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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 gas-expansion method is the measurement of porosity based on the boyle-mariotte's gas laws [16].?

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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 dispersion (Keyword) returned 37 results for the whole karstbase:
Showing 1 to 15 of 37
Distribution and dispersion of the troglobitic Carabid Beetle Rhadine subterranea, 1971, Mitchell Robert W.
Intracave distribution and dispersion patterns within a population of the troglobitic carabid beetle Rhadine subterranea were studied. Distribution was markedly heterogeneous, the beetles being almost entirely restricted to substrata of deep, uncompacted silt. Dispersion of the beetles on the silt substrata did not depart from random expectation. It is shown, however, that this is a functionally emergent pattern resulting from an intrasex repulsion related to feeding which tends to produce regularity counterbalanced by an intersex attraction related to reproduction which tends to produce contagion.

Distribution and dispersion of the troglobitic Carabid Beetle Rhadine subterranea, 1971, Mitchell Robert W.
Intracave distribution and dispersion patterns within a population of the troglobitic carabid beetle Rhadine subterranea were studied. Distribution was markedly heterogeneous, the beetles being almost entirely restricted to substrata of deep, uncompacted silt. Dispersion of the beetles on the silt substrata did not depart from random expectation. It is shown, however, that this is a functionally emergent pattern resulting from an intrasex repulsion related to feeding which tends to produce regularity counterbalanced by an intersex attraction related to reproduction which tends to produce contagion.

Size and growth of the eyes of the troglobitic Salamander Typhlotriton spelaeus., 1974, Besharse Joseph C. , Brandon Ronald A.
The eyes of larval T. spelaeus grow by negative allometry, but in allometric coefftcients they are not greatly different from E. lucifuga. The major differences in eye size, both absolute and relative to body size, between T~ spelaeus and E. lucifuga are established prior Io the larval growth period. The eyes of T. spelaeus cease to grow at metamorphosis and are reduced in size thereafter. In addition, there is increased individual variability and bilateral asymmetry of eye size in adult T spelaeus compared to both adulI E lucifuga and larval T. spelaeus. This variability, expressed as relative dispersion about mean eye size, is significantly greater than in E luci.fuga, and appears to result from three factors: 1) postmetamorphic cessation of eye growth, 2) wide variation in body size and eye size al metamorphosis, and 3) postmetamorphic shape changes and reduction of eye size.

Observations on Stenasellus virei in its natural biotopes (Crustacea Isopoda Asellota of Subterranean Waters)., 1974, Magniez Guy
Thanks to intensive exploration and to new methods for capturing aquatic underground fauna. 117 localities are now known for Stenasellus virei. The description of some typical biotopes suggests that the species lives as well in karstic waters as in phreatic ones, inside the different environment of the hydrogeological classification of subterranean waters. St. virei buchneri and St. v. hussoni are almost cavernicolous. St. v. angelieri is distributed in the underground waters of Catalonia. St. v. boui is located in the underflow of Salat river basin. St. v. virei is widely distributed in the alluvial water-level of Garonne and Ebro rivers basins. The dispersion of St. virei into the alluvial environment explains the process of colonization of continental underground waters. It explains also the existence of an apparently insulated population into the sink-hole of Padirac. The actual distribution of the five subspecies is explained by important restrictions of the area in quaternary glacial ages, followed by local (in the water-level of the tributaries of Garonne river) spreading during postglacial time. The postglacial reconquest of the Salat river underflow by this species seems to have been responsible for the latest subspeciation (St. v. boui). The endemic populations of fossil karstic systems seem to have an abnormal composition. They include unusually large adults, juvenile stages being rare. They differ from the phreatic populations, which exhibit a normal distribution is size groups, with a formal percentage of juveniles. These differences between karstic and interstitial populations may result from the fact that in caves, Sr. virei is often insulated from its original phreatic biocoenosis: an intraspecific competition between size classes has taken the place of normal heterospecific struggle for existence.

Utilisation de la mthode des traages pour l'tude des aquifres fissurs en milieu calcaire, 1986, Fourneaux J. C. , Sommeria L.
USE OF THE TRACING METHODS TO STUDY THE FISSURED AQUIFERS IN LIMESTONES - The limestones aquifers study by tracing shows the fissured zones, with or without karstic stream channels. Inversely that happens when the tracer is injected in a place in connection with an important drain, the tracer injected anywhere in the aquifer (wells, drill...) will be dispersed in space and in time. The dispersion will be more important especially as the jointing is developed. Analysis of the relation between concentration and time permit often to separate the open-channels flow from the flow in fissured zone. The results presented here come from different multi-tracing operations in limestone areas, in France.

Analyse d'une opration de traage dans la rgion du Pic St-Loup (Hrault), 1989, Fourneaux J. C. , Couturier B. , Sommeria L.
Dye tracing in the Pic Saint-Loup area (Hrault, France) - A fluorescein dye tracing has been made in the sinkhole in the Mortis valley, in the Dogger limestones of the south flank of the Pic Saint-Loup, north of Montpellier (south of France). The tracer has been found in two wells near Saint-Mathieu-de-Trviers, in the Gour noir spring and in the Lez spring, where the most important part of the tracer was recovered. The dispersion of the tracer gives an indication about the presence of an important water table in the fissures of the limestones, in connection with the Corconne fault. The low speeds and the low restitution rate show that the water flow in the fissured area, dominates in karst conduits, but it is probably not the same during high waters.

ISOTOPE HYDROLOGICAL STUDY OF MEAN TRANSIT TIMES IN AN ALPINE BASIN (WIMBACHTAL, GERMANY), 1992, Maloszewski P. , Rauert W. , Trimborn P. , Herrmann A. , Rau R. ,
Measurements of tritium and O-18 concentrations in precipitation and runoff were used to provide further insight into the groundwater storage properties of the Wimbachtal Valley, a catchment area of 33.4 km2, extending between 636 and 2713 m a.s.l. in the Berchtesgaden Alps. The catchment includes three aquifer types: a dominant porous aquifer; a fractured dolomite; a karstic limestone aquifer. Employing a simple hydrological model, information about mean transit times of environmental tracers is derived for the groundwater runoff component and several karst springs from the application of the exponential and dispersion flow models to the isotopic input and output data. The mean transit times calculated from a dispersion model with transit times of 4.1 years for O-18 and 4.2 years for tritium, which agree well, allow calculation of total (mobile stagnant) groundwater storage volume, which is equivalent to 6.6 m of water depth. Direct runoff appears negligible as in many other cases

HYDROGEOLOGY OF GRAND CAYMAN, BRITISH-WEST-INDIES - A KARSTIC DOLOSTONE AQUIFER, 1992, Ng K. C. , Jones B. , Beswick R. ,
On Grand Cayman, freshwater bodies present in the Bluff Formation are typically small and occur as thin lenses floating on top of dense saline water. Evaluation of the water resource potential of these freshwater lenses is difficult because of their variable hydrological conditions, complex paleohydrogeology and aquifer heterogeneity. Secondary porosity created by preferential dissolution of aragonitic fossil components is common. Open fissures and joints developed under tectonic stress and karst development associated with sea-level fluctuations are, however, the two most important causes of porosity and permeability in the aquifers on Grand Cayman. Fracture and karst porosity control the lens occurrence by: (1) acting as avenues for the intrusion of seawater or upward migration of saline water; (2) acting as recharge focal points; (3) enhancing hydrodynamic dispersion; (4) defining lens geometry; (5) facilitating carbonate dissolution along joints and fissures. A clear understanding of the hydrological and geological conditions is important in developing small lenses in a setting similar to that on Grand Cayman. This pragmatic approach can help identify the optimum location of the well field and avoid areas particularly susceptible to saline water intrusion

The cricket fauna of Chiapanecan caves (Mexico): systematics, phylogeny and the evolution of troglobitic life (Orthoptera, Grylloidea, Phalangopsidae, Luzarinae), 1993, Desuttergrandcolas Laure
The present study deals with the cavernicolous Grylloidea of Chiapas. It details the composition of this fauna, which belongs exclusively to the Phalangopsid group Amphiacustae, and considers its troglobitic evolution in the methodological framework of Comparative Biology. This method consists in analysing the evolution of biological features in reference to phylogeny, using character state optimization. The material studied comes mostly from Italian biospeological expeditions, but also from the authors work in Mexico, from North American biospeological expeditions achieved in Central America and the West Indies, and from the collections of the Academy of Natural Sciences of Philadelphia, the Museum National d'Histoire naturelle de Paris and the University of Michigan Museum of Zoology. I first present a systematic and phylogenetic analysis of Amphiacustae. Six new genera are defined and the genus Amphiacusta Saussure, 1874 is clearly delimited; twenty-three of the twenty six species considered in the paper are new and described. A key for genera and species groups is given. Phylogenetic relationships among genera are established using cladistics (implicit enumeration of Hennig 86 program). The evolution of troglobitic Amphiacustae is then analyzed. Available data on the biology of Amphiacust genera are presented and compared with what is known on other Phalangopsidae. Three biological attributes are moreover defined (troglobitic versus non troglobitic; cavernicolous versus non cavernicolous; leaf litter foraging versus leaf litter not foraging). The mapping of the attributes upon our cladogram has shown that Amphiacustae evolved twice toward cave life and that their ancestral habitat could be characterized by cavernicolous habits and leaf litter foraging. The results are discussed in reference to theories on troglobitic taxa evolution, and to the exaptation concept of Gould & Vrba (1982). This leads to three main conclusions: 1/ Amphiacust adaptation to caves could be the result of a tentative to exploit karstic resources in Central America; 2/ An epigean dispersion by cave living species can be hypothesized; 3/ For Grylloidea, having cavernicolous habits at ground level appears to be exaptative to troglobitic life.

DAMPENING OF TRANSVERSE DISPERSION IN THE HALOCLINE IN KARST LIMESTONE IN THE NORTHEASTERN YUCATAN PENINSULA, 1995, Stoessell R. K. ,
A range of hydrodynamic dispersion coefficients was estimated for fracture-fluid and combined fracture and pore-fluid now within the halocline of the limestone aquifer forming the surface of the northern Yucatan Peninsula. The coefficients are fit parameters in a model reproducing observed halocline profiles in a sinkhole and in a borehole near the northeastern coast. Fitted coefficients range from 10(-7) to 10(-4) cm(2)/sec, of which molecular diffusion, without transverse (vertical) dispersion, can account for 10(-7) to 10(-5) cm(2)/sec. The mechanical stability of the vertical density gradient in the halocline dampens transverse dispersion in pore fluids and in fracture fluids that are transitional between laminar and turbulent flow. The dampening is proportional to the ratio of the energy needed for the fluid to rise and displace a less dense fluid to the vertical component of the kinetic energy of the fluid. The ratio of these two energies is at a maximum during the initial stage of development of a halocline and decreases as the halocline widens

Risk assessment methodology for karst aquifers .1. Estimating karst conduit-flow parameters, 1997, Field Ms, Nash Sg,
Quantitative ground-water tracing of conduit-dominated karst aquifers allows for reliable and practical interpretation of karst ground-water flow. Insights into the hydraulic geometry of the karst aquifer may be acquired that otherwise could not be obtained by such conventional methods as potentiometric-surface mapping and aquifer testing. Contamination of karst aquifers requires that a comprehensive tracer budget be performed so that karst conduit hydraulic-flow and geometric parameters be obtained. Acquisition of these parameters is necessary for estimating contaminant fate-and-transport. A FORTRAN computer program for estimating total tracer recovery from tracer-breakthrough curves is proposed as a standard method. Estimated hydraulic-flow parameters include mean residence time, mean flow velocity, longitudinal dispersivity, Peclet number, Reynolds number, and Froude number. Estimated geometric parameters include karst conduit sinuous distance, conduit volume, cross-sectional area, diameter, and hydraulic depth. These parameters may be used to (1) develop structural models of the aquifer, (2) improve aquifer resource management, (3) improve ground-water monitoring systems design, (4) improve aquifer remediation, and (5) assess contaminant fate-and-transport. A companion paper demonstrates the use of these hydraulic-flow and geometric parameters in a surface-water model for estimating contaminant fate-and-transport in a karst conduit. Two ground-water tracing studies demonstrate the utility of this program for reliable estimation of necessary karst conduit hydraulic-flow and geometric parameters

Dispersion and tailing of tracer plumes in a karstic system (Milandre, JU, Switzerland), 1997, Jeannin Py. , Marechal Jc.
A large number of tracing experiments have been carried out in a karstic aquifer in the Swiss Jura. These allow to observe the evolution of a tracer plume along the length of a karst conduit. The method of Sauty was used to make possible the comparison between all the observed breakthrough curves. The flow velocities and the dispersivities obtained are extremely variable. The dispersivities measured at different points along the length of an underground stream in the course of the same tracing experiment increase with distance (scale effect). If the fit of theoretical Sauty curves on the experimental curves works well for rising limbs, this is not always the case for falling limbs: a tailing effect or lag of the experimental curves compared to the theoretical ones is often observed. Micro-tracings have shown that the lag effect is linked more to the karst conduit geometry than to the types of flows (turbulent or laminar). Measurable tailing effect is induced by the presence of a single conduit enlargement (also called pool). Further, the experiments have shown that a succession of enlargements along the length of the underground stream causes a clear increase in the dispersivity and a "homogenisation" of the recovery curve which shows up by the apparent disappearance of the lag effect. These observations show clearly the influence of the heterogeneity of the karst conduit geometry on the breakthrough curves. This effect might be considered when one interprets the shape of the breakthrough curves especially for dispersivity estimation.

Evolution of size distributions of natural particles during aggregation: modelling versus field results, 1998, Atteia O,
In this paper a discretized model simulating aggregation of size distributions jointly with sedimentation and transport is presented. A review of the current theory provides some helpful hints about the relative importance of each aggregation process, i.e. Brownian motion, shear flow and differential sedimentation, which are tested by using collision efficiency factors. The novel aspect of the model arises from the use of a varying mean particle diameter in each size class. This allows both non-steady-state and steady-state calculations and free choice of size classes. A comparison with a classical approach shows the exactitude of the results and the improvment obtained for several cases. The simulations gave a family of curves characterized by three parts corresponding to peri-, and orthokinetic aggregation and to sedimentation. The role of collision effciency is crucial in the relative extent of each part of the size distribution. The comparison with a series of data from a karst spring showed that the model was able to fit most of the particle size distributions using significant values of each parameter. This allowed information about particle aggregation and transport within a non-accessible aquifer to be inferred.

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.


Quelques aspects des conditions de circulation des eaux souterraines dans les karsts du gypse des Alpes internes, 1999, Couturier Bernard, Fourneaux Jeanclaude, Sommeria Laure
The Triassic gypsum outcrops are widespread, in the French Inner Alps. They are often found in large heaps between two structural units. Karstic landforms with sinkholes and collapse zones are visible even when they are covered with glacial deposits or fallen rocks. There is also much evidence of underground flows, but the springs do not have any karstic characteristics. The water tracings (two examples) show that the local tectonics have a great influence in the subterranean circulation conditions. At "La Norma" in the Arc valley (Maurienne) the water infiltrated in a large sinkhole supplies several small springs after transit in a fissured aquifer. The spring flow is well regulated. At "Le Clou" in the upper Isre valley (Tarentaise) several sinkholes with loss of ephemeral streams during melting snow supply a large fissured aquifer. There is no spring with karstic features either. The water infiltrated in a sinkhole has been found in several springs during a very long period of time. Whereas the upper part of these aquifers are really like a karstic aquifer, with large stream channels, on the contrary the deeper part is like a fissured aquifer with large water dispersion and low velocity. The fissured and porous aquifer has a throttling action and explains the absence of true resurgence. The underground water flow is unbroken between the different aquifers but permeability decreases according to the depth. These phenomenon are in connection with tectonic activity and the interpenetration of the different geological formations at the bottom of the gypsum layer.

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