Karst and Cave RSS news feed Like us on Facebook! follow us on Twitter!
Community news

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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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 eolian calcarenite is a terrestrial limestone formed by the cementation by carbonates of calcareous coastal dune sand. often shorted to eolianite. synonym: dune-limestone; aeolianite. compare beachrock.?

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

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
See all featured articles
Featured articles from other Geoscience Journals
Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
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
See all featured articles from other geoscience journals

Search in KarstBase

Your search for bridges (Keyword) returned 19 results for the whole karstbase:
Showing 1 to 15 of 19
Karst-like features in badlands of the Arizona Petrified Forest, 1963, Mears Brainerd,
Sinks, disappearing streams, hanging valleys, and natural bridges add a karst-like element to the miniature mountain topography represented in badlands. The Chinle Formation [Triassic] of the Petrified Forest in Arizona largely consists of compact, montmorillonitic and illitic claystones. Sinks in it result from disaggregation of swelling clay minerals rather than solution which affects limestone in true karsts. Ravines whose bottoms are pierced by sinks may develop into hanging valleys because their channels, robbed of surface flow downstream from these swallow holes, cannot keep pace with downcutting in the master drainage to which they are tributary. Growth of the sinks soon creates a disappearing stream that continues to deepen the upstream segment of a ravine. Thus the abandoned downstream segment beyond the sinks, no longer eroded by the stream, develops into a transverse barrier. Where the abandoned channel was initially short, the barrier may be eventually narrowed by weathering and slope erosion to form a natural bridge. Other bridges consist of jumbled material. that has collapsed from steep valley walls, undercut by small stream meanders

Un pseudo-karst dans les argiles (Las Bardenas, Navarre, Espagne), 1986, Maire R. , Pernette J. F.
PSEUDO-KARST IN SANDY-CLAY (LAS BARDENAS NAVARRA-, SPAIN) - The spectacular badlands of Las Bardenas are situated south of the Navarra province (NE Spain); they develop in the sandy-clay (Oligo-Miocene) of the tertiary Ebra basin, with a semi-arid climatic context (<400 mm/year). Pseudo-karstic landforms have been observed near mini-canyons: sinkholes, pits, caves, natural bridges... This morphology of mechanical origin is possible because the running waters disappear underground into the decompression fissures generated on the edges of canyon cliffs. Yet, in a few caves, the gallery is made directly in the mass of sandy-clay, without the help of joints, cracks or fissures ("piping"). This recent pseudo-karst and badlands are the obvious consequence of the historical destruction of forest during the Middle Age.

Rakov Skocjan Karst Valley., 1989, Gospodaric Rado, Habic Peter
Geological, geomorphological and speleological description of the Rak Valley with several caves and natural bridges.

Potential construction problems for bridge foundations in areas underlain by a complex marble formation in Hong Kong, 1995, Irfan T. Y. ,
Complex and varied geological conditions were encountered during the site investigation for a number of bridge foundations along the proposed route of a trunk road between two new towns in the North West New Territories of Hong Kong. Special care is needed in the construction of the deep foundations for these bridges, particularly in areas underlain by a marble formation which has a varied karstic surface underneath a thick superficial cover and locally contains solution features, includinglarge cavities. Foundation conditions are further complicated by varying lithology, weathering, dyke intrusions and the related alterations and thrust faulting

Karst and hydrogeology of Lebanon, 1997, Edgell Hs,
Karst is very well-developed in Lebanon in thick, exposed, fractured and folded Jurassic, Cretaceous, and Eocene carbonates, as well as in localized, coastal Miocene limestones. This karstification not only results from the predominant calcareous lithology, but is also caused by the high, northerly trending ranges of he country, which cause abundant precipitation, as heavy rain and thick snow, to fall on Mt. Lebanon, Jabal Barouk, Jabal Niha, and Mt. Hermon. Lesser amounts fall on the Anti-Lebanon, Beqa'a Valley and the coastal hills of the country. Some 80% of precipitation occurs from November through February. The karst water emerges from five first-magnitude springs (Ain ez Zarqa (11 m(3)/sec), Ain Anjar (max. 10m(3)/sec), Nabaa Ouazzani (max. 6m(3)/sec), Nabaa Arbaain (mau. 3 m(3)/sec) and Nabaa Barouk (max. 3m(3)/sec), plus hundreds of second-and third-magnitude springs, and thousands of smaller springs. The large springs are all karstic and contribute to 13 perennial springs in the main Lebanese ranges, and 2 in the Anti-Lebanon. These include major rivers, such as the Nahr el Litani, Nahr el Assi (Orontes) and Nabr el Hasbani (upper Jordan River). More than two-thirds of the area of Lebanon (i.e. 6900 km(2)) is karstified and includes surface karst features, such as poljes, uvalas, dolines, blind valleys, natural bridges, and ponors, as well as smaller features, like karren and hoodoos. Subsurface karst features include many types of solutional shafts and galleries, grottoes, subsurface lakes and rivers and most types of speleothems. There are at least 15 aquifers in Lebanon, of which 14 are in karstified carbonate strata. The 1700m thick limestone/dolomite core of the ranges and over 2000m thickness of flanking, or overlying, Cretaceous limestones provide the majority of these aquifers, while significant aquifers are also found in thick Eocene limestones. High transmissivity values (T = or > 1.83 x 10(-1) m(2)) occur in these karstic aquifers, as is shown by the rapid decline in spring flow over the dry summer and autumn months, and their very quick recharge by winter and spring rains and heavy snow on the Lebanese ranges

Thalweg variability at bridges along a large karst river: the Suwannee River, Florida, 1998, Mossa J. , Konwinski J. ,
Geomorphologists and engineers have different perspectives and approaches for examining river channels and the changes that occur during floods. The field-oriented approach typically adopted by geomorphologists has little predictive ability and design usefulness. In contrast, the empirical approach adopted by engineers is based on predictive equations or models that often differ greatly from reality. Such equations are not based on comprehensive field data and often fail to consider a number of site conditions, especially geology and geomorphology. Yet, in order for geomorphic techniques to be useful to the design and planning of engineering structures such as bridges, it is important that sufficient observations exist in order to characterize long-term and short-term changes in bottom topography and scour potential. Six gaging stations on the Suwannee River, a large river draining karst terrain in the southeastern US, were used to examine the temporal variability in thalweg elevation, the deepest point in a given cross-section. The cross-sections have maximum thalweg variability of just a few meters, despite the occurrence of several large floods. suggesting that the bottoms are fairly stable. Historical approaches can be applied to design the length and depth placement of pilings by providing information on site conditions not considered in engineering equations, such as response of bottom materials to various flow conditions, and thus have potential benefits to public safety and cost effectiveness. (C) 1998 Elsevier Science B.V

Flared slopes revisited, 1998, Twidale C. R. , Bourne J. A. ,
Flared slopes are smooth concavities caused by subsurface moisture-generated weathering in the scarp-foot zone of hillslopes or boulders. They are well represented in granitic terrains but also developed in other massive materials such as limestone, sandstone, dacite, rhyolite, and basalt, as well as other plutonic rocks. Notches, cliff-foot caves, and swamp slob are congeners of flared slopes. Though a few bedrock flares are conceivably caused by nivation or by a combination of coastal processes, most are two-stage or etch forms. Appreciation of the origin of these forms has permitted their use in the identification and measurement of recent soil erosion and an explanation of natural bridges. Their mode of development is also germane to the origin of the host inselberg or bornhardt and, indeed, to general theories of landscape evolution. But certain discrepancies have been noted concerning the distribution and detailed morphology of flared slopes. Such anomalies are a result of structural factors (sensu late), of variations in size of catchment and in degree of exposure, and of several protective factors. Notwithstanding, the original explanation of flared slopes stands, as do their wider implications

Natural bridges on the Vratna River (Eastern Serbia) as the last remnants of a former cave, 2000, Ć, Alić, Ljubojević, Jelena

The Vratna River is a right-side tributary of the Danube and its drainage area is situated at the western rim of the Dacian Basin. Along its 22 km long course, the Vratna flows through a 3,5 km long gorge cut in Tithonian limestones. Across the gorge there are three natural bridges, which shelter, in total 94 metres of the river course. There is a strong assumption that two of the natural bridges are the only remaining parts of roof of a former cave. Due to the process of surface denudation and to the disruption of stability, the cave roof almost completely collapsed, with the exception of these two sections. Several short caves and rock shelters exist in the gorge, and the longest cave (305 m) is situated next to the biggest of the three natural bridges.


Speleology of gypsum caves in Oklahoma, 2002, Bozeman J, Bozeman S,
The gypsum caves of western Oklahoma are situated in three separate areas of evaporite karst: (1) the Cimarron Gypsum Hills, in the northwest, along the Cimarron River; (2) the Weatherford Gypsum Hills, in west-central Oklahoma, to the north of the Wichita Mountains; and (3) the Mangum Gypsum Hills, in the southwest, west of the Wichita Mountains. Caves of the Cimarron Gypsum Hills and the Mangum Gypsum Hills are developed in the alternating dolomite, gypsum/anhydrite, and shale beds of the Permian Blaine Formation. Ranging from natural bridges to extensive cave systems, the largest is the 10 km of passages in Jester Cave in the Mangum Gypsum Hills. Cave passages formed in the normally paired gypsum and dolomite beds exhibit narrow (1.5-5 in wide), sinuous, canyon-like profiles. The development of broader passages, with widths from 5 in to more than 3 5 in, involve the shale beds. Some are bedding-plane passages with extremely low ceilings, whereas others are comfortable, walking-height passages with ceilings from 3-15 in high. The Blaine Formation, in the area of humanly mappable cave development, is from 12 in to approximately 50 in thick. The caves drain the bluffs/escarpments and normally end in karst spring resurgences. Roof collapse often modifies these resurgences into breakdown mazes. The Weatherford Gypsum Hills caves are formed in the Permian Cloud Chief Formation. The Cloud Chief gypsum is chalkier than the Blaine gypsums and the resultant cave development is more segmented, ranging from natural bridges (1.5-15 in in length) to cave segments (locally referred to as 'tunnels') that are tens of meters to more than one kilometer in length. These caves exhibit very little vertical development, and none of the bedding-plane development found in the Blaine Formation

A rare landform: Yerkopru travertine bridges in the Taurids Karst Range, Turkey, 2002, Bayari Cs,
Two examples of travertine bridges are observed at 8 to 15 in above stream level in the Lower Zamanti Basin, Eastern Taurids, Turkey. Yerkopu-1 and Yerkopru-2 bridges are currently being deposited front cool karstic groundwaters with log P-CO2 > 10(-2) atm. The surface area and the total volume of travertine in Yerkopru-1 bridge are 4350 m(2) and 40 000 m(3), whereas the values for Yerkopru-2 are 2250 m(2) and 20000 m(3), respectively. The interplay of hydrogeological Structure, local topography, calcite-saturated hanging springs, algal activity and rapid downcutting in the streambed appear to have led to the formation of travertine bridges. Aeration through cascades and algal uptake causes efficient carbon dioxide evasion that enhances travertine formation. Algal curtains aid lateral development of travertine rims across the stream. Model calculations based on a hypothetical deposit in the form of a half-pyramid implied that lateral development should have occurred from both banks of the stream in the Yerkopru-1 bridge, whereas one-sided growth has been sufficient for Yerkopru-2. The height difference between travertine springs and the main strearn appears to be a result of Pleistocene glaciation during which karstic base-level lowering was either stopped or slowed down while downcutting in the main strearn continued. Copyright (C) 2002 John Wiley Sons, Ltd

Gypsum karst and its evolution east of Hafik (Sivas, Turkey), 2005, Dogan U, Ozel S,
Sivas and its surroundings is the most important gypsum karst terrain in Turkey with a massive Lower Miocene gypsum formation 750 m thick. The region east of Hafik has a wide variety of well developed karstic features such as karrens, dissolution dolines, collapse dolines, blind valleys, karstic springs, swallow holes, caves, unroofed caves, natural bridges, gorges and poljes. The karstification started in the Early Pliocene. The piezometric level to the east of Hafik has lowered at least 200 m since the Early Pliocene and 90-100 m since the Early Pleistocene. There is a youthful karst (doline karst) on the Higher Plateau (1520-1600 m) and a mature karst on Lower Plateau (1315-1420 m). The mature karst evolved in two stages, first stage where excessively karstic paleovalleys, uvalas and collapse dolines appear and the second stage where poljes, collapse dolines and degraded collapse dolines dominated

The strategic position of upper Pivka and the intermittent lakes after implementation of the rapallo treaty, 2005, Č, Uč, Ek M.

Its strategic position has given Upper Pivka (Zgornja Pivka) an important role in history on several occasions. The last of these occurred after the implementation of the Rapallo Treaty at the end of the First World War, when the area was annexed to Italy and turned into borderland. Across the border the ‘Kontrabant’ developed. Through the Pivka Basin (Pivška kotlina) ran the second line of the Alpine Wall, which was a mighty defence system build to protect Italy’s eastern border with Yugoslavia. The natural north-east passage, a good view of the valley, and good conditions for supplying military units were the main reasons for building fortifications on the Primož hill. The command centre for the nearby bunkers was also located there. For military purposes, water reservoirs, roads, bridges, a powder magazine, and an airfield were built; the bed of the Pivka river was regulated, and the parts most exposed to strong winds (“burja”) were forested. Lakes Petelinjsko jezero and Palško jezero were used as training fields by the army. The two military fields had already been in service in Austro-Hungarian times. The Yugoslav People’s Army also used the lakes for its manoeuvres and did much more damage to them than the Italian army had done previously. The bottom of Palško jezero was reconstructed in 1990, and the owners were compensated. On Petelinjsko jezero, however, bomb craters, gunnests, and a trench can still be seen.


Cathedral Cave, Wellington Cave, New South Wales, Australia. A multiphase, non-fluvial cave., 2007, Osborne R. A. L.
Cathedral Cave is an outstanding example of a class of multiphase caves with largely non-fluvial origins. It contains large cavities such as cathedrals and cupolas, characteristic of excavation by convection currents in rising waters. Smaller-scale features such as rising half-tubes, pseudonotches, curved juts, projecting corners, blades and bridges indicate intersection and exhumation of older cavities during the formation of younger ones. It is possible to recognize at least ten significant phases of speleogenesis by morphostratigraphy, in addition to the four generations of cave-filling palaeokarst deposits intersected by the cave. The cave we see today results from the progressive integration of a number of previously disconnected or poorly connected solution cavities.

Peculiarities of development and distribution of karst features in evaporite successions of the Western Caucasus, 2009, Ostapenko, A. A. , Kritskaya, O. Yu.

Karst landforms are well represented in the upper Jurassic evaporite rocks of the Western Caucasus. Upper part of evaporite successions is represented by gypsum, and lower parts are composed with anhydrite. Gypsum rocks extend by a narrow band to the north from the Skalisty (Rocky) Ridge. Maximum thickness of gypsum successions is observed at the area between rivers Belaya and Bolshoy Zelenchouk. Most of karst landforms occur here.

Climate conditions are favorable for karst process. The amount of precipitation is about 600-900 mm per year. Dissolution rates are about 500-800 m3 year/km2.

Karst features at the surface are presented by dolines, blind valleys and depressions. Dolines with diameters of 60-70 m are most common. Karrens are developed under the soil. Positive karst landforms are presented by cone-like hills, arches and bridges. Some residual hills are composed by calcite dripstones of ancient caves, buried under the soil. Shelter caves are related to active or old destructed caves.

Underground karst  features are mainly presented by through caves, accessible from sink point to resurgence. There is known 9 caves longer than 500 m. All caves longer than 1 km are situated in the area between Khodz and Urup rivers. Passage shapes are stretched vertically, with some terraces.  Cave deposits are presented mostly by gravel, breakdown clasts and dripstones (mostly calcite).

Cave regions were distinguished by areas between rivers that drain karst massives. We analyzed distribution of caves and their parameters at selected areas. Some of cave regions are well-explored.

Cave exploration and protection are important because some caves are situated at the areas where gypsum mining is planned, so that caves can be destroyed.


Flash flood hydrology in karstic terrain: Flumineddu Canyon, central-east Sardinia, 2010, De Waele Jo, Martina Mario L. V. , Sanna Laura, Cabras Salvatore, Cossu Quirico Antonio

In the last five winters (2004–2008) several exceptional meteorological events producing flash floods have been registered in central-east Sardinia. The first of these (December 2004) was the most severe and caused important geomorphic changes in the Riu Flumineddu watershed where the influence of human activity is limited. The hydrological characterisation of this flood is extremely difficult because of the lack of streamflow gauges and the relative paucity of meteorological stations in the region. Peak discharge of the fluviokarstic Riu Flumineddu Canyon has been estimated based on a distributed hydrological model (TOPKAPI) and on empirical methods based on geomorphic and sedimentological observations. The comparison between the results derived from these independent methods allows us to obtain the best possible estimate of peak discharge. Differences between modelled and measured peak flows can be attributed to water losses and/or gains along the river channel from interactions with the underground karst drainage network.

The December 2004 flood, with an estimated recurrence interval of at least 65 years, generated overbank flow and destroyed several bridges in upstream reaches, caused important changes in channel morphology and sediment distribution and was able to move boulders up to 1 m in diameter in downstream reaches.


Results 1 to 15 of 19
You probably didn't submit anything to search for