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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. ...

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 velocity, average interstitial is the average rate of ground-water flow in interstices expressed as the product of hydraulic conductivity and hydraulic gradient divided by the effective porosity. synonymous with average linear ground-water velocity or effective velocity.?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
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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
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Your search for condensation (Keyword) returned 83 results for the whole karstbase:
Showing 1 to 15 of 83
Measuring Cave Air Movements with Condensation Nuclei, 1970, Went, F. W.

On the Wad-Minerals from the Cavern Environment., 1983, Kashima Naruhiko
The wad-minerals from limestone caves of Yugoslavia, China and Japan were studied. X-ray diffraction analysis revealed five minerals; birnessite, 10A-manganite, pyrolusite, todorokite and goethite. The heavy metal elements, Mn, Zn, Fe and Cr have been detected by X-ray fluorescence analysis and their contents were roughly determined. The condensation water introduced directly from the covering soils formed by the continental weathering and the deriving corrosive water interaction with limestone could be the input sources of manganese and other metal elements into the system.

Evidence for karstic mechanisms involved in the evolution the Moroccon hamadas., 1986, Castellani Vittorio, Dragoni Walter
Underground tubular karst features, observed in an arid envinronment of southern Morocco, are described. On the basis of various evidences, it is suggested that such features were originated mainly by condensation water. A computation of the time necessary for their formation supports this hypothesis.

The speleogenetic role of air flow caused by convection. First contribution., 1986, Cigna Arrigo A. , Forti Paolo
In the past some authors described the speleogenetic role of convection in phreatic conditions. Similar effects exist also in the air-fiLled part of vadose passages of caves as a consequence of an air circulation due to a relevant temperature gradient; the effects can be enhanced by the presence of some acids as, e.g., H2S, H2SO4, etc. In this paper the conditions matching convection and condensation which produce typical forms, very similar to those found under phreatic conditions, are discussed both for limestone and gypsum caves.

BACTERIA, FUNGI AND BIOKARST IN LECHUGUILLA CAVE, CARLSBAD-CAVERNS-NATIONAL-PARK, NEW-MEXICO, 1995, Cunningham Ki, Northup De, Pollastro Rm, Wright Wg, Larock Ej,
Lechuguilla Cave is a deep, extensive, gypsum- and sulfur-bearing hypogenic cave in Carlsbad Caverns National Park, New Mexico, most of which (> 90%) lies more than 300 m beneath the entrance. Located in the arid Guadalupe Mountains, Lechuguilla's remarkable state of preservation is partially due to the locally continuous Yates Formation siltstone that has effectively diverted most vadose water away from the cave. Allocthonous organic input to the cave is therefore very limited, but bacterial and fungal colonization is relatively extensive: (1) Aspergillus sp. fungi and unidentified bacteria are associated with iron-, manganese-, and sulfur-rich encrustations on calcitic folia near the suspected water table 466 m below the entrance; (2) 92 species of fungi in 19 genera have been identified throughout the cave in oligotrophic (nutrient-poor) ''soils'' and pools; (3) cave-air condensate contains unidentified microbes; (4) indigenous chemoheterotrophic Seliberius and Caulobacter bacteria are known from remote pool sites; and (5) at least four genera of heterotrophic bacteria with population densities near 5 x 10(5) colony-forming units (CFU) per gram are present in ceiling-bound deposits of supposedly abiogenic condensation-corrosion residues. Various lines of evidence suggest that autotrophic bacteria are present in the ceiling-bound residues and could act as primary producers in a unique subterranean microbial food chain. The suspected autotrophic bacteria are probably chemolithoautotrophic (CLA), utilizing trace iron, manganese, or sulfur in the limestone and dolomitic bedrock to mechanically (and possibly biochemically) erode the substrate to produce residual floor deposits. Because other major sources of organic matter have not been detected, we suggest that these CLA bacteria are providing requisite organic matter to the known heterotrophic bacteria and fungi in the residues. The cavewide bacterial and fungal distribution, the large volumes of corrosion residues, and the presence of ancient bacterial filaments in unusual calcite speleothems (biothems) attest to the apparent longevity of microbial occupation in this cave

Grottes hydrothermales dans le nord-ouest de la Namibie : splogense et implications dans le dveloppement des karsts en climat aride, 1996, Martini J. E. J. , Marais J. C. E.
The authors investigated ten caves in Western Namibia, which is characterised by a semi- to hyper-arid climate. They seem to have formed in the past under hydrothermal conditions, which are evidenced by circular embayments, ceiling alveoles, avens, deposits of dog-tooth calcite and barite. The latter has been observed in one cave only. Fluid inclusions in calcite and barite indicate very low salinity and temperatures generally below + 70? C. It is proposed that the caves formed by mixing of hydrothermal solutions of deep origin with more surficial ground water in the vicinity of karst springs. Such ground water circulation patterns, close to the water-table, are suggested in several cases by the horizontal extension in caves, forming definite levels of passage networks cutting across the country rock stratigraphy. The alveolar avens developed upwards from these horizontal passages and seem to have formed subaerally by water evaporation from warm pools at the bottom, with condensation and corrosion above, against cooler rock. The suggested genetic processes are in agreement with models proposed by other authors. It is suggested that in arid climates, conditions are more favourable for development of this type of deep karst water circulation than under wetter conditions. It could possibly even be the predominant process of speleogenesis in very arid conditions. By extension, this concept - mixing of water of deep origin, not necessarily significantly hydrothermal with surficial ground water - could explain the peculiar nature of most of the Namibian caves. The latter are typically characterised by the development of very large chambers and phreatic networks, but with restricted extension and not forming well integrated systems.

Condensation Corrosion in Movile Cave, Romania, 1997, Sarbu, S. M. , Lascu, C.
Condensation corrosion is the dissolution of carbonate by acidic vapors condensing above the water table. This process is rarely noted and receives little attention in the mainstream cave literature. The oolitic limestone walls in Movile Caves upper dry passages are severely altered by a selective corrosion mechanism. Temperature differences between the water in the lower passages and the walls in the upper passages and high concentrations of CO2 in the cave atmosphere create favorable conditions for condensation corrosion to take place. Carbon and oxygen stable isotope data support the hypothesis that condensation corrosion is the major mechanism currently affecting the morphology of Movile Caves upper dry level.

The Problem of Condensation in Karst Studies, 1998, Dublyansky, V. N.
Condensation in karst occurs over a wide range of natural settings, at latitudes from 25 to 70 and altitudes from sea level to 2600 m. In summer (April through September), condensation introduces a significant amount of water into the karst massifs (from 0.1% to as much as 20% of the total dry-season runoff). Contrary to common belief, in winter evaporation does not withdraw appreciable amounts of water from the massifs. Evaporating at depth, the water condenses near the surface within the epikarstic zone or on the snow cover and flows back. Condensation can sustain springs during prolonged dry periods (such as summer and winter) when there is no recharge by liquid precipitation. Condensation can play a significant role in speleogenesis, and many forms of cave macro-, meso-, and micromorphologies are attributable to condensation corrosion. It can be particularly efficient in the latter stages of hydrothermal cave development (during partial dewatering) when the temperature and the humidity gradients are highest. Coupled with evaporation, air convection, and aerosol mass transfer, condensation can play a crucial role in the formation of a number of speleothems, as well as create peculiar patterns of cave microclimate.

Condensation Corrosion in Caves on Cayman Brac and Isla de Mona, 1998, Tarhulelips, R. F. A. , Ford, D. C.
Many speleothems in caves on Cayman Brac and Isla de Mona have suffered considerable dissolution. It is suggested that this is a consequence of condensation corrosion rather than of aqueous flooding of the entire cave. A program of temperature and relative humidity measurements during the rainy seasons showed that the entrance zones are areas of comparatively large diurnal variation where condensation from warm air onto cooler walls may occur. Artificial condensation was induced using ice bottles: chemical analysis of the condensation waters determined that they were generally undersaturated with respect to calcite and/or dolomite but that this changes over space and time. Gypsum tablets were suspended inside three sample caves on Cayman Brac and one on Isla de Mona for 16 and 13 months, respectively. At the end of this period, tablets close to the entrances and to the floor were found to have undergone considerable dissolution; this could only have been the result of condensation corrosion

Contribution to knowledge of gypsum karstology, PhD thesis, 1998, Calaforra Chordi, J. M.

The objective of this study was not to establish a definitive judgement regarding a topic for which very little previous information was available, but rather to open new routes for research into karst by means of a particularized analysis of some of the factors involved in the speleogenesis of gypsiferous materials. The main obstacle to the attainment of this goal has been the scientific community's lack of interest in karst in gypsum, particularly in our country, until the nineteen eighties. To overcome this neglect it was decided, in my opinion quite correctly, to extend the bounds of the study as far as possible, so that the information obtained from the contrast found between the most important worldwide zones of karst in gypsum could be applied to the gypsiferous karst in our country, and in particular, to the most significant, the karst in gypsum of Sorbas.
This is the justification for the numerous references in the text to the gypsiferous karst and cavities in gypsum that are most relevant in Spain (Sorbas, Gobantes, Vallada, Archidona, Estremera, Baena, the Ebro Basin, Estella, Beuda, Borreda, etc.) and also to the best-known gypsiferous karsts worldwide (Podolia, Secchia, Venna del Gesso Romagnolo, Sicily and New Mexico). By means of these comparisons, the initial lack of information has been overcome.
The study is based on three central tenets, which are interrelated and make up the first three chapters of this report. The first consideration was to attempt to characterize the particular typology of gypsiferous karst from the geological (both stratigraphic and structural) point of view. This chapter also provides an introduction to each of the gypsiferous karsts examined. The second chapter is dedicated to the geomorphology of gypsiferous karst, under both superficial and subterranean aspects. It is important to note that the study of a gypsiferous karst from the speleological point of view is something that may seem somewhat unusual; however, this is one of the points of principle of this paper, the attempt to recover the true meaning of a word that has historically been unfairly condemned by a large part of the Spanish scientific community. Thirdly, a detailed study has been made of the hydrochemistry of the most important gypsiferous karsts in our region, together with the presentation of a specific analytical methodology for the treatment of the hydrochemical data applicable to the gypsiferous karst.
Geological characterization of gypsum karst
In the characterization of karst in gypsum, the intention was to cover virtually all the possibilities from the stratigraphic and structural standpoints. Thus, there is a description of widely varying gypsiferous karsts, made up of Triassic to Miocene materials, some with a complex tectonic configuration and others hardly affected by folding. The gypsiferous karsts described, and their most significant geological characteristics, are as follows:
Karst in gypsum at Sorbas (Almeria): composed of Miocene gypsiferous levels with the essential characteristic of very continuous marly interstrata between the layers of gypsum, which decisively affect the speleogenesis of the area. The gypsum layers have an average thickness of about 10 m and, together with the fracturing in the zone, determine the development of the gypsiferous cavities. These are mainly selenitic gypsum - occasionally with a crystal size of over 2 m - and their texture also has a geomorphologic and hydrogeologic influence. This area is little affected by folding and so the tectonic influence of speleogenesis is reduced to the configuration of the fracturing.
The Triassic of Antequera (Malaga): this is, fundamentally, the gypsiferous outcrop at Gobantes-Meliones, originating in the Triassic and located within the well-known "Trias" of Antequera. It is made up of very chaotic gypsiferous materials containing a large quantity of heterometric blocks of varied composition; the formation may be defined as a Miocene olitostromic gypsiferous breccia that is affected by important diapiric phenomena. The presence of hypersoluble salts at depth is significant in the modification of the hydrochemical characteristics of the water and in the speleogenetic development of the karst.
The Triassic of Vallada (Valencia): Triassic materials outcrop in the Vallada area; these mainly correspond to the K5 and K4 formations of the Valencia Group, massive gypsum and gypsiferous clays. The influence of dolomitic intercalations in the sequence is crucial to the speleogenesis of the area and this, together with intense tectonic activity, has led to the development in this sector of the deepest gypsiferous cavity in the world: the "Tunel dels Sumidors". As in the above case, the presence of hypersoluble salts at depth and the varied lithology influence the variations in the hydrodynamics and hydrochemistry of the gypsiferous aquifer.
Other Spanish gypsum karsts: this heading covers a group of gypsiferous areas and cavities of significant interest from the speleogenetic standpoint. They include the area of Estremera (Madrid), with Miocene gypsiferous clays and massive gypsum arranged along a large horizontal layer; this has produced the development of the only gypsiferous cavity in Spain with maze configuration, the Pedro Fernandez cave. The study of this cave has important hydrogeological implications with respect to speleogenesis in gypsum in phreatic conditions. The Baena (Cordoba) sector, in terms of its lithology, is comparable to the "Trias de Antequera". Here, the cavities developed in gypsiferous conglomerates, following structural discontinuities have enabled contact between carbonate and gypsiferous levels, and so we may speak of a mixed karstification: a karst in calcareous rocks and gypsum. The karst of Archidona (Malaga) is similar to that of the Gobantes-Meliones group and is significant because of the geomorphologic evolution of the karst, which is related to the diapiric ascent of the area and the formation of karstic ravines. The karst in the Miocene and Oligocene gypsum of the Ebro Basin (Zaragoza), has been taken as a characteristic example of a gypsiferous karst developed under an alluvial cover, with the corresponding geomorphological implications in the evolution of the surface landforms. In the gypsiferous area of Borreda (Barcelona), the presence of anhydritic levels in the sequence might have influenced the speleogenesis of its cavities. The cavity of La Mosquera, in Beuda (Girona), developed in massive Paleogene gypsum. This is the only Spanish example of a phreatic gypsiferous cavity developed in saccaroid gypsum, which is related to the particular subterranean morphology discovered. Finally, this group includes other Spanish gypsiferous outcrops visited during the preparation of this report, the references to which may be found in the relevant chapters.
Karst in gypsum in Europe and America: In order to complete the study of karst in gypsum, and with the idea of using all the available data on the karstology of gypsiferous materials for comparative studies of data for our country, a complementary activity was to define the most significant geological characteristics of the most important gypsiferous karsts in the world. An outstanding example is the gypsiferous karst at Podolia (Ukraine), developed in microcrystalline Miocene gypsum which has undergone block tectonics related to the collapse of the Precarpatic foredeep. This gypsum provides interesting data on speleogenesis in gypsiferous materials, as its evolution is related to the confining of the only gypsiferous stratum (of 10 to 20 m depth) producing interconnected labyrinthine galleries of over 100 km in length. Another well-known karst in gypsum is the one located at "Venna del Gesso Romagnolo" (Italy), in the Bologna region, with a lithology that is very similar to that which developed at Sorbas, but with the difference that it underwent more intense tectonics with folding and fracturing of the Tertiary sediments of the Po basin. In the same Italian province, in "L'alta Val di Sec-chia", there are outcrops of karstified Triassic materials which correspond to the formation of Burano, composed of gypsum and anhydrite with hypersoluble salts at depth and very notable diapiric phenomena. The study of this area has been used for a comparative analysis - geomorphology and hydrogeochemistry - with the Spanish gypsiferous karsts developed in Triassic levels. The third Italian gypsiferous karst to be considered is the one developed in Sicily, which has extensive Messinian outcrops of microcrystalline and selenitic gypsum as well as a great variety of lithologic types within the gypsiferous sequence, which we term the "gessoso solfifera" sequence. This gypsiferous karst is especially interesting from the geomorphologic standpoint due to the great quantity and variety of present superficial karstic forms. This has also served as a guide for the study of Spanish gypsiferous karsts. Finally, considering the relation between climatology and the development of karstic forms, we have also studied the karst in gypsum in New Mexico, where there is an extensive outcrop of Permian gypsum, both micro and macrocrystalline, situated on a large platform almost unaffected by deformation, and where the conditions of aridity are very similar to those found in the gypsiferous karst of Sorbas.
Geomorphological characterization of gypsum karst
From the geomorphological standpoint, the intention is to give an overview of the great variety of karstic forms developed in gypsum, traditionally considered less important than those developed in carbonate areas. This report shows this is not the case.
The theory of Convergence of Forms has been shown to be an efficient tool for the study of the morphology of karst in gypsum. Here, its principles have been used to provide genetic explanations for various gypsiferous forms derived from carbonate studies, and for the reverse case. In fact, studying a karst in gypsum is like having available a geomorphological laboratory where not only are the processes faster but they are also applicable to the karstology of carbonate rocks.
A large number of minor karstic forms (Karren) have been identified. The most important factors conditioning their formation are the texture of the rock, climatology and the presence of overlying deposits. The first, particularly, is largely responsible for determining the abundance of certain forms with respect to others. Thus, Rillenkarren, Trittkarren and small "kamenitzas" are more frequently found in microcrystalline and sandstone gypsum (for example, karst in gypsum in Sicily (Italy) and Va-llada (Valencia, Spain). Others seem to be more exclusive to selenitic gypsum, such as exfoliation microkarren, or are closely related to the climatology of the area (Spitzkarren develops from the alteration of gypsum in semiarid conditions). Others are related either to the presence of developed soil cover (Rundkarren, using Convergence of Forms), or to their specific situation (candelas and Wallkarren around dolines and sinkholes) or to the microtexture of the gypsum and the orientation of the 010 and 111 crystalline planes and twinning planes for the development of nanokarren.
The tumuli are the most peculiar forms of the Sorbas karst in gypsum, though they have also been identified in other gypsiferous karsts (Bolonia, New Mexico, Vallada, etc.). These are subcircular domes of the most superficial layer of the gypsum. Their formation has been related to processes of precipitation-solution and of capillary movement through the gypsiferous matrix. Their extensive development is largely determined by the climatology of the area and by the structural organization. It is therefore clear that the best examples are found in the karst of Sorbas due to the abrupt changes in temperature and humidity that occur in a semiarid climate, and because of the horizontality of the gypsiferous sequence.
Karst in gypsum and its larger exokarstic forms, apart from being climatically determined, also depend on the structural state and lithological determinants of the area. Thus, it is possible to differentiate between gypsiferous karsts where the lithology, together with erosive breakup, is more important (Sorbas and New Mexico) and others where confining hydraulic conditions persist (Estremera and Podolia). In other cases, tectonics has played a significant modelling role, and there is a clear possibility of an inversion of the relief (Bolonia or Sicily) or of the effect of diapiric processes (Secchia, Vallada, Antequera). The typological diversity of the dolines is obviously also related to these premisses. Another example is the relation existing between carbonate precipitation and gypsum solution, as evidenced in contrasting examples (Bolonia versus Sorbas).
Subterranean karstic forms have been examined from a double perspective: the morphology of the passages and the mineralization within the cavities. With respect to the former, a noteworthy example is the interstratification karst of Sorbas, where subterranean channels have developed during two well-differentiated phases, the phreatic and the vadose. The first was responsible for the formation of the small proto-galleries, currently relicts that are observable as false dome channels in the bottom of the gypsiferous strata. The second, with an erosive character, enabled the breakup of the marly interstrata and the formation of the large galleries found today. Other aspects considered include the speleogenetic influence of the presence of calcareous intercalations in the gypsiferous sequence (Vallada karst), gypsiferous agglomerates (Baena karst), anhydrite (Rotgers karst), suffusion processes (Sorbas karst) and the importance of condensation.
Spelothemes in gypsiferous cavities have been approached with special concern for gypsiferous speleothemes, in particular those which, due to their genetic peculiarity or to the lack of previous knowledge about them, are most significant. Among these are gypsum balls, with phenomena of solution, detritic filling, capillarity and evaporation; gypsum hole stalagmites, where the precipitation-solution of the gypsum controlling the formation of the central orifice is related to the previous deposit of carbonate speleothemes; gypsum trays that mark the levels of maximum evaporation; gypsum dust, determined by abrupt changes in temperature and humidity in areas near the exterior of gypsiferous cavities. All of these are characteristic of, and practically exclusive to, gypsiferous karsts in semiarid ztenes such as Sorbas and New Mexico.
Karst in gypsum has been morphologically classified with reference to the previously-mentioned criteria: the presence and typology of epigean karstic forms, both macro and microform; the typology of hypogean karstic forms (passages) and the type of speleothemes within the cavities (gypsiferous or carbonate). All these variables are clearly influenced by climatology, and so a study of the geomorphology of gypsiferous karst is seen to be an efficient tool for the analysis of the paleoclimatology of an area.
Hydrogeochemical characterization of gypsum karst
The hydrogeochemical characterization of karst in gypsum was approached in two stages. The first one was intended to establish themodels to be applied to the hydrochemistry approach, while the second provided various examples of hydrochemical studies carried out in gypsiferous karsts.
The theoretical framework which has been shown to be most accurate with respect to the formulation of chemical equilibria in water related to gypsiferous karst is the Virial Theory and the Pitzer equations.
For this study, we used a simplification of these equations as far as the second virial coefficient by means of a simple, polynomial variation to obtain the equilibrium state of the water with respect to the gypsum, for an ionic strength value greater than 0.1 m and temperatures of between 0.5 and 40 "C. This was the case of the gypsiferous karsts found to be related to hypersaline water at depth (Vallada, Gobantes-Meliones, Poiano). In the remaining situations, where the ionic strength was below 0.1 m, only the theory of ionic matching was used.
The hydrochemical study of the gypsiferous karst of Gobantes-Meliones (Malaga) led to the hypothesis of the possible influence of hypersaline water on karstification in gypsum. Using theoretical examples of the mixing of water derived both from hypersaline water and from water related only to the gypsiferous karst, it was shown that above a percentage content of 0.1:0.9 of saline and sulphated water, the mixture is subsaturated with respect to gypsum and other minerals. On reaching percentages greater than 0.5:0.5, values of oversaturation are again found. This could mean that the contact between sulphated and hypersaline water is a karstification zone in gypsum at depth.
In the gypsiferous karst at Salinas-Fuente Camacho (Granada), a study has been made of the hydrochemical influence of dolomitic levels in the sequence by means of the analysis of the hydrochemical routes between hydraulically-connected points. The generic case of mass transfer in this gypsiferous aquifer implies a precipitation of calcite which is in-congruent with dolomitic solution, proving that the process of dedolomitization in gypsiferous aquifers with an abundance of dolomitic rocks can be an effective process. In situations of high salinity, with contributions of hypersaline water, the process may be inverted, such as occurs in coastal carbonate aquifers influenced by the fresh-saltwater interface.
The gypsiferous aquifer of Sorbas-Tabernas (Almeria) provides the best case of karstification in gypsum in Spain; the hydrochemical study carried out has been used as an example of karstification in gypsum completely uninfluenced by sodium-chloride facies. It is shown, from the hydrochemical similarities between the different sectors, that the uniformity of the flow from the system main spring (Los Molinos) responds to the delayed hydraulic input through the overlying post-evaporitic materials and to the pelitic intercalations of the gypsiferous sequence. The aquifer is partially semiconfined, a situation which is comparable to the onset of the karstification stage, while the area of the Sorbas karst, strictly speaking, bears no hydriaulic relation to the rest of the system, behaving like a free aquifer intrinsically related to the epikarstic zone. This fact is demonstrated by the hydrochemical differences between the main spring and those related to gypsiferous cavities.
Apart from the general study of the Sorbas-Tabemas aquifer, a study was also made of the hydrochemical-time variations within cavities, and in particular within the Cueva del Agua, where it is possible to observe particular processes affecting karstification in gypsum, such as the precipitation of carbonates on the floor of the cavity which produce, in that area, a greater solution of gypsum (the phenomenon of hyperkarstification). Furthermore, the temporal evolution of the chemistry of the cavity, along 800 m of subterranean flow through its interior, shows the existence of inertial sectors where the variations were less abrupt. Only in the case of particular sectors, related to sporadic hydriaulic contributions or to the proximity to points of access., was a notable seasonal influence detected.
A similar hydrochemical study was carried out in the karst of Vallada (Valencia), along the cavity of the Tunel dels Sumidors. The chemistry here was compared with that of the springs of Brolladors (whose water rapidly infiltrates into the cavity) and Saraella (a saline resurgence of the whole system). Unexpected increases in the ionic content of certain salts (sulphates and chlorides) were detected during periods of increased flow; these were interpreted as the effect of the recharging of the Saraella spring arising from the immediate contribution of rapidly circulating sulfated water coming from the cavity and the subsequent mobilization of interstitial water with an ionic content higher than the characteristic level of the spring.
We present as a hypothesis the idea that, in addition to the hydrogeochemical processes described that can affect the evolution of a gypsiferous karst, the processes of sulphate reduction also influence karstification in gypsum, at least during the earliest stages. Some examples such as the presence of gypsum with abundant organic matter reprecipitated into phreatic channels (Sorbas) or veins of sulphur related to gypsiferous karsts (Podolia, Sicily) lend support to this idea.
Studies of the solution-erosion of gypsum have been performed by physical methods (tablets and M.E.M.) showing that the solution-erosion of gypsum within cavities is minimal (0.03 mm/ year) compared to that existing in the exterior (0.3 mm/year). The speleogenetic effect of condensation within the cavities has also been shown, with solution-erosion rates of 0.005 mm/year to be like the equivalent surface lowering. These data correspond to the karst in gypsum at Sorbas, where, additionally, a study about the time variation of the solution-erosion was carried out. It was found that the process is not continuous but clearly sporadic. During periods of torrential rain, the solution-erosion ranges from a weight loss of 400 mg/cm2/year on the surface of the karst to 75 mg/cm2/year inside the caves, while during the rest of the year the weight loss was barely 1 mg/cm2/year. The physical methods were compared with the results obtained from chemical methods, and it was found that, in general, higher values were obtained with the former (10-20% higher when weighted for the rainfall during the measuring periods). Thus it is reasonable to consider that the erosive process is more marked than was at first assumed.
In total, three cavity tracing experiments were carried out, all with fluoresceine, two of them in Cueva del Agua in Sorbas (during periods of high and low water levels) and the other in Tunel dels Sumidors in Vallada. At the first site, the comparison of the two tracing tests reveals a differential hydrodynamic behaviour of the cavity for the two contrasting situations; periods of high water input and periods of low rainfall. This behaviour is characteristic of well developed karstic aquifers, where the hydrodynamic effect of the circulation of water through small channels or, in this case, through the gypsiferous matrix and interbedded marly layers, seems to be more important under conditions of low hydraulic input than when rainfall is abundant. The two situations tested seem to confirm that the Cueva del Agua system, an epikarstic aquifer, which is representative of karstification in gypsum, has scarce retentive power and so large volumes of precipitation are totally discharged via the spring within a few days. However, the explanation of the small but continuous flow from the base of the cavity requires the inclusion of other factors in the interpretation. In this case, the flow seems to be fairly independent of rainfall and attributable to other processes, in addition to the previously described ones, such as the retentive power of the gypsiferous matrix and the marly interstrata. These might include the high degree of condensation measured over long periods, both on the surface of the karst in gypsum and within the cavities. In the case of the Tunel dels Sumidors, a highly irregular response was found, despite the fact that the coefficient of dispersivity was found to be 0.4. This value is similar to that obtained for the karst in gypsum at Sorbas in response to low water conditions, and so, here too, one might assume the influence of greater than expected flow-retaining processes, between the entry and exit points. Doubtless the karstic system of the Tunel dels Sumidors is more complex than was initially expected and in fact, the irregularity reflected by the fluoresceine concentration curve over time implies the existence of other factors to explain the diversity of the relative maxima obtained. Firstly, the presence of numerous Triassic clay intercalations might delay the flow, in addition to retaining a certain quantity of fluoresceine by ionic exchange. There is also a possibility that the flow is dispersed through a network of small conduits and pores, due to the permeability of the gypsiferous matrix. Finally, we cannot discount the possible existence of a deep-level input which, in this case, would be responsible for the variation in the flow and the chemical composition. This set of suppositions, as a whole, would explain the fact that the response of the spring to tracing is so irregular, even though we cannot achieve a definition of the qualitative influence of each one on the hydrodynamics of the system.
In order to verify some of the above hypotheses, particularly those referring to the process of condensation within cavities, an experiment was designed, consisting of a microtracing test at some points where condensation had been detected within the Cueva del Agua at Sorbas. The test produced a range of condensation flow speed values of 0.2 to 30 cm/hour and shows that, in those sections where the presence of condensation flow is visually apparent, there is a rapid dispersion of the colourant. However, it also shows that at points where there is no apparent condensation the process also occurs, but at a lower rate of efficiency. The importance of condensation within cavities has two aspects; firstly, speleogenetic, with the development of solution forms (cupolas) and deposit forms (capillarity boxwork); and secondly, hydrogeological, as this is the reason why certain processes (strong changes in temperature and humidity, multiple routes of airflow exchange with the exterior) may in themselves constitute a hydraulic contribution, of slight importance, but sufficient to explain a large part of the base flow (0.2 - 0.8 L/s) of a whole cavity system such as the Cueva del Agua in semiarid conditions.
With the intention of completing the analyses carried out in various karsts in gypsum, instruments were installed in the Cueva del Agua at Sorbas to measure, by continuous registration, some important physico-chemical parameters that might provide additional data on the hydro-geologic behaviour of this gypsiferous karst, especially at the level of the epikarstic zone. The parameters of temperature and water conductivity were considered most important, due to their singular behaviour patterns. During the experiment there were two periods of rainfall that modified the chemistry of the cavity, one of 30 mm in two days and another of 200 mm (almost the annual total) in four days. In the second case, which was much more extreme, a very significant increase in water temperature (up to 7 °C during the initial period of high water flow) was detected, while conductivity fell. But suddenly, when the minimum conductivity was reached, the temperature dropped sharply by 6-7 °C to return to the base temperature of the cavity. Subsequently, the temperature again stabilized at about 7 °C above the data recorded during the dry period. This behaviour pattern was not detected when the rainfall was slight. The explanation for this dual behaviour observed is fundamentally based on the quantity of rainfall and on the differences between the exterior air temperature, the temperature of interstitial water and the temperature recorded in the spring during high water flow. When water temperature in the cavity during high water flow is higher than the base temperature recorded in the period immediately before, it means that the interstitial water does not mobilize. However, when at any time the two temperatures coincide, one might suppose that there might have existed a process of mobilization of the water previously resident in the rock, by a piston effect, but in the unsaturated zone. On the other hand, the temporal variations of these parameters during the months following periods of high rainfall have enabled us to detect the existence of distinct periods during the return to normal cavity conditions. By carefully examining the decrease curve of water temperature inside the cavity while conductivity regained its maximum stable value, two periods may be differentiated. The first may be termed the "inertial influence period", when the rainfall occurring removes all signs of natural variation in the cavity. Thus, the daily external influences are not clearly detectable and the curve is downward-sloping and asymptotic with no significant oscillations. In the second period, which ends with the total stabilization of the parameter at the level of the initial conditions, the asymptotic descent is seen to be affected by daily temperature variations. This is termed the "inertial recovery period", during which external variations start to have an effect on the interior of the cavity such that there is a progressive increase in the amplitude of the daily variation in water temperature, air temperature and relative humidity. This behaviour pattern of variation of these parameters during periods of high rainfall, might be extended to all karstic systems, varying only in magnitude and temporal extent.


The potential corrosion of speleothems by condensation water , 1998, Linhua Song, Jingrong Yang, Laihong Wang

Because of the development of tourist activities and facilities in show caves, the closed system of the caves has been changed into complicated open system. The visitor flow and the high energy of landscape lights give a great deal of thermoenergy to the show cave system, which makes the temperature rise and reduces the humidity very fast. After the visitors leave and the lights are switched off, the temperature goes down and humidity increases even up to saturation, condensation takes place. The humidity of Yaolin cave reaches 97%-100% throughout the year. The visitors give average CO2 content of 13000-15000 ppm by breathing and one visitor breathes 40 litre of CO2 per hour. The visitors strongly influence the CO2 content of the cave atmosphere.


Karst processes on Cayman Brac, a small oceanic carbonate island, PhD Thesis, 1999, Tarhulelips, Rozemarijn Frederike Antoinette

Cayman Brac is a good example of a small oceanic carbonate island which has undergone several periods of submergence and emergence since the Tertiary, resulting in the geological formations being well karstified. This study investigated several karst phenomena on the island including the occurrence and morphology of caves, the water chemistry and microclimate inside the caves, periods of speleothem growth and dissolution, and bell holes. Caves occur throughout the island at various elevations above sea level. Using elevation as a criterion, the caves were divided into Notch caves, located at, or one-two metres above, the Sangamon Notch, and Upper caves, located at varying elevations above the Notch. Analysis of the morphology, age and the relative abundance of speleothem in the caves further supports this division. The close proximity of the Notch and the Notch caves is coincidental: speleothem dating by U-series methods shows that the caves predate the Notch. They are believed to have formed between 1400 and 400 ka, whereas a late Tertiary to Early Quaternary age is assigned to the Upper caves. Speleothem on the island has suffered minor, moderate and major dissolution. Minor dissolution is due to a change in the degree of saturation of the drip water feeding the speleothem, whereas the last two are caused by flooding or condensation corrosion. Many of the speleothems in fact experienced several episodes of dissolution followed by regrowth. The latest episode appears to be caused by condensation corrosion rather than flooding. Eleven speleothems containing growth hiatuses were dated by U-series methods. The results indicate that growth cessation did not occur synchronously. Furthermore, the timing of the hiatuses during the Quaternary is not restricted to glacial or interglacial periods. Oxygen and carbon stable isotope analyses of seven of the samples reveal an apparent shift towards a drier and warmer climate around 120 ka. However, more data and further collaborative evidence is desirable. Of six samples with hiatuses, five show a bi-modal distribution of stable isotope values: before and after the hiatus. Oxygen isotope analyses of modern drip water found inter-sample variations of over 2[per thousand]. This is due to cave environmental factors such as evaporation, infiltration velocity and roof thickness. Inside the caves δ 18 O of drip water decreases with increasing distance from the entrance and thus decreasing external climatic influence. This distance-climatic effect is also reflected in the δ18 O calculated for modern calcite: -5.3, -6.5 and -7.6[per thousand] VPDB at 3, 10 and 20 m respectively. The morphology of bell holes, found only in certain Notch caves, was studied in detail. It is proposed that the bell holes are formed by condensation corrosion, probably enhanced by microbiological activity. The study represents a comprehensive and thorough analyses of karst features on a small oceanic island, and provides information useful for climatic reconstruction during the Quaternary


Origin and development of an old alpine cave (Zadlaźka jama, Julian Alps), 1999, Knez Martin, Slabe Tadej

The entrance into Zadlaźka jama lies in Maastrichtian limestone breccias at the extreme northern border of the Outer Dinarid tectonic unit; from the presence of Megalodontid shells it is presumed that the northern parts of the cave developed in Upper Triassic limestones. Tectonically the Cretaceous and also Triassic carbonates are strongly broken. Several systems of former water passages controlled by geological factors are found in the cave. Two of them are more distinctive: one developed along bedding-planes or at the contact of beds parallel to bedding and the other along fissures and faults which are transverse to local bedding. The cave is an anastomosis network system of initial tubes that develop into passages. The first and the most important factor was water that slowly flowed through the passages. Later the cave was filled by fine-grained sediments. Water flowed above them leaving above-sediment rocky features. The parts of the lower lying passages from which the sediments had been removed were shaped by fast water flow after the lowering of the underground water level. Relatively soon the cave remained hanging in the slope and was dry. Then the rocky perimeter was partly reshaped by condensation water.


Clays in Caves of the Guadalupe Mountains, New Mexico, 2000, Polyak, V. J. , Gven, N.
The origins of clay minerals in the caves of the Guadalupe Mountains, New Mexico are categorized as (1) detrital, (2) inherited from the weathering of dolostone and siltstone, and (3) authigenic. Clay minerals found in these caves include hydrated halloysite, kaolinite, dickite, illite, montmorillonite, illite-smectite mixed-layers, palygorskite, and trioctahedral smectite. The detrital clay minerals are montmorillonite, illite, dickite and kaolinite. The clay minerals inherited from the bedrock by condensation-induced weathering (in wall residues) are illite and dickite. Cave-authigenic clay minerals include hydrated halloysite (endellilte), trioctahedral smectite, montmorillonite, and probably palygorskite. Hydrated halloysite formed by the alteration of illite, montmorillonite, illite-smectite mixed-layers, kaolinite, or dickite during sulfuric acid-related speleogenesis. Trioctahedral smectite precipitated with Mg-carbonate minerals in dolomite crusts and huntite moonmilk. Montmorillonite formed in saturated ledge deposits of redistributed wall residues. Less clear is the origin of palygorskite in laminated silt and clay deposits in Carlsbad Cavern.

Phnomnes de karstification observs dans une cavit artificielle du Rincn Blanco (Argentine), 2000, Barredo, Silviap.
The Rincon Blanco subbasin is located in San Juan Province, Argentina, between 69 15' west by 314' to 31 33' south and is characterised by a non marine continental infilling. During the Tertiary times it underwent compressional deformation folding it into a tight north-_south trending syncline. The whole sedimentary sequence is comprised of coarse-grained units interfingered with sandstones and shales. In particular, these latter were deposited in an alkaline lake and are composed of carbonate and organic rich strata. These characteristic lacustrine facies bear bituminous shales widely known as "Rincon Blanco oil slates". During the 1950' s and 1970' s, they were densely explored resulting in a number of galleries that presently are abandoned. They were cut in the bituminous rocks exposing west-east and southeast-northwest systems of minor faults and local fractures. These discontinuities permitted the inflow of meteoric waters through the overlying layers and into these artificial caves, thus resulting in carbonate cement dissolution, and, re-precipitation as tiny stalactites, stalagmites, thick travertine deposits in the floor with incipient microchannels accompanied by pools (gurs) with pearls and botroidal-like concretions. Several solutional speleothems are also found and correspond to ceiling and wall pockets and floor pits. This phenomena seemed to be related to acidic water coming from small discharges and flowing through the network of integrated tectonic openings to the innermost tunnel sections where humid air reaches saturation. Water trickling resulting from condensation produces erosional features and, together with dropping and occasional flows, the speleothems. Events of slight flow turbulence in some enlarged fractures are also inferred by the presence of ceiling and floor dissolutional features.

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