MWH Global

Enviroscan Ukrainian Institute of Speleology and Karstology

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 5
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 pressure head is hydrostatic pressure expressed as the height of a column of water that the pressure can support at the point of measurement [22]. see also head, static; pressure, hydrostatic.?

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

Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 7
What is Karstbase?



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 acid (Keyword) returned 258 results for the whole karstbase:
Showing 31 to 45 of 258
Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida, 1996,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Lee T. M. ,
Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain

History of sulfuric acid theory of speleogenesis in the Guadalupe Mountains:, 1996,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Jagnow D. H.

The geomorphology of solution cave sequences in the Kalk Bay Mountains, southern Cape Peninsula. BSc thesis, 1996,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Shearer, H.

The Kalk Bay Mountains of the southern Cape Peninsula, South Africa, show marked development of pseudokarstic features such as caverns, dolines and grikes. These features have formed over at least 100 million years on supposed inert quartzitic sandstones of the Peninsula Formation of the Table Mountain Group. Pseudokarst on sandstone is relatively rare world-wide and various aspects of cave genesis are highlighted in the Cape Peninsula. Cape Peninsula pseudokarst is relict, occurs at high altitudes above the present water table and could provide clues to palaeoenvironmental conditions during the African erosion period.
The cave systems in the Kalk Bay Mountains occur in at least three levels in the thickly-bedded sandstone. These different levels are the result of differential uplift during the Miocene and Pliocene. The Cape Peninsula Mountains are tabular and blocky, as opposed to the fold mountains of the rest of the South Western Cape. Much more of the overlying sedimentary layers in the Cape Peninsula have also been removed by weathering and erosive processes. The caves can be compared to similar pseudokarst features on sandstone in areas such as Gran Sabana, Venezuela. The acidic water chemistry in Venezuela contributes to a very intensive weathering environment. Present day humid tropical conditions in Venezuela are likely to be similar to palaeoclimatic conditions in the Kalk Bay Mountains, contributing to sandstone cave genesis.

Palaeosecular variation observed in speleothems from western China and northern Spain, PhD thesis, 1996,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Openshaw, S. J.

This study has produced records of the palaeosecular variation (PSV) of the earth's magnetic field from Speleothems from China and Spain. The ultimate aim of this project was to produce contemporaneous PSV records which would show that Speleothems accurately record ambient geomagnetic field behaviour. From Sichuan Province, China, five Speleothems were collected of which four were studied for their records of PSV. Eight Spanish Speleothems from the Cantabrian coast were collected but their weak magnetisation allowed only one record of PSV to be produced.
All speleothem sub-samples were weakly magnetised and had, on average, initial intensities of <100 x 10-8 Am2kg-1. Despite this, the majority of sub-samples were stable during stepwise alternating-field and thermal demagnetisation and each displayed a single component of magnetisation after removal of any secondary overprints. Rock magnetic experiments were hampered by low mineral concentrations but suggested that the remanences of each speleothem were carried by a mixture of multi and single-domain (titano-) magnetite and also by haematite present in significant quantities. The primary method of remanence acquisition appeared to be a depositional remanence sourced from flooding. This was corroborated by a linear relationship between sub-sample intensities and weight % acid insoluble detritus.
A selection of sub-samples from each speleothem were dated using uranium-thorium disequilibrium and alpha spectrometry. For the majority of sub-samples the low concentrations of uranium, high levels of detrital contamination and initially low chemical yields raised the associated dating inaccuracies above the quoted level for alpha spectrometry of 5-10%. Two Spanish Speleothems had high uranium concentrations and little, or no, detrital contamination. Percent age errors of these Speleothems ranged from 1 to 6%. Comprehensive experiments on the efficiencies of three electrodeposition methods were also undertaken. The most efficient method was found to be a modified version of the Hallstadius method (Hallstadius, 1984), which consistently achieved chemical yields between 40 and 90% for uranium and thorium.
In order to correct more analytically for the presence of detrital contamination, the leachate/leachate method of Schwarcz and Latham (1989) was tested. The maximum likelihood estimation data treatment technique (Ludwig and Titterington, 1994) was used to calculate dates from these analyses. Tests on Mexican speleothem SSJ2 gave excellent results allowing a revised dating scheme to be adopted. Tests on some sub-samples from Chinese Speleothems were generally unsuccessful due to analytical errors.
The isotope 210Pb was used to date the top surface of one speleothem. A constant growth rate was inferred which was significantly less than that calculated from the 230Th - 234U dating method. This was thought to be due to the former techniques inability to resolve growth rates of periods of less than 200 years.
Despite the dating errors associated with each speleothem the records of PSV compare well with each other and with contemporaneous records from China, Japan and also the UK (for the Spanish record). In addition. agreement with PSV data modelled from observatory records suggested that westward drift of the non-dipole geomagnetic field was predominant during the past 10ka.

Condensation Corrosion in Movile Cave, Romania, 1997,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Sarbu, S. M. , Lascu, C.
Condensation corrosion is the dissolution of carbonate by acidic vapors condensing above the water table. This process is rarely noted and receives little attention in the mainstream cave literature. The oolitic limestone walls in Movile Caves upper dry passages are severely altered by a selective corrosion mechanism. Temperature differences between the water in the lower passages and the walls in the upper passages and high concentrations of CO2 in the cave atmosphere create favorable conditions for condensation corrosion to take place. Carbon and oxygen stable isotope data support the hypothesis that condensation corrosion is the major mechanism currently affecting the morphology of Movile Caves upper dry level.

Phnomnes pseudo-karstiques dans les roches plutoniques et mtamorphiques du sud de Cameroun, 1997,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Vicat Jeanpaul, Lips Bernard, Pouclet Andr, Leger Jeanmarc, Willems Luc
Plutonic and metamorphic rocks of South Cameroon show numerous surficial and deep pseudo-karstic features. Most surficial landforms are recent. The deep features are fossils and posterior to the Cretaceous peneplain surface. All the studied pseudo-karstic features are related to the plagioclases dissolution by acid rainwaters.

Ce-anomalies in the textural components of upper Cretaceous karst bauxites from the Apulian carbonate platform (southern Italy), 1997,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Mongelli G. ,
The chemical and mineralogical composition of Upper Cretaceous Apulian karat bauxites (southern Italy) and their textural components, i.e. ooids and matrix, has been studied. The bulk samples are composed of boehmite, hematite, anatase and kaolinite. The samples collected along a vertical profile show a downward enrichment for the elements Rb, Sr, Ba, Ni and Cr. A similar distribution is observed in deposits bauxitized in situ at the expense of matrix-like material collected in the karst zone. The ooids consist mainly of hematite with minor boehmite and anatase, whereas in the matrix boehmite prevails on hematite, kaolinite and anatase. In the void fillings in the matrix there is a Ca-fluorocarbonate having a Ce/Ce* of 5.8. The ooids, with the exception of Ce, are enriched in REE and show a higher (La/Yb)(ch) ratio relative to the matrix. The matrix exhibits a large positive Ce-anomaly whereas the ooids have negative Ce-anomaly. The Ce fractionation between the textural components can be explained assuming: (1) Ce oxidation and cerianite precipitation in the uppermost part of the deposits; (2) scavenging of REE from Ce-depleted percolating solutions by the iron oxide, inducing both REE-enrichment and Ce-negative anomalies in ooids; (3) remobilization of cerium as fluoride complex, as a consequence of more acidic conditions in the uppermost part of the deposit, and precipitation of Ce3 as fluorocarbonate mineral toward the carbonate bedrock barrier, at alkaline pH. Alternatively, the cerium remobilization, possibly as a carbonate-fluoride complex, could be due to an Eh decrease, favoured by a rise of the groundwater level. (C) 1997 Elsevier Science B.V

Thermodynamic equilibrium, kinetics, activation barriers, and reaction mechanisms for chemical reactions in Karst Terrains, 1997,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
White W. B. ,
Chemical reactions pertinent to karst systems divide broadly into (a) speciation reactions within aqueous solutions, (b) dissolution/precipitation and other acid/base reactions between aqueous solutions and solid minerals, and (c) redox reactions involving various carbon and sulfur-bearing species. As a backdrop against which other chemistry can be evaluated, selected phase diagrams and equilibrium speciation diagrams were calculated for the system Ca--Mg--O--H--C--S. The kinetics of reactions within this system span time scales from milliseconds for homogeneous reactions in solution through hundreds of hours for carbonate mineral dissolution reactions, to geologic time scales for reactions such as the aragonite/calcite inversion or the oxidation/reduction of native sulfur. In purely inorganic systems, kinetic barriers, typically on the order of tens of kJ/mole, are set by nucleation processes and by activated complex formation. Biological processes impact the purely inorganic chemistry by the following mechanisms: (a) Secretions and waste products from biological activity or consumption of CO2 by organisms changes the chemistry in the microenvironments of reaction surfaces. Oxidation potentials, pH, and ion activities may be modified, thus shifting equilibria. (b) Reaction rates may be increased due to modification of activated complexes and thus the activation barriers to reaction. (c) Organic compounds or microorganisms may act as substrates, thus lowering nucleation barriers. The preservation of microorganisms in cave deposits does not necessarily prove a cause and effect relationship

The effect of metal cations on the kinetics of limestone neutralisation of acid waters, 1997,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Vantonder G. J. , Schutte C. F. ,
Limestone (CaCO3), is a lower cost alternative to lime (CaO) for the neutralisation of acid water, but the limestone neutralisation reaction is impaired by iron(II), iron(III) and aluminium in solution. This paper describes the kinetics of limestone neutralisation in the presence of these metals. The reaction rate is affected by the type of metal cation, by the concentration of the cation and by pH. At pH levels below 2.0 the limestone dissolution reaction rate decreases sharply with increasing pH. In the pH range 4.0 to 5.5 the reaction rate decreases linearly with increasing pH. The pH range 2.0 to 4.0 is a transition range, from the non-linear to linear dissolution rate characteristics. Metal concentrations below 80 mg l(-1): At pH levels less than 4, iron(II) had the strongest suppressing effect followed by aluminium, while the presence of iron(III) increased the reaction rate. In the pH range 4.0 to 5.5 aluminium had the strongest suppressing effect followed by iron(III) and iron(II). Metal concentrations above 80 mg l(-1): Iron(II) and aluminium suppress the reaction rate at all pH levels. At pH levels less than 4 iron(II) had the strongest suppressing effect, followed by aluminium. In the pH range 4.0 to 5.5 aluminium had the strongest suppressing effect followed by iron(II). With iron(III) the rate is suppressed at pH levels below 2, however the rate is speeded up in the pH range 25 to 3.5. At higher pH levels, the iron(III) concentration is limited to less than 80 mg l(-1) because of precipitation of iron(III) at pH levels higher than 2.5. The extent to which the overall neutralisation reaction proceeds was modelled to assist in reactor design. The overall reaction is impaired most by aluminium, followed by iron(II) and iron(III)

Occurrence of selected herbicides and herbicide degradation products in Iowa's ground water, 1995, 1997,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Kolpin D. W. , Kalkhoff S. J. , Goolsby D. A. , Sneckfahrer D. A. , Thurman E. M. ,
Herbicide compounds were prevalent in ground water across Iowa, being detected in 70% of the 106 municipal wells sampled during the summer of 1995, Herbicide degradation products were three of the four most frequently detected compounds for this study. The degradation product alachlor ethanesulfonic acid was the most frequently detected compound (65.1%), followed by atrazine (40.6%), and the degradation products deethylatrazine (34.9%), and cyanazine amide (19.8%). The corn herbicide acetochlor, first registered for widespread use in the United States in March 1994, was detected in a single water sample, No reported herbicide compound concentrations for this study exceeded current U.S. Environmental Protection Agency's maximum contaminant levels or health advisory levels for drinking water, although the herbicide degradation products examined have get to have such levels established. The occurrence of herbicide compounds had a significant, inverse relation to well depth and a significant, positive relation to dissolved-oxygen concentration. It is felt that both well depth and dissolved oxygen are acting as rough surrogates to ground-water age, with younger ground water being more likely to contain herbicide compounds. The occurrence of herbicide compounds was substantially different among the major aquifer types across Iowa, being detected in 82.5% of the alluvial, 81.8% of the bedrock/ karst region, 40.0% of the glacial-drift, and 25.0% of the bedrock/nonkarst region aquifers. The observed distribution was partially attributed to variations in general ground-water age among these aquifer types. A significant, inverse relation was determined between total herbicide compound concentrations in ground water and the average soil slope within a 2-km radius of sampled wens. Steeper soil slopes may increase the likelihood of surface runoff occurring rather than ground-water infiltration-decreasing the transport of herbicide compounds to ground water. As expected, a significant positive relation was determined between intensity of herbicide use and herbicide concentrations in ground water

Geochemistry of Fluorite and Related Features of the Kugitangtou Ridge Caves, Turkmenistan, 1998,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Maltsev, V. , Korshunov, V.
This paper presents a model explaining the fluorine geochemistry in the Cupp-Coutunn Cave System, in the Kugitangtou Ridge, southeastern Turkmenistan. By the corrosive activity of biologically derived sulfuric acid, HF gas is released by weathering of fluorite in residual cave deposits and in speleothems formed during a period of thermal activity. Secondary fluorite is produced, and conditions are provided for silica and aluminum mobility in the caves. The latter process helps to explain the origin of the clay mineral sauconite, Zn3(Si4O10)(OH)2nH2O, and fraipontite, (Zn,Al)3(SiAl)2O5(OH)4, a member of the kaolinite-serpentine group.

Mapping Chicxulub crater structure with gravity and seismic reflection data, 1998,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Hildebrand A. R. , Pilkington M. , Ortizaleman C. , Chavez R. E. , Urrutiafucugauchi J. , Connors M. , Granielcastro E. , Camarazi A. , Halpenny J. F. , Niehaus D. ,
Aside from its significance in establishing the impact-mass extinction paradigm, the Chicxulub crater will probably come to exemplify the structure of large complex craters. Much of Chicxulub's structure may be mapped' by tying its gravity expression to seismic-reflection profiles revealing an [~]180 km diameter for the now-buried crater. The distribution of karst topography aids in outlining the peripheral crater structure as also revealed by the horizontal gradient of the gravity anomaly. The fracturing inferred to control groundwater flow is apparently related to subsidence of the crater fill. Modelling the crater's gravity expression based on a schematic structural model reveals that the crater fill is also responsible for the majority of the negative anomaly. The crater's melt sheet and central structural uplift are the other significant contributors to its gravity expression. The Chicxulub impact released [~]1.2 x 1031 ergs based on the observed collapsed disruption cavity of [~]86 km diameter reconstructed to an apparent disruption cavity (Dad) of [~]94 km diameter (equivalent to the excavation cavity) and an apparent transient cavity (Dat) of [~]80 km diameter. This impact energy, together with the observed [~]2 x 1011 g global Ir fluence in the Cretaceous-Tertiary (K-T) fireball layer indicates that the impactor was a comet estimated as massing [~]1.8 x 1018 g of [~]16.5 km diameter assuming a 0.6 gcm-3 density. Dust-induced darkness and cold, wind, giant waves, thermal pulses from the impact fireball and re-entering ejecta, acid rain, ozone-layer depletion, cooling from stratospheric aerosols, H2O greenhouse, CO2 greenhouse, poisons and mutagens, and oscillatory climate have been proposed as deleterious environmental effects of the Chicxulub impact with durations ranging from a few minutes to a million years. This succession of effects defines a temperature curve that is characteristic of large impacts. Although some patterns may be recognized in the K-T extinctions, and the survivorship rules changed across the boundary, relating specific environmental effects to species' extinctions is not yet possible. Geochemical records across the boundary support the occurrence a prompt thermal pulse, acid rain and a [~]5000 year-long greenhouse. The period of extinctions seems to extend into the earliest Tertiary

High-resolution records of soil humification and paleoclimate change from variations in speleothem luminescence excitation and emission wavelengths, 1998,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Baker A, Genty D, Smart Pl,
Recent advances in the precision and accuracy of the optical techniques required to measure luminescence permit the nondestructive analysis of solid geologic samples such as speleothems (secondary carbonate deposits in caves). In this paper we show that measurement of speleothem luminescence demonstrates a strong relationship between the excitation and emission wavelengths and both the extent of soil humification and mean annual rainfall. Raw peat with blanket bog vegetation has the highest humification and highest luminescence excitation and emission matrix wavelengths, because of the higher proportion of high-molecular-weight organic acids in these soils. Brown ranker and rendzina soils with dry grassland and woodland cover have the lowest wavelengths. Detailed analysis of one site where an annually laminated stalagmite has been deposited over the past 70 yr during a period with instrumental climate records and no vegetation change suggests that more subtle variations in luminescence emission wavelength correlate best with mean annual rainfall, although there is a lag of approximately 10 yr. These results are used to interpret soil humification and climate change from a 130 ka speleothem at an upland site in Yorkshire, England. These data provide a new continuous terrestrial record of climate and environmental change for northwestern Europe and suggest the presence of significant variations in wetness and vegetation within interglacial and interstadial periods

Changes in the isotopic and chemical composition of ground water resulting from a recharge pulse from a sinking stream, 1998,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Katz B. G. , Catches J. S. , Bullen T. D. , Michel R. L. ,
The Little River, an ephemeral stream that drains a watershed of approximately ss km(2) in northern Florida, disappears into a series of sinkholes along the Cody Scarp and flows directly into the carbonate Upper Floridan aquifer, the source of water supply in northern Florida. The changes in the geochemistry of ground water caused by a major recharge pulse from the sinking stream were investigated using chemical and isotopic tracers and mass-balance modeling techniques, Nine monitoring wells were installed open to the uppermost part of the aquifer in areas near the sinks where numerous subterranean karst solution features were identified using ground penetrating radar. During high-flow conditions in the Little River, the chemistry of water in some of the monitoring wells changed, reflecting the mixing of river water with ground water. Rapid recharge of river water into some parts of the aquifer during high-flow conditions was indicated by enriched values of delta O-18 and delta deuterium (-1.67 to -3.17 per mil and -9.2 to -15.6 per mil, respectively), elevated concentrations of tannic acid, higher (more radiogenic) Sr-87/Sr-86 ratios, and lower concentrations of Rn-222, silica, and alkalinity compared to low-how conditions. The proportion of river water that mixed with ground water ranged from 0.10 to 0.67 based on binary mixing models using the tracers O-18, deuterium, tannic acid, silica, Rn-222, and Sr-87/Sr-86. On the basis of mass-balance modeling during steady-state how conditions, the dominant processes controlling carbon cycling in ground water are the dissolution of calcite and dolomite in aquifer material, and aerobic degradation of organic matter. (C) 1998 Elsevier Science B.V. All rights reserved

Determining the Age of What Is Not There., 1998,
Deprecated: Function get_magic_quotes_gpc() is deprecated in /home/isthin5/public_html/addon-domains/ on line 943
Sasowsky I. D.
How old is a cave? This is not an easy question. A cave is not an actual object but is rather the absence of material, and ascertaining the age of what is not there is difficult. In his research commentary, Sasowsky discusses results presented in the same issue by Polyak et al. in which a new strategy has been developed for dating caves created by the dissolving action of acidic ground water in limestone. In particular, the method has been applied to two of the most famous caves in the world: Carlsbad and Lechuguilla caves in New Mexico, USA.

Results 31 to 45 of 258
You probably didn't submit anything to search for