Community news

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 pseudokarren is these are karren appearing features that form mostly on insoluble, silicate rocks by means of weathering processes. they appear as a rounded type of rinnenkarren and less frequently as an atypical form of solution pan [3]. see also karren; rinnenkarren; solution pan.?

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

What is Karstbase?

Search KARSTBASE:

keyword
author

Browse Speleogenesis Issues:

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 root (Keyword) returned 52 results for the whole karstbase:
Showing 46 to 52 of 52
New insights into the carbon isotope composition of speleothem calcite : an assessment from surface to subsurface, 2012, Meyer, Kyle William

The purpose of this study was to provide new insights into the interpretation of speleothem (cave calcite deposit) δ13C values. We studied two caves in central Texas, which have been actively monitored for over 12 years. We compared δ13C values of soil CO2 (δ13Cs), cave drip water (δ13CDIC), and modern cave calcite (δ13Ccc). Measured average δ13C values of soil CO2 were -13.9 ± 1.4‰ under mixed, shallowly-rooted C3-C4 grasses and were -18.3 ± 0.7‰ under deeply-rooted ashe juniper trees (C3). The δ13CDIC value of minimally-degassed drip water in Natural Bridge Caverns was -10.7 ± 0.3‰. The carbon isotope composition of CO2 in equilibrium with this measured drip water is -18.1 ± 0.3‰. The agreement between juniper soil CO2 and drip water (within ~0.2‰) suggests that the δ13C value of drip water (δ13CDIC) that initially enters the cave is controlled by deeply-rooted plants and may be minimally influenced by host-rock dissolution and/or prior calcite precipitation (PCP). At Inner Space Caverns, δ13CDIC values varied with vegetation above the drip site, distance from the cave entrance, and distance along in-cave flow paths. Whereas CO2 derived from deeply-rooted plants defines the baseline for drip water δ13CDIC entering the caves, kinetic effects associated with the degassing of CO2 and simultaneous precipitation of calcite account for seasonal variability in δ13CDIC and δ13Ccc. We documented increases in δ13CDIC at a rate of up to 0.47‰/hour during the season of peak degassing (winter), suggesting that δ13CDIC variations may be controlled by total elapsed time of CO2 degassing from drip water (Ttotal). We also observed seasonal shifts in the δ13C values of modern calcite grown on glass substrates that are correlated with shifts in drip water δ13CDIC values and drip-rate. Therefore, we suggest that increased aridity at the surface above a given cave results in, slower drip-rates, higher Ttotal, and therefore higher δ13CDIC values. We propose that large variability (>2‰) in speleothem δ13Ccc values dominantly reflect major vegetation changes, and/or increasing Ttotal by slowing drip-rates. Based on these findings, variability in speleothem carbon isotope records may serve as a proxy for paleoaridity and/or paleovegetation change.


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.


Hydrogeological approach to distinguishing hypogene speleogenesis settings, 2013, Klimchouk, A. B.

The hydrogeological approach to defining hypogene speleogenesis (HS) relates it to ascending groundwater flow (AF). HS develops where AF causes local disequilibria conditions favoring dissolution and supports them during sufficiently long time in course of the geodynamic and hydrogeological evolution. The disequilibrium conditions at depth are invoked by changing physical-chemical parameters along an AF paths, or/and by the interaction between circulation systems of different scales and hydrody-namic regimes. The association of HS with AF suggests a possibility to discern regulari-ties of development and distribution of HS from the perspectives of the regional hy-drogeological analysis. In mature artesian basins of the cratonic type, settings favorable for AF and HS, are as follows: 1) marginal areas of discharge of the groundwaters of the 2nd hydrogeological story (H-story), 2) zones of topography-controlled upward cir-culation within the internal basin area (at the 1st and, in places, at the 2nd H-stories; 3) crests of anticlinal folds or uplifted tectonic blocs within the internal basin area where the upper regional aquitard is thinned or partially breached; 4) linear-local zones of deep-rooted cross-formational faults conducting AF from internal deep sources across the upper H-stories. Hydrodynamics in the 3rd and 4th stories is dominated by ascending circulation strongly controlled by cross-formational tectonic structures. Specific circula-tion pattern develops in large Cenozoic carbonate platforms (the Florida-type), side-open to the ocean, where AF across stratified sequences in the coastal parts, driven by both topography-induced head gradients and density gradients, involves mixing with the seawater. The latter can be drawn into a platform at deep levels and rise in the plat-form interior (the Kohout’s scheme). In folded regions, AF and HS are tightly con-trolled by faults, especially those at junctions between large tectonic structures. In young intramontaine basins with dominating geostatic regime, HS is favored at margin-al discharge areas where circulation systems of different origins and regimes may inter-act, such as meteoric waters flows from adjacent uplifted massifs, basinal fluids expelled from the basin’s interiors, and endogenous fluids rising along deep-rooted faults. Spe-cific and very favorable settings for HS are found in regions of young volcanism with carbonate formations in a sedimentary cover


THE USE OF DROUGHT-INDUCED “CROP LINES” AS A TOOL FOR CHARACTERIZATION OF KARST TERRAIN, 2013, Panno S. V. , Luman D. E. , Kelly W. R. , Alschuler M. B.

The persistent drought of the 2012 summer in the Midwestern United States significantly impacted the health and vigor of Illinois’ crops. An unforeseen outcome of the extreme drought was that it provided a rare opportunity to examine and characterize the bedrock surface and underlying karst aquifer within the Driftless Area of northwestern Illinois. Complex networks of vegetated lines and polygonal patterns, herein referred to as crop lines, crisscrossed the dry summer landscape of Jo Daviess County. Initially, the crop lines were examined and photographed using a handheld digital camera on the ground and from a small aircraft at 300 meters altitude above ground level (AGL). The orientations, widths and horizontal separations of the lines were measured. Crop lines and their patterns and orientations were compared with those of crevices in outcrops, road cuts and quarries, and with lineaments seen in LiDAR elevation data of Jo Daviess County.
Primarily confined to alfalfa fields and, to a lesser extent, soybeans and corn, the crop lines are the result of a combination of extremely dry conditions, and a thin soil zone overlying fractured and creviced Galena Dolomite bedrock. The plants forming the lines tend to grow denser, taller (0.5 m vs 0.15 m) and darker/greener than those in adjacent areas. Alfalfa taproots are the deepest of the aforementioned crops extending up to 7 m below the surface. Groundwater and associated soil moisture within the vadose zone present within bedrock fractures and crevices provide the necessary moisture to sustain the overlying healthy plants, while the remaining area of the field exhibits stunted and sparse plant growth. Overall, the crop lines are a reflection of the creviced pattern of the underlying karst bedrock and associated karst aquifer, and reveal the degree and extent of karstification in eastern Jo Daviess County. The crop lines were consistent with the angular lines of adjacent streams that show a rectangular drainage pattern. Stream patterns like these are well known and are due to drainage controlled by crevice/fracture patterns in the top of bedrock. The lines appear to have been formed by two sets of fractures trending roughly north-south and east-west with occasional cross-cutting fractures/crevices. The east-west trending lines are consistent with tension joints, and the north-south lines are consistent with the shear joints identified by earlier researchers. The trends of the crop lines, tension and shear joints are similar to those of lineaments identified from LiDAR elevation data in the same area (N 20° W, and N 70° W and N 70° E) and coincide with the occurrence of karst features throughout eastern Jo Daviess County.The pattern observed in the crop lines closely mimics the fracture/crevice patterns of the bedrock surface. The widths and extent of the lines may be used as a surrogate for the karst features present on the bedrock surfaces. Crop lines, coupled with solution-enlarged crevices seen in bedrock exposures, yield a three dimensional view of the bedrock crevice-fracture system, and ultimately could provide a more complete and accurate model of the karst aquifer in the study area and similar karst areas in the Midwestern United States and perhaps in other karst regions of the world.


Using hydrogeochemical and ecohydrologic responses to understand epikarst process in semi-arid systems, Edwards plateau, Texas, USA, 2013, Schwartz Benjamin F. , Schwinning Susanne, Gerrard Brett, Kukowski Kelly R. , Stinson Chasity L. , Dammeyer Heather C.

The epikarst is a permeable boundary between surface and subsurface environments and can be conceptualized as the vadose critical zone of epigenic karst systems which have not developed under insoluble cover. From a hydrologic perspective, this boundary is often thought of as being permeable in one direction only (down), but connectivity between the flow paths of water through the epikarst and the root systems of woody plants means that water moves both up and down across the epikarst. However, the dynamics of these flows are complex and highly dependent on variability in the spatial structure of the epikarst, vegetation characteristics, as well as temporal variability in precipitation and evaporative demand. Here we summarize insights gained from working at several sites on the Edwards Plateau of Central Texas, combining isotopic, hydrogeochemical, and ecophysiological methodologies. 1) Dense woodland vegetation at sites with thin to absent soils (0-30 cm) is in part supported by water uptake from the epikarst. 2) However, tree transpiration typically becomes water-limited in dry summers, suggesting that the plant-available fraction of stored water in the epikarst depletes quickly, even when sustained cave drip rates indicate that water is still present in the epikarst. 3) Flow paths for water that feeds cave drips become rapidly disconnected from the evaporation zone of the epikarst and out of reach for plant roots. 4) Deep infiltration and recharge does not occur in these systems without heavy or continuous precipitation that exceeds some threshold value. Thresholds are strongly correlated with antecedent potential evapotranspiration and rainfall, suggesting control by the moisture status of the epikarst evapotranspiration zone. The epikarst and unsaturated zone in this region can be conceptualized as a variably saturated system with storage in fractures, matrix porosity, and in shallow perched aquifers, most of which is inaccessible to the root systems of trees, although woody vegetation may control recharge thresholds.


PERMIAN HYDROTHERMAL KARST IN KRAKÓW REGION (SOUTHERN POLAND) AND ITS PECULIAR INTERNAL SEDIMENTS, 2014, Gradziński M. , Lewandowska A. , Paszkowski M. , Duliński M. , Nawrocki J. , Żywiecki M.

The development of caves influenced by the deep circulation of water has received increasing interest for the last thirty years. Presently, hypogene caves have been recognized all around the world. Conversely, the ancient examples filled with sediments and representing palaeokarst forms are not so common.
The karst forms and their sediment fillings were encountered in the Dębnik Anticline (Kraków region, Southern Poland) composed of Middle Devonian to Mississippian carbonates. The development of karst slightly postdates the Permian (ca. 300 Ma) volcanic activity in the Kraków region. In this region major transcontinental strike and slip Hamburg-Kraków-Dobruja fault zone induced a series of minor, en echelon, extensional faults, which served as magma passages and guided karst conduits.
The karst forms in the Dębnik Anticline reach several to tens of meters in size. They are filled with: i) massive, subaqueous, coarse crystalline calcite spar; ii) crystalloclastic, bedded limestones; iii) jasper lenses; iv) kaolinitised tuffs. The sediments are characterized by red colouration caused by iron compounds.
Coarse crystalline calcite spar composes beds up to several dozen centimeters in thickness. They are laminated and comprise frutexites type structures. The calcites are interbedded with pinkish-red crystalloclastic limestones, which are built of detritic calcite crystals from silt size to a few millimeters across. Some of the crystals are of skeletal type. Crystalloclastic limestones are normally graded. Both calcite spar and crystalloclastic limestones underwent synsedimentary deformations, which resulted in brecciation and plastic deformations.
The above deposits fill karst forms up to a few metres in lateral extent. However, analogously filled enormously huge (up to around 100 m across) forms were recognized in the early 80s of the last century. Presently, they are completely exploited.
The karst forms were fragments of extensive circulation system. It was fed by waters of elevated temperature, rich in endogenic CO2, which is proved by fluid inclusion analysis and stable isotope investigation. The origin of this system was associated with volcanic activity. The roots of the system are represented by fissures filled with coarse crystalline, red and white calcites of onyx type, which are common in the Dębnik Anticline. Water issuing from this system on the surface caused precipitation of red travertines. These travertines are preserved only as clasts in the Lower Permian conglomerates deposited in the local tectonic depressions.
The study was financed by Ministry of Science and Higher Education project N307 022 31/1746.


The formation of the pinnacle karst in Pleistocene aeolian calcarenites (Tamala Limestone) in southwestern Australia, 2015,

A spectacular pinnacle karst in the southwestern coastal part of Western Australia consists of dense fields of thousands of pinnacles up to 5 m high, 2 m wide and 0.5–5 m apart, particularly well exposed in Nambung National Park. The pinnacles have formed in the Pleistocene Tamala Limestone, which comprises cyclic sequences of aeolian calcarenite, calcrete/microbialite and palaeosol. The morphology of the pinnacles varies according to the lithology in which they have formed: typically conical in aeolianite and cylindrical in microbialite. Detailed mapping and mineralogical, chemical and isotopic analyses were used to constrain the origin of the pinnacles, which are residual features resulting mainly from solutional widening and coalescence of solution pipeswithin the Tamala Limestone. The pinnacles are generally joined at the base, and the stratigraphy exposed in their sides is often continuous between adjacent pinnacles. Some pinnacles are cemented infills of solution pipes, but solution still contributed to their origin by removing the surrounding material. Although a number of pinnacles contain calcified plant roots, trees were not a major factor in their formation. Pinnacle karst in older, better-cemented limestones elsewhere in theworld is similar inmorphology and origin to the Nambung pinnacles, but is mainly influenced by joints and fractures (not evident at Nambung). The extensive dissolution associatedwith pinnacle formation at Nambung resulted in a large amount of insoluble quartz residue, which was redeposited to often bury the pinnacles. This period of karstification occurred at aroundMIS 5e, and therewas an earlier, less intense period of pinnacle development duringMIS 10–11. Both periods of pinnacle formation probably occurred during the higher rainfall periods that characterise the transition from interglacial to glacial episodes in southern Australia; the extensive karstification around MIS 5e indicates that the climate was particularly humid in southwestern Australia at this time.


Results 46 to 52 of 52
You probably didn't submit anything to search for