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Speleology in Kazakhstan

Shakalov on 04 Jul, 2018
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That vasque is a large, shallow solution pan formed in the intertidal zone of warm seas by the action of brine and marine organisms [19].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
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Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
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Your search for pliocene (Keyword) returned 134 results for the whole karstbase:
Showing 31 to 45 of 134
Petroleum geology of the Black Sea, 1996, Robinson A. G. , Rudat J. H. , Banks C. J. , Wiles R. L. F. ,
The Black Sea comprises two extensional basins formed in a back-arc setting above the northward subducting Tethys Ocean, close to the southern margin of Eurasia. The two basins coalesced late in their post-rift phases in the Pliocene, forming the present single depocentre. The Western Black Sea was initiated in the Aptian, when a part of the Moesian Platform (now the Western Pontides of Turkey) began to rift and move away to the south-east. The Eastern Black Sea probably formed by separation of the Mid-Black Sea High from the Shatsky Ridge during the Palaeocene to Eocene. Subsequent to rifting, the basins were the sites of mainly deep water deposition; only during the Late Miocene was there a major sea-level fall, leading to the development of a relatively shallow lake. Most of the margins of the Black Sea have been extensively modified by Late Eocene to recent compression associated with closure of the Tethys Ocean. Gas chromatography--mass spectrometry and carbon isotope analysis of petroleum and rock extracts suggest that most petroleum occurrences around the Black Sea can be explained by generation from an oil-prone source rock of most probably Late Eocene age (although a wider age range is possible in the basin centres). Burial history modelling and source kitchen mapping indicate that this unit is currently generating both oil and gas in the post-rift basin. A Palaeozoic source rock may have generated gas condensate in the Gulf of Odessa. In Bulgarian waters, the main plays are associated with the development of an Eocene foreland basin (Kamchia Trough) and in extensional structures related to Western Black Sea rifting. The latter continue into the Romanian shelf where there is also potential in rollover anticlines due to gravity sliding of Neogene sediments. In the Gulf of Odessa gas condensate has been discovered in several compressional anticlines and there is potential in older extensional structures. Small gas and oil discoveries around the Sea of Azov point to further potential offshore around the Central Azov High. In offshore Russia and Georgia there are large culminations on the Shatsky Ridge, but these are mainly in deep water and may have poor reservoirs. There are small compressional structures off the northern Turkish coast related to the Pontide deformation; these may include Eocene turbidite reservoirs. The extensional fault blocks of the Andrusov Ridge (Mid-Black Sea High) are seen as having the best potential for large hydrocarbon volumes, but in 2200 m of water

The geomorphology of solution cave sequences in the Kalk Bay Mountains, southern Cape Peninsula. BSc thesis, 1996, Shearer, H.

The Kalk Bay Mountains of the southern Cape Peninsula, South Africa, show marked development of pseudokarstic features such as caverns, dolines and grikes. These features have formed over at least 100 million years on supposed inert quartzitic sandstones of the Peninsula Formation of the Table Mountain Group. Pseudokarst on sandstone is relatively rare world-wide and various aspects of cave genesis are highlighted in the Cape Peninsula. Cape Peninsula pseudokarst is relict, occurs at high altitudes above the present water table and could provide clues to palaeoenvironmental conditions during the African erosion period.
The cave systems in the Kalk Bay Mountains occur in at least three levels in the thickly-bedded sandstone. These different levels are the result of differential uplift during the Miocene and Pliocene. The Cape Peninsula Mountains are tabular and blocky, as opposed to the fold mountains of the rest of the South Western Cape. Much more of the overlying sedimentary layers in the Cape Peninsula have also been removed by weathering and erosive processes. The caves can be compared to similar pseudokarst features on sandstone in areas such as Gran Sabana, Venezuela. The acidic water chemistry in Venezuela contributes to a very intensive weathering environment. Present day humid tropical conditions in Venezuela are likely to be similar to palaeoclimatic conditions in the Kalk Bay Mountains, contributing to sandstone cave genesis.

Interprtation morphomtrique et splo_gense : exemple de rseaux karstiques de Basse-Provence (directions de galeries, modle et maillage structural), 1997, Blanc Jeanjoseph, Monteau Raymond
Successive tectonic phases on limestone massifs are at the origin of a fracturation grid with several pattern dimensions, and linear or organized drain directions. Mechanical reactivations are observed from Oligocene until Plio-Quaternary on a former "pyreneo-provenale" structure (Eocene). Statistical analysis of gallery and fracture directions, cave levels and descent stages (overdeepening) show several erosional stages occurring after the formation of the Antevindobonian erosional surface. The active speleogenesis during Oligocene and Miocene was controlled by tectonics in connection with European rifting and mediterranean opening. In Messinian a short and significant lowering of mediterranean base level (and water table) made drastic erosion and created vertical pits. The horizontal cave level dug during the stabilization phase of Pliocene, now perched over underground rivers, shows a new overdeepening because of glacio-eustatic Quaternary oscillations. Compressive or distensive mechanical reactivations (Upper Miocene, Pliocene, Quaternary) modified the drainage and consequently the cave organization: self-piracy, confluence and diffluence. In the endokarst, the drainage inversion can be detected in late Upper continental Miocene and early Messinian (6,5 Ma), in correlation with the tilting and extension of the continental margin. Five caves in Provence are studied: Sabre, Petit Saint-Cassien, Rampins, Planesselve river, and Tete du Cade networks.

A pre-Pliocene or Pliocene land surface in County Galway, Ireland, 1997, Coxon P, Coxon C,
This paper describes a site on the Carboniferous limestone of County Galway, Ireland, where a complex of gorges, cave passages and shallow surface depressions is filled with organic silt and clay overlain by white quartz sand. The dating of the biogenic deposits to the Late Pliocene by biostratigraphical means provides a record of this largely undocumented period of Irish geological history. However, the particular importance of this site is that unlike other Irish karst infills, it represents not just the localized preservation of material in a closed depression but evidence of a more widespread cover of sediments suggesting the preservation of a Pliocene or pre-Pliocene land surface. This implies that glacial action throughout the Pleistocene has resulted in relatively little bedrock erosion in this region and raises the possibility that the present day landscape of the western Irish limestone lowlands may retain influences of preglacial karstification

Terrestrial hot-spring Co-rich Mn mineralization in the Pliocene-Quaternary Calatrava Region (central Spain), 1997, Crespo A, Lunar R,
Central Spain hosts a series of high-Co (up to 1.7% Co) Mn mineralizations displaying a variety of morphologies: spring aprons and feeders, pisolitic beds, wad beds and tufa-like replacements of plants and plant debris. The Mn mineralogy consist of cryptomelane, lithiophorite, birnessite and todorokite. The spring apron deposits formed in close proximity to Pliocene volcanic rocks (alkaline basaltic lava flows and pyroclastics) belonging to the so-called Calatrava Volcanic Field. The spring aprons are found along or near to normal faults bounding small basins and topographic highs. Mn tufa-like deposits are found near to the spring sources, while both pisolitic and wad beds are clearly distal facies occuring well within the Pliocene basins. The two latter are interbedded with clastic lacustrine and fluvial sediments. Collectively, these deposits contain a complex suite of Mn-(Co) mineralization ranging from proximal, hot-spring-type Mn facies, grading into more distant sedimentary, stratabound mineralization. Volcanism, basin formation and Mn deposition took place within a failed rift environment which triggered hydrothermal activity and Mn-(Co) deposition as proximal (near to the volcanic axes) and distal (of sedimentary affinities, within the basins) facies

Karst Development and Speleogenesis, Isla de Mona, Puerto Rico, 1998, Frank, E. F. , Mylroie, J. , Troester, Jo. , Alexander, Jr. , E. C. , Carew, J.
Isla de Mona consists of a raised table-top Miocene-Pliocene reef platform bounded on three sides by vertical cliffs, up to 80 m high. Hundreds of caves ring the periphery of the island and are preferentially developed in, but not limited to, the Lirio Limestone/Isla de Mona Dolomite contact. These flank margin caves originally formed at sea level and are now exposed at various levels by tectonic uplift of the island (Frank 1983; Mylroie et al. 1995b). Wall cusps, a characteristic feature of flank margin caves, are ubiquitous features. Comparisons among similar caves formed in the Bahamas and Isla de Mona reveal the same overall morphology throughout the entire range of sizes and complexities. The coincidence of the primary cave development zone with the Lirio Limestone/Isla de Mona Dolomite contact may result from syngenetic speleogenesis and dolomitization rather than preferential dissolution along a lithologic boundary. Tectonic uplift and glacioeustatic sea level fluctuations produced caves at a variety of elevations. Speleothem dissolution took place in many caves under phreatic conditions, evidence these caves were flooded after an initial period of subaerial exposure and speleothem growth. Several features around the perimeter of the island are interpreted to be caves whose roofs were removed by surficial denudation processes. Several large closed depressions and dense pit cave fields are further evidence of surficial karst features. The cliff retreat around the island perimeter since the speleogenesis of the major cave systems is small based upon the distribution of the remnant cave sections.

Geology of Isla de Mona, Puerto Rico, 1998, Frank, E. F. , Wicks, C. , Mylroie, J. , Troester, J. , Alexander, Jr. , E. C. , Carew, J.
Isla de Mona is a carbonate island located in the Mona Passage 68 km west of Puerto Rico. The tectonically uplifted island is 12 km by 5 km, with an area of 55 km?, and forms a raised flat-topped platform or meseta. The meseta tilts gently to the south and is bounded by near vertical cliffs on all sides. These cliffs rise from 80 m above sea level on the north to 20 m above the sea on the southern coast. Along the southwestern and western side of the island a three- to six-meter-high Pleistocene fossil reef abuts the base of the cliff to form a narrow coastal plain. The meseta itself consists of two Mio-Pliocene carbonate units, the lower Isla de Mona Dolomite and the upper Lirio Limestone. Numerous karst features, including a series of flank margin caves primarily developed at the Lirio Limestone/Isla de Mona Dolomite contact, literally ring the periphery of the island.

Rapport entre karst et glaciers durant les glaciations dans les valles pralpines du sud des Alpes, 1998, Bini Alfredo, Tognini Paola, Zuccoli Luisa
At least 13 glaciations occurred during the last 2.6Ma in the Southern pre_alpine valleys. The glaciers scouring alpine and pre-alpine valleys had all the same feature, being valley temperated glaciers. Their tracks and feeding areas were always the same, just like the petrological contents of their deposits. Contrary to previous assumptions until a few years ago, the origin of these valleys and of the lakes occupying the floor of some of them (Orta, Maggiore, Como, Iseo, Garda Lakes) is due to fluvial erosion related to Messinian marine regression. The valley slopes modelling is Messinian in age, too, while most caves are older. As a general rule, glaciers worked on valley slopes just as a re_modelling agent, while their effects were greater on valley floors. The karstic evolution began as soon as the area was lifted above sea level (upper Oligocene - lower Miocene), in a palaeogeographical environment quite different from the present one, although the main valley floors were already working as a base level. During Messinian age, the excavation of deep canyons along pre-existing valleys caused a dramatic lowering of the base level, followed by a complete re-arrangement of the karstic networks, which got deeper and deeper. The Pliocene marine transgression caused a new re-arrangement, the karst network getting mostly drowned under sea level. During these periods, the climate was hot-wet tropical, characterised by a great amount of water circulating during the wet season. At the same time tectonic upliftings were at work, causing breaking up of the karst networks and a continuous rearrangement of the underground drainage system. In any case, karstic networks were already well developed long before the beginning of Plio-Quaternary glaciations. During glaciations, karst systems in pre-alpine valleys could have been submitted to different drainage conditions, being: a) isolated, without any glacial water flowing; b) flooded, connected to the glacier water-filled zone; c) active, scoured by a stream sinking at glacier sides or in a sub glacial position. The stream could flow to the flooded zone (b), or scour all the unflooded system long down to the resurgence zone, the latter being generally located in a sub glacier position. The glacier/karst system is a very dynamic one: it could get active, flooded or isolated depending on endo- and sub-glacial drainage variations. Furthermore, glaciers show different influences on karstic networks, thus working with a different effect during their advance, fluctuations, covering and recession phases. Many authors believe, or believed, the development of most surface and underground karst in the Alps is due to glaciations, with the last one held to be mostly responsible for this. Whatever the role of glaciers on karstic systems, in pre-alpine valleys caves, we do not have evidence either of development of new caves or of remarkable changes in their features during glaciations. It is of course possible some pits or galleries could have developed during Plio-Quaternary glaciations, but as a general rule glaciers do not seem to have affected karstic systems in the Southern pre-alpine valleys with any remarkable speleogenetic effects: the glaciers effects on them is generally restricted to the transport of great amounts of debris and sediments into caves. The spotting of boulders and pebbles trapped between roof stalactites shows that several phases of in- and out-filling of galleries occurred with no remarkable changing in pre-dating features, including cave decorations. The presence of suspended karst systems does not prove a glacial origin of the valleys, since most of them pre-date any Plio-Quaternary glaciation, as shown by calcite cave deposits older than 1,5Ma. The sediments driven into caves might have caused a partial or total occlusion of most galleries, with a remarkable re-arrangement of the underground drainage system. In caves submitted to periglacial conditions all glaciations long, we can find deposits coming from weathered surface sediments, sharp-edged gelifraction debris and, more rarely, alluvial deposits whose origin is not related to the circulation of the glacial meltwater. In caves lower than or close to the glaciers limit we generally find large amounts of glacier-related deposits, often partly or totally occluding cave galleries. These sediments may be directly related to glaciers, i.e. carried into caves by glacial meltwaters, resulting from surface glacial deposit erosion. They generally show 3 dominant facies: A) lacustrine deposits; B) alluvial deposits and C) debris flow deposits facies. The only way of testing the soundness of the forementioned hypothesis is to study the main characters and spreading of cave sediments, since they are the only real data on connection of glaciers to endokarst networks.

Les apports de lendokarst dans la reconstitution morphognique dun karst ; exemple de lAntre de Vnus (Vercors, France), 1998, Delannoy Jeanjacques, Caillault Serge
The whole of the informations which can be found in the endokarst gives a better knowledge of the hydrogeologic, geomorphologic, tectonic and climatic evolution of a calcareous mountain mass. However, the study of the cavities is not yet developed or integrated in the karst studies. The objective of the present work is to show the interest of such a proceeding by the study of a cavity in the northern Vercors : "Antre de Vnus". From the simple observation of the shapes, the deposits and their relation, a speleogenic reconstitution of this cavity and, mainly, of the environment, is proposed.

Gemorphogenetics of the Classical Karst - Kras, 1998, Gams, Ivan

Between Eocene and Pliocene, erosion of flysch strata on the top of Cretaceous limestone anticlinorium in the central and western part of the Kras plateau and the Kozina-Podgrad anticline uncovered and widened - and simultanously lowered - the karst plain in the conditions of dammed karst. The largest portion of Kras plateau is covered with karst plain, its oldest part. In Pliocene, the karst plain was fractured and subsided towards the NW regardless of older folded structure; during this process, several zones of elevations were formed through slower subsiding or uplifting. Due to faster lowering of the Vipava syncline, water streams stopped running over the Kras plateau before the flysch, damming the waters from the Kras plateau to the south was removed due to the subsiding in the northern Gulf of Trieste. Thus, no fossil blind valleys or poljes are found on the Kras plateau. However, there is considerable density of dolines and the surface is stony, giving the karst its original name. Both phenomena are typical of deforrested, densely populated and cultivated Submediterranean Dinaric karst plains.

Karst landforms on the eastern slopes of Davras Dagi (western Taurus): karren, sinkholes and uvalas, 1999, Dayan E, Bilgin A, Hancer M,
A characteristic of the study area is the low frequency of gully and rill karren. By length, width and depth they are not comparable with the same type of karren in the alpine karst, as they have attained only insignificant dimensions. This difference in size cannot primarily be attributed to differences of annual precipitation, but rather to the fact that they are only 2-3000 years old. Their formation started with anthropogenic forest destruction and concomitant soil stripping. As gully and rill karren depend on bare rock surfaces for their formation, they cannot have formed before that time. Joint-oriented and cavernous karren, in conrast, are widely spread in the study area. As the formation of these two types of karren is related to the existence of joints, their frequency is explained by severe fracturing of the limestone during recent tectonic movements. Although cavernous karren may also form on bare rock surfaces, Lest conditions for their development exist underneath a soil cover. As this no longer exists, the formation of cavernous karren has become much reduced in the historical era. Sinkholes are frequent in the planation surfaces of Mid- to Upper Miocene age and are of Pliocene and Pleistocene age. The uvalas are also not very old, as many of them contain terra rossa

Summary of the Timing of Sulfuric-Acid Speleogenesis for Guadalupe Caves Based on Ages of Alunite, 2000, Polyak, V. J. , Provencio, P. P.
The H2SO4 caves in the Guadalupe Mountains, New Mexico, USA, such as Carlsbad, Cottonwood, Endless, Lechuguilla, and Virgin caves, formed during the late Miocene and early Pliocene (12-4 Ma). It has been demonstrated that the caves at the higher elevations are the oldest. The timing of speleogenesis was determined by the 40Ar/39Ar dating of the mineral alunite, which is a direct by-product of H2SO4 speleogenesis.

La grotte et le karst de Cango (Afrique du Sud), 2000, Martini, J. E. J.
The author describes a small karst area in the extreme south of the African Continent, with special reference to the Cango Cave, which is a major tourist attraction. Compared with the other karsts of Southern Africa, this area is unique. The karst is typically exogenic, with caves forming by stream disappearance into swallow holes, where the thalweg intersects steeply dipping Precambrian limestone. Wet caves are vadose, with only short phreatic segments and exhibit rectilinear, longitudinal sections. Passages are low, but wide with bevelled ceilings, often terraced. This peculiar morphology is typical of the caves developing exactly on the water-table and seems to be controlled by the abundance of sediments introduced from the swallow holes. If one excepts a short active lower level, Cango is a dry cave of the same type than the wet ones. It is practically linear in plan and in profile, with a length of 2.6 km from entrance to end for a total of 5.2 km of passages. The age of the speleogenesis has been estimated as early Pleistocene from the entrance elevation, which is in between the altitude of the actual thalweg and the one of the Post African I erosion surface, which started to be eroded during the Upper Pliocene. This relatively young age is in contrast with a Miocene model, which was accepted by most of the previous authors. Cango is well adorned with speleothems, in particular with outstanding abundant shields, monocrystalline stalagmites and pools coated with calcite crystals. In the first chambers from entrance, the speleothems have been deeply corroded by bat guano, with deposition of hydroxylapatite. Previously this corrosion was attributed to resolution due to several rises of the paleowater-table. The meteorology is discussed, in particular the high carbon dioxide, which indicates that the cave is poorly ventilated and which constitutes a problem for management and conservation.

Determination of escarpment age using morphologic analysis: An example from the Galilee, northern Israel, 2000, Matmon A. , Zilberman E. , Enzel Y. ,
We used topographic and structural data and very limited age control to perform quantitative morphometric analyses and to determine relative ages of escarpments bounded by late Cenozoic normal faults in the Galilee, Israel. The Galilee is an extensional zone composed of a series of uplifted and tilted blocks forming large escarpments built mainly of carbonate rocks. Two parameters used to discriminate tectonic stages are the ratio between the height of the escarpment and the total stratigraphic displacement (L) and the degree of concavity of escarpment slopes relative to a reference slope. The only dated reference slope is Mount Tur'an, [~]300 m high and formed by the Tur'an fault system, which has a total stratigraphic displacement of 625 m. A basalt flow that delimits the age of the Tur'an escarpment is dated to 4.23 {} 0.23 Ma and displaced 300 m, which is identical to the present-day topographic expression of this escarpment. The L value for this escarpment is [~]0.5. The Tur'an fault system was active prior to 4.23 Ma at slow uplift rates that enabled erosion to maintain the gentle slope over which the basalt flowed. Increased offset rates following the basalt extrusion led to the formation of the escarpment. The preservation of the basalt at the top of the escarpment indicates that erosional lowering of the upper surface of the Tur'an block has been minor since its formation. The L values indicate two stages of uplift; an early stage during which offset rates were probably low enough that they did not form topography, and a later stage that formed topography, which is preserved. The timing of the change in displacement rates from a slow continuous stage to a fast, topography-forming stage was determined by comparing the shape of the dated slope of Tur'an to that of other slopes. We conclude the following: (1) generally, the topographic profiles of different parts of each individual escarpment have similar shapes indicating similar ages; (2) escarpments having slopes that are more concave or convex than the reference Tur'an escarpment are older or younger than 4 Ma, respectively; and (3) the Galilee escarpments did not form simultaneously. A few escarpments were already major morphologic features by the early to middle Pliocene, whereas the rest formed during the late Pliocene. Morphometric analysis is a useful method for studying the geologic history of a landscape controlled by normal fault uplift and characterized by the absence of sediment deposition and where carbonate dissolution is the main erosional process. This and similar approaches can be used to discriminate tectonic stages and understand the relationship between tectonic activity and surface processes in other extensional regions

Speleogenesis of the Mammont cave system, Kentucky, USA, 2000, Palmer A. N.
The Mammoth Cave System, in southwestern Kentucky, USA, is located in carbonate rocks of Mississippian (early Carboniferous) age, which dip less that one degree toward the northwest into the Illinois structural basin. The cave is contained within the Chester Upland, a fluvially dissected plateau of limestones and dolomites capped by clastic rocks. However, much of the groundwater recharge to the cave today and in the past has been from the nearby karst surface of the Pennyroyal Plateau, up-dip from the Chester Upland, where the insoluble cap-rock has been removed by erosion, exposing the carbonate rocks over a broad surface. The local bedrock is very prominently bedded, with very few large fractures, and as a result the cave passages are sinuous canyons and tubes, interspersed with vertical shafts that have developed downward in sequence, bed by bed. Passages of vadose origin are oriented almost invariably down the local dip, which is complicated by many irregularities superimposed on the regional dip. Phreatic passages show no inherent relation to the dip and are mostly oriented at very shallow angles to the strike direction. Depth of cave development below the water table is limited to a few tens of meters by the small amount of structural deformation. Dating of sediment shows that most of the earliest passages probably formed during the late Pliocene Epoch, although the very highest passages may be considerably older. These passages are few but large, and consist mainly of wide canyons and tubes that were later almost filled with silt, sand, and gravel during periods of regional aggradation. Diversion of drainage into the Ohio River by glacial ice during the early Pleistocene caused rapid entrenchment of the Ohio and its tributaries in the Mammoth Cave region. Passages became much more numerous as the landscape was dissected and as erosional base levels fluctuated more rapidly. Several major passage levels developed during periods of relatively static base level. The Mammoth Cave System thus provides many clues to the geomorphic history of the surrounding region.

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