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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 consolidation is 1. the binding of grains by cementing material to solid matrix [16]. 2. the gradual reduction in the water content (void ratio) of a saturated soil, as a result of an increase in the pressure acting on it, because of the addition of overlying sediments or the application of an external load. a laboratory test commonly known as a one-dimensional consolidation test (odometric test), is performed consolidation, cv usually expressed in cm2/sec, is calculated as the ratio where k is the hydraulic conductivity, on soil samples to evaluate consolidation. from such a test, the coefficient of mv is the coefficient of volume compressibility, and ?w is the unit weight of water. the theory of consolidation leads to a relation between degree of consolidation and time: in this expression u is the degree of consolidation or the percentage of total consolidation occurring in some time t; cv is the coefficient of consolidation; and h is half of the sample's thickness when the odometric test is performed [21].?

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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 variation (Keyword) returned 464 results for the whole karstbase:
Showing 451 to 464 of 464
Variability of groundwater flow and transport processes in karst under different hydrologic conditions, 2013, Ravbar, Nataša

Significance of hydrological variability in karst is presented, which also discusses factors inducing such variability and consequences it may cause. Groundwater flow in karst aquifers is often characterized by strong variability of flow dynamics in response to different hydrologic conditions within a short time period. Consequently, water table fluctuations are often in the order of tens of meters, differences in flow velocities between low- and high-flow conditions can reach ten or even more times. In dependence to respective hydrologic conditions groundwater flow also results in variations of flow directions, and thus in contribution of different parts of the aquifer to a particular spring. The described hydrological variability has many implications for contaminant transport, groundwater availability and vulnerability. Groundwater level rising reduces thickness of the unsaturated zone and decreases protectiveness of the overlying layers. Higher water flow velocities reduce underground retention. Due to more turbulent flow, transport and remobilization of solute and insoluble matter is more effective. During high-flow conditions there is usually more surface flow and hence more concentrated infiltration underground. Particularly in karst systems that show very high hydrologic variability, this should be considered to correctly characterize, understand or predict the aquifers’ hydrological behaviour and to prepare proper protection strategies.


From Slots to Tubes: The Influence of Dimensionality on Fracture Dissolution Models, 2013, Szymczak, Piotr

We briefly review the models of fracture dissolution process, discussing the experimental and numerical evidence showing that this phenomenon is inherently two-dimensional and hence cannot be accurately described by one-dimensional models. The physical reason for this incompatibility is that a dissolution front in a single rock fracture is potentially unstable to small variations in local permeability, leading to spontaneous formation of dissolution channels in the rock. This leads to a dramatic increase of fissure opening rates, which must be taken into account not only in the estimation of karstification times but also in the assessment of ground subsidence, dam collapse or toxic seepage risks.


‘Looping caves’ versus ‘water table caves’: The role of base-level changes and recharge variations in cave development, 2014, Gabrovšek Franci, Häuselmann Philipp, Audra Philippe

The vertical organisation of karst conduit networks has been the focus of speleogenetic studies for more than a century. The four state model of Ford and Ewers (1978), which still is considered as the most general, relates the geometry of caves to the frequency of permeable fissures. The model suggests that the ‘water table caves’ are common in areas with high fissure frequency, which is often the case in natural settings. However, in Alpine karst systems, water table caves aremore the exception than the rule. Alpine speleogenesis is influenced by high uplift, valley incision rates and irregular recharge. To study the potential role of these processes for speleogenesis in the dimensions of length and depth, we apply a simple mathematical model based on coupling of flow, dissolution and transport.We assume a master conduit draining thewater to the spring at a base level. Incision of the valley triggers evolution of deeper flow pathways,which are initially in a proto-conduit state. Themaster conduit evolves into a canyon following the valley incision,while the deep pathways evolve towards maturity and tend to capture the water fromthe master conduits. Two outcomes are possible: a) deep pathways evolve fast enough to capture all the recharge, leaving the master conduit dry; or b) the canyon reaches the level of deep pathways before these evolve to maturity. We introduce the Loop-to-Canyon Ratio (LCR), which predicts which of the two outcomes is more likely to occur in certain settings. Our model is extended to account for transient flow conditions. In the case of an undulating master conduit, floodwater is stored in troughs after the flood retreat. This water seeps through sub-vertical fractures (‘soutirages’) connecting the master conduitwith the deep pathways. Therefore, the loops evolve also during the dry season, and the LCR is considerably increased. Although themodel is based on several approximations, it leads to some important conclusions for vertical organisation of karst conduit networks and stresses the importance of base-level changes and transient recharge conditions. It therefore gives an explanation of speleogenesis that relies much more on the dynamic nature of water flow than on the static fracture density


EARTH TIDE, A POTENTIAL DRIVER FOR HYPOGENIC FLUID FLOW: OBSERVATIONS FROM A SUBMARINE CAVE IN SW TURKEY, 2014, Bayari C. S. , Ozyurt N. N.

Initiation and development of karstification requires a con­tinuous flushing of pore water in equilibrium with carbon­ate minerals. Under confined flow conditions, the energy required for pore water transport is supplied by external pressure sources in addition to the by earth’s gravity. Earth tides and water loads over the confined flow system are the main sources of ex­ternal pressure that drives the pore water. Earth tides, created by the sum of the horizontal components of tide generation forces of moon and sun, causes expansion and contraction of the crust in horizontal direction. Water load on top of the confined flow system causes vertical loading/unloading and may be in the form of recharge load or ocean loading in the inland and sub-oceanic settings, respectively. Increasing and decreasing tide generating force results in pore water transport in the confined system by means of contraction and expansion, respectively. Since these forces operate in perpendicular directions, pore water flushing by earth tides becomes less effective when water load on top of the confined flow system increases. Temporal variation of fresh­water content in a submarine cave is presented as an example of groundwater discharge driven by earth tides and recharge load.


Rockmagnetic and palaeomagnetic studies of unconsolidated sediments of Bukovynka Cave ( Chernivtsi region, Ukraine), 2014, Bondar K. , Ridush B.

Rockmagnetic, palaeomagnetic, and paleontological studies of loamy non-consolidated sediments of the Bukovynka Cave (Chernivtsi region, Ukraine) have been carried out. The sections include three main types of deposits: 1 – fluvial deposits containing travertine grus derived from the karst massif, 2 – fluvial deposits derived from temporary waterflows from outside the cave, 3 – aeolian deposits. Deposits of type 2 and 3 were examined in Sections 1 and 2 in the Trapeznyi Chamber. Their low field magnetic susceptibility (χ) reflects climatic conditions in the Late Pleistocene. The layer with cave hyena bones has higher magnetic susceptibility and appeared to indicate warmer climate. Deposits of type 1 and 2 were investigated in the Section 3 in the Dry Chamber of the cave. Low-field magnetic susceptibility of fluvial deposits, derived from inside of the karst massif, is much higher than for deposits derived from outside the cave. Deposits in Section 3 sharply differ in χ, NRM intensity and Keonigsberger ratio. The fluvial strata of type 1 in Section 3, dated using paleontological remains as Holocene, contains the record of palaeosecular variations of the geomagnetic field. The Etrussia excursion dated 2.8 ka BP was found at 1 m depth in Section 3. The lowest layer has anomalous polarity.
 


Hydrological role of karst in the Chalk aquifer of Upper Normandy, France, 2014, Janyani S. El, Dupont J. P. , Massei N. , Slimani S. , Dörfliger N.

The role of karst on large-scale groundwater flow is defined for the Chalk aquifer of Upper Normandy (western Paris Basin), France. In the regional context, chalk plateaus occupy the greater part of watersheds and are the main sites of groundwater recharge. Previous studies focused on karstic output systems in the valleys and less on water-level variations in the recharge zones upstream. This study assesses the relevant hydrogeological processes using time-series data (boreholes and springs) recorded along a down-gradient hydrologeological cross-section in two selected watersheds. These hydrological data are interpreted in the framework of previous descriptions of the morphological organization of the study area’s karst network. The results highlight the hydrological role of (1) the input karst (vertical conduits) which drains recharging water, (2) the output karst (sub-horizontal conduits widely developed in the vicinity of valleys in the surface watersheds) which drains the output flows, and (3) the connections between these two (input and output) networks, which control the upstream water levels and allow quick transfer to springs, particularly after strong rainfall events. A conceptual model of the hydrological functioning of this covered karst aquifer is established, which should serve for the structuring and parameterization of a numerical model


Microhabitat influences the occurrence of airborne fungi in copper mine in Poland, 2014, Pusz W. , Kita W. , Weber R.

From January to April 2012 we studied the occurrence of air-borne fungi in the Lubin mining site, property of KGHM Polska Miedz´ SA. The research was conducted in three copper-mining shafts: Bolesław, Lubin Zachodni (Lubin West shaft), and Lubin Gło´wny (Lubin Main shaft) at about 610 to 850 meters below ground level. Air samples were collected between 6 and 9 a.m. using the impact method (Air Ideal 3P Sampler) onto Potato Dextrose Agar. The volume of air sampled for each agar plate was 50 liters. We found twenty-seven fungal species, the most numerous being Penicillium notatum, P. urticae, and Aspergillus flavus. As the application of log-linear and correspondence analyses have shown, the population of fungi varied considerably among the copper mine shafts or shaft parts. P. notatum and P. urticae were found to be the best adapted to grow in copper-mine conditions. The significant interaction among the shafts and the sample collection sites suggests a substantial microclimate influence on the population-size variations of studied fungal species in each shaft. The fungal-spore concentration in the majority of the shafts of this copper mine does not present a health risk to the mine workers. But it is enhanced in some portions of the mine, so it may constitute a health hazard locally.


Bacterial migration through low-permeability fault zones in compartmentalised aquifer systems: a case study in Southern Italy., 2014,

The aim of this study was to experimentally verify the significance of microbial transport through low-permeability fault zones in a compartmentalised carbonate aquifer system in Southern Italy.

The temporal variability of microbial communities in two springs fed by the same aquifer system, but discharging up- and down-gradient of two low-permeability fault zones, was analysed using a 16S rDNA polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)-based approach. At both springs, a remarkable temporal variation in PCR-DGGE profiles was detected throughout the observation period. When comparing the PCR-DGGE profiles of the two springs, a synchronous evolution over time was observed. Moreover, the per cent of PCR-DGGE bands common to both springs progressively increased from early (23%) to late recharge (70%), only to decrease once more in late recession (33%). Considering the results of the hydrogeological and isotopic investigations and EC measurements, the results of biomolecular analyses demonstrate that, at the study site, compartments straddling the analysed fault zones have microbial interconnections, despite the existence of low-permeability fault cores.


Niche differentiation in Meta bourneti and M. menardi (Araneae, Tetragnathidae) with notes on the life history, 2014,

Meta menardi and M. bourneti are two species of spiders inhabiting caves and other subterranean habitats. The occurrence of both species within the same cave has never been proved convincingly and several authors hypothesized a complete niche differentiation mainly based on microclimatic conditions.In order to study the apparent niche differentiation of the two species, we studied several populations of M. menardi and M. bourneti occurring in six caves in the Western Italian Alps (NW Italy). A series of squared plots were monitored monthly from March 2012 to February 2013. At each survey, we counted individuals and we collected the main environmental variables at each plot, namely distance from cave entrance, structural typology (wall, floor or ceiling), light intensity, wind speed and counts of potential prey. Moreover, temperature and relative humidity were continuously logged in each cave. We run several statistical models (GLMMs) in order to relate the counts of individuals to the environmental parameters. The distance from the cave entrance, structural typology and prey availability resulted most important factors driving the abundance of both species within the cave. On the other hand, despite life cycles appeared very similar, the two species seems to exhibit different tolerance to the microclimatic variations within the cave, which emerged as the main factors determining the differentiation of their niche. At least in our study area, M. bourneti tolerates broad microclimatic fluctuations and is potentially able to colonize a wide variety of caves. On the other hand, when the climatic conditions in a cave are suitable for M. menardi (narrow ranges of relatively low temperature and high humidity), M. bourneti is excluded.


Hydrogeological Characteristics of Carbonate Formations of the Cuddapah Basin, India, 2014, Farooq Ahmad Dar

Karst hydrogeology is an important field of earth sciences as the aquifers in carbonate formations represent vital resource of groundwater that feeds a large part of the world population particularly in semi-arid climates. These unique aquifers posses peculiar characteristics developed by dissolutional activities of water. Karst aquifers possess a typical hydrogeological setup from surface to subsurface. The aquifers are governed by slow groundwater flow in matrix porosity, a medium to fast flow in fractures and rapid flow in conduits and channels. This large variability in their properties makes the prediction and modeling of flow and transport very cumbersome and data demanding. The aquifers are vulnerable to contamination as the pollutants reach the aquifer very fast with little or no attenuation. The geomorphological and hydrogeological properties in these aquifers demand specific techniques for their study. The carbonate aquifers of the semi-arid Cuddapah basin were characterized based on geomorphological, hydrogeological and hydrochemical investigations. All the formations are highly karstified possessing one of the longest and deepest caves of India and few springs along with unique surface features. Karstification is still in progress but at deeper levels indicated by growing speleothems of different architectural size. Model of karstification indicates that lowering of base level of erosion resulted in the dissolution of deeper parts of the limestone as represented by paleo-phreatic conduits in the region. Moist conditions of the past were responsible for the karst development which has been minimized due to the onset of monsoon conditions. Karst has developed at various elevations representing the past base levels in the region.

The recharge processes in these aquifers are complex due to climatic and karst specificities. Point recharge is the major contributor which enters the aquifer as allogenic water. It replenishes the groundwater very rapidly. Diffuse recharge travels through soil and epikarst zone. Average annual recharge of semi-arid Narji limestone aquifer is 29% of the rainfall which occurs during 5-7 rain events in the year.

The hydrogeochemical characteristic of karst aquifers is quite varaible. A significant difference is observed in hydrochemistry. High concentrations of SO42-, Cl-, NO3- suggests the anthropogenic source particularly from agriculture. Local Meteoric Water Line of δ2H and δ18O isotopes of rain and groundwater shows a slope of 7.02. Groundwater isotope data shows more depletion in heavy isotopes -a result of high evaporation of the area. Groundwater samples show a trend with a slope of 4 and 3.1 for δ2H and δ18O respectively. Groundwater during dry months gets more fractionated due to higher temperature and little rainfall. The irrigated water becomes more enriched and then recharges the aquifer as depleted irrigation return flow. The isotopes show large variation in spring water. Few springs are diffuse or mixed type and not purely of conduit type in the area. Tracer results indicate that the tracer output at the sampling location depends on the hydrogeological setup and the nature of karstification.

The study has significantly dealt with in disclosing the typical characteristics of such aquifer systems and bringing out a reliable as well as detailed assessment of various recharges to the system. The groundwater chemistry has been elaborated to establish the nature of possible hydrochemical processes responsible for water chemistry variation in semi-arid karst aquifer. Such study has thrown light on the aquifers that are on one hand very important from social and strategic point of view and on the hand were left unattended from the detailed scientific studies.


Thermal damping and retardation in karst conduits, 2015, Luhmann A. J. , Covington M. D. , Myre J. M. , Perne M. , Jones S. W. , Alexander Jr. E. C. , Saar M. O

Water temperature is a non-conservative tracer in the environment. Variations in recharge temperature are damped and retarded as water moves through an aquifer due to heat exchange between water and rock. However,within karst aquifers, seasonal and short-term fluctuations in recharge temperature are often transmitted over long distances before they are fully damped. Using analytical solutions and numerical simulations, we develop relationshipsthat describe the effect of flow path properties, flow-through time, recharge characteristics, and water and rock physical properties on the damping and retardation of thermal peaks/troughs in karst conduits. Using these relationships, one can estimate the thermal retardation and damping that would occur under given conditions with a given conduit geometry. Ultimately, these relationships can be used with thermal damping and retardation field data to estimate parameters such as conduit diameter. We also examine sets of numerical simulations where we relax some of the assumptions used to develop these relationships, testing the effects of variable diameter, variable velocity, open channels, and recharge shape on thermal damping and retardation to provide some constraints on uncertainty. Finally, we discuss a multitracer experiment that provides some field confirmation of our relationships. High temporal resolution water temperature data are required to obtain sufficient constraints on the magnitude and timing of thermal peaks and troughs in order to take full advantage of water temperature as a tracer.

 


The hydrogeology of high-mountain carbonate areas: an example of some Alpine systems in southern Piedmont (Italy), 2015,

The hydrogeological characteristics of some springs supplied by high-mountain carbonate rock aquifers, located in the south of Piedmont, in Italy, are presented in this work. The aquifers have different geological-structural conditions, including both deep and superficial karstification. Their catchment areas are located in a typical Alpine context at a high altitude of about 2000 m. These aquifers are ideal representations of the different hydrogeological situations that can be encountered in the high-altitude carbonate aquifers of the Mediterranean basin. It is first shown how the high-altitude zones present typical situations, in particular related to the climate, which control the infiltration processes to a great extent. Snowfall accumulates on the ground from November to April, often reaching remarkable thicknesses. The snow usually begins to melt in spring and continues to feed the aquifer for several months. This type of recharge is characterized by continuous daily variations caused by the typical thermal excursions. The hourly values are somewhat modest, but snowmelt lasts for a long time, beginning in the lower sectors and ending, after various months, in the higher areas. Abundant rainfall also occurs in the same period, and this contributes further to the aquifer supply. In the summer period, there is very little rainfall, but frequent storms. In autumn, abundant rainfall occurs and there are there fore short but relevant recharge events. It has been shown how the trend of the yearly flow of the high mountain springs is influenced to a great extent by the snowmelt processes and autumn rainfall. It has also been shown, by means of the annual hydrographs of the flow and the electric conductivity of the spring water, how the different examined aquifers are characterized by very different measured value trends, according to the characteristics of the aquifer.

 


Depth and timing of calcite spar and “spar cave” genesis: Implications for landscape evolution studies, 2015,

Calcite spar (crystals >1 cm in diameter) are common in limestone and dolostone terrains. In the Guadalupe Mountains, New Mexico and west Texas, calcite spar is abundant and lines small geode-like caves. Determining the depth and timing of formation of these large scalenohedral calcite crystals is critical in linking the growth of spar with landscape evolution. In this study, we show that large euhedral calcite crystals precipitate deep in the phreatic zone (400–800 m) in these small geode-like caves (spar caves), and we propose both are the result of properties of supercritical CO2 at that depth. U-Pb dating of spar crystals shows that they formed primarily between 36 and 28 Ma. The 87Sr/86Sr values of the euhedral calcite spar show that the spar has a signifi cantly higher 87Sr/86Sr (0.710–0.716) than the host Permian limestone (0.706–0.709). This indicates the spar formed from waters that are mixed with, or formed entirely from, a source other than the surrounding bedrock aquifer, and this is consistent with hypogene speleogenesis at signifi cant depth. In addition, we conducted highly precise measurements of the variation in nonradiogenic isotopes of strontium, 88Sr/86Sr, expressed as 88Sr, the variation of which has previously been shown to depend on temperature of precipitation. Our preliminary 88Sr results from the spar calcite are consistent with formation at 50–70 °C. Our fi rst U-Pb results show that the spar was precipitated during the beginning of Basin and Range tectonism in a late Eocene to early Oligocene episode, which was coeval with two major magmatic periods at 36–33 Ma and 32–28 Ma. A novel speleogenetic process that includes both the dissolution of the spar caves and precipitation of the spar by the same speleogenetic event is proposed and supports the formation of the spar at 400–800 m depth, where the transition from supercritical to subcritical CO2 drives both dissolution of limestone during the main speleogenetic event and precipitation of calcite at the terminal phase of speleogenesis. We suggest that CO2 is derived from contemporaneous igneous activity. This proposed model suggests that calcite spar can be used for reconstruction of landscape evolution


Influence of the f low rate on dissolution and precipitation features during percolation of CO 2 - rich sulfate solutions through fractured limestone samples , 2015,

Calcited issolution and  gypsum precipitation is expected to occur  when injecting CO2  in  a limestone reservoir with sulfate - rich resident brine. If the reservoir is fractured, These reactions will take place mainly in the fractures, which serve as preferential paths for fluid  flow. As a consequence, the geometry of the fractures will vary leading to changes  in their hydraulic and transport properties. In this study, a set of percolation  experiments  which  consisted of injecting CO 2 - rich solutions through fractured  limestone  cores were performed under P  =  150 bar and  T  =  60  ºC .  Flow rate s ranging from 0.2 to 60 mL/ h and sulfate - rich and sulfate - free solutions  were used. Variation in fracture volume induced by calcite dissolution and  gypsum precipitation was measured by X - ray computed microtomography  (XCMT) and aqueous chemistry. An increase in flow rate led to  an increase in  volume of dissolved limestone per unit of  time , which indicated that the calcite dissolution rate in the fracture  was transport  controlled. Moreover, the dissolution pattern varied from face dissolution to wormhole formation  and uniform dissolution by increasing the flow rate (i.e.,  Pefrom 1 to 346 ). Fracture permeability always increased and depended on the type of dissolution pattern.


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