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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 smithsonite is a cave mineral - znco3 [11].?

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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 saturated zone (Keyword) returned 86 results for the whole karstbase:
Showing 16 to 30 of 86
INFILTRATION MECHANISMS RELATED TO AGRICULTURAL WASTE TRANSPORT THROUGH THE SOIL MANTLE TO KARST AQUIFERS OF SOUTHERN INDIANA, USA, 1995, Iqbal M. Z. , Krothe N. C. ,
A hydrogeological study was conducted, during the 1991-1992 water year, in the clay-soil mantled portion of a limestone terrain in southern Indiana. The purpose of the study was to investigate the modes of soil-water infiltration contributing to rapid transport of nitrate to the saturated zone. The I-year-cycle profiles of nitrate concentration vs. time show a consistent increase of nitrate at various depths in the unsaturated zone during the period of investigation. The increase of nitrate in soil water is attributed to the rapid flushing of the inorganic fertilizers from the fields after the area received sufficient rainfall in late fall. The investigation also showed a major movement of nitrate in quick pulses through the unsaturated zone, rather than a slow uniform recharge, immediately after a major storm event. The asymmetric profiles of nitrate concentration vs. depth point to the existence of preferential flow through macropores in the clay-soil mantle above the bedrock. Soil-water transport between storm events is by matrix type flow. Nitrogen isotopes were analyzed for representative groundwater samples collected before and immediately after fertilization of fields in the summer, 1991. The delta(15)N values of the samples did not show any major shift in nitrate sources between the sampling periods. The summer of 1991 was extremely dry prohibiting vertical transport of nitrate from the fields to the groundwater system. Any change in nitrate concentration in groundwater during this time is attributed to the mixing through lateral flow within the aquifer

Le Luirographe : tude de la crue du 22 avril 1995 (rseau de la Luire, Vercors), 1996, Morel, L.
The Luirographe can record automatically parameters such as the water height in a karstic network. Placed at the beginning of April 1995, at -200 m, it recorded for the first time the Luire swelling, which lasted two days. The cave of the Luire is situated in the massif of Vercors, with an hydrogeological basin of 230 km2. The Vercors is a forest of middle mountain within the French Pre-Alps of the North. The Luire swelling only exits when there are very big nival spate accentued by important rainfalls and by a southern wind. Such event arrives only every other year on average. The difference between the high and low level of karst flood can reach the impressive height of 475 m, the most important known in the world. It is the difference between altitude of saturated zone where there is the continuous spring of Arbois and the temporary emergence of the Luire, known up to -451 m and are 20 km apart.

Laquifre de la source du Lez : un rservoir deau et de biodiversit, 1997, Malard Florian, Gibert Janine, Laurent Roger
The Lez spring is the main source of drinking water for the inhabitants of the city of Montpellier. This spring has been exploited since the eighteenth century but the amount of groundwater pumped has markedly increased over the last 30 years. This karst harbours an extremely diversified community of groundwater species (at least 37 species) that is a several Million-year-old heritage. Overpumping induces a loss of habitats by lowering the water table during periods of low groundwater recharge. It also results in an artificial fragmentation of mesohabitats by increasing the hydraulic disconnection of different regions in the saturated zone. Thus, overpumping may strongly affect the groundwater fauna but few data are available yet to evaluate the potential loss of biodiversity. There is clearly a need to integrate studies of groundwater fauna within the framework of interdisciplinary groundwater monitoring, management and/or protection programmes.

Hydrogeochemical vertical zonality in the Cid karst aquifer (Alicante, Spain), 1998, Pulidobosch A. , Andreu J. M. , Estevez A. , Ayanz J. ,
Study of hydrochemical data, conductivity and temperature logs and the samples taken at different depths reveals a marked hydrogeochemical vertical zonality in the Cid karst aquifer. Most saline waters lie in the deepest parts of the aquifer, while those of lowest mineralization occupy the areas of the saturated zone closest to the surface. The hydrodynamic system thus formed is considered to be influenced by two flows: a more superficial one, presenting a lower level of water mineralization; and a deep flow system in which the water, due to contact with Triassic evaporitic materials, experiences a considerable increase in mineralization. (C) Academie des sciences/Elsevier, Paris

Migration of dissolved petroleum hydrocarbons, MTBE and chlorinated solvents in a karstified limestone aquifer, Stamford, UK, 1998, Banks D,
Two incidents of hydrocarbon contamination to the Lincolnshire Limestone in east Stamford, UK, have been investigated. No evidence of LNAPL contamination of groundwater was observed, suggesting that the spills may largely have been retained in the unsaturated zone. Some groundwater contamination by dissolved hydrocarbons occurred, apparently especially at times of high recharge. Rapid flow paths were proven to nearby springs in the River Welland (with groundwater flow velocities of up to 240 m day-1), and dissolved hydrocarbon and MTBE contamination appears to have been flushed rapidly from these systems. MTBE contamination at Tallington Pumping Station (5 km east of the site) is not clearly linked to these incidents. Of potentially more concern was the discovery of dissolved chlorinated solvent contamination in the groundwater at the spill sites, possibly related to a landfilled quarry and/or a nearby engineering works. No direct evidence of DNAPL was observed. A conceptual model of solvent distribution suggests independent sources of TCE, PCE and TCA

Mapping groundwater vulnerability: the Irish perspective, 1998, Daly D, Warren Wp,
The groundwater protection scheme used in the Republic of Ireland since the 1980s had not encompassed the vulnerability mapping concept. Yet internationally, vulnerability maps were becoming an essential part of groundwater protection schemes and a valuable tool in environmental management. Consequently, following a review of protection schemes world-wide, the scheme used in Ireland was updated and amended to include vulnerability maps as a crucial component of the scheme. The approach taken to vulnerability assessments and mapping in the Republic of Ireland has been dictated by the following fundamental questions: Vulnerability of what? Vulnerability to what? Which factors determine the degree of vulnerability? What is the appropriate scale for map production? How can limitations and uncertainties be taken into account? How can vulnerability assessments be integrated into environmental and resource management? The following decisions were made: (i) we should map the vulnerability of groundwater, not aquifers or wells/springs; (ii) the position in the groundwater system specified to be of interest is the water-table (i.e. first groundwater encountered) in either sand/gravel aquifers or in bedrock; (iii) we should map the vulnerability of groundwater to contaminants generated by human activities (natural impacts are a separate issue); (iv) as the main threat to groundwater in Ireland is posed by point sources, we should map the vulnerability of groundwater to contaminants released at 1-2 m below the ground surface; (v) the characteristics of individual contaminants should not be taken into account; (vi) the natural geological and hydrogeological factors that determine vulnerability are the sub-soils above the watertable, the recharge type (whether point or diffuse) and, in sand/gravels, the thickness of the unsaturated zone; (vii) based on these factors, four vulnerability categories are used (extreme, high, moderate and low); (viii) map scales of 1:50 000 and 1:10 000 are preferred; (ix) limitations and uncertainties are indicated by appropriate wording on the maps and a disclaimer; (x) vulnerability maps should be incorporated into groundwater protection schemes, which should be used in decision-making on the location and control of potentially polluting developments. Vulnerability maps have now been produced for a number of local authority areas. They are an important part of county groundwater protection schemes as they provide a measure of the likelihood of contamination, assist in ensuring that protection schemes are not unnecessarily restrictive of human economic activity, help in the choice of engineering preventative measures, and enable major developments, which have a significant potential to contaminate, to be located in areas of relatively low vulnerability and therefore of relatively low risk, from a groundwater perspective

Recharge: the key to groundwater pollution and aquifer vulnerability, 1998, Robins N. S. ,
Recharge is pivotal to understanding the processes by which groundwater pollution can occur. It is implicit in the classification of aquifer units according to their vulnerability to pollution. The management of both groundwater resources and of individual groundwater sources cannot sensibly be undertaken without some knowledge of recharge: its quantity, its seasonality and, above all, the different routes through the sub-soil and the unsaturated zone by which it can occur. However, current estimates of recharge, other than on a research site basis, may be poor, both in the UK and overseas. This volume provides a review of current research into these issues; this introductory paper attempts to highlight the thread throughout all of this work which collectively provides the basic information in support of the current and future management of groundwater resources and sources

The hydrogeological effect of quarrying karstified limestone: options for prediction and mitigation, 1998, Hobbs S. L. , Gunn J. ,
The hydrogeological effect of limestone extraction from open pits (quarries) depends on the location of the site in the landscape, the vertical and horizontal extent of the excavation, the methods used to excavate the stone, and the extent of karstification. Groundwater quality is commonly affected by quarrying through increased fine sediment concentrations and accidental spillages. Removal of any soil cover allows direct access for pollutants into the aquifer, a problem which may be exacerbated by licensed or illegal tipping of waste following cessation of stone extraction. Quarrying also removes the entire subcutaneous (epikarstic) zone which is an important ground-water store, together with part or all of the unsaturated zone. Pumping of water from the excavation will change the ground-water balance and can alter the direction and amounts of conduit flow, particularly if the quarry extends beneath the water table. Prediction of such impacts is difficult, especially when the limestone is karstified, such that there will always be a degree of uncertainty associated with the impact of the workings. Hence, it is essential that for new quarries monitoring is undertaken prior to, throughout, and following mineral working, with options for mitigation if mineral working causes an unacceptable impact. When a quarry ceases to be worked, the direct impacts on groundwater quality may rapidly decrease but there are important implications for after-use of the site. Impacts on groundwater quantity are likely to be more long-term

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.


Carbon stable isotopic composition of karst soil CO2 in central Guizhon, China, 1999, Zheng L. P. ,
The delta(13)C values of soil CO2 are less than that of atmosphere CO2 in the karst area. On the soil-air interface, the delta(13)C vlaues of soil CO2 decrease with the increase in soil depth; below the soil-air interface, the delta(13)C values of soil CO2 are invariable. The type of vegetation on the land surface has an influence on the delta(13)C values of soil CO2. Due to the activity of soil microbes, the delta(13)C values of soil CO2 are variable dth seasonal change in grass. Isotopic tracer indicates that atmosphere CO2 has a great deal of contribution to soil CO2 at the lower parts of soil profile

From a conceptual model of karst hydrological systems to water-vulnerability mapping, 1999, Jeannin Py. , Zwahlen F. , Doerfliger N.
A conceptual model of karst hydrological systems is presented hereIt considers that water flows through four cascading subsystems: soils, epikarst, unsaturated zone, and saturated zoneThis model lead us to define four criteria which appear to be significant for intrinsic vulnerability assessment with respect to a spring or a well: characteristics of epikarst (E), characteristics of protective cover (P), recharge or infiltration type (I) and presence/absence of a well-developed conduit network (K)The method has proved to be adequate for karst in Central EuropeIn the future, it should be tested in other areas and compared to numerical approaches of karst systems

The catchment of the Brassus karst spring (Swiss Jura): a synthesis of the tracer tests, 2000, Perrin J. , Jeannin P. Y. , Lavanchy Y. ,
Two successive tracer tests were carried out in the Pleine Lune cave which is located in the central part of the Brassus karstic spring catchment area (South-western Jura, Switzerland). During both experiments, the tracers were not recovered neither. at the Brassus spring nor at the secondary springs. Following this amazing result, the available data on this spring have been studied and a synthesis is proposed in this paper. The Brassus karstic spring, situated in the south-western part of Vallee de Joux, is an important resurgence from this part of the folded Jura. The water emerges from Cretaceous limestones covered by a thin layer of moraine: the main alimentation comes however from the underlying Maim limestone aquifer, Cretaceous limestones bring only a limited part of the total discharge. Within the supposed Brassus spring catchment areal 18 tracer tests were realised, but only half of them gave positive results. Positive tracer rests show low velocities and poor restitution percentage, particularly during low water periods. Such peculiarities are attributed to an important saturated zone, favouring dilution and dispersion of the tracers. The average discharge at the: spring is assumed to be less than 500 l/s and the average specific discharge is about 40 l/s/km(2), following previous data on other springs of the area. A calculated catchment area with such values would have a surface of 13,5 km(2); but the catchment area derived from the topography of the base of the Maim aquifer (top of the argovian marls considered as an aquitard) covers 56 km(2). This important difference as well as the negative results obtained from the Pleine Lune cave tracer tests show how difficult it is to define a catchment area for limestone aquifers: on one hand a delimitation based on water balance calculations tends to underestimate the catchment area by neglecting outlets as direct infiltration in the alluviums and secondary springs. On the other hand a delimitation based on geological considerations seems to overestimate the surface; this is illustrated by negative tracer tests results with injection points situated well inside the catchment area

Infiltration measured by the drip of stalactites, 2000, Sanz E. , Lopez J. J. ,
The hydrodynamic processes and mechanisms involved in rain infiltration and recharge in local areas of karst terrain can be identified and quantified by using measurements of the seepage of cave stalactites, Detailed measurements of the seepage of stalactites in seven caves located in an area close to the land surface, or the subcutaneous area of the karst, show a diversity of complex factors involved in infiltration: type of precipitation (rain or snow), air temperature, soil type and thickness, etc., which give rise to larger or smaller variations of flow in the espeleothem hydrographs, In some cases, no explanation can be found for the response of stalactites to rainfall, while in others there is a relationship between outer atmospheric parameters and the recharge represented by the stalactite drip. Romperopas Cave (Spain) has both a rapid and a basic flow, with hydrograph recessions similar to those observed in other caves. Water seepage in this cave varies greatly both in space and in time. The infiltration in Altamira Cave (Spain) was calculated and a multiple regression was found between infiltration, rain and outside air temperature. In other cases, the balance of the water on the soil is responsible for the seepage, Thus, a precipitation runoff numerical model that simulated the stalactite hydrographs could be applied to the Baradla and Beke Caves (Hungary), The complex properties of the ground, which are required for other flow numerical models for the unsaturated zone, were not taken into consideration

Mechanisms of water storage and flow in the unsaturated zone of the Chalk aquifer., 2000, Price M. , Low R. G. , Mccann C.

Speleogenesis in the Picos de Europa massif, Northern Spain, 2000, Fernandezgibert E. , Calaforra J. M. , Rossi C.
The Picos de Europa mountain range in Northern Spain represents one of the most important alpine karsts in the world, containing a great concentration of deep limestone caves. It comprises Carboniferous limestones with thicknesses up to 2000 m and severely deformed by tectonic action. The structure and geological evolution, fracturing and Quaternary glaciation are among the main factors influenced the development of the caves. This paper proposes a speleogenetic model of the evolution, with an initial stage during which a Permo-Triassic cover provided semiconfinement for the entire carbonate series. Under these circumstances, the earliest known phreatic conduits were formed. Occasional relict sediments in them are related to the erosion of the cover. During the second stage, with the uplift of the massif, the cover was eroded and vadose conditions established; they were linked to glacial processes that intensified karstification, creating an unsaturated zone almost 2000 m thick. The karstification and vadose entrenchment in this zone are especially marked along preferential flow paths coinciding with pre-existing dolomitized and sulfide-mineralized fractures in the massif. These fractures may also have played a precursor role in the karstic evolution of the massif, as the source for more aggressive waters with a higher content of weak acids due to the oxidation of sulfides.

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