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Enviroscan Ukrainian Institute of Speleology and Karstology


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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 lecontite is a cave mineral - (nh4,k)na(so4).2h2o [11].?

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


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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;
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Your search for mg (Keyword) returned 231 results for the whole karstbase:
Showing 211 to 225 of 231
New data on the dolines of Velebit Mountain: An evaluation of their sedimentary archive potential in the reconstruction of landscape evolution , 2012,
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Ballut Christle, Faivre Sanja

The first approach to the relationships between societies and physical environments on Velebit Mountain shows narrow correlations between spatial distribution of dolines, soil formation, hydric resources, vegetation and land occupation. In 2002, sediment cores have been obtained from different dolines of Velebit Mountain to evaluate the potential of their sedimentary archives in order to reconstruct the landscape history. On the littoral slopes and on the top parts of the mountain, the dolines were difficult to dig due to the presence of rocks in depth. Nevertheless, the cores have been sampled and soil analyses have been made (physical and chemical analyses: colour, grain size, pH, CaCO3, C, N, P, K, Mg, CEC). No dating materials were found. The first results attest to rather homogeneous pedologic processes in each area studied (Kamenica, Stinica, Baške Oštarije and Bilensko Mirevo), but they also indicate colluvial contributions. These contributions differ from one doline to another according to their location and morphology. Dolines reveal themselves to be not very good traps, as the representative nature of their sedimentary archives could be very local. However, the best profile has been obtained at Bilensko Mirevo, which shows a change in the soil nutrient content from an impoverishment in its middle part toward an increase of the soil nutrients in recent parts. Those environmental changes could not be precisely dated, but could be correlated with the 17th to 20th century phase of strong human impact on the Velebit environment and with the rural depopulation observed since the second half of the 20th century.


105 Jahre Forschung am Hlloch im Mahdtal und seiner Umgebung, Bayern, 2012,
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Wolf, A.
Hlloch im Mahdtal is currently Germanys second longest cave. One branch of this system extends into the province of Vorarlberg (Austria). This article summarises the caving activities of the last five years since 2007, during which a total of 1400 m of new passages were surveyed.

Hydrogeology of the Gokpinar karst springs, Sivas, Turkey, 2012,
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Kacaroğ, Lu F.

Gökpınar karst springs are located 8 km to the south of the Gürün district centre, Sivas, Turkey. The springs have two main outlets (Gökpınar-1 and Gökpınar-2) and outflow from Jurassic-Cretaceous Yüceyurt formation (limestone). The total discharge of the springs ranges between 4.5 and 7.8 m3/s.The study area is formed of allocthonous and autocthonous lithological units whose ages range from Upper Devonian to Quaternary. These lithologies are mostly formed of limestones. Yüceyurt formation (limestone), from which Gökpınar karst springs outflow, constitute the main aquifer in the study area and is karstified. The unit has a well developed karst system comprising karren, dolines, ponors, underground channels and caves. The recession (discharge) analysis of the Gökpınar springs was carried out and the storage capacitiesand discharge (recession) coefficients of the Gökpınar-1 and Gökpınar-2 springs were calculated as 141×10^6 m3 and 98×10^6 m3, and 2.71×10^-3 day-1 and 2.98×10^-3 day-1, respectively. The storage capacities and discharge (recession) coefficients obtained suggest that the karst aquifer (Yüceyurt limestone) has large storage capacity, and drainage occurs very slow. The major cations in the study area waters are Ca2+ and Mg2+, and anion is HCO3-. The waters are calcium bicarbonate type. Some of the water chemistry parameters of the Gökpınar springs range as follows: T=10.8–11.1°C, pH=7.65–7.95,EC=270–310 μS/cm, TDS=170–200 mg/L, Ca2+=40.0–54.0 mg/L,Mg2+=4.5–10.0 mg/L, HCO3-=144.0–158.0 mg/L. Temperature, EC, TDS, and Ca2+ and HCO3- concentrations of the Gökpınar springs did not show significant variations during the study period.


THERMOMINERAL WATERS OF INNER DINARIDES KARST, 2012,
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Milenić, D. , KruniĆ, O. , MilankoviĆ, D.

The Dinarides are the largest continuous karst region in Europe. With regard to a geotectonic view, they are divided into the Outer, Central and Inner Dinarides occupying the territories of Slovenia, Croatia, Bosnia and Herzegovina, Serbia and Montenegro. Numerous occurrences of thermomineral water have been recorded in the Inner Dinarides area. The majority of them are genetically related to carbonate sediments of Mesozoic age. This paper deals with occurrences of thermomineral waters of the Inner Dinarides karst, their quantitative and qualitative characteristics, basic genetic types, the age of karst thermomineral waters of the Inner Dinarides, the available quantities of hydrogeothermalmineral energy, balneological potential and the possibility of rational multi-purpose utilisation. Hydrochemical and isotope methods have been used for the analysis of basic genetic types and age of karst thermomineral waters, while a geothermometer method has been used for the calculation of primary temperatures in water-bearing horizons(geothermal reservoirs) themselves. The carried out research has pointed out that karst thermomineral waters formed in carbonate sediments of Mesozoic age are characterized by temperatures ranging from 15.5oC (Kneina Ilida) to 75oC (Bogatić), being most frequently of a HCO3-Ca, Mg type with neutral to poor alkaline reaction and mineralization below 1 g/l. Karst thermomineral waters of the Inner Dinarides are most frequently related to geothermal systems formed in carbonate sediments covered by rocks of poor water permeability. In case of some thermomineral water occurrences, the mixing of the karst thermomineral waters with those formed in sedimentary basins occurs due to their hydraulic relation, thus it is not possible to determine only one geothermal system in which they are formed. The overall geothermal potential of the thermomineral waters of the Inner Dinarides karst is about 160 MW. In addition to the geothermal aspect, these waters have been widely utilised in balneology, wellness programmes, as well as for the needs of bottling. The level of research activity and with that the way of the utilisation of these waters are various. With regard to the number of occurrences known so far and their potential, it can be claimed with certainty, that the utilisation of thermomineral water occurring in the karst of the Inner Dinarides will increase significantly in future. An example of the multi-purpose utilisation of the Pribojska Banja Spa thermomineral waters illustrates a possible way of doing it.


Hydrogeology of the Gokpinar karst springs, Sivas, Turkey , 2012,
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Kaaroğ, Lu Fikret

Gökpınar karst springs are located 8 km to the south of the Gürün district centre, Sivas, Turkey. The springs have two main outlets (Gökpınar-1 and Gökpınar-2) and outflow from Jurassic-Cretaceous Yüceyurt formation (limestone). The total discharge of the springs ranges between 4.5 and 7.8 m3/s.The study area is formed of allocthonous and autocthonous lithological units whose ages range from Upper Devonian to Quaternary. These lithologies are mostly formed of limestones. Yüceyurt formation (limestone), from which Gökpınar karst springs outflow, constitute the main aquifer in the study area and is karstified. The unit has a well developed karst system comprising karren, dolines, ponors, underground channels and caves. The recession (discharge) analysis of the Gökpınar springs was carried out and the storage capacitiesand discharge (recession) coefficients of the Gökpınar-1 and Gökpınar-2 springs were calculated as 141×10^6 m3 and 98×10^6 m3, and 2.71×10^-3 day-1 and 2.98×10^-3 day-1, respectively. The storage capacities and discharge (recession) coefficients obtained suggest that the karst aquifer (Yüceyurt limestone) has large storage capacity, and drainage occurs very slow. The major cations in the study area waters are Ca2+ and Mg2+, and anion is HCO3-. The waters are calcium bicarbonate type. Some of the water chemistry parameters of the Gökpınar springs range as follows: T=10.8–11.1°C, pH=7.65–7.95,EC=270–310 μS/cm, TDS=170–200 mg/L, Ca2+=40.0–54.0 mg/L,Mg2+=4.5–10.0 mg/L, HCO3-=144.0–158.0 mg/L. Temperature, EC, TDS, and Ca2+ and HCO3- concentrations of the Gökpınar springs did not show significant variations during the study period.


Thermomineral waters of inner Dinarides Karst, 2012,
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Milenić, Dejan, Krunić, Olivera, Milanković, Djuro

The Dinarides are the largest continuous karst region in Europe. With regard to a geotectonic view, they are divided into the Outer, Central and Inner Dinarides occupying the territories of Slovenia, Croatia, Bosnia and Herzegovina, Serbia and Montenegro. Numerous occurrences of thermomineral water have been recorded in the Inner Dinarides area. The majority of them are genetically related to carbonate sediments of Mesozoic age. This paper deals with occurrences of thermomineral waters of the Inner Dinarides karst, their quantitative and qualitative characteristics, basic genetic types, the age of karst thermomineral waters of the Inner Dinarides, the available quantities of hydrogeothermalmineral energy, balneological potential and the possibility of rational multi-purpose utilisation. Hydrochemical and isotope methods have been used for the analysis of basic genetic types and age of karst thermomineral waters, while a geothermometer method has been used for the calculation of primary temperatures in water-bearing horizons(geothermal reservoirs) themselves. The carried out research has pointed out that karst thermomineral waters formed in carbonate sediments of Mesozoic age are characterized by temperatures ranging from 15.5oC (Kneina Ilida) to 75oC (Bogatić), being most frequently of a HCO3-Ca, Mg type with neutral to poor alkaline reaction and mineralization below 1 g/l. Karst thermomineral waters of the Inner Dinarides are most frequently related to geothermal systems formed in carbonate sediments covered by rocks of poor water permeability. In case of some thermomineral water occurrences, the mixing of the karst thermomineral waters with those formed in sedimentary basins occurs due to their hydraulic relation, thus it is not possible to determine only one geothermal system in which they are formed. The overall geothermal potential of the thermomineral waters of the Inner Dinarides karst is about 160 MW. In addition to the geothermal aspect, these waters  have been widely utilised in balneology, wellness programmes, as well as for the needs of bottling. The level of research activity and with that the way of the utilisation of these waters are various. With regard to the number of occurrences known so far and their potential, it can be claimed with certainty, that the utilisation of thermomineral water occurring in the karst of the Inner Dinarides will increase significantly in future. An example of the multi-purpose utilisation of the Pribojska Banja Spa thermomineral waters illustrates a possible way of doing it.


Cure from the cave: volcanic cave actinomycetes and their potential in drug discovery, 2013,
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Cheeptham N. , Sadoway T. , Rule D. , Watson K. , Moote P. , Soliman L. C. , Azad N. , Donkor K. K. , Horne D.

Volcanic caves have been little studied for their potential as sources of novel microbial species and bioactive compounds with new scaffolds. We present the first study of volcanic cave microbiology from Canada and suggest that this habitat has great potential for the isolation of novel bioactive substances. Sample locations were plotted on a contour map that was compiled in ArcView 3.2. Over 400 bacterial isolates were obtained from the Helmcken Falls cave in Wells Gray Provincial Park, British Columbia. From our preliminary screen, of 400 isolates tested, 1% showed activity against extended spectrum ß-lactamase E. coli, 1.75% against Escherichia coli, 2.25% against Acinetobacter baumannii, and 26.50% against Klebsiella pneumoniae. In addition, 10.25% showed activity against Micrococcus luteus, 2% against methicillin resistant Staphylococcus aureus, 9.25% against Mycobacterium smegmatis, 6.25% Pseudomonas aeruginosa and 7.5% against Candida albicans. Chemical and physical characteristics of three rock wall samples were studied using scanning electron microscopy and f lame atomic absorption spectrometry. Calcium (Ca), iron (Fe), and aluminum (Al) were the most abundant components while magnesium (Mg), sodium (Na), arsenic (As), lead (Pb), chromium (Cr), and barium (Ba) were second most abundant with cadmium (Cd) and potassium (K) were the least abundant in our samples. Scanning electron microscopy (SEM) showed the presence of microscopic life forms in all three rock wall samples. 16S rRNA gene sequencing of 82 isolates revealed that 65 (79.3%) of the strains belong to the Streptomyces genus and 5 (6.1%) were members of Bacillus, Pseudomonas, Nocardia and Erwinia genera. Interestingly, twelve (14.6%) of the 16S rRNA sequences showed similarity to unidentif ied ribosomal RNA sequences in the library databases, the sequences of these isolates need to be further investigated using the EzTaxon-e database (http://eztaxon-e. ezbiocloud.net/) to determine whether or not these are novel species. Nevertheless, this suggests the possibility that they could be unstudied or rare bacteria. The Helmcken Falls cave microbiome possesses a great diversity of microbes with the potential for studies of novel microbial interactions and the isolation of new types of antimicrobial agents.


Natural and anthropogenic factors which influence aerosol distribution in Ingleborough Show Cave, UK, 2013,
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Smith A. C. , Wynn P. M. , Barker P. A.

Monitoring in Ingleborough Show Cave (N. Yorkshire, UK) reveals the influence of tourism and cave management techniques on different parameters of the cave atmosphere. Exploratory aerosol monitoring identified a 0.015 ± 0.03 mg/m3 (≈70%) reduction in airborne particulates within the first 75 meters of cave passage and two major aerosol sources within this artificially ventilated show cave. Autogenic aerosol production was identified close to active stream ways (increases of <0.012 mg/m3), suggesting the expulsion of water-borne aerosols during turbulent water flow. The presence of tourist groups also increased aerosol concentrations within the cave (increases of <0.021 mg/m3), either by transporting them from an allogenic source or through the disturbance of particles which had previously been deposited within the cave environment. Exploratory aerosol data is presented alongside more routine analytical monitoring, helping to contextualise the impact of cave management strategies on natural cave atmospherics.


Isotopic and hydrochemical data as indicators of recharge areas, flow paths and waterrock interaction in the Caldas da RainhaQuinta das Janelas thermomineral carbonate rock aquif, 2013,
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Marques J. M. , Graa H. , Eggenkamp H. G. M. , Neves O. , Carreira P. M. , Matias M. J. , Mayer B. , Nunes D. , Trancoso V. N.

An updated conceptual circulation model for the Caldas da Rainha and Quinta das Janelas thermomineralwaters was developed. These thermomineral waters (T _ 33 _C) are related to a huge syncline ascribed tothe regional flow paths. Two diapiric structures were responsible for the uplift and subsequent folding ofregional Jurassic carbonate rocks. Environmental isotopic (d2H and d18O) data indicates that the mainrecharge area of the thermomineral system is linked to the Jurassic limestones (Candeeiros Mountains,E border of the syncline). The thermomineral waters belong to the Cl–Na sulphurous-type, with a totalmineralization of about 3000 mg/L. The thermomineral aquifer system seems to be ‘‘isolated’’ fromanthropogenic contamination, which is typical for the local shallow groundwater systems, due to theexistence of impermeable layers composed of a series of loamy and detritic rocks of the Upper Jurassic.The presence of 3H in some thermomineral borehole waters, not accompanied by an increase in SO2_4 andNO_3 , could be ascribed to different underground flow paths and different mean residence time. Thed34S(SO4) and d18O(SO4) values of dissolved sulphate of groundwaters of the Caldas da Rainha Spas indicatethat the sulphate is the result of water–rock interaction with evaporitic rocks (e.g. gypsum and anhydrite)ascribed to the regional synclinal structure.


Forty years of epikarst: what biology have we learned?, 2013,
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Pipan T. , Culver D. C.

Epikarst is not only an important component of the hydrogeology of karst and an active site of speleogenesis, it is habitat for a number of species adapted to subterranean life. Water in epikarst, with a residence time of days to months, is a highly heterogeneous habitat, and the animals are primarily sampled from continuously sampling dripping water or collecting from residual drip pools. While the subterranean fauna of cracks and crevices has been known for over 100 years, it is only in the past several decades that epikarst has been recognized as a distinct habitat, with reproducing populations of stygobionts. Dissolved organic carbon in epikarst drip water is a primary and sometimes the only source of organic matter for underlying caves, especially if there are not sinking streams that enter the cave. Typical concentrations of organic carbon are 1 mg L-1. The fauna of epikarst is dominated by copepods, but other groups, including some terrestrial taxa, are important in some areas. Most of the diversity is β-diversity (between drips and between caves). In Slovenia, an average of nearly 9 stygobiotic copepod species were found per cave. In studies in Romania and Slovenia, a number of factors have been found to be important in determining species distribution, including ceiling thickness, habitat connectivity and habitat size. In addition to eye and pigment loss, epikarst copepod species may show a number of specializations for life in epikarst, including adaptations to avoid displacement by water flow. Several geoscientists and biologists have challenged the uniqueness and importance of epikarst, but on balance the concept is valid and useful. Fruitful future research directions include development of better sampling techniques, studies to explain differences among nearby epikarst communities, phylogeographic studies, and assessing the possible role of copepods as tracers of vadose water.


INVESTIGATIONS INTO THE POTENTIAL FOR HYPOGENE SPELEOGENESIS IN THE CUMBERLAND PLATEAU OF SOUTHEAST KENTUCKY, U.S.A., 2013,
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Florea Lee J.

 

This manuscript offers preliminary geochemical evidence that investigates the potential for hypogene speleogenesis in the Cumberland Plateau of southeastern Kentucky, U.S.A. The region was traditionally considered a classic example of epigenic karst, but new insights have uncovered tantalizing observations that suggest alternatives to simple carbonic acid speleogenesis. Such first-order observations have included natural petroleum seeps at the surface and in caves, occasional cave morphologies consistent with action of hypogene fluids, and prolific gypsum within cave passages. To this point, geochemical data from caves and springs verify carbonic acid as the primary dissolutional agent; however, these same analyses cannot rule out sulfuric acid as a secondary source of dissolution. In this paper, Principal Component Analysis of ionic data reveals two components that coordinate with parameters associated with “karst water” and shallow brine. In contrast, molar ratios of Ca+ and Mg+ as compared to HCO3 - and SO4 2- closely follow the reaction pathway stipulated by the carbonate equilibria reactions. Despite these data, the role, if any, of hypogene speleogenesis in the karst of the Cumberland Plateau remains inconclusive. It is very likely that carbonic acid dominates speleogenesis; however, contributions from sulfuric acid may influence our understanding of “inception” and carbon flux within these aquifers.


LITTLE LIMESTONE LAKE: A BEAUTIFUL MARL LAKE IN MANITOBA, CANADA, 2013,
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Ford Derek

 

Marl lakes are those accumulating fine-grained bottom sediments that include at least 15% CaCO3. They are found worldwide. The most visually attractive, however, have higher proportions of CaCO3, with crystallites precipitating in the water to give it a rich and opaque duck-egg blue colouration. From the literature, such lakes are largely limited to recently glaciated carbonate rock terrains. Most are also shallow, with much or all of the water column being in the photic zone. Little Limestone Lake, (Lat. 53°47’N, Long. 99°19’W in the province of Manitoba) is the finest example that the author has seen. It stands out sharply from neighbouring lakes in summertime colour satellite imagery due to the intensity and uniformity of its colour. The lake occupies a shallow glacial trough scoured in a plain of flat-lying cyclothem dolomites. It is ~12 km long, 1–5 km wide, rarely >7 m deep. Including bordering wetlands, it occupies ~45 % of the area of an elongated, narrow topographic basin. Recharge is through impoverished boreal forest with little soil cover; it discharges chiefly as springs and seeps along and below the shore. Mean annual temperature is ~0 °C, and precipitation is ~475 mm.y1. Previous studies of springs in the surrounding region showed ground waters to be simple bicarbonate composition, with TDS = 230–300 mg.l-1 (Ca 40–60 mg.l-1, Mg 30–40 mg.l-1). Grab sampling at 27 sites throughout the lake found the waters de-gassed to 125–135 mg.l-1, placing them in the mid-range of one hundred marl lakes investigated in more detail in the British Isles. Ca was reduced to 25–30 mg.l-1, while Mg was stable at 30–40 mg.l-1. There were 2–3 mg.l-1 of free CO3 in two fully analysed samples, indicating that plankton photosynthesis might be occurring. However, samples of the bottom marl were predominantly inorganic in their composition. Little Limestone Lake is visually spectacular because it is almost entirely groundwater-fed, with a ratio of recharge area to lake area that is low. It has no large, chemically equilibrated, surface streams entering it. In contrast, the dozens of nearby lakes (similar, larger or smaller in size) are regularly flushed by channelled storm water and, although they also produce some carbonate marl, cannot maintain high densities of crystallites in suspension. Little Limestone Lake was placed under legislated protection as a provincial park in June 2011.


Rapidcreekite in the sulfuric acid weathering environment of Diana Cave, Romania, 2013,
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Onac B. P. Effenberger H. S. Wynn J. G. Povară, I.

The Diana Cave in SW Romania develops along a fault line and hosts a spring of hot (Tavg = 51 °C), sulfate-rich, sodium-calcium-chloride bearing water of near-neutral pH. Abundant steam and H2S rises from the thermal water to condensate on the walls and ceiling of the cave. The sulfuric acid produced by H2S oxidation/hydrolysis causes a strong acid-sulfate weathering of the cave bedrock generating a sulfate-dominated mineral assemblage that includes rapidcreekite, Ca2(SO4)(CO3)•4H2O closely associated with gypsum and halotrichite group minerals. Rapidcreekite forms bundles of colorless tabular orthorhombic crystals elongated along [001] and reaching up to 1.5 mm in length. For verifying the hydrogen bond scheme and obtaining crystal-chemical details of the carbonate group a single-crystal structure refinement of rapidcreekite was performed. Its unit-cell parameters are: a = 15.524(2), b = 19.218(3), c = 6.161(1) Å; V = 1838.1(5) Å3, Z = 8, space group Pcnb. Chemi¬cal composition (wt%): CaO 35.65, SO3 24.97, CO2 13.7, H2O 23.9, Na2O 0.291, MgO 0.173, Al2O3 0.07, total 98.75%. The empirical formula, based on 7 non-water O atoms pfu, is: Ca1.98Na0.029Mg0.013 Al0.004(S0.971 O4)(C0.97O3)•4.13H2O. The d34S and d18O values of rapidcreekite and other cave sulfates range from 18 to 19.5‰ CDT and from –9.7 to 7.8‰ SMOW, respectively, indicating that the source of sulfur is a marine evaporite and that during hydration of the minerals it has been an abundant 18O exchange with percolating water but almost no oxygen is derived from O2(aq). This is the first descrip¬tion of rapidcreekite from a cave environment and one of the very few natural occurrences worldwide. We also report on the mineral stability and solubility, parameters considered critical to understand the co-precipitation of carbonates and sulfates, a process that has wide applications in cement industry and scaling prevention.


THE SAN PAOLO MINE TUNNEL AT SA DUCHESSA (DOMUSNOVAS, SW SARDINIA): TEN INTERCEPTED NATURAL CAVES AND FIRST DATA ON THE COMPOSITION OF SOME SPELEOTHEMS , 2013,
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Simone Argiolas, Caddeo Guglielmo Angelo, Casu Lucilla, Muntoni Alberto, Papinuto Silvestro

Since many years cavers from different caving teams are carrying out a systematic study on the caves of Sulcis-Iglesiente, including geomorphological studies. Over thirty natural caves have been explored, surveyed and registered in the past few years, and over half of these have been made accessible by mine galleries. Among these are worth to be mentioned the “Tre Sorelle” of Domusnovas: these are three mine caves intercepted by the San Paolo mine tunnel. This tunnel, whose collapsed entrance has been reopened after a long digging campaign, has been explored and surveyed for around 700 meters. A total of 10 natural caves, mostly developed along fractures, have been explored and mapped, with developments ranging between 10 and 250 meters and depths from 15 to over 160 meters. Only two of these caves were previously known in the Regional Cave Register. In most of the caves, speleothems consist mainly of flowstones, some of which are clear or usually white, others are dark-brown or tending to black. Some samples of the first and the second flowstone types were collected respectively from the “Sesta Sorella” and “Seconda Sorella” Caves. The powders of these samples were analysed by an X-ray diffractometer. The first type consists of thicker layers of white and fibrous aragonite, which sometimes alternate with thinner layers of grey columnar calcite. In some samples, however, calcite interlayers were absent and just aragonite was found. The second type is composed of alternating layers of darkbrown hemimorphite. Some additional analyses were performed on these samples by Laser Ablation ICP-MS to determine the concentration of minor and trace elements in the different layers and mineralogical phases. The most abundant minor elements in calcite layers are Mg and Zn. Magnesium is about constant (~ 2000 ppm) on different spots and remains under the average Mg content of the cave calcite in this region, whereas Zn ranges from 103 to 104 ppm and is well above the Zn average in calcite of caves in the world. Barium concentration is about 80 ppm and more abundant than Pb (20 ppm) and Sr (10 ppm). Barium is also the main minor element in aragonite, where it can reach almost 2000 ppm. The Zn concentration is very high even in aragonite and is comparable to that of Sr (400-500 ppm), overcoming considerably the Pb concentration (20 ppm). In hemimorphite, the most abundant minor elements are Al and Fe (about 104 ppm). However, it was not quantified how much of these are in the hemimorphite lattice or come from some impurities. Actually, we notice that concentration of Fe and Al in the black layers of hemimorphite is an order of magnitude greater than in the brown ones. In addition, the black layers show an abrupt increase of Mn concentration, which overcomes Fe and Al. The evolution of these flowstones is most probably related to the circulation of fluids connected to the oxidation of sulphides, specially sphalerite.


Biological Control on Acid Generation at the Conduit-Bedrock Boundary in Submerged Caves: Quantification through Geochemical Modeling, 2013,
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Herman Janet S. , Hounshell Alexandria G. , Franklin Rima B, Mills Aaron L.

No-mount Cave, located in wekiwa Springs State Park in central Florida, USA, is an aphotic, submerged, freshwater cave in which large colonies of sulfur-oxidizing bacteria live in filamentous microbial mats. Upwardly discharging groundwater enters the cave from the Upper Floridan aquifer, specifically the Eocene-aged Ocala Limestone. we undertook a combined field, laboratory, and modeling study in which we sought to determine the amount of calcite dissolution attributable to the generation of protons by microbially mediated sulfide oxidation. The chemical compositions of groundwater within the limestone formation collected through a newly designed sampling device and of water in the cave conduit were used in geochemical modeling. we used the reaction-path model PHREEqCI to quantify the amount of calcite dissolution expected under various plausible scenarios for mixing of formation water with conduit water and extent of bacterial sulfide oxidation. Laboratory experiments were conducted using flow-through columns packed with crushed limestone from the study site. Replicate columns were eluted with artificial groundwater containing dissolved HS- in the absence of microbial growth. without biologically mediated sulfide oxidation, no measurable calcite dissolution occurred in laboratory experiments and no additional amount of speleogenesis is expected as formation water mixes with conduit water in the field. In contrast, significant calcite dissolution is driven by the protons released in the biological transformation of the aqueous sulfur species. Although a range of results were calculated, a plausible amount of 158 mg Ca2+ released to conduit water per liter of groundwater crossing the formation-conduit boundary and mixing with an equal volume of conduit water was predicted. Our modeling results indicate that significant cave development can be driven by microbially mediated sulfide oxidation under these hydrogeochemical conditions


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