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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 scaling chip is a thin small rather irregular piece of limestone, commonly crumbly, which has fallen from the ceiling or wall of a cave. a form of cave breakdown [10].?

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.
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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 pco2 (Keyword) returned 44 results for the whole karstbase:
Showing 16 to 30 of 44
A rare landform: Yerkopru travertine bridges in the Taurids Karst Range, Turkey, 2002, Bayari Cs,
Two examples of travertine bridges are observed at 8 to 15 in above stream level in the Lower Zamanti Basin, Eastern Taurids, Turkey. Yerkopu-1 and Yerkopru-2 bridges are currently being deposited front cool karstic groundwaters with log P-CO2 > 10(-2) atm. The surface area and the total volume of travertine in Yerkopru-1 bridge are 4350 m(2) and 40 000 m(3), whereas the values for Yerkopru-2 are 2250 m(2) and 20000 m(3), respectively. The interplay of hydrogeological Structure, local topography, calcite-saturated hanging springs, algal activity and rapid downcutting in the streambed appear to have led to the formation of travertine bridges. Aeration through cascades and algal uptake causes efficient carbon dioxide evasion that enhances travertine formation. Algal curtains aid lateral development of travertine rims across the stream. Model calculations based on a hypothetical deposit in the form of a half-pyramid implied that lateral development should have occurred from both banks of the stream in the Yerkopru-1 bridge, whereas one-sided growth has been sufficient for Yerkopru-2. The height difference between travertine springs and the main strearn appears to be a result of Pleistocene glaciation during which karstic base-level lowering was either stopped or slowed down while downcutting in the main strearn continued. Copyright (C) 2002 John Wiley Sons, Ltd

Quantification of Macroscopic Subaerial Exposure Features in Carbonate Rocks, 2002, Budd Da, Gaswirth Sb, Oliver Wl,
The macroscopic features that characterize subaerial exposure surfaces in carbonates are well known, but their significance has not been quantitatively evaluated. This study presents such an analysis in the lower Oligocene Suwannee Limestone of west-central Florida. Eleven cores were point counted on a foot-by-foot basis for the abundance of caliche, rhizoliths, karst breccia, open vugs, infiltrated sediment, fractures, and pedogenic alteration. These features occur at and below intraformational exposure surfaces, which represent hiatuses estimated at 104 to 105 years, and an uppermost sequence-bounding unconformity representing 0.5 Myr, as revealed by Sr-isotope data. Statistical analyses of the point-count data reveal only a few significant relationships. (1) The hierarchy of exposure surfaces, and by inference duration of exposure, is differentiated only at a marginally significant level by sediment-filled vugs preferentially associated with the sequence boundary. Duration of exposure did not have a significant impact on the relative abundance of all other features. (2) Proximity (< 5 ft; 1.5 m) to any exposure surface is indicated only by rhizoliths, caliche, and pedogenic alteration, whereas karst breccia is preferentially found distal (> 5 ft) to both types of surfaces. Fractures, open vugs, and infiltrated sediment show no proximal or distal preference for either type of surface. (3) Depositional texture has no statistically significant affect on the presence or abundance of the exposure features, with the exception that rhizoliths and open vugs are preferentially more abundant in packstones relative to grainstones. This is interpreted to be the result of a soil-moisture effect. Factor analysis defines four factors that explain 46% to 52% of the total variance in the abundance data relative to the sequence boundary and the intraformational surfaces, respectively. The loading of each exposure feature on each factor is the same with respect to both types of surfaces, which is further evidence that the abundance of exposure features is independent of duration of exposure. Factor 1 is interpreted to be the amplitude of base-level changes and controls the abundance of karst breccia. Factor 2 is interpreted to be abundance of vegetation and relates to the abundance of rhizoliths and fractures. Factor 3 is interpreted to be a combination of soil-zone PCO2 and the availability of water and affects the abundance of pedogenic overprinting, caliche, and open vugs. Factor 4 is stratigraphic proximity to the sequence boundary, which controls the presence of sediment-filled voids. The amount of uncorrelated unique variance associated with infiltrated sediments, pedogenic overprinting, caliche, and open vugs is large (> 60%), meaning that feature abundance is also influenced by other unidentified site-specific factors. These results demonstrate that quantifying the abundance of macroscopic subaerial exposure features in limestones has the potential to yield more insight into the significance of those features than a mere qualitative assessment. This is particularly true when assessing the potential role of the many variables that can affect the development of these features

CONTROL OF ENVIRONMENTAL PARAMETERS FOR MANAGEMENT AND CONSERVATION OF NERJA CAVE (MALAGA, SPAIN), 2002, Carrasco Francisco, Vadillo Iñ, Aki, Liñ, á, N Cristina, Andreo Bartolomé, , Durá, N Juan José,

The Nerja Cave receives on average more than 500,000 visitors per year. In order to know the possible impact in the underground environment by human visits, a monitoring network was installed since 1993, to control hourly several parameters. Also, since 1991 a hydrochemical control has been carried out in the drip water points of the cave and in the natural discharge points of the carbonate aquifer. This continuous record of physical-chemical parameters of drip water, its daily outflow, as well as temperature and relative humidity in the air, CO2 concentration and rock temperature shows the human influence. The main changes in environmental parameters are the following: 1. cave air temperature rises 0.2 °C by 1000 visitors/day; 2. a daily increase between 2 and 3 % in relative air humidity, reaching saturation on summer days; 3. CO2 concentration in air increases up to values between 500 and 700 ppm during low visitability periods and 10 times the background value during high visitability periods (2.800 ppm); 4. temperature of the rock rises between 0.02 °C and 0.15 °C/day, and (5) PCO2 of drip water also presents variations, increasing during the big influx of visits and decreasing the saturation index of carbonated minerals.


On feasibility of condensation corrosion in caves (Comment to the paper: ''Hypogenic caves in Provence (France): Specific features and sediments'' by Ph. Audra, J.Y. Bigot and L. Mocochain), 2003, Dreybrodt, W.

In Fig. 6 of this paper the authors suggest how condensation corrosion could shape ceiling cupolas. Hot water containing high concentration of carbon dioxide rises to a lake filling the lower part of the cave room. Degassing of CO2 creates a CO2-containing atmosphere, which is heated by the warmer water below and becomes saturated with vapor, which condenses to the cooler wall of the cave, dissolves limestone and flows back to the lake.
If this process would continue in time it would be perfect to shape large cupolas. However, it does not because condensation stops when the temperature of the cave walls approaches that of the heated air. The reason is that condensation of water at the cave wall releases heat of condensation of 2.45 kJoule/g. This corresponds to an energy flux of 28 Watt/square-meter if a film of 1 mm depth would condensate to the wall in one day. In addition there is also a flux of heat from the warm air to the cave wall. Since the thermal conductivity of limestone (1.3 Watt/m°K) and its thermal diffusivity (5.6 x 10-7 m2/s) are low this heat cannot be rapidly transported into the bedrock, and consequently the temperature of the cave wall rises. Therefore the amount of condensation is reduced. 

One further comment should be given. There have been attempts to measure the effect of condensation corrosion by suspending gypsum plates freely in the air and determining weight loss after a defined time. For the reasons stated above the heat of condensation and the heat flux from the air raise the temperature of such samples much quicker than that of the cave walls. Reliable measurements can only be performed when such samples are fixed to the cave walls by using a high thermal conductivity glue.

A further suggestion to prove condensed water on cave walls is to take samples and analyse them for Ca-concentration and 13 carbon isotopic ratio. Since CO2 comes from the atmosphere exclusively should be below or close to zero, and Ca-concentration should be about 0.6 mmol/liter, when the pCO2 of the cave atmosphere is atmospheric.


Hydrochemical variations during flood pulses in the south-west China peak cluster karst: impacts of CaCO3-H2O-CO2 interactions, 2004, Liu Z. H. , Groves C. , Yuan D. X. , Meiman J. , Jiang G. H. , He S. Y. , Li Q. A. ,
High-resolution measurements of rainfall, water level, pH, conductivity, temperature and carbonate chemistry parameters of groundwater at two adjacent locations within the peak cluster karst of the Guilin Karst Experimental Site in Guangxi Province, China, were made with different types of multiparameter sonde. The data were stored using data loggers recording with 2 min or 15 min resolution. Waters from a large, perennial spring represent the exit for the aquifer's conduit flow, and a nearby well measures water in the conduit-adjacent, fractured media. During flood pulses, the pH of the conduit flow water rises as the conductivity falls. In contrast, and at the same time, the pH of groundwater in the fractures drops, as conductivity rises. As Ca2 and HCO3- were the dominant (>90%) ions, we developed linear relationships (both r(2) > 0.91) between conductivity and those ions, respectively, and in turn calculated variations in the calcite saturation index (SIc) and CO2 partial pressure (PCO2) of water during flood pulses. Results indicate that the PCO2 of fracture water during flood periods is higher than that at lower flows, and its SIc is lower. Simultaneously, PCO2 of conduit water during the flood period is lower than that at lower flows, and its SIc also is lower. From these results we conclude that at least two key processes are controlling hydrochemical variations during flood periods: (i) dilution by precipitation and (ii) water-rock-gas interactions. To explain hydrochemical variations in the fracture water, the water-rock-gas interactions may be more important. For example, during flood periods, soil gas with high CO2 concentrations dissolves in water and enters the fracture system, the water, which in turn has become more highly undersaturated, dissolves more limestone, and the conductivity increases. Dilution of rainfall is more important in controlling hydrochemical variations of conduit water, because rainfall with higher pH (in this area apparently owing to interaction with limestone dust in the lower atmosphere) and low conductivity travels through the conduit system rapidly. These results illustrate that to understand the hydrochemical variations in karst systems, considering only water-rock interactions is not sufficient, and the variable effects of CO2 on the system should be evaluated. Consideration of water-rock-gas interactions is thus a must in understanding variations in karst hydrochemistry. Copyright (C) 2004 John Wiley Sons, Ltd

Geological, structural and geochemical aspects of the main aquifer systems in Kuwait, 2004, Alsulaimi Js, Alruwaih Fm,
The paper summarizes the lithology, structure and the geometry of the main aquifer systems in Kuwait (the Dammam Formation and the Kuwait Group) along with the hydrochemical characteristics of the aquifers. Kuwait lies between the Arabian Shield and Zagros fold belt at the periphery of the Arabian platform. Structures associated with the Kuwait Arch noticeably control the subsurface configuration of the Dammam Formations and, hence regulate the distribution of the overlying Kuwait Group sediments. For the broad setting, the paleogeography of the Eocene has been constructed. The main lithologies of concern, both in the surface and subsurface, are the recent and subrecent sediments. The Kuwait Group includes the Dibdibba Formation, and the undifferentiated Ghar and Fars Formations, as well as the Hasa Group comprising the Dammam, Rus and Umm Er-Radhuma Formations. Subsurface geological cross-sections were constructed for the Dammam Formation, showing its structures, configuration, unconformity, and zones of uplift. Potential sites of karst formation in the Dammam limestone have been identified in the cross-sections. The structural study enables the reconstruction of the paleomorphostructural sections of the Dammam Formation. The chemical investigation indicates that the Kuwait Group aquifer is occupied by Na2SO4 and NaCl water types. In addition, the Kuwait Group aquifer is supersaturated with respect to calcite and is undersaturated with respect to halite, gypsum, anhydrite and dolomite. The Dammam Formation aquifer has Na2SO4, CaSO4 and NaCl water types. Moreover, the Dammam Formation is supersaturated with calcite and dolomite and is undersaturated with respect to halite, gypsum, and anhydrite. The calculated mean values of the PCO2 of the Kuwait Group and the Dammam Formation aquifers are 3.8 x 10(-3) atm. and 2.99 x 10(-3) atm. respectively, which are significantly above the PCO2 of the Earth's atmosphere. This may suggest a deep closed environment

The Upper Valanginian (Early Cretaceous) positive carbonisotope event recorded in terrestrial plants, 2005, Grocke D. R. , Price G. D. , Robinson S. A. , Baraboshkin E. Y. , Mutterlose J. , Ruffell A. H.

Our understanding of the ancient ocean-atmosphere system has focused on oceanic proxies. However, the study of terrestrial proxies is equally necessary to constrain our understanding of ancient climates and linkages between the terrestrial and oceanic carbon reservoirs. We have analyzed carbon–isotope ratios from fossil plant material through the Valanginian and Lower Hauterivian from a shallow-marine, ammonite-constrained succession in the Crimean Peninsula of the southern Ukraine in order to determine if the Upper Valanginian positive carbon–isotope excursion is expressed in the atmosphere.d 13 Cplantvalues fluctuate around 23xto 22xfor the Valanginian–Hauterivian, except during the Upper Valanginian where d 13 C plantvalues record a positive excursion to ~ 18x. based upon ammonite biostratigraphy from Crimea, and in conjunction with a composite Tethyan marined 13 Ccarb curve, several conclusions can be drawn: (1) thed 13 Cplantrecord indicates that the atmospheric carbon reservoir was affected; (2) the defined ammonite correlations between Europe and Crimea are synchronous; and (3) a change in photosynthetic carbon–isotope fractionation, caused by a decrease in atmosphericpCO2, occurred during the Upper Valanginian positived 13 C excursion. Our new data, combined with other paleoenvironmental and paleoclimatic information, indicate that the Upper Valanginian was a cool period (icehouse) and highlights that the Cretaceous period was interrupted by periods of cooling and was not an equable climate as previously thought.


Calcite dissolution kinetics and solubility in Na-Ca-Mg-Cl brines of geologically relevant composition at 0.1 to 1 bar pCO2 and 25 to 80°C. Doctoral dissertation, Texas A&M University. , 2005, Gledhill, Dwight Kuehl

Sedimentary basins can contain close to 20% by volume pore fluids that are commonly classified as brines. These fluids can become undersaturated with respect to calcite as a result of processes such as migration, dispersive mixing, or anthropogenic injection of CO2. This study measured calcite solubility and dissolution rates in geologically relevant Na-Ca-Mg-Cl synthetic brines (35 to 200 g L-1 TDS). In brines < 50 g L-1 TDS, the EQPITZER calculated calcium carbonate ion activity product (IAP) at steady-state was in reasonable agreement (±10%) with the thermodynamic solubility constant for calcite (Kc). However, the IAP systematically exceeded Kc in more concentrated brines. The deviation was strongly correlated with calcium concentration and also was observed in magnesium-free solutions. This is interpreted as an uncertainty in the carbonate ion activity coefficient, and minor adjustment in stoichiometric association constants (K*M2+CO30) for the CaCO30 or MgCo30 ion pairs would correct for the error. The dissolution rate dependency on brine composition, pCO2 (0.1 to 1 bar), and temperature (25.0 to 82.5 °C) was modeled using the empirical rate equation ()nkRΩ−=1 where R is the rate, k and n are empirical fitting terms, and Ω the degree of disequilibrium with respect to calcite. When Ω was defined relative to an apparent kinetic solubility, n could be assumed first-order over the range of Ω investigated (Ω = 0.2 to 1.0). Rates increased with increasing pCO2 as did the sensitivity to brine concentration. At 0.1 bar, rates were nearly independent of concentration (k = 13.0 ±2.0 x 10-3 moles m-1 hr-1). However, at higher CO2 partial pressures rates became composition dependent and the rate constant, k, was shown to be a function of temperature, pCO2, ionic strength, and calcium and magnesium activity. The rate constant (k) can be estimated from a multiple regression (MR) model of the form k = B0 + B1(T) + B2(pCo2) + B4(aCa2+) + B5(aMg2+). A relatively high activation energy (Ea = 20 kJ mol-1) was measured, along with a stirring rate independence suggesting the dissolution is dominated by surface controlled processes at saturation states Ω > 0.2 in these calcium-rich brines. These findings offer important implications to reaction-transport models in carbonate-bearing saline reservoirs.


Carbon dioxide sources, sinks, and spatial variability in shallow temperate zone caves: Evidence from Ballynamintra Cave, Ireland., 2006, Baldini J. U. L. , Baldini L. M. , Mcdermott F. , Clipson N.
Carbon dioxide concentrations in Ballynamintra Cave, S. Ireland, generally increase with distance from the entrance, but this trend is non-linear because physical constrictions and slope changes compartmentalize the cave into zones with distinct Pco2 signatures. In this cave, CO2 originates from the soil and enters the cave by degassing from drip-water and by seeping through fractures, and is then transported throughout the cave by advection. Elevated concentrations in roof fissures, joints, and adjacent to vails suggest that these locations shelter CO2 gas from advection and permit local accumulation. CO2 enrichment was noted over a sediment accumulation, suggesting that microbial oxidation of organic compounds in the sediment provided an additional CO2 source distinct from the soil zone above the cave. Advection driven by external barometric pressure variations caused ventilation, which is the principal CO2 sink. The data presented here underscore the need for high resolution data to adequately characterize cave air Pco2 variability.

Effects of high-frequency cave atmosphere PCO2 variability on stalagmite climate proxy records, 2006, Baldini Jul, Mcdermott F, Clipson N,

Anthropogenic CO2-flux into cave atmosphere and its environmental impact: A case study in the Cisarska Cave (Moravian Karst, Czech Republic), 2006, Faimon J, Stelcl J, Sas D,
The evolution of CO2 levels was studied in the ventilated and unventilated Nagel Dome chamber (the Cisarska Cave) with- and without human presence. Based on a simplified dynamic model and CO2/Rn data (222Rn considered as a conservative tracer), two types of CO2-fluxes into the chamber were distinguished: (1) the natural input of (2-4) x 10- 6[no-break space]m3 s- 1, corresponding to a flux of (8.5-17) x 10- 10[no-break space]m3 m- 2 s- 1 and (2) an anthropogenic input of (0.6-2.5) x 10- 4[no-break space]m3 s- 1, corresponding to an average partial flux of (4.8-7.7) x 10- 6[no-break space]m3 s- 1 person- 1. The chamber ventilation rates were calculated in the range from 0.033 to 0.155[no-break space]h- 1. Comparison of the chamber CO2-levels with chamber dripwater chemistry indicates that the peak CO2-concentrations during stay of persons (log pCO2 ~ - 2.97, - 2.89, and - 2.83) do not reach the theoretical values at which dripwater carbonate species and air CO2 are at equilibrium (log pCO2[DW] ~ - 2.76 to - 2.79). This means that CO2-degassing of the dripwaters will continue, increasing supersaturation with respect to calcite (dripwater saturation index defined as SIcalcite = aCa2? / 10- 8.4 varied in the range from 0.76 to 0.86). The pCO2[DW] values, however, would easily be exceeded if the period of person stay in the chamber had been slightly extended (from 2.85 to 4[no-break space]h under given conditions). In such case, the dripwater CO2-degassing would be inverted into CO2-dissolution and dripwater supersaturation would decrease. Achieving the threshold values at which water become aggressive to calcite (log pCO2[EK] ~ - 1.99, - 2.02, and - 1.84) would require extreme conditions, e.g., simultaneous presence of 100 persons in the cave chamber for 14[no-break space]h. The study should contribute to a better preservation of cave environment

Speleothems as indicators of wet and dry periods, 2007, Fairchild Ian John And Mcmillan Emily Anne
Calcareous speleothems provide a record of dripwater composition which in turn is a function of climatic conditions. The historical focus of speleothem palaeoclimate studies has been on the derivation of palaeotemperatures through oxygen isotope studies. However, it is now realized that water availability is a more generally important control on their characteristics. Growth rate and growth morphology in principle should give rise to recognizable changes at low flow. However, accidental plumbing effects during aquifer evolution, can also lead to variations in water supply and it is not easy to distinguish these effects. In areas where there is a strong amount effect on the ?18O composition of atmospheric precipitation, the speleothem ?18O composition can be a direct (and inverse) function of rainfall. High-resolution methods are now available to distinguish the composition and relative abundance of winter and summer precipitation in speleothems which formed from drips of seasonally-varying composition. Two seasonally varying processes can be responsible for significant geochemical effects during the year. Seasonal (normally summer) dryness enhances CO2-degassing which leads to elevated ?13C, Mg/Ca and Sr/Ca in dripwaters, characteristics which are transferred to speleothems. The same effects can arise by enhanced degassing at low PCO2. High-resolution analysis can distinguish the seasonal processes and, where conducted at several time intervals, allows a more confident interpretation of longer-term records.

Speleothems as indicators of wet and dry periods., 2007, Fairchild Ian John, Mcmillan Emily Anne
Calcareous speleothems provide a record of dripwater composition which in turn is a function of climatic conditions. The historical focus of speleothem palaeoclimate studies has been on the derivation of palaeotemperatures through oxygen isotope studies. However, it is now realized that water availability is a more generally important control on their characteristics. Growth rate and growth morphology in principle should give rise to recognizable changes at low flow. However, accidental plumbing effects during aquifer evolution, can also lead to variations in water supply and it is not easy to distinguish these effects. In areas where there is a strong amount effect on the ?18O composition of atmospheric precipitation, the speleothem ?18O composition can be a direct (and inverse) function of rainfall. High-resolution methods are now available to distinguish the composition and relative abundance of winter and summer precipitation in speleothems which formed from drips of seasonally-varying composition. Two seasonallyvarying processes can be responsible for significant geochemical effects during the year. Seasonal (normally summer) dryness enhances CO2-degassing which leads to elevated ?13C, Mg/Ca and Sr/Ca in dripwaters, characteristics which are transferred to speleothems. The same effects can arise by enhanced degassing at low PCO2. High-resolution analysis can distinguish the seasonal processes and, where conducted at several time intervals, allows a more confident interpretation of longer-term records.

Speleothems as indicators of wet and dry periods, 2007, Fairchild I. J. , Mcmillan E. A.

Calcareous speleothems provide a record of dripwater composition which in turn is a function of climatic conditions. The historical focus of speleothem palaeoclimate studies has been on the derivation of palaeotemperatures through oxygen isotope studies. However, it is now realized that water availability is a more generally important control on their characteristics. Growth rate and growth morphology in principle should give rise to recognizable changes at low flow. However, accidental plumbing effects during aquifer evolution, can also lead to variations in water supply and it is not easy to distinguish these effects. In areas where there is a strong amount effect on the δ18O composition of atmospheric precipitation, the speleothem δ18O composition can be a direct (and inverse) function of rainfall. High-resolution methods are now available to distinguish the composition and relative abundance of winter and summer precipitation in speleothems which formed from drips of seasonally-varying composition. Two seasonallyvarying processes can be responsible for significant geochemical effects during the year. Seasonal (normally summer) dryness enhances CO2-degassing which leads to elevated δ13C, Mg/Ca and Sr/Ca in dripwaters, characteristics which are transferred to speleothems. The same effects can arise by enhanced degassing at low PCO2. High-resolution analysis can distinguish the seasonal processes and, where conducted at several time intervals, allows a more confident interpretation of longer-term records.


Monitoring climatological, hydrological and geochemical parameters in the Pre Nol cave (Belgium): implication for the interpretation of speleothem isotopic and geochemical time-series, 2008, Verheyden S. , Genty D. , Deflandre G. , Quinif Y. And Keppens E.
Pre Nol cave climatology (air and water temperature, PCO2), hydrology (drip rate, conductivity) and geochemistry of water and calcite deposits (?18O, ?13C, Mg/Ca and Sr/Ca) where studied to better interpret stable isotopic and trace element variations of speleothems. Results of an automated monitoring station and of manual sampling between 1991 and 1998 have demonstrated the highly seasonal signal of drip rate, its control by water excess and rainfall, and, at a shorter scale to air pressure changes. The modern calcite deposit study suggests a relationship between cave calcite isotopic composition (?18O and ?13C) and drip rate likely due to variations in degree of isotopic equilibrium during calcite precipitation. ?18O and ?13C of the calcite are therefore, through drip rate, linked to water recharge. Mg/Ca and Sr/Ca ratios of Pre Nol cave calcite, depend closely on the residence time of the water, and therefore are also linked to drip rate and therefore to water recharge. This crossed link of ?18O and ?13C as of Mg/Ca and Sr/Ca to water recharge may explain the very similar variations of these four parameters along the longitudinal axis of a Holocene stalagmite, but it may also be the consequence of kinetic effects during calcite precipitation as suggested by similar variations of the four parameters along a single layer of the Holocene stalagmite.

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