsapto/ "seven" < SEPTEM . From Udaina. Stress-marks have been omitted. Dalmatian would also have been spoken on major islands and in towns along

1271-649: The surface between layers of rock, cascades some distance, 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, even under a different name, like Ljubljanica , the "river of seven names". Another example of this is the Popo Agie River in Fremont County, Wyoming , where, at a site named "The Sinks" in Sinks Canyon State Park ,

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1312-415: The surface, complex underground drainage systems (such as karst aquifers ) and extensive caves and cavern systems may form. 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

1353-1002: The system ( pyrite or hydrogen sulfide ) to form sulfuric acid (H 2 SO 4 ). Sulfuric acid then reacts with calcium carbonate, causing increased erosion within the limestone formation. This chain of reactions is: This reaction chain forms gypsum . 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 solution flutes (or rillenkarren), runnels , limestone pavement (clints and grikes), kamenitzas 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 karst valleys. Mature karst landscapes, where more bedrock has been removed than remains, may result in karst towers , or haystack/eggbox landscapes. Beneath

1394-461: The water may have run unimpeded from a sinkhole in a cattle pasture, bypassing the normal filtering that occurs in a porous aquifer . 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. Geologists are concerned with these negative effects of human activity on karst hydrology which, as of 2007 , supplied about 25% of

1435-417: The water. Once the rain reaches the ground, it may pass through soil that provides additional CO 2 produced by soil respiration . Some of the dissolved carbon dioxide reacts with the water to form a weak carbonic acid solution, which dissolves calcium carbonate . The primary reaction sequence in limestone dissolution is the following: In very rare conditions, oxidation can play a role. Oxidation played

1476-515: The western Highland Rim in the eastern United States is at the second-highest risk of karst sinkholes. In Canada, Wood Buffalo National Park , Northwest Territories contains areas of karst sinkholes. Mexico hosts important karst regions in the Yucatán Peninsula and Chiapas . The West of Ireland is home to The Burren , a karst limestone area. The South China Karst in the provinces of Guizhou , Guangxi , and Yunnan provinces

1517-454: The word are derived from a Romanized Illyrian base (yielding Latin : carsus , Dalmatian : carsus ), later metathesized from the reconstructed form * korsъ into forms such as Slovene : kras and Serbo-Croatian : krš , kras , first attested in the 18th century, and the adjective form kraški in the 16th century. As a proper noun, the Slovene form Grast

1558-596: The words pen , teta , chesa , fachir and indicates the meanings 'bread', 'father', 'house', 'to do'. There are also some 14th-century texts in Ragusan, but these show extensive Croatian and Venetian influence, to the point that it is difficult to discern which if any of their features are genuinely Dalmatian. A notable feature of Ragusan was its preservation (without palatalisation ) of Latin /k/ and /ɡ/ before front vowels, which can be seen in attested forms like colchitra < Latin CULCITRA . In

1599-486: The wreck is still visible from the beach, now situated within the Isimangaliso Wetland Park . In his 2019 work Underland , British author Robert Macfarlane tracks the source of the Timavo and discusses the history of its exploration. 45°47′38″N 13°34′48″E  /  45.794°N 13.58°E  / 45.794; 13.58 Karst topography Karst ( / k ɑːr s t / )

1640-476: Was able to recall more and more Vegliote from his youth, albeit in a form still tinged by his Venetian. Like Ragusan, Vegliote did not participate in the broader Romance palatalisation of [k] and [ɡ] before front vowels. (Compare Vegliote [ɡeˈlut] "cold" and Italian [dʒeˈlato] < Latin GELATUM .) Nevertheless it appears to have undergone a later, and independent, palatalisation of [k] to [tʃ] before

1681-589: Was first attested in 1177. Ultimately, the word is of Mediterranean origin. It has also been suggested that the word may derive from the Proto-Indo-European root karra- 'rock'. The name may also be connected to the oronym Kar(u)sádios oros cited by Ptolemy , and perhaps also to Latin Carusardius . Johann Weikhard von Valvasor , a pioneer of the study of karst in Slovenia and

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