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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 vertical cave is a vertical passage within a cave system, formed along joints by which underground watercourses are transferred from a higher to a lower bedding plane [19]. they may become transformed into vertical shafts by sufficiently uniform dissolution as to create a rounded vertical passage. see also fissure cave; vertical shaft.?

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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 width (Keyword) returned 106 results for the whole karstbase:
Showing 16 to 30 of 106
Early evolution of karst aquifers in limestone: Models on two-dimensional percolation clusters, 1997, Dreybrodt W. , Siemers J.
Two-dimensional nets of initial fractures are constructed on a square-lattice by occupying the lines between nearest neighbour sites by a water leading fissure of width a"SUBo" and length l with an occupation probability p. For p > 0.5 percolating nets occur which lead water. To simulate cave genesis we calculate the water flow rates driven by the hydraulic head h through all fissures. By employing nonlinear dissolution rates of the type F=k"SUBn"(l-c/c"SUBeq")'"SUPn" the widening of the fractures is obtained. At the onset of karstification flow is evenly distributed on all fractures. As the system develops solutional widing creates preferred pathways, which attract more and more flow, until at breakthrough both widening and flow increase dramatically. We discuss the evolution of karst aquifers for natural conditions and also upon human impact at dam sites where steep hydraulic gradients may generate water leading conduits below the dam in times comparable to the lifetime of the structure.

Chemical deposits in volcanic caves of Argentina., 1998, Benedetto Carlos, Forti Paolo, Galli Ermanno, Rossi Antonio
During the last Conference of the FEALC (Speleological Federation of Latin America and Caribbean Islands) which was held in the town of Malargue, Mendoza, in February 1997, two volcanic caves not far from that town were visited and sampled for cave mineral studies. The first cave (Cueva del Tigre) opens close to the Llancanelo lake, some 40 kms far from Malargue and it is a classical lava tube. Part of the walls and of the fallen lava blocks are covered by white translucent fibres and grains. The second visited cave is a small tectonic cavity opened on a lava bed some 100 km southward of Malargue. The cave "El Abrigo de el Manzano" is long no more than 10-12 meters with an average width of 3 meters and it hosts several bird nests, the larger of which is characterized by the presence of a relatively thick pale yellow, pale pink flowstone. Small broken or fallen samples of the secondary chemical deposits of both these caves have been collected in order to detect their mineralogical composition. In the present paper the results of the detailed mineralogical analyses carried out on the sampled material are shortly reported. In the Cueva del Tigre lava tube the main detected minerals are Sylvite, Thenardite, Bloedite and Kieserite, all related to the peculiar dry climate of that area. The flowstone of "El Abrigo de el Manzano" consists of a rather complex admixture of several minerals, the large majority of which are phosphates but also sulfates and silicates, not all yet identified. The origin of all these minerals is related to the interaction between bird guano and volcanic rock.

An example of identifying karst groundwater flow, 1998, Stevanovic Z. , Dragisic V. ,
Hydrogeological investigations for the purpose of regulating the karst aquifer were carried out in the mountain massif of Kucaj in the Carpatho-Balkan range of eastern Serbia. Different geo-physical methods were applied in order to identify the position of karstified zones with active circulation of karst underground streams. Especially good results were obtained by using the spontaneous potential method for the exploration and construction of boreholes and wells. In the valleys of Crni Timok and Radovanska reka the measurements have been carried out upstream along the whole width of the alluvium to the limestone periphery. A number of positive and negative anomalies have been recorded. In the centres of positive anomalies several boreholes were located: HG-19 (centre of anomaly 30 mV, total length of the biggest cavern is 9 m); HG-1 ( mV, cavern of 2m); HG-15 (max, ? mV, effective cavernousness is 17%)

Ancient helictites and the formation of vadose crystal silt in upper Jurassic carbonates (Southern Germany), 1998, Reinhold C. ,
Speleothems and vadose crystal silt are effective indications for karstification processes in the fossil record. Upper Jurassic limestones in Southern Germany that have undergone vadose diagenesis contain on crystal margins and tips of coarse bladed calcites numerous fibrous calcite crystals, formed by abnormal growth conditions, and internal sediment within fractures and vugs, Fibrous calcite crystals grew as crusts, in fence and mesh-like arrangements. Fibrous crystals, which have a length:width ratio of greater than 1:10, are made up of stacked subcrystals composed of an alternation of hexagonal prisms and rhombohedra, They exhibit a central to somewhat eccentric capillary. Electron probe microanalysis shows low-Mg calcite mineralogy with negligible amounts of Fe, Mn, and Sr as well as dis seminated clay and metal hydroxide impurities. Stable-isotope data show relatively C-13-enriched and O-18-depleted values (delta(13)C similar to parts per thousand PDB, delta(18)O similar to -6 parts per thousand PDB), suggesting a meteoric environment and CO2 degassing as the main process of formation, Fibrous calcite crystals form from capillary fluids that are highly supersaturated with respect to calcium carbonate, contaminated with alien mineral impurities. The abnormal growth pattern is suggested to be substrate-controlled and attributed to mineral impurities that produce numerous crystallization nuclei. Fibrous calcite crystals are comparable to helictites of the filiform type that are reported only from Quaternary caves. Nevertheless, the diagenetic sequence and oxygen isotope data suggest a Late Cretaceous to early Tertiary age for their formation. The internal sediment consists exclusively of silt-size fragments of fibrous crystals and therefore is comparable to vadose crystal silt. Crystal silt is generated by the erosion of fibrous crystals both by va dose seepage and air currents. This study is the first observation of ancient helictites and related vadose crystal silt, documenting the close relationship between pore ceiling vadose cements and the generation of crystal silt

Salt cave cross sections and their paleoenvironmental implications, 1998, Frumkin, A.
Salt caves respond rapidly to environmental changes. Direct measurement and 14C dating show that complex cross sections may develop in a few hundred years. Two basic forms are discussed: (1) ingrowing vadose canyons where changing width may correspond to changing discharge; (2) wide low passages with flat ceiling, developed by upward dissolution, which may indicate rising base level. Some cross sections are deformed by Holocene tectonics.

A 3000-year high-resolution stalagmitebased record of palaeoclimate for northeastern South Africa, 1999, Holmgren K. , Karlen W. , Lauritzen S. E. , Leethorp J. A. , Partridge T. C. , Piketh S. , Repinski P. , Stevenson C. , Svanered O. , Tyson P. D. ,
High-resolution stable isotope variations and growth structure analyses of the last three millennia of a 6600-year stalagmite record at Cold Air Cave, Makapansgat Valley, South Africa, are presented. Growth layers, which are measurable over the last 250 years, are shown to be annual. The correlation between the width of growth layers and precipitation is strongly positive. Changes in{delta}18O and{delta}13C are positively correlated and inversely correlated to changes in the colour of the growth layers in the stalagmite. Variations in colour are directly correlated with mean annual temperature. Dark colouration is the product of increased temperature and mobilization of organic matter from the soil, and is associated with wetter summers and enhanced growth of C4 grasses. Darker colouring and enriched{delta}18O and{delta}13C reflect a warmer, wetter environment, whereas lighter colouring and depleted isotopic values are indicative of cooler, drier conditions. The dominant episode in the 3000-year record is the cool, dry 500-year manifestation of the Little Ice Age', from ad 1300 to about 1800, with the lowest temperatures at around ad 1700. The four centuries from ad 900 to 1300, experiencing above-average warming and high variability, may be the regional expression of the medieval warming. Other cool, dry spells prevailed from around ad 800 to 900 and from about ad 440 to 520. The most prolonged warm, wet period occurred from ad 40 to 400. Some extreme events are shown to correspond well with similar events determined from the Greenland GISP2 ice-core record and elsewhere. Distinct periodicities occur within the record at around 120, 200-300, 500-600 and at about 800 years BP

Karst landforms on the eastern slopes of Davras Dagi (western Taurus): karren, sinkholes and uvalas, 1999, Dayan E, Bilgin A, Hancer M,
A characteristic of the study area is the low frequency of gully and rill karren. By length, width and depth they are not comparable with the same type of karren in the alpine karst, as they have attained only insignificant dimensions. This difference in size cannot primarily be attributed to differences of annual precipitation, but rather to the fact that they are only 2-3000 years old. Their formation started with anthropogenic forest destruction and concomitant soil stripping. As gully and rill karren depend on bare rock surfaces for their formation, they cannot have formed before that time. Joint-oriented and cavernous karren, in conrast, are widely spread in the study area. As the formation of these two types of karren is related to the existence of joints, their frequency is explained by severe fracturing of the limestone during recent tectonic movements. Although cavernous karren may also form on bare rock surfaces, Lest conditions for their development exist underneath a soil cover. As this no longer exists, the formation of cavernous karren has become much reduced in the historical era. Sinkholes are frequent in the planation surfaces of Mid- to Upper Miocene age and are of Pliocene and Pleistocene age. The uvalas are also not very old, as many of them contain terra rossa

Comparative study of a stalagmite sample by stratigraphy, laser induced fluorescence spectroscopy, EPR spectrometry and reflectance imaging, 2000, Perrette Yves, Delannoy Jean Jacques, Bolvin Herve, Cordonnier Michel, Destombes Jean Luc, Zhilinskaya Elena A. , Aboukais Antoine,
In the last few years, it has been shown that multi-proxy data are recorded in speleothems and that these secondary deposits can be used to retrieve records of environmental evolution in extra-glacial continental conditions. The goal of many current research is to obtain a better understanding of the processes leading to the growth of these chemical sediments and to relate them to changes in environmental conditions. In the present research, the multi-proxy study of a well-laminated speleothem sample points out the interest of reflectance trend measurement as a water excess indicator. Results from stratigraphy, laser induced fluorescence spectroscopy, EPR spectrometry and reflectance imaging have been combined in order to get a better understanding of the environmental conditions pertaining during speleothem growth. Several parameters have been measured: (i) Mn2 concentration evolution (shown to be linked to soil processes); (ii) linewidth [Delta]H of the low field Mn2 EPR line (linked to crystalline properties of the speleothem); (iii) intensities of the laser excited fluorescence (linked to organic matter content of calcite) and reflectance (linked to calcite porosity); (iv) wavelength [lambda]peak of the intensity maximum of laser excited fluorescence bands (linked to the size of trapped organic molecules). Other data resulting from statistical treatment of the annual fluorescence cycles have also been used. Significant correlations demonstrate the covariation of [lambda]peak and calcite reflectance with the hydrological regime of the cave. In the well drained soils of a karstic area, Mn2 and [lambda]peak appear to be accurate proxies for soil moisture evolution, directly linked to the water excess. These results are confirmed by the comparison with historical knowledge of environmental changes of the surrounding plateau

Field assessment of the microclimatology of tropical flank margin caves, 2000, Gamble Dw, Dogwiler Jt, Mylroie J,
Temperature observations were collected inside 2 caves in the Bahamas and 1 cave in Puerto Rico to characterize the microclimatology of tropical flank margin cave systems. Three aspects of these tropical cave temperatures agree with temperate cave microclimate theory. Specifically, external atmospheric disturbances can affect temperatures inside tropical flank margin cave systems, tropical flank margin caves are warmer than the exterior temperatures during winter, and water can impact temperatures deep into a tropical flank margin cave system. The temperature observations collected also indicate potential differences between the microclimatology of tropical and temperate cave systems. In particular, the temperate 3-zone cave microclimate model may not be applicable to tropical flank margin caves, diurnal fluctuations were not apparent in tropical flank margin cave systems, and the existence of a temperature inversion in a down-sloping cave may not be applicable to all tropical flank margin caves. The potential differences in temperate and these tropical cave systems can be linked to the physical dimensions of the tropical flank margin cave systems and the unique hydrology of small carbonate islands. Specifically, tropical flank margin caves have a width greater than length while temperate fluvio-karst caves have a length greater than width and tidal water can exist in the pits and depressions of tropical flank margin caves as opposed to flowing streams in temperate cave systems

A model of early evolution of karst conduits affected by subterranean CO2 sources, 2000, Gabrovsek F, Menne B, Dreybrodt W,
In investigating early karstification of one-dimensional conduits by computer models, so far one has assumed that the CO2 content of the calcite aggressive water stems entirely from the surface. Subterranean sources of CO2, however, can rejuvenate the solutional power of water already close to equilibrium with respect to calcite, and boast dissolution rates. In a first scenario we have investigated the influence of a punctual source of CO2 as the most simple case of release of CO2 into a karstifiable fracture at some position KL from its entrance of the widening joint with length L, (K < 1). The results show that only a small increase of the p(CO2) in the solution to about 0.01 atm is sufficient to reduce the breakthrough times to about 0.3 with respect to the case, where no CO2 is delivered. Other sources of CO2 are due to the metabolic activity of microorganisms. The existence of such diverse subterraneous microbial life in karst systems demonstrated. Whether situated on the fissure surfaces or free floating in the karst water, one basic product of their metabolism is CO2. This contributes over the whole flow path to the p(CO2) of the karst water. Therefore in a second scenario we assumed a constant rate of CO2-input along parts of the fracture, as could be delivered by the activity of aerobic bacteria dwelling at its walls. Such a scenario also applies to an extended diffuse CO2 migration from volcanic activity deep underground. In this case drastic reductions of the breakthrough time by about one order of magnitude are observed. These reductions are enhanced when the fracture aperature width of the initial fracture decreases. The physicochemical mechanisms of enhancement of karstification are discussed in detail by considering the evolution of the fracture aperature width and of the dissolution rates in space and time

Simulation of daily and monthly stream discharge from small watersheds using the SWAT model, 2000, Spruill C. A. , Workman S. R. , Taraba J. L. ,
The Soil and Water Assessment Tool (SWAT) was evaluated and parameter sensitivities were determined while modeling daily streamflows in a small central Kentucky watershed over a two-year period. Streamflow data from 1996 were used to calibrate the model and streamflow data from 1995 were used for evaluation. The model adequately predicted the trends in daily streamflow during this period although Nash-Sutcliffe R-2 values were -0.04 and 0.19 for 1995 and 1996, respectively The model poorly predicted the timing of some peak flow values and recession rates during the last half of 1995. Excluding daily peak flow values from August to December improved the daily R-2 to 0.15, which was similar to the 1996 daily R2 value. The Nash-Sutcliffe R-2 for monthly total flows were 0.58 for 1995 and 0.89 for 1996 which were similar to values found in the literature. Since very little information was available on the sensitivity of the SWAT model to various inputs, a sensitivity analysis/calibration procedure was designed to evaluate parameters that were thought to influence stream discharge predictions. These parameters included, drainage area, slope length, channel length, saturated hydraulic conductivity, and available water capacity. Minimization of the average absolute deviation between observed and simulated streamflows identified optimum values/ranges for each parameter. Saturated hydraulic conductivity alpha baseflow factor; drainage area, channel length, and channel width were the most sensitive parameters in modeling the karst influenced watershed. The sensitivity analysis process confirmed die trace studies in the karst watershed that a much larger area contributes to streamflow than can be described by the topographic boundaries. Overall, the results indicate that the SWAT model can be an effective tool for describing monthly, runoff from small watersheds in central Kentucky that have developed on karat hydrology however calibration data are necessary to account for solution channels draining into or out of the topographic watershed

Role of mixing corrosion in calcite-aggressive H2O-CO2-CaCO3 solutions in the early evolution of karst aquifers in limestone, 2000, Gabrovsek F, Dreybrodt W,
Two cave-forming mechanisms in limestone are discussed currently. First, when two H2O-CO2-CaCO3 solutions, saturated with respect to calcite but with different chemical compositions mix, renewed aggressiveness to limestone dissolution occurs. This process called mixing corrosion [Bogli, 1964, 1980], in combination with linear dissolution kinetics, has been suggested as cave forming. Second, it has been shown that solely the action of nonlinear dissolution kinetics can generate extended karst conduits. This paper combines both mechanisms. By digital modeling of the evolution of the aperture widths of a confluence of two fractures into a third one it is shown that the first mechanism does not create large cave conduits. The combination of mixing corrosion and nonlinear kinetics, however, considerably intensifies karstification, compared to that of nonlinear kinetics solely. The times to terminate early evolution of karst are significantly reduced when the CO2 concentrations of the inflowing solutions differ by no more than 30%. We discuss the underlying mechanisms by inspection of the time dependence of the evolution of aperture widths, flow rates through them, and of the renewed undersaturation of the mixed solution at the confluence of two fractures. Finally, the evolution of a karst aquifer on a two-dimensional percolation network is modeled when mixing corrosion is present, and compared to that on an identical net with identical nonlinear dissolution kinetics, but mixing corrosion excluded. Large differences in the morphology of the net of cave conduits are found and also a reduction of the time of their evolution. From these findings we conclude that climatic changes, which influence the p(CO2) in the soil, can divert the evolving cave patterns

Karst aquifer evolution in fractured, porous rocks, 2000, Kaufmann G. , Braun J. ,
The evolution of flow in a fractured, porous karst aquifer is studied by means of the finite element method on a two-dimensional mesh of irregularly spaced nodal points. Flow within the karst aquifer is driven by surface recharge from the entire region, simulating a precipitation pattern, and is directed toward an entrenched river as a base level. During the early phase of karstification both the permeable rock matrix, modeled as triangular elements, and fractures within the rock matrix, modeled as linear elements, carry the now. As the fractures are enlarged with time by chemical dissolution within the system calcite-carbon dioxide-water, flow becomes more confined to the fractures. This selective enlargement of fractures increases the fracture conductivity by several orders of magnitude during the early phase of karstification. Thus flow characteristics change from more homogeneous, pore-controlled flow to strongly heterogeneous, fracture-controlled flow. We study several scenarios for pure limestone aquifers, mixed sandstone-limestone aquifers, and various surface recharge conditions as well as the effect of faulting on the aquifer evolution. Our results are sensitive to initial fracture width, faulting of the region, and recharge rate

Dynamics of the evolution of single karst conduit, 2000, Dreybrodt W. , Gabrovsek F.
The evolution of karst conduits by calcite-aggressive water flowing in initially narrow fractures require a non-linear rate law FSUBn(c)=kSUBn(1-c/cSUB eg)SUPn for limestone dissolution close to equilibrium with respect to calcite. A mathematical analysis of the evolution of limestone dissolution rates of water in such early, narrow fractures as a function of the distance from the input reveals an exponential decrease of the dissolution rates for linear dissolution rate laws (n=1), such that subsurface karstification is prevented. For non-linear kinetics (n>2), however, the decrease of rates proceeds by a hyperbolic relation, such that dissolution rates at the exit of the fracture are still sufficiently high to create a feedback mechanism by which after a long time of gestation a dramatic increase in the widths of the conduits is established. After this breakthrough event, uniform widening along the entire channel determines the further evolution. The time to achieve breakthrough is given by T=aSUB0/2gammaF(L,0), where 2gammaF(L,0) is the initial widening in cm/year at the exit of the conduit. This however is only true when the inflow solution is at less than 99% of saturation. Otherwise the positive feedback loop is switched off and the conduit widens evenly along its entire length with rates of 10SUP-9 cm/year to enlarge extremely narrow fractures with initial widths of several ten microns over distances of kilometers to sizes of about 0.1mm within several ten millions of years. This provides a general explanation for the concept of inception horizons, where usually other mechanisms have been assumed.

Influence of fracture roughness on karstification times, 2000, Dreybrodt W. , Gabrovsek F.
Karst aquifers develop along water-transmitting fractures which are rough by nature. Most numerical models on the evolution of the widths of those fractures by limestone dissolution, however, approximate such rough fractures by two parallel smooth planes. Here we investigate the influence of fracture roughness on the breakthrough time of conduits. All results show that even when the flow through a fracture is reduced by its roughness by a factor of ten in comparison to a corresponding smooth fracture, breakthrough time is increased only by a factor of 4. This gives a first answer to the influence of natural fracture roughness on the evaluation of karst and shows that extreme roughness, unlikely in nature, is necessary to exert significant influence on karstification time.

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