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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 resequent river is a river flowing according to a consequent drainage pattern but at a lower level than the original slope [16].?

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

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KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
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;
See all featured articles from other geoscience journals

Search in KarstBase

Your search for saturated zone (Keyword) returned 86 results for the whole karstbase:
Showing 1 to 15 of 86
Significance and origin of very large regulating power of some karst aquifers in the Middle East. Implication on karst aquifer classification, , Elhakim M, Bakalowicz M,
SummaryKarst aquifers are the main groundwater resource in Lebanon as well as in most Mediterranean countries. Most of them are not exploited in a sustainable way, partly because their characteristics remain unknown. Karst aquifers are so complex that the assessment of their resource and their exploitable storage requires an analysis of their whole functioning, particularly by analysing the spring hydrograph. Among all various methods, the method proposed by Mangin aims to characterize at the same time the recharge conditions and the storage and recession of the saturated zone by analyzing the spring hydrograph. This method defines two parameters, the infiltration delay i, and the regulating power k which are the roots of a classification of karst systems. This classification makes the distinction between karst and porous aquifers considering the value of the regulating power. k is assumed to be lower than 0.5 in karst, and between 0.5 and 1 for all other aquifers, 1 being the upper limit.The study of karst aquifers in Lebanon shows values of k > 0.5, and even 1; former data from the literature show that other karst springs in Middle East have comparable characteristics. In fact, what is not considered by Mangin and others, k is equivalent to a mean residence time in years of water in the saturated zone. So long residence times are normally observed in poorly karstified aquifers, or containing abandoned, not functioning karstification. The geological framework in which the studied springs are located in fact shows that these aquifers have been subject to a long, complex evolution, as a consequence of the base level rising. This rising produced the flooding of the successive karst drainage network, which does not really function anymore and provides a large storage capacity to the aquifer. The very interesting properties of these aquifers make them prime targets for fulfilling the increasing needs of water

Anomalous behaviour of specific electrical conductivity at a karst spring induced by variable catchment boundaries: the case of the Podstenjšek spring, Slovenia, , Ravbar, N. , Engelhardt, I. , Goldscheider, N.

Anomalous behaviour of specific electrical conductivity (SEC) was observed at a karst spring in Slovenia during 26 high-flow events in an 18-month monitoring period. A conceptual model explaining this anomalous SEC variability is presented and reproduced by numerical modelling, and the practical relevance for source protection zoning is discussed. After storm rainfall, discharge increases rapidly, which is typical for karst springs. SEC displays a first maximum during the rising limb of the spring hydrograph, followed by a minimum indicating the arrival of freshly infiltrated water, often confirmed by increased levels of total organic carbon (TOC). The anomalous behaviour starts after this SEC minimum, when SEC rises again and remains elevated during the entire high-flow period, typically 20–40 µS/cm above the baseflow value. This is explained by variable catchment boundaries: When the water level in the aquifer rises, the catchment expands, incorporating zones of groundwater with higher SEC, caused by higher unsaturated zone thickness and subtle lithologic changes. This conceptual model has been checked by numerical investigations. A generalized finite-difference model including high-conductivity cells representing the conduit network (“discrete-continuum approach”) was set up to simulate the observed behaviour of the karst system. The model reproduces the shifting groundwater divide and the nearly simultaneous increase of discharge and SEC during high-flow periods. The observed behaviour is relevant for groundwater source protection zoning, which requires reliable delineation of catchment areas. Anomalous behaviour of SEC can point to variable catchment boundaries that can be checked by tracer tests during different hydrologic conditions.

Carbon dioxide in the atmosphere of the unsaturated zone: an important control of groundwater hardness in limestones, 1977, Atkinson T. C.

Water movement and storage in the unsaturated zone of a maturely karstified carbonate aquifer, Mendip Hills, England,, 1987, Smart P. L. , Friederich H.

Le karst de Vaucluse (Haute Provence), 1991, Mudry J. , Puig J. M.
The catchment area of the Fontaine de Vaucluse system is more than 1100km2 wide, with an average altitude of 870m. The thickness of the Lower Cretaceous limestone (1500m) gives the system a very thick (800m) unsaturated zone. Karstification is highly developed (four shafts are more than 500m deep) as well as on the valley (pit of 300m depth inside the spring). The bottom of the shafts of the Plateau does not reach the saturated zone of the karst, as their flows are the chemical content of the seepage water. The maximum hydraulic gradient from the Plateau to the spring is low, only 0.3%. Dye tracings permit the assignment of the Ventoux-Lure rang (including its calcareous northern slope with a southward dipping) and the Vaucluse Plateau in the catchment area. The water balance computed by altitude belts shows that the rainfall strongly increases with altitude: 120mm at 200m, 1380mm over 1800m. The dynamic of the system, studied by discharge and physical and chemical content, shows of a well karstified media, that reacts with slight inertia upon the rainy periods, and that is made up of important reserves, particularly within the unsaturated zone, that supply long decline and depletion episodes.

Limestone caves form along ground-water paths of greatest discharge and solutional aggressiveness. Flow routes that acquire increasing discharge accelerate in growth, while others languish with negligible growth. As discharge increases, a maximum rate of wall retreat is approached, typically about 0.01-0.1 cm/yr, determined by chemical kinetics but nearly unaffected by further increase in discharge. The time required to reach the maximum rate is nearly independent of kinetics and varies directly with flow distance and temperature and inversely with initial fracture width, discharge, gradient, and P(CO2). Most caves require 10(4) - 10(5) yr to reach traversable size. Their patterns depend on the mode of ground-water recharge. Sinkhole recharge forms branching caves with tributaries that join downstream as higher-order passages. Maze caves form where (1) steep gradients and great undersaturation allow many alternate paths to enlarge at similar rates or (2) discharge or renewal of undersaturation is uniform along many alternate routes. Flood water can form angular networks in fractured rock, anastomotic mazes along low-angle partings, or spongework where intergranular pores are dominant. Diffuse recharge also forms networks and spongework, often aided by mixing of chemically different waters. Ramiform caves, with sequential outward branches, are formed mainly by rising thermal or H2S-rich water. Dissolution rates in cooling water increase with discharge, CO2 content, temperature, and thermal gradient, but only at thermal gradients of more than 0.01-degrees-C/m can normal ground-water CO2 form caves without the aid of hypogenic acids or mixing. Artesian flow has no inherent tendency to form maze caves. Geologic structure and stratigraphy influence cave orientation and extent, but alone they do not determine branch-work versus maze character

Symposium Abstract: Tracing of waterflow in the unsaturated zone above White Scar Cave [Yorkshire], 1992, Bottrell S. H. , Atkinson T. C.

The karst aquifer of the well-known Fontaine de Vaucluse has been recently studied, results have been got about delimitation of the system and its working. Geological data (lithology and structure) have allowed to delimit an 1115 Km2 intake area including Ventoux-Lure north facing range (1,909-1,826 m) and the Plateau which is prolonging it southwards (Fig. 1 and 2). The average altitude of the whole area, obtained by balancing elevation belt surfaces, is about 870 m. This elevation squares with results of tracing tests (Fig. 3), environmental physical, chemical and isotopic tracings, that allow to value a 850 m average altitude for the intake area (Fig. 4). The moisture balance has been computed from an altitude belts climatic model, using local rain an temperature gradients (Fig. 5 and Table II), because the weather network is not representative. So, rainfalls rise of about 55 mm per 100 m elevation and temperature decreases of about 0.5-degrees-C per 100 m. The consequence of these two antagonist phenomena is the quasi constant value of actual evapotranspiration on each altitude belt. With the Fig. 7 organigram, curves of effective rainfalls and infiltration coefficient versus elevation can be plotted (Fig. 6). This computation shows that 3/4 of the total and the whole of dry season effective rainfalls are provided by the part of the intake area situated above the average altitude: on the lowest belt, effective rainfalls are only 120 mm per year and increase to 1380 mm on the upper section (Fig. 8 and Table 1). The weighted effective rainfalls are about 570 mm per year for the whole intake area. Hydrodynamical and physico-chemical studies show, despite its large size, the weak inertia of the system, so proves its good karstification, that confirms for the whole system the pin-point speleological observations. The discharge of the spring, which average value is 21 m3.s-1 (only 18 for the last ten years), can exceed 100 m3.s-1 and the minimum has never been lower than 3.7 m3.s-1 (Fig. 9). When it rains on the intake area, the increase of the discharge is very sudden in a rainy period : one to four days. This short delay is due to seepage through epikarst and unsaturated zone. During dry periods, the spring reaction is deadened, due to storage in the unsaturated zone. The silica content distribution was plotted during several hydrokinematical phases (Fig. 10). It shows: an almost unimodal distribution for the 8 km2 fissured limestone aquifer of Groseau; a multimodal one for the 1115 km2 karst aquifer of Fontaine de Vaucluse. This proves that karstification is more important than size in the response of the system. Weak summer rainfalls do not influence the discharge, nevertheless they influence chemistry of the spring water, and so interrupts the water depletion phasis. Then, the decrease of discharge can continue after the end of the chemical depletion phasis, water which is overflowing after summer rainfalls (in a dry period) is influenced hy the chemistry of seepage water : on the graph of a principal components analysis, done on chemical variables. an hysteresis phenomenon can be seen (Fig. 11). A discriminant analysis (Fig. 12) confirms that these autumn waters, with high ratio seepage tracers, are not reserve waters from the saturated zone. The ratio of reserve water in the total discharge, is preponderant: 3/4 and 2/3 respectively of the yearly runoff volumes for 1981 and 1982 (Fig. 13), but an important part of these reserves can be stored in the unsaturated zone. This storage capacity can be valued by different means: transposing to Vaucluse (1115 km2) the volume measured on another karst system in the Pyrenees (13 km2); it gives about 100 million m2; using setting parameters of Bezes model (1976) on the same aquifer: it gives 113 million m3; using depletion curves, that show, for instance during the 1989 summer and autumn dry period, a 80 million m3 volume. In all cases, we get a value of about one hundred million m3 for the storage capacity of the unsaturated zone. With a 20 m range of fluctuation for the water table and with a 10(-2) specific yield, on a 500 to 1,000 km2 saturated zone, the zone of fluctuation can release about 10 to 20 million m3. Then, the volume of water stored in the whole saturated zone, with a 300 m minimum thickness (depth of the waterlogged pit of the Fontaine), a 500 km2 minimum surface and a 10(-3) specific yield, is about 150 million m3, including 27 million m3 stored in the channels. So, the unsaturated zone represents a significant part of the whole storage capacity and most of the yearly renewable reserves. Paradoxically, the biggest french spring is not tapped at all; as its intake area is neither a regional nor a national park, no general protection covers it : because of its good karstification, the vulnerability of the system is important. Good quality of water is attributable to the low population and human activities density on the intake area (4 inh.km-2). A great part of the intake area is uncultivated (large forest and ''garrigues'' areas). Due to the lack of surface water and scantness of soils, agriculture is not intensive (lavender, thyme, sage and bulk wheat fields. meadowlands). On the mountainous zone, roads are salted in winter and snowmelt water can reach a significantly high chloride ratio than in a natural climatic functioning (for instance 25 mg.l-1 in Font d'Angiou where the ratio would have been 3 mg.l-1). As tourism is developing both on the mountain and on the plateau, the management of the highest intake area must be carefully held: its part is preponderant in the feeding of the system

Stone forest aquifers are the most widely exploited sources for ground water in the vast south China karst belt. These aquifers occupy a thin epikarst zone that has been infilled with clastic sediments. The aquifers are characterized by large lateral permeabilities and small reservoir capacities owing to their thinness. The carbonate rocks which comprise the framework for the aquifers are usually buried under the karst plains and large karst depressions where development is desired. The stone forest aquifer exploration procedure must first locate saturated zones. Second, those parts of the saturated zone having the greatest dissolution porosity must be identified because the infilled dissolution voids contain the water. The best indicators of saturation include the combination of low topography and the presence of active karst features such as springs, karst windows (natural openings exposing the water table), and live surface streams. These elements are readily observed on intermediate scale (1:20,000) aerial photography. The depth and degree of carbonate dissolution porosity is a function of several geologic and hydrologic factors including carbonate rock type, carbonate purity, fracture density, specific discharge, age of the circulation system, etc. These variables cannot be measured directly because the carbonate rocks are usually buried under a thin mantle of clastic sediments. However, if it is recognized that the ground-water system has already exploited the most favorable geology and that dissolution is an ongoing process, a simple indirect method can be used to identify the areas having the greatest porosity. The presence of karst depressions and recent sinkholes are indicative of the most intensely karstified and hydraulically active parts of the epikarst zone. Mapping of these surface features from stereo aerial photography is a simple geomorphology exercise that can be used to directly identify the most favorable well sites. Current well construction practices in the south China karst belt involve both dug and drilled wells. Dug wells are preferred in many locations owing to both cost-effectiveness associated with cheap labor and lack of available drilling equipment. The dug wells look and function identically to karst windows and thus conform to timeless water use traditions in the region

Isotopic investigation of infiltration and unsaturated zone processes at Carlsbad Cavern, 1992, Chapman J. A. , Ingraham N. L. , Hess J. W.

Tracer study and storage in the unsaturated zone of a karstic limestone aquifer, 1992, Bottrell S. H. , Atkinson T. C.

Analyse des conditions de dveloppement de la karstification profonde, 1994, Fourneaux, J. C.
Karstification is a dissolving process which enlarges some channels clefts and fractures and eventually creates caves. The phenomenon Is only possible in deep areas located under the base level, if water flows easily. The analysis of the physical and chemical data accumulated at the beginning of the flood shows hotter and more mineralised waters once the flow starts accelerating. The hydrodynamic study of the phenomenon allows to build a model that explains the deep karstification process. The deep karstification process occurs when a very heterogenous distribution of pressures briefly takes place in the aquiferous system at the beginning of the recharge. This is due to the fact that the waters reach the karstic conduits at different times and therefore the refill and the eviction of waters do not occur uniformly in the saturated zone. Actually, the very mineralised waters located under the base level in the caves, conduits and other holes are evicted first. Then, these waters are replaced by aggressive waters, which are often with a high C02 concentration. As a result, the limestones dissolution process starts again in the area under the outlet point and the splits and bed ding joints keep on enlarging. The heterogeneous distribution of pressures also opens new splits through a corner effect and leads to the development in depth of the karstification process.

Evaluation of recession hydrographs, from four karst springs in Europe, provides important information concerning the flow process operating in karst aquifer systems. Three analytic equations are used to evaluate the hydrographs: Mangin's equation, that assumes the recession is composed of both quickflow and baseflow; Coutagne's equation which considers the recession to be the response of a single reservoir; and a new function, H(t) (which is derived from Coutagne's equation), that refers to the whole recession curve. Using Mangin's equation it is apparent that the saturated zone and thus baseflow exerts nearly complete control over the discharge of La Villa spring and is fairly important at Fuente Mayor and Baget springs, but is much less significant at Aliou spring. The saturated zone accounts for 100%, 90%, 91%, and 40% respectively for these springs. Using Coutagne's equation and H(t) it is concluded that for Aliou and Baget springs, water flows freely in the high transmissive zones, but in the poorly transmissive zones, there is little continuity of connection in the system. At Fuente Mayor spring the differences in these zones are not so apparent and a gradual transition occurs. However, at La Villa spring, the karst aquifer is evidently much more homogeneous and the discharge is similar to that of a porous intergranular aquifer

Karstification is a slow geodynamical process, controlled by the interaction between dissolution kinetics and flow dynamics. Moreover, mechanisms of network clogging by calcite precipitation or non-soluble clay accumulation are slow and continuous phenomena. This evolution of a karst system can be widely modified during exceptional rainfall episodes, such as the 22/09/92 storm (> 300 mm) near Vaison-la-Romaine. Such an impulse can modify the hydraulical behaviour of a massif, by unclogging the outlets of the saturated zone or the drainage network of the aquifer, and change hydrodynamical features of a spring (storage capacity etc.). This phenomenon has been demonstrated in a north Vaucluse karst aquifer whose recession coefficient has increased 7-fold and stored volume divided by 6

Paleoclimate implications of mass spectrometric dating of a British flowstone, 1995, Baker A, Smart Pl, Edwards Rl,
The timing of growth phases in a cave flowstone from Yorkshire, England, has been precisely dated by thermal ionization mass spectrometric 238 U- 234 U- 230 Th dating. Six growth periods of both short duration and fast growth rate are separated by nondepositional hiatuses. The ages of these phases were determined to be 128.8 or -2.7, 103.1 or -1.8, 84.7 or -1.2, 57.9 or -1.5, 49.6 or -1.3, and 36.9 or -0.8 ka. There is a remarkably good correlation between the periods of active speleothem growth and the timing of solar insolation maxima, derived from orbital parameters, which has not previously been reported. Speleothem growth theory and evidence from other terrestrial paleoclimate records suggest that episodic, rapid growth phases at the insolation maxima are most likely to be caused by changes in either precipitation intensity or volume, which caused switching in the routing of water flow in the unsaturated zone above the cave. Such a result provides new evidence of the importance of variations in solar insolation for terrestrial paleoclimate and offers the potential for derivation of a paleowetness index from speleothem growth

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