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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. ...

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. ...

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
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. ...

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That experimental basin is a basin chosen for the thorough study of hydrological phenomena [16].?

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Your search for river loire (Keyword) returned 4 results for the whole karstbase:
Oxidation of organic matter in a karstic hydrologic unit supplied through stream sinks (Loiret, France), 1998, Alberic P, Lepiller M,
The aim of this paper is to appraise the ability of the oxidation of riverine organic matter in the control of limestone dissolution, in a karst network. Biogeochemical processes during infiltration of river water into an alluvial aquifer have already been described for an average flow velocity of 4-5 m d(-1) (Jacobs, L. A., von Gunten, H. R., Keil, R, and Kuslys, M. (1988) Geochemical changes along a river-groundwater infiltration flow path: Glattfelden, Switzerland. Geochim. Cosmochim. Acta 52, 2693-2706; Von Gunten, H. R., Karametaxas, G., Krahenbuhl, U., Kuslys, M., Giovanoli R., Hoehn E. and Keil R. (1991) Seasonal biogeochemical cycles in riverborne groundwater. Geochim. Cosmochim. Acta 55, 3597-3609; Bourg, A. C. M. and Bertin, C. (1993) Quantitative appraisal of biogeochemical chemical processes during the infiltration of river water into an alluvial aquifer. Environ. Sci. Technol. 27, 661-666). Karstic drainage networks, such as in the River Loire-Val d'Orleans hydrologic system (Fig. 1), make possible flow velocities up to 200 m h(-1 a) and provide convenient access to different water samples several tens of km apart, at both extremities of the hydrologic unit (Chery, J.-L. (1983) Etude hydrochimique d'un aquifere karstique alimente par perte de cours d'eau (la Loire): Le systeme des calcaires de Beauce sous le val d'Orleans. These, Universite d'Orleans; Livrozet, E. (1984) Influence des apports de la Loire sur la qualite bacteriologique et chimique de l'aquifere karstique du val d'Orleans. These, Universite d'Orleans). Recharge of the karstic aquifer occurs principally from influent waters from stream sinks, either through coarse alluvial deposits or directly from outcrops of the regional limestone bedrock (Calcaires de Beauce). Recharge by seepage waters From the local catchment basin is small (Zunino, C., Bonnet, M. and Lelong, F. (1980) Le Val d'Orleans: un exemple d'aquifere a alimentation laterale. C. R. somm. Soc. Geol. Fr. 5, 195-199; Gonzalez R. (1992) Etude de l'organisation et evaluation des echanges entre la Loire moyenne et l'aquifere des calcaires de Beauce. These, Universite d'Orleans) and negligible in summer. This karstic hydrologic: system is the largest in France in terms of flow (tens to hundreds of m(3)/s) and provides the main water resource of the city of Orleans. Chemical compositions of influent waters (River Loire) and effluent waters (spring of the river Loiret) were compared, in particular during floods in summer 1992 and 1993 (Figs 2-4). Variation of chloride in the River Loire during the stream rise can be used as an environmental tracer of the underground flow (Fig. 2). Short transit times of about 3 days are detectable (Fig, 2) which are consistent with earlier estimations obtained with chemical tracers (Ref. in Chery, J.-L. (1983) These, Universite d'Orleans). Depending on the hydrological regime of the river, organic carbon discharge ranges between 3-7 and 2-13 mg/l for dissolved and particulate matter respectively (Fig. 3). Eutrophic characteristics and high algal biomasses are found in the River Loire during low water (Lair, N. and Sargos, D. (1993) A 10 year study at four sites of the middle course of the River Loire. I - Patterns of change in hydrological, physical and chemical variables in relation to algal biomass. Hudroecol. Appl. 5, 1-27) together with more organic carbon rich suspended particulate matter than during floods (30-40 C-org % dry weight versus 5-10%). Amounts of total organic carbon and dissolved oxygen (Fig. 3) dramatically decrease during the underground transport, whereas conversely, dissolved calcium, alkalinity and inorganic carbon increase (Fig. 4). Anoxia of outflows map start in April. Dissolution of calcium carbonates along the influent path outweighs closed system calcite equilibrium of inflow river waters (Table 3). The impact of organic matter oxidation on calcite dissolution may be traced by variations of alkalinity and total carbonates in water. Following, Jacobs, L. A., von Gunten, H. R., Keil, R. and Kuslys, M. (1988) Geochemical changes along a river-groundwater infiltration flow path: Glattfelden, Switzerland. Geochim. Cosmochim. Acta 52, 2693-2706), results are shown graphically (Fig. 5). Extent of reactions is controlled by the consumption of dissolved O-2 and nitrate for organic matter oxidation and by the release of Ca2 for calcite dissolution (Table 2). The karstic network is considered to behave like a biological reactor not exchanging with the atmosphere, with steady inhabitant microbial communities (Mariotti A., Landreau A, and Simon B. (1988) N-15 isotope biogeochemisrry and natural denitrification process in groundwater: Application to the chalk aquifer of northern France. Geochim. Cosmochim. Acta 52, 1869-1878; Gounot, A.-M. (1991) Ecologie microbienne des eaux ei des sediments souterrains. Hydrogeologie, 239-248). Thus, energy requirements only are considered, not carbon assimilation. Moreover, there is no necessity to invoke any delay for nitrification enhancement, as observed elsewhere, after waste water discharge into the river (Chesterikoff, A., Garban, B., Billen, G. and Poulin, M. (1992) Inorganic nitrogen dynamics in the River Seine downstream from Paris (France). Biogeochem. 17, 147-164). Main microbial processes are assumed to be aerobic respiration, nitrification and denitrification. Reactions with iron and manganese, real but not quantitatively important, were neglected. Sulphate reduction and methane formation, certainly not active, were not considered. Denitrification, which is suggested by low nitrate and ammonium concentrations and anoxia in the outflow, is known to be rapid enough to be achieved in a short time (Dupain, S. (1992) Denitrification biologique heterotrophe appliquee au traitement des eaux d'alimentation: Conditions de fonclionnement et mise au point d'un procede. These, Universite Claude Bernard, Lyon). Reaction are somewhat arbitrary but conform to general acceptance (Morel, M. M. and Hering, J. G. (1993) Principles and Applications of Aquatic Chemistry. Wiley, New York). Anaerobic ammonium oxidation (Mulder A., van de Graaf, A. A., Robertson, L: A. and Kuenen, J. G. (1995) Anaerobic ammonium oxidation discovered in a denitrifying fluidized bed reactor. FEMS Microbiol. Ecol. 16, 177-184). although possible, was not considered. In fact, C/N ratio of the reactive organic matter has only mild repercussions on the results; i.e. in the same range as the analytical errors for alkalinity and total carbonates. The objective was simply to roughly confront characteristics of outflowing waters and the calculation. Respective roles of aerobes and denitrifiers, for instance, are not certain. Several periods during low water or floods were selected with various ranges for calcium dissolution or nitrate and oxygen concentrations. The result is that in most cases simulation and data are in reasonable accordance (Fig. 5). Amounts of organic matter in River Loire are generally sufficient to sustain the process (Table 3. Particulate organic matter is probably the most reactive. The balance of oxidation of organic matter indicates that about 65 mu g C-org/l.h are oxidized during the transport without much variation with the river regime or organic discharge. It is concluded that limestone dissolution is directly dependent on organic matter oxidation, but variation occurs (7-29 mg CuCO3/l) with the level of bases that can be neutralized in the River Loire water. (C) 1998 Elsevier Science Ltd. All rights reserved

River backflooding into a karst resurgence (Loiret, France), 2004, Alberic P,
The group of springs located in the west part of the Val d'Orleans exemplifies a type of karstic emergence which has the particularity to get most of its recharge water from a single surface water source, which in this particular case is the River Loire. Hence the flow of this group of springs is known to fluctuate in a close relationship with the water level of the River Loire. Since the second half of the 1990s, the conduit of the upstream spring of the Loiret river (so-called Le Bouillon) has been periodically seen to be invaded by the turbid waters of a small surface tributary (Le Dhuy) flowing back from the confluence to the spring, which then functioned as a swallow-hole. Plotted in a Dhuy versus River Loire diagram, stages of backflooding days describe a domain limited by a curve of the form HDhuy = c e((aH Loire)). The exponential form of the relation corresponds to the increasing resistance of the emerging flow of the spring to the backflooding of the tributary waters, as the River Loire stages rise. The equation above was used to compute a daily backflow index enabling the effective reconstruction of all occurrences effectively counted during the regular period of observation of the spring. Extended to 1985, one can observe that the early 1990s do not appear as a favorable period to backflow events but some may have occurred during the years 1986 to 1989. The observation of rainfall intensity preceding backflooding shows that in a short time span there is no necessity to evoke intrinsic changes inside the Val d'Orleans basin to explain what might appear as a troublesome new phenomenon. In conclusion backflooding has probably existed for a long time and is simply under the control of local heavy rainfall during low River Loire stages. (C) 2003 Elsevier B.V. All rights reserved

Natural and EDTA-complexed lanthanides used as a geochemical probe for aquifers: a case study of Orleans valley's alluvial and karstic aquifers, 2005, Borgne Fl, Treuil M, Joron Jl, Lepiller M,
The transit of chemical elements within the different parts of Orleans valley's aquifer is studied by two complementary methods. Those methods rely on the fractionation of lanthanides (Ln) during their migration in natural waters. The first method consists in studying natural lanthanides patterns within the watershed, at its entries and exits. The second one lies on multi-tracer experiments with Ln-EDTA complexes. This work is completed through an observation network consisting of 52 piezometers set on a sand and gravel quarry, and the natural entries and exits of the aquifer. Orleans valley's aquifer, which is made of an alluvial watershed lying on a karstic aquifer, is mainly fed by the Loire river via a large karstic network. At the entries of the aquifer (Loire river at Jargeau), the Ln concentrations in the dissolved fraction (< 0,22 {micro}m) vary with the flow of the river. During floods, Loire river waters display bulk continental crust-like Ln compositions with a slight enrichment in heavy Ln from Dy to Lu. When the Loire river flow becomes low level, the crust-normalised Ln patterns show a depletion in light Ln whereas Lu concentrations remain identical. The same evolution spatially occurs between the entries and exits of the karstic network. Spring waters are depleted in light Ln relative to the Loire river whereas heavy Ln (Yb, Lu) remain constant during transit. Furthermore, the depletion in light Ln increases with the distance between entries and exits. Tracer experiments using EDTA-complexed Ln within and between the alluvial and calcareous parts of the watershed have shown that complexed Ln are fractionated across all these geological strata. The recoveries of tracers always follow the order light Ln < heavy Ln. Moreover, both sediments analyses and filtering experiments at a porosity of 0,02 {micro}m show that, in the presence of EDTA, Ln adsorb onto sediments and colloids in the order light Ln > heavy Ln. On the other hand, the filtration of alluvial groundwater with high colloids content induces no significant Ln fractionation when the solution contains no strong chelating agent. Hence, the transit of natural and artificial Ln in Orleans valley aquifer can be explained by two complementary processes. (1) Decanting/filtering or, on the opposite, stirring of colloids. Those processes induce no important Ln fractionation. (2) Exchanges of Ln between solute complexes, colloids and sediments due to the presence of strong chelating agents. Those exchanges fractionate the Ln in the order of their stability constants. Considering the natural Ln fractionation that occurs in the Loire river and in the studied aquifer, the carbonates, the stability constants of which follow the order light Ln < heavy Ln, are the best candidates as natural strong chelating agents. From the hydrodynamic point of view, both tracer experiments and natural Ln concentrations show that the transfer of elements within the alluvial watershed is pulsed by the Loire river movements. During an ascent phase, the elements migrate away from and perpendicularly to the karstic channels direction. During the river descent, horizontal flows are quasi absent and migrations are mainly vertical from the alluvia down to the calcareous part of the aquifer. Due to those hydrodynamic characteristics, alluvia and non fissured limestone have a high dynamic confining capacity. Elements with high affinity for solid or colloidal phases (e.g. light Ln) have an increased confining capacity in the whole aquifer, by sorption and colloid filtration within the alluvia and at the alluvial-calcareous interface, and by colloid decanting within the karstic channels. Overall, this model combines two components. The first one, hydrodynamical, results from the repartition of the loads pulsed by river Loire through the karst. The second one physico-chemical, results from the element distribution mainly controlled by colloide/solute complexes exchange coefficients

Hydrogeochemical balance sheet of natural and anthropogenic impacts onto Orleans valley karstic network performed with major elements : the 'dynamic confinement' model quantification, 2006, Le Borgne Francois, Treuil Michel, Joron Jean Louis, Lepiller Michel,
The Orleans valley aquifer comprises both the alluvia of the Loire river and its underlying calcareous stratum. This aquifer is fed by river recharge, thanks to a substantial karstic network in its calcareous part. The main outlets of the aquifer are the Loiret springs, including the famous 'le Bouillon' spring. As a result, entries and exits of Orleans valley watertable make a natural observatory, allowing study of the transit of the chemical species inside the aquifer. Since 1997, this natural observatory has been improved with the installation of 52 piezometers (37 in the alluvial aquifer and 15 in the carbonate aquifer) within an alluvial quarry located in the middle of Orleans valley. Tracer experiments, carried out in this extended observatory, have shown that the porous calcareous and alluvial part of the aquifer constitute a 'dynamically confined system'. As a result, the hydrochemical input of the porous domain of the aquifer to the karstic flow must be negligible. The aim of this study is to confirm this theory with the use of major elements as large-scale temporal and spatial tracers of these exchanges. At 'le Bouillon' karstic spring, the Na, K, Mg2, Cl- and SO42- concentrations are closely correlated to those of the Loire river if a 3-4 day time lag is considered. This indicates a quasi-conservative transit of these elements in the karst. Conversely, calcite dissolution accompanying the organic matter biodegradation induces significant enrichments in Ca2, HCO3- and NO3- (mean annual concentrations of which are, respectively, 27.0, 87.8 and 4.9 mg.L-1 in the Loire river and 37.3, 127 et 7.3 mg.L-1 at 'le Bouillon' spring). After fertiliser spreading, the alluvial waters are highly enriched in NO3-, Cl-, SO42- (respectively 67.2, 24.0, 57.5 mg.L-1) compared to the Loire river (respectively 5.5, 12.7, 17.5 mg.L-1). The anthropogenic input is insignificant for Na, of which the average concentration in the alluvial watershed (11.7 mg.L-1) remains close to the Loire river (12.9 mg.L-1). The alluvial watershed is depleted in K (1.3 mg.L-1) with respect to the Loire river (3.7 mg.L-1) and correlatively enriched in Mg2 (17.0 mg.L-1 against 5.0 mg.L-1). High major element concentrations are measured in several calcareous piezometers confirming that vertical flows occur between the alluvial and calcareous parts of the aquifer. Furthermore, enrichment heterogeneity in those two strata is induced by a dynamic redistribution, with no significant leaching of anthropogenic inputs which were previously homogeneously spread. This redistribution is pulsed by ascents of the Loire river, impacts of which on the watershed are clearly identified on Mg/K-Na/K diagrams showing a main K {leftrightarrows} Mg exchange between Loire water and clays minerals. Taking into account average K and Mg concentrations in the different parts of Orleans valley's watershed, the volume of porous aquifer water brought to the karstic network flow mean estimated is 2.4 % of the total volume which transits between the Loire and the 'le Bouillon' spring, showing the dynamic confining action of the aquifer porous domain. Taking into account more precisely seasonal river Loire and spring composition variation, these inputs can be more precisely established : 1.6% during winter and 1.2% during summer at 'Le Bouillon' spring; 2.4% during winter and 3.9% during summer at 'La Pie' spring. But such a weak global contribution of the porous domain accounts for 10% nitrate composition of the karstic springs. Seasonal spring nitrate composition balance is clearly explained by 60% river Loire, 30 % organic matter oxydation - carbonate dissolution and 10% porous domain inputs during winter, and 30% river Loire, 60% organic matter, - carbonate dissolution and 10% porous domain inputs. Same calcium mass balance calculations point out the necessity of CO2 winter complementary input by local rain fall penetrations

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