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Speleology in Kazakhstan

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

Speleology in Kazakhstan

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

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

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

The deepest terrestrial animal

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

Caves - landscapes without light

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

Did you know?

That liquid is an incompressible or nearly incompressible fluid.?

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Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
Engineering challenges in Karst, Stevanović, Zoran; Milanović, Petar
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Featured articles from other Geoscience Journals
Geochemical and mineralogical fingerprints to distinguish the exploited ferruginous mineralisations of Grotta della Monaca (Calabria, Italy), Dimuccio, L.A.; Rodrigues, N.; Larocca, F.; Pratas, J.; Amado, A.M.; Batista de Carvalho, L.A.
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
See all featured articles from other geoscience journals

Search in KarstBase

Your search for saturation (Keyword) returned 131 results for the whole karstbase:
Showing 121 to 131 of 131
Free-living amoebae in sediments from the Lascaux Cave in France, 2013, Garciasanchez A. M. , Ariza C. , Ubeda J. M. , Martinsanchez P. M. , Jurado V. , Bastian F. , Alabouvette C. , Saizjimenez C.

The Lascaux Cave in France is an old karstic channel where the running waters are collected in a pool and pumped to the exterior. It is well-known that water bodies in the vicinity of humans are suspected to be reservoirs of amoebae and associated bacteria. In fact, the free-living amoebae Acanthamoeba astronyxis, Acanthamoeba castellanii, Acanthamoeba sp. and Hartmannella vermiformis were identif ied in the sediments of the cave using phylogenetic analyses and morphological traits. Lascaux Cave sediments and rock walls are wet due to a relative humidity near saturation and water condensation, and this environment and the presence of abundant bacterial communities constitute an ideal habitat for amoebae. The data suggest the need to carry out a detailed survey on all the cave compartments in order to determine the relationship between amoebae and pathogenic bacteria.


Sources of water aggressiveness the driving force of karstification, 2013, Auler, A. S.

Chemically aggressive water is needed in order to promote bedrock dissolution and karstification. Aggressiveness is generated through a number of processes that include acids from the atmosphere and soil zone (epigenic acids) and from deep-seated mechanisms (hypogenic acids). Carbon dioxide and hydrogen sulfide are the main players, although additional acidity may be provided by processes that involve mixing of solutions with different degrees of saturation, temperature effects, and microbiological agents. Rainfall will generally have an acid pH due to natural CO2 and mostly anthropogenic gases such as H2S in the atmosphere. The soil zone will further boost acidity levels due to abundant CO2 production in the root and plant horizons. Although the buffering capacity of the carbonate will cause groundwater to quickly achieve saturation, mixing corrosion effects may rejuvenate aggressiveness in situations where waters of different chemistry are in contact. Bacterially mediated processes will both enhance and mediate processes of acid generation and dissolution. Mixing zones between fresh and salt water and between oxygen-rich groundwater (mostly epigenic) and rising thermal water will be important zones where increased levels of acidity will accelerate cave formation. The degree and effectiveness of aggressiveness will depend on a number of variables, such as the geological setting, solubility of the rock, position of the bedrock, and climate, sometimes operating together at various scales and strengths.


Central concepts of karst hydrology, 2013, Palmer, Arthur N.

The solutional growth of karst features involves a simple mass transfer, in which the mass removed from the walls of a void equals the mass removed in solution by flowing water. Mass removed = volume  rock density, and mass in solution = discharge  solute concentration. Therefore (e.g., in a solution conduit) the rate of volume increase = discharge  gain in dissolved load  time / rock density. Density is essentially con-stant, so conduit size depends only on the cumulative values of discharge, dissolution rate, and time. All three are essential, and all are equally important.
Discharge in a conduit depends on catchment area and water balance; and the distribu-tion of water among all solution conduits depends on hydraulic variables and conduit geometry. Dissolution rate varies with rock type, undersaturation, and solution kinetics, the last of which can be determined by laboratory and field measurements. Together, they provide a tool for quantifying the local geomorphic history.
These relationships seem simple, but applying them quantitatively is complex. This requires a finely divided 2- or 3-dimensional grid in which each segment varies in dis-charge and dissolution rate within each of many small time increments. Computer modelers use this approach to simulate conduit growh; but the results depend on the specific boundary conditions of the model.
It is more challenging to use this concept intuitively to solve real field problems, where the variables are only partly understood. In this case, one must show that the water source, dissolution rate, and available time are all great enough to account for the ob-served solution features. All three variables are closely linked by a web of interactive processes, all of which can be expressed quantitatively. Whether the goal is to under-stand what is already known, or to predict the unknown, this approach provides a solid basis for interpreting karst systems.


Isotopes of Carbon in a Karst Aquifer of the Cumberland Plateau of Kentucky, USA, 2013, Florea Lee J.

In this study, the concentration and isotopic composition of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) are measured in the karst groundwater of the Otter Creek watershed of the Cumberland Plateau of Kentucky, USA. Comparisons among these data and with the geochemistry of carbonate and gypsum equilibrium reactions reveal that DOC concentration is inversely related to discharge, multiple reaction pathways provide DIC with isotopic enrichment that may be directly related to mineral saturation, and oxidation of reduced sulfur is possible for dissolution. DOC is derived from C3 vegetation with an average δ13C DOC of ‒27‰. DIC in groundwater is derived from both pedogenic CO2  and HCO3 - from dissolved carbonate. At input sites to the karst aquifers DIC concentrations are expectedly low, less than 1 mmol/L, in waters that are undersaturated with respect to calcite. At the output of these karst aquifers DIC concentrations reach 3 mmol/L in waters that are at or above calcite saturation. Values of δ13C DIC range between ‒6.3 and ‒12.4‰ with CO2 degassing and calcite precipitation at some sites obfuscating a simple relationship between δ13C DIC, discharge, and mineral saturation. In addition, concentrations of DIC in sulfur seeps within the watershed range between 2–7 mmol/L with δ13C DIC values in some samples skewed more toward the anticipated value of carbonate bedrock than would be expected from reactions with carbonic acid alone. This suggests that the oxidation of reduced sulfur from shallow oilfield brines liberates bedrock DIC through reactions with sulfuric acid.


Influence of meteorological variables to water quality in five lakes over the Aggtelek (Hungary) and Slovak karst regions – a case study, 2013, Samu Andrea, Csépe Zoltán, Báránykevei Ilona

The main objective of this study is to analyse the effect of tendencies in the meteorological variables on the water quality on the example of five lakes in the Aggtelek and Slovak karst. The data set used eleven water quality parameters (oxygen saturation, chemical oxygen demand, nitrate, nitrite, orthophosphate, total phosphorus, ammonium, pH, conductivity, iron, manganese), as well as daily data of six climatic parameters from the period 2008­2010. A cluster analysis is performed in order to determine the climate impact on the water quality parameters. Furthermore, factor analysis with special transformation, as a novelty in the study, is implemented to find out the weight of the climate parameters as explanatory variables and hence their rank of importance in forming the given water quality parameter as an influencing variable. The study introduces a methodology for analysing the climate impact on the water quality parameters. In order to reduce the number of the water quality parameters, a so called two­stage factor analysis was performed, which is a novel procedure. Application of the two­stage factor analysis involves both benefits and disadvantages. Its benefit is that it substantially reduces the number of resultant variables. In this way, information loss of the retained factors is around 20%. As a result, we received that both positive and negative extreme values of water quality parameters can be associated with weak or breaking­up warm fronts passing through over the region. On the contrary, the role of anticyclones or anticyclone ridge weather situations is supposed to be irrelevant. Unstable and extreme weather conditions act in the direction of breaking up the balance that would support the good water quality. This process does not benefit the water use nor the sensitive karst hydrogeological system


Carbon fluxes in Karst aquifers: Sources, sinks, and the effect of storm flow, 2013, White William B.

An effective carbon loading can be calculated from measured alkalinity and pH of karst waters. The carbon loading is independent of the degree of saturation of the water and does not depend on the water being in equilibrium with the carbonate wall rock. A substantial data base of spring water analyses accumulated by students over the past 40 years has been used to probe the CO2 generation, transport, and storage in a variety of drainage basins that feed karst springs. Carbon loading in the water exiting karst drainage basins depends on the rate of CO2 generation in the soils of the catchment areas and on the partitioning between CO2 dissolved in infiltration water and CO2 lost by diffusion upward to the atmosphere. For any given drainage basin there are also influences due to vegetative cover, soil type, and the fraction of the water provided by sinking stream recharge. Losses of CO2 back to the atmosphere occur by speleothem deposition in air-filled caves, by degassing of CO2 in spring runs, and by tufa deposition in spring runs. There are seasonal cycles of CO2 generation that relate growing season and contrasts in winter/summer rates of CO2 generation. Overall, it appears that karst aquifers are a net, but leaky, sink for atmospheric CO2


Temporal variability of karst aquifer response time established by the sliding-windows cross-correlation method, 2013, Delbarta Célestine, Valdesd Danièle, Barbecotg Florent, Tognellia Antoine, Richona Patrick, Couchouxh Laurent

We study the temporal variability of water transfer through the infiltration zone of a karst aquifer by estimating the impulse response of the system using cross-correlogram analyses between rainfall and piezometric level time series. We apply a sliding-window cross-correlation method, which calculates cross-correlograms on partially superposed short time series windows. We apply this method for rainfall and piezometric level time series at six boreholes in a fractured karstic aquifer located in Burgundy, France. Based on cross-correlogram functions, we obtain a time series of response time. At most of the boreholes, the cross-correlation functions change over time, and the response times vary seasonally, being shorter during the summer. This unusual structure can be partly explained by the seasonal variability in rainfall intensity, which is higher during the summer (May–September), inducing the seasonal behaviour of the epikarst. During the summer, when rainfall intensity is higher, the epikarst is more easily and quickly saturated. This induces an increase in lateral water transfer within the epikarst and an increase in concentrated fast flows. We also show that the response time seems to tend towards a limit which represents the maximum saturation of the epikarst.


Permeability evolution due to dissolution and precipitation of carbonates using reactive transport modeling in pore networks, 2013, Nogues J. P. , Fitts J. P. , Celia M. A. , Peters C. A.

A reactive transport model was developed to simulate reaction of carbonates within a pore network for the high-pressure CO2-acidified conditions relevant to geological carbon sequestration. The pore network was based on a synthetic oolithic dolostone. Simulation results produced insights that can inform continuum-scale models regarding reaction induced changes in permeability and porosity. As expected, permeability increased extensively with dissolution caused by high concentrations of carbonic acid, but neither pH nor calcite saturation state alone was a good predictor of the effects, as may sometimes be the case. Complex temporal evolutions of interstitial brine chemistry and network structure led to the counterintuitive finding that a far-from-equilibrium solution produced less permeability change than a nearer-to-equilibrium solution at the same pH. This was explained by the pH buffering that increased carbonate ion concentration and inhibited further reaction. Simulations of different flow conditions produced a nonunique set of permeability-porosity relationships. Diffusive-dominated systems caused dissolution to be localized near the inlet, leading to substantial porosity change but relatively small permeability change. For the same extent of porosity change caused from advective transport, the domain changed uniformly, leading to a large permeability change. Regarding precipitation, permeability changes happen much slower compared to dissolution-induced changes and small amounts of precipitation, even if located only near the inlet, can lead to large changes in permeability. Exponent values for a power law that relates changes in permeability and porosity ranged from 2 to 10, but a value of 6 held constant when conditions led to uniform changes throughout the domain


Fingerprinting water-rock interaction in hypogene speleogenesis: potential and limitations of isotopic depth-profiling, 2014, Spötl Ch, Dublyansky Y.

Dissolution processes in karst regions commonly involve (meteoric) water whose stable isotopic (O, H, C) composition is distinctly different from that of the paleowaters from which the host rock (limestone, dolostone) formed. This, in theory, should lead to isotopic alteration of the host rock beyond the active solution surface as the modern karst water is out of isotopic equilibrium with the carbonate rock. No such alteration has been reported, however, in epigenetic karst systems. In contrast, isotopic alteration, commonly referred to as isotopic halos or fronts, are known from various hypogene systems (ore deposits, active hydro­thermal systems, etc.). These empirical observations suggest that stable isotope data may be a diagnostic tool to identify hypogene water-rock interactions particularly in cave systems whose origin is ambiguous.

We have been testing the applicability of this assumption to karst settings by studying the isotopic composition of carbonate host rocks in a variety of caves showing clear-cut hypogene morphologies. Cores drilled into the walls of cave chambers and galleries were stud­ied petrographically and the C and O isotope composition was analyzed along these cores, which typically reached a depth of 0.5 to 1.2 m. We identified three scenarios: (a) no isotopic alteration, (b) a sigmoidal isotope front within a few centimeters of the cave wall, and (c) pervasive isotope alteration throughout the entire core length. Type (a) was found in caves where the rate of cave wall retreat apparently outpaced the rate of isotopic alteration of the wall rock (which is typical, for example, for sulfuric acid speleogenesis). Type (c) was observed in geologically young, porous limestone showing evidence of alteration zones up to 5 m wide. The intermediate type (b) was identified in hypogene karst cavities developed in tight limestone, dolostone and marble.

Our data in conjunction with evidence from speleothems and their geochemical and fluid-inclusion composition suggest that the spa­tial extent of the isotopic alteration front depends on the porosity and permeability, as well as on the saturation state of the water. Wider alteration zones primarily reflect a higher permeability. Shifts are most distinct for oxygen isotopes and less so for carbon, whereby the amplitude depends on a number of variables, including the isotopic composition of unaltered host rock, the isotopic composition of the paleofluid, the temperature, the water/rock ratio, the surface of water-rock contact, the permeability of the rock, and the time available for isotope exchange. If the other parameters can be reasonably constrained, then semi-quantitative temperature estimates of the paleowater can be obtained assuming isotopic equilibrium conditions.

If preserved (scenarios b and c), alteration fronts are a strong evidence of hypogene speleogenesis, and, in conjunction with hypogene precipitates, allow to fingerprint the isotopic and physical parameters of the altering paleofluid. The reverse conclusion is not valid, however; i.e. the lack of evidence of isotopic alteration of the cave wall rock cannot be used to rule out hypogene paleo-water-rock interaction.


Vadose CO2 gas drives dissolution at water tables in eogenetic karst aquifers more than mixing dissolution, 2014, Gulley J. , Martin J. , Moore P.

Most models of cave formation in limestone that remains near its depositional environment and has not been deeply buried (i.e. eogenetic limestone) invoke dissolution from mixing of waters that have different ionic strengths or have equilibrated with calcite at different pCO2 values. In eogenetic karst aquifers lacking saline water, mixing of vadose and phreatic waters is thought to form caves. We show here calcite dissolution in a cave in eogenetic limestone occurred due to increases in vadose CO2 gas concentrations and subsequent dissolution of CO2 into groundwater, not by mixing dissolution. We collected high-resolution time series measurements (1 year) of specific conductivity (SpC), temperature, meteorological data, and synoptic water chemical composition from a water table cave in central Florida (Briar Cave).We found SpC, pCO2 and calcite undersaturation increased through late summer, when Briar Cave experienced little ventilation by outside air, and decreased through winter, when increased ventilation lowered cave CO2(g) concentrations.We hypothesize dissolution occurred when water flowed from aquifer regions with low pCO2 into the cave, which had elevated pCO2. Elevated pCO2 would be promoted by fractures connecting the soil to the water table. Simple geochemical models demonstrate that changes in pCO2 of less than 1% along flow paths are an order of magnitude more efficient at dissolving limestone thanmixing of vadose and phreatic water.We conclude that spatially or temporally variable vadose CO2(g) concentrations are responsible for cave formation becausemixing is too slow to generate observed cave sizes in the time available for formation. While this study emphasized dissolution, gas exchange between the atmosphere and karst aquifer vadose zones that is facilitated by conduits likely exerts important controls on other geochemical processes in limestone critical zones by transporting oxygen deep into vadose zones, creating redox boundaries that would not exist in the absence of caves.


Chemistry and Karst, 2015, White, William B.

The processes of initiation and development of characteris­tic surface karst landforms and underground caves are nearly all chemical processes. This paper reviews the advances in understanding of karst chemistry over the past 60 years. The equilibrium chemistry of carbonate and sulfate dissolution and deposition is well established with accurate values for the necessary constants. The equations for bulk kinetics are known well enough for accurate modeling of speleogenetic processes but much is being learned about atomic scale mechanisms. The chemistry of karst waters, expressed as parameters such as total dissolved carbonates, saturation index, and equilibrium carbon dioxide pressure are useful tools for probing the internal char­acteristics of karst aquifers. Continuous records of chemical parameters (chemographs) taken from springs and other karst waters mapped onto discharge hydrographs reveal details of the internal flow system. The chemistry of speleothem deposi­tion is well understood at the level of bulk processes but much has been learned of the surface chemistry on an atomic scale by use of the atomic force microscope. Least well understood is the chemistry of hypogenetic karst. The main chemical reac­tions are known but equilibrium modeling could be improved and reaction kinetics are largely unknown.


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