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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 parent material is material from which soil or sediment was formed [16].?

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 separation (Keyword) returned 52 results for the whole karstbase:
Showing 16 to 30 of 52
Derivation of effective hydraulic parameters of a karst aquifer from discharge hydrograph analysis, 2001,
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Baedke Sj, Krothe Nc,
In well-developed karst terrains, three or more distinct portions of the karst continuum can be identified from hydrographs of springs issuing from the karat aquifer. Hydrographs from mio karat springs within the same drainage basin at the Crane Naval Surface Warfare Center, Indiana, have been analyzed, and ratios of transmissivity and specific yield (T/S-y) have been established for the conduit and diffuse flow systems. These ratios have been compared with values of T derived from aquifer tests, so that independent values of S-y can be calculated for the diffuse system. Similarly, if the value of S-y is assumed to be 1.0 for a pure conduit, then independent values of T can be calculated for this end-member of the karst continuum. The values of T and S-y derived from this study are similar to values obtained from a dye trace of the conduit-dominated flow system and of values derived from aquifer tests of the diffuse flow system. Values of T for the conduit system of these springs may need to be established at a local scale, while the values for the diffuse flow system may be applicable at a regional scale. A hydrograph separation using isotopic data suggests that the intermediate-flow system represents a mix of water from the conduit and diffuse flow systems. If this portion of the hydrograph is a truly mixing phenomena, ratios of TIS cannot be determined from the hydrograph analysis presented herein. However. if instead, the intermediate-flow system represents water released from a third reservoir (such as small fractures), ratios of T/S, can be established for the intermediate-flow system

Inverse modeling of the hydrological and the hydrochemical behavior of hydrosystems: Characterization of karst system functioning, 2001,
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Pinault J. L. , Plagnes V. , Aquilina L. , Bakalowicz M. ,
Inverse modeling of mass transfer characterizes the dynamic processes affecting the function of karst systems and can be used to identify karst properties. An inverse model is proposed to calculate unit hydrographs as well as impulse response of fluxes from rainfall-runoff or rainfall-flux data, the purpose of which is hydrograph separation. Contrary to what hydrologists have been doing for years, hydrograph separation is carried out by using transfer functions in their entirety, which enables accurate separation of fluxes, as was explained in the companion paper [Pinault et al., this issue]. The unit hydrograph as well as impulse response of fluxes is decomposed into a quick and a slow component, and, consequently, the effective rainfall is decomposed into two parts, one contributing to the quick flow (or flux) and the other contributing to the slow flow generation. This approach is applied to seven French karstic aquifers located on the Larzac plateau in the Grands Causses area (in the south of France). Both hydrodynamical and hydrogeochemical data have been recorded from these springs over several hydrological cycles. For modeling purposes, karst properties can be represented by the impulse responses of flow and flux of dissolved species. The heterogeneity of aquifers is translated to time-modulated flow and transport at the outlet. Monitoring these fluxes enables the evaluation of slow and quick components in the hydrograph. The quick component refers to the 'flush flow' effect and results from fast infiltration in the karst conduit network when connection is established between the infiltration and phreatic zones, inducing an increase in water head. This component reflects flood events where flow behavior is nonlinear and is described by a very short transfer function, which increases and decreases according to water head. The slow component consists of slow and fast infiltration, underground runoff, storage in annex-to-drain systems, and discharge from the saturated zone. These components can be further subdivided by measuring chemical responses at the karst outlet. Using Such natural tracers enables the slow component of the unit hydrograph to be separated into preevent water, i.e., water of the reservoir and event water, i.e., water whose origin can be related to a particular rainfall event. These measurements can be used to determine the rate of water renewal. Since the preevent water hydrograph is produced by stored water when pushed by a rainfall event and the event water hydrograph reflects rainwater transfer, separating the two components can yield insights into the characteristics of karst aquifers, the modes of infiltration, and the mechanisms involved in karstification, as well as the degree of organization of the aquifer

Surface and Groundwater Interaction of the Bela Stream and Vipava Springs in Southwestern Slovenia, 2001,
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Baker Gerry, Petrič, Metka, Parkin Geoff, Kogovš, Ek Janja

Previous studies suggest a hydrogeologic link between the Vipava springs and the neighbouring Bela surface stream. The Vipava springs drain the Nanos karst plateau. The Bela stream drains the very low permeable flysch to the north west of the Nanos plateau before flowing onto limestone where it gradually sinks along its course. A tracer, uranine, was injected into the Bela upstream of the village Vrhpolje and hydraulic connection with all the Vipava springs was proved. A dispersion model was used to characterise the tracer breakthrough curve of one of the springs where the highest concentrations were found. The hydrology of the Bela was analysed by measuring the discharge of the stream at 8 different sections and analysing the difference in flow between each section. The conclusion drawn from the analysis was that the Bela stream has a different hydrological response related to whether the majority of recharge comes from the karstic or flysch area of the catchment. A flow separation analysis based on hydrochemical measurements indicated that the hydrological response of the Vipava springs also depends on the recharge source area. Proved connection leads to environmental concern for the water quality of the Vipava springs, which are the main water supply of the area, because untreated wastewater is discharged into the Bela stream.


Les karsts littoraux des Alpes-Maritimes : inventaire des mergences sous-marines et captage exprimental de Cabb, 2002,
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Gilli, ric
Inventory of coastal and submarine springs in the Alpes-Maritimes (France) - Experimental catchment at the Cabb spring. Several submarine freshwater springs are present on karst shore in the Alpes-Maritimes (France). Salinity and conductivity measuring coupled with GPS location has permitted to inventory these springs. Three main springs have an average flow around 500 l/s. A balance on inland and offshore springs allows to explain the deficit observed on karst units of Arc de Nice area. A dam was built in the submarine karst spring of Cabb Massolin (Roquebrune-Cap-Martin, France) to study the effects of an artificial augmentation of the pressure on the salinity of a karst aquifer. Trials in low and high water levels show the impossibility to increase the pressure. The presence of several springs and the important jointing of limestone dont allow a sufficient impermeability of the dam site. Nevertheless, the salinity decreases, due to the physical separation between the two kinds of water.

Genesis of the Dogankuzu and Mortas Bauxite Deposits, Taurides, Turkey: Separation of Al, Fe, and Mn and Implications for Passive Margin Metallogeny, 2002,
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Ozturk Huseyin, Hein James R. , Hanilci Nurullah,
The Taurides region of Turkey is host to a number of important bauxite, Al-rich laterite, and Mn deposits. The most important bauxite deposits, Do[g]ankuzu and Morta[s], are karst-related, unconformity-type deposits in Upper Cretaceous limestone. The bottom contact of the bauxite ore is undulatory, and bauxite fills depressions and sinkholes in the footwall limestone, whereas its top surface is concordant with the hanging-wall limestone. The thickness of the bauxite varies from 1 to 40 m and consists of bohmite, hematite, pyrite, marcasite, anatase, diaspore, gypsum, kaolinite, and smectite. The strata-bound, sulfide- and sulfate-bearing, low-grade lower part of the bauxite ore bed contains pyrite pseudomorphs after hematite and is deep red in outcrop owing to supergene oxidation. The lower part of the bauxite body contains local intercalations of calcareous conglomerate that formed in fault-controlled depressions and sinkholes. Bauxite ore is overlain by fine-grained Fe sulfide-bearing and calcareous claystone and argillaceous limestone, which are in turn overlain by massive, compact limestone of Santonian age. That 50-m-thick limestone is in turn overlain by well-bedded bioclastic limestone of Campanian or Maastrichtian age, rich with rudist fossils. Fracture fillings in the bauxite orebody are up to 1 m thick and consist of bluish-gray-green pyrite and marcasite (20%) with bohmite, diaspore, and anatase. These sulfide veins crosscut and offset the strata-bound sulfide zones. Sulfur for the sulfides was derived from the bacterial reduction of seawater sulfate, and Fe was derived from alteration of oxides in the bauxite. Iron sulfides do not occur within either the immediately underlying or overlying limestone. The platform limestone and shale that host the bauxite deposits formed at a passive margin of the Tethys Ocean. Extensive vegetation developed on land as the result of a humid climate, thereby creating thick and acidic soils and enhancing the transport of large amounts of organic matter to the ocean. Alteration of the organic matter provided CO2 that contributed to formation of a relatively 12C-rich marine footwall limestone. Relative sea-level fall resulted from strike-slip faulting associated with closure of the ocean and local uplift of the passive margin. That uplift resulted in karstification and bauxite formation in topographic lows, as represented by the Do[g]ankuzu and Morta[s] deposits. During stage 1 of bauxite formation, Al, Fe, Mn, and Ti were mobilized from deeply weathered aluminosilicate parent rock under acidic conditions and accumulated as hydroxides at the limestone surface owing to an increase in pH. During stage 2, Al, Fe, and Ti oxides and clays from the incipient bauxite (bauxitic soil) were transported as detrital phases and accumulated in the fault-controlled depressions and sinkholes. During stage 3, the bauxitic material was concentrated by repeated desilicification, which resulted in the transport of Si and Mn to the ocean through a well-developed karst drainage system. The transported Mn was deposited in offshore muds as Mn carbonates. The sulfides also formed in stage 3 during early diagenesis. Transgression into the foreland basin resulted from shortening of the ocean basin and nappe emplacement during the latest Cretaceous. During that time bioclastic limestone was deposited on the nappe ramp, which overlapped bauxite accumulation

Using stable isotope analysis (delta D-delta O-18) to characterise the regional hydrology of the Sierra de Gador, south east Spain, 2002,
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Vandenschrick G. , Van Wesemael B. , Frot E. , Pulidobosch A. , Molina L. , Stievenard M. , Souchez R. ,
Water stress is rapidly increasing in many Mediterranean coastal zones mainly due to expansion in agriculture and tourism. In this paper, we focus on the Sierra de Gador-Campo de Dalias aquifer system (southeastern Spain) in order to assess the capability of water stable isotope analysis (deltaD-delta(18)O) to refine the understanding on recharge of this karstic aquifer system. Different types of surface and groundwater were sampled along an altitudinal gradient from the recharge zone in the mountains to the coastal plain. Surface water is restricted to local runoff, collected in closed reservoirs. Runoff amounts, collected in three of these reservoirs were monitored together with the precipitation in their catchments. Meteorological maps were used to detect the origin of the precipitation generating the majority of the runoff. The results were compared to literature data on local and regional precipitation. The use of oxygen and hydrogen isotopic composition has proved to be a useful tool to explain the origin of groundwater in a Mediterranean karstic system. Such studies are, however, not numerous and are often limited to local scale recharge for fast-reacting systems. This paper focuses on the delta(18)O-deltaD relationships of local precipitation to explain the isotopic variability of a large karstic aquifer system. The isotopic compositions of groundwater sampled along an altitudinal gradient from the recharge zone to the coastal plain are well displayed, in a deltaD-delta(18)O diagram, on a mixing line connecting a pole of Mediterranean waters to a pole of Atlantic waters. The Atlantic signature predominates in the shallow groundwater of natural springs, reflecting the rainfall which produced the local runoff sampled. The Mediterranean signature is mainly restricted to deep groundwater from boreholes in the coastal plain. The existence of a degree of spatial separation of groundwater types demonstrates that groundwater flow in a complex karstic system is not always continuous. The Mediterranean signature of deep groundwater could be due to past extreme rainfall events during which connectivity between recharge and reservoir exists, while at the same time the Atlantic signature of recent winter rains dominates in shallow groundwater. The assumption that an equilibrium in isotopic composition is established within a continuous aquifer and that therefore a slope lower than 8 in a deltaD-delta(18)O diagram indicates evaporation is not necessarily valid.

The Padaeng Supergene Nonsulfide Zinc Deposit, Mae Sod, Thailand, 2003,
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Reynolds Neal A. , Chisnall Tony W. , Kaewsang Kriangsak, Keesaneyabutr Chanan, Taksavasu Taksorn,
The Padaeng deposit near Mae Sod in western Thailand was the first supergene nonsulfide zinc deposit in the world to be developed as a large modern mining operation. The mine and associated zinc smelter, operated by Padaeng Industry Public Company Ltd. since 1984, went into production with reserves of 4.59 Mt at a grade of 28.9 percent zinc with a 10 percent zinc cutoff. Current resources are 5.14 Mt at a grade of 12.0 percent zinc with a 3 percent zinc cutoff. The Padaeng deposit is hosted by a mixed carbonate-clastic sequence of Middle Jurassic age. The deposit occurs in the hanging wall of the Padaeng fault, a major northwest-trending structure that was active through Cretaceous and Tertiary tectonism and uplift. Nonsulfide zinc ore comprises dominant hemimorphite with minor smithsonite and hydrozincite. Strata-bound ore zones occur within a northwest-dipping, deeply weathered, dolomitic sandstone; steeply dipping and irregular karstic zones in underlying massive, silty dolomite are controlled by north-trending fracture zones. Sulfide zinc-lead mineralization of Mississippi Valley type occured extensively in the vicinity of the Padaeng mine, most notably the small resources at Pha De and Hua Lon. Mineral deposits are typically sphalerite rich with minor galena and pyrite, forming small-scale open-space fillings, veins, and replacements within hydrothermal dolomite. Mineralization is dominantly strata bound within a horizon of intense hydrothermal dolomitization that forms the stratigraphic hanging wall to the nonsulfide ore zones at Padaeng. The only significant sulfide at the Padaeng mine is within this unit. Only trace sulfide occurs peripheral to, or down dip of, strata-bound or steeply dipping, nonsulfide orebodies. Sulfide mineralization is believed to have accompanied Cretaceous uplift and deformation, related to the onset of oblique subduction beneath the western margin of the Shan-Thai terrane. The nonsulfide deposit is believed to have formed when a substantial body of sulfide ore was uplifted on the margin of the Mae Sod Tertiary intermontane basin, commencing in the middle to late Miocene. Zinc-bearing acidic supergene fluids, generated by oxidation of the precursor sulfide body, reacted with carbonate in the underlying stratigraphic section to precipitate hemimorphite and smithsonite. Fluids were channeled by permeable dolomitic sandstones and by steep fracture and fault zones. Acidic fluids promoted deep weathering and karst formation, allowing mineralization to extend down dip in sandstone units for at least 150 m and vertically for a similar distance in steep structural zones. Transport of zinc out of the precursor sulfide body was facilitated by a falling water table, owing to uplift of the Padaeng fault block and a change from wet tropical to monsoonal or semiarid climatic conditions. There is no evidence for significant in situ replacement of sulfide deposits, and the leached remnants of the precursor sulfide body have been removed by erosion. The supergene process of dissolution and reprecipitation of zinc in the host rocks increased zinc grades and separation of zinc from lead, producing an economically attractive deposit. Successful exploration for this type of deposit requires a good understanding of the controls on primary sulfide mineralization and a good knowledge of local neotectonism, uplift history, hydrogeology, climatic evolution, and weathering history

Evaluation of aquifer thickness by analysing recession hydrographs. Application to the Oman ophiolite hard-rock aquifer, 2003,
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Dewandel B, Lachassagne P, Bakalowicz M, Weng P, Almalki A,
For more than a century, hydrologists and hydrogeologists have been investigating the processes of stream and spring baseflow recession, for obtaining data on aquifer characteristics. The Maillet Formula [Librairie Sci., A. Hermann, Paris (1905) 218], an exponential equation widely used for recession curve analysis, is an approximate analytical solution for the diffusion equation in porous media whereas the equation proposed by Boussinesq [C. R. Acad. Sci. 137 (1903) 5; J. Math. Pure Appl. 10 (1904) 5], that depicts baseflow recession as a quadratic form, is an exact analytical solution. Other formulas currently used involve mathematical functions with no basis on groundwater theory. Only the exact analytical solutions can provide quantitative data on aquifer characteristics. The efficiency of the two methods was compared on the basis of recession curves obtained with a 2D cross-sectional finite differences model that simulates natural aquifers. Simulations of shallow aquifers with an impermeable floor at the level of the outlet show that their recession curves have a quadratic form. Thus, the approximate Maillet solution largely overestimates the duration of the 'influenced' stage and underestimates the dynamic volume of the aquifer. Moreover, only the Boussinesq equations enable correct estimates of the aquifer parameters. Numerical simulations of more realistic aquifers, with an impermeable floor much deeper than the outlet, proves the robustness of the Boussinesq formula even under conditions far from the simplifying assumptions that were used to integrate the diffusion equation. The quadratic form of recession is valid regardless of the thickness of the aquifer under the outlet, and provides good estimates of the aquifer's hydrodynamic parameters. Nevertheless, the same numerical simulations show that aquifers with a very deep floor provide an exponential recession. Thus, in that configuration, the Maillet formula also provides a good fit of recession curves, even if parameter estimation remains poor. In fact, the recession curve appears to be closer to exponential when flow has a very important vertical component, and closer to quadratic when horizontal flow is dominant. As a consequence, aquifer permeability anisotropy also changes the recession form. The combined use of the two fitting methods allows one to quantify the thickness of the aquifer under the outlet. (C) 2003 Elsevier Science B.V. All rights reserved

Carbon 13 of TDIC to quantify the role of the unsaturated zone: the example of the Vaucluse karst systems (Southeastern France), 2003,
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Emblanch C, Zuppi Gm, Mudry J, Blavoux B, Batiot C,
The total dissolved inorganic carbon (TDIC) and C-13(TDIC) have been used as chemical and isotopic tracers to evaluate the contribution of different water components discharging at the Fontaine de Vaucluse karst spring near Avignon. At the same time they have been used to separate its flood hydrograph. Waters flowing from unsaturated zone (UZ) and saturated zone (SZ) show similar concentration in TDIC. In UZ and SZ water rock interactions do not obey to the same kinetic. The mixing rate between water coming from the UZ characterised by a short residence time and water from the SZ with a longer residence time has been evaluated in the spring discharge. In a hydrodynamic system, which is rather complex as it is open to the soil CO2 in UZ and closed to the same CO2 in the SZ, C-13(TDIC) has excellent characteristics as an environmental tracer. In order to better describe the inwardness of mass movements within the aquifer, the apparent contrasting information obtained using two different isotopes (O-18 of water molecules and C-13 of TDIC) must be combined. O-18 informs whether the hydrodynamic system acts as piston flow (PF) or follows a well mixing model (WMM). Conversely, C-13 gives more complete information on the UZ contributes to the total discharge. (C) 2003 Elsevier B.V. All rights reserved

Assessment of direct transfer and resuspension of particles during turbid floods at a karstic spring, 2003,
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Massei N. , Wang H. Q. , Dupont J. P. , Rodet J. , Laignel B. ,
Turbid water can be the source of important sanitary problems in karstic regions. It is the case of the Pays de Caux, in Haute Normandie, where the main resource in drinking water is provided by the chalk aquifer. In the case of the typical binary karst of the Pays de Caux, turbidity results from the input in sinkholes of turbid surface water induced by erosion on the plateaus. At some spring tappings, water may be very turbid in period of intense rainfall. The turbidity observed at a karstic spring is a complex signal which contains a part of direct transfer and a part of resuspension of the particles being transported. The aim of this study is turbidigraph separation, which would permit to distinguish the direct transfer and resuspension components of the turbidigraph. These two components are separated by comparing the elementary surface storm-derived water fluxes and elementary turbidity signals at the spring. The procedure takes place in three phases: (i) spring hydrograph separation by means of a two components mixing model (surface water and karstic groundwater) using specific electrical conductivity, (ii) decomposition of storm-derived water flux and turbidity thanks to the second-derivative method, (iii) comparison of the transfer times (approximate tomodal times) of the elementary turbidity and surface water flux signals, respectively. The mass corresponding to direct transfer, computed after signal decomposition, is then used to re-calculate a particle recovery rate, which passes so from 514 to 373%. Relations between particle flux and hydrodynamics show that resuspension can be either the fact of the dynamics of the introduction system, or that of the chalk karstic aquifer in general (case of resuspension not associated to surface water flux). In this sense, evolution of particle flux (and consequently of turbidity) can be also a marker of the karst structure. (C) 2003 Elsevier Science B.V. All rights reserved

Comparison of immunofluorescence assay and immunomagnetic electrochemiluminescence in detection of Cryptosporidium parvum oocysts in karst water samples, 2003,
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Kuczynska E. , Boyer D. G. , Shelton D. R. ,
Immunofluorescence assay (IFA) and immunomagneticelectrochemiluminescence (IM-ECL) were used for comparison of the percent recovery of Cryptosporidium parvum in environmental water samples obtained from a spring draining a karst basin. The monoclonal antibodies to C. parvum, isotype IgG3 were used for optimization of the IM-ECL protocol. The combination of biotinylated and TAG-labeled anti-C. parvum antibodies with the streptavidin beads gave a linear regression slope for log ECL vs. log fresh oocysts of 0.79 (from 5 to 5000 oocysts), which indicates a constant ECL signal per oocyst. Standard curves gave a dynamic range of 5 to 5000 oocysts/ml (fresh) and 10 to 100,000 cells/ml (4-month-old oocysts) with the maximum limit of linear detection higher than 100,000. The linear slope of 4-month-old oocysts decreased to 0.62, which indicates that ECL signal is a function of oocyst age. The experiment associated with bead storage time shows that even after 4 months of storage of the biotinylated antibodies, the complex retains the ability for binding the oocysts and generating the ECL signal. Based on the IFA results in the experiment evaluating different protocols for oocysts recovery from karst water samples, the most efficient protocol involved dispersion, followed by flotation and immunomagnetic separation (IMS) (24% recovery). The ECL results obtained in that experiment were very similar to the results obtained in the IFA method, which indicates that the IM-ECL method is accurate. Results of the IFA in the study of the prevalence of C. parvum in the groundwater showed that oocysts were present in 78% of 1 L water samples with average number of oocysts of 6.4 5.5 and ranged from 0 (13 samples) to 23.3 (2 samples). The ECL signal generated from these water samples ranged from 3771 to 622 (average 1620 465). However, the background value estimated in groundwater samples with low number of oocysts detected by IFA was highly variable and elevated (from 3702 to 272, average 1503 475). The background value as a result of nonspecific binding to beads by unidentified organic components in the water can inhibit or even completely mask the signal generated by oocysts. Our investigations showed that the IM-ECL method appears to be promising for the qualitative and quantitative detection of C parvum from the environmental water; however, the method requires further development to improve sensitivity and account for background signals. Published by Elsevier Science B.V

Discrimination of effective from ineffective porosity in heterogeneous Cretaceous carbonates, Al Ghubar field, Oman , 2003,
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Smith L. B. , Eberli G. P. , Masaferro J. L. , Aldhahab S.

The Natih E heavy-oil reservoir (21j API) atAl Ghubar field, Oman has produced less than 5% of the calculated oil in place. Porosity logs used to calculate reserves show high porosity throughout the reservoir, but further analysis of the only continuous core taken from the field indicates that much of the porosity is ineffective. There are four heavily oil-stained, high-permeability skeletalpelletal grainstone units with interparticle porosity in the core that probably contributed most of the production. The four permeable grainstone units occur at the top of small-scale accommodation cycles that have wackestone and packstone bases. These grainstones make up about 20% of the total thickness of the porous Natih E reservoir. The other 80% is composed of packstone and wackestone with ineffective microporosity, interparticle porosity in burrows, and isolated moldic and intraskeletal porosity. The small-scale reservoirbearing cycles can be correlated across the field using the separation between the medium and deep induction curves as a guide. Resistivity logs are the most reliable tool to distinguish effective from ineffective porosity. Most high-permeability grainstone units have deep induction values more than 100 ohmmand separation of more than 10 ohm m between the medium and deep induction curves. The ineffective intervals with microporosity, burrow porosity, and moldic porosity have lower resistivity and little separation between the medium and deep induction curves 


Cryogenic cave calcite from several Central European caves: age, carbon and oxygen isotopes and a genetic model, 2004,
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Zak Karel, Urban Jan, Cilek Vaclav, Hercman Helena,
Cryogenic cave calcite (CCC), formed by segregation of solutes during water freezing, was found in three Central European caves. This calcite type forms accumulations of loose calcite grains on cave floor. The calcite grains are of highly variable crystal morphology, and of sizes ranging from less than 1 mm to over 1 cm. The most typical feature is their accumulation as loose (uncemented) crystals. U-series dating indicates the formation of CCC in the studied caves during several climatic oscillations of the Weichselian (between 61 and 36 ka BP in the Chelsiowa Jama-Jaskinia Jaworznicka cave system in Poland, between 34 and 26 ka BP in the BUML Cave in the Czech Republic, and between 26 and 21 ka BP in the Stratenska Jaskyna cave system, Slovakia). At the time of CCC formation, the studied caves were lying in a periglacial zone.Detailed C and O stable isotope study of CCC samples revealed that slow water freezing under isotope equilibrium was the dominant formational process in the studied Polish and Czech caves. Significantly higher [delta]13C values of CCC in the Stratenska Jaskyna Cave indicate either water freezing in a more opened system with continuous CO2 escape (Rayleigh fractional separation), or participation of another CO2 source. The model of slow water freezing under isotope equilibrium is supported by isolated character of the caves having limited ventilation.In contrast, modern cryogenic cave calcite powders sampled directly on the ice surface of two recently iced caves in Slovakia with high ventilation showed much higher [delta]18O and [delta]13C data, similar to cryogenic calcites obtained in experimental rapid water freezing

Physical modelling of the seawater intrusion within a karst aquifer: the case of the Almyros of Heraklion (Crete), 2004,
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Arfib B, Ganoulis J,
Physical modelling of the seawater intrusion within a karst aquifer: the case of the Almyros of Heraklion (Crete). Coastal aquifers are subjected to natural seawater intrusion. Laboratory experiments were made to model the hydraulic conditions of saltwater inflow into a porous karstic conduit through which the freshwater flows. The conceptual model is based on the functioning scheme of the coastal karst system Almyros of Heraklion, Crete. The experiments show that seawater intrusion in a karst conduit can be diffuse, does not always lead to density separation of freshwater and seawater, and is not necessarily related to a conduit-network directly connected to the sea.

A pipe-based, first approach to modeling closed conduit flow in caves, 2004,
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Springer Gregory S. ,
A closed conduit model is constructed for a discrete cave segment using the energy equation and the assumption that energy losses in the segment are generated by large-scale flow separation associated with expansions and bends. As employed, the model uses paleostage indicators and passage geometry to estimate total head loss across the study reach. Channel roughness is estimated using pipe-based equations and a skin friction factor estimated from secondary means. Discharge is varied in the model until calculated head loss matches observed head loss. The model is employed to estimate discharge for a flood recorded in Buckeye Creek Cave, West Virginia as high water marks consisting of silt lines. Under varying assumptions, the model yields paleodischarges in the range of 22-29 m3 s-1. Shear stress values calculated using model output are in general agreement with the size distribution of gravel on the stream bed and shear stress values are relatively insensitive to changes in discharge. The apparent friction factor for the study reach is estimated to be in the range of 0.4-0.7, which is in general agreement with previous studies of large conduits. The model is applicable to similar cave reaches, but requires further testing and validation because so little is known about conduit flow in karst

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