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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 hydrograph is 1. a graph relating stage, flow, velocity, or other characteristics of water with respect to time [22]. 2. a time record of stream discharge at a given cross section of the stream or of the stream surface elevation at a given point [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 interface (Keyword) returned 67 results for the whole karstbase:
Showing 16 to 30 of 67
Depositional Facies and Aqueous-Solid Geochemistry of Travertine-Depositing Hot Springs (Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, U.S.A.), 2000, Fouke Bw, Farmer Jd, Des Marais Dj, Pratt L, Sturchio Nc, Burns Pc, Discipulo Mk,
Petrographic and geochemical analyses of travertine-depositing hot springs at Angel Terrace, Mammoth Hot Springs, Yellowstone National Park, have been used to define five depositional facies along the spring drainage system. Spring waters are expelled in the vent facies at 71 to 73{degrees}C and precipitate mounded travertine composed of aragonite needle botryoids. The apron and channel facies (43-72{degrees}C) is floored by hollow tubes composed of aragonite needle botryoids that encrust sulfide-oxidizing Aquificales bacteria. The travertine of the pond facies (30-62{degrees}C) varies in composition from aragonite needle shrubs formed at higher temperatures to ridged networks of calcite and aragonite at lower temperatures. Calcite 'ice sheets', calcified bubbles, and aggregates of aragonite needles ('fuzzy dumbbells') precipitate at the air-water interface and settle to pond floors. The proximal-slope facies (28-54{degrees}C), which forms the margins of terracette pools, is composed of arcuate aragonite needle shrubs that create small microterracettes on the steep slope face. Finally, the distal-slope facies (28-30{degrees}C) is composed of calcite spherules and calcite 'feather' crystals. Despite the presence of abundant microbial mat communities and their observed role in providing substrates for mineralization, the compositions of spring-water and travertine predominantly reflect abiotic physical and chemical processes. Vigorous CO2 degassing causes a unit increase in spring water pH, as well as Rayleigh-type covariations between the concentration of dissolved inorganic carbon and corresponding {delta}13C. Travertine {delta}13C and {delta}18O are nearly equivalent to aragonite and calcite equilibrium values calculated from spring water in the higher-temperature ([~]50-73{degrees}C) depositional facies. Conversely, travertine precipitating in the lower-temperature (<[~]50{degrees}C) depositional facies exhibits {delta}13C and {delta}18O values that are as much as 4{per thousand} less than predicted equilibrium values. This isotopic shift may record microbial respiration as well as downstream transport of travertine crystals. Despite the production of H2S and the abundance of sulfide-oxidizing microbes, preliminary {delta}34S data do not uniquely define the microbial metabolic pathways present in the spring system. This suggests that the high extent of CO2 degassing and large open-system solute reservoir in these thermal systems overwhelm biological controls on travertine crystal chemistry

Hydrothermal speleogenesis: its settings and peculiar features, 2000, Dublyansky Y. V.
Three major settings of hydrothermal karst development are: endokarst, deep-seated karst, and shallow karst. Endokarst develops at great depth, where the pressure exceeds the strength of the rock and voids can exist only if they are filled with overpressured fluid, which prevents them from collapse. In the deep-seated setting hydrothermal karst develops in response to changes of pressure and temperature of upwelling fluids. Two large zones: (1) zone of carbonate dissolution and (2) zone of carbonate precipitation form within hydrothermal systems. The shallow setting encompasses the interface between thermal and low-temperature waters or the zone near the upper surface of thermal waters. Four major conditions, which create and enhance solutional capacity in hydrothermal systems are: (1) elevated temperature gradients (for carbonated waters); (2) elevated rate of discharge (for carbonated waters); (3) oxidation of hydrogen sulfide; and (4) mixing waters of contrasting chemistry. These features readily occur in the shallow hydrothermal karst setting; the largest hydrothermal caves are formed there. Morphologies and dimensions of hydrothermal caves range from pores, individual rooms, and single conduit caves to large three-dimensional mazes. Cave deposits hold clues as to their origin in their mineralogy, morphology, chemistry, isotopic properties, and fluid inclusion temperatures.

Speleogenesis on tectonically active carbonate islands, 2000, Gunn J. , Lowe D. J.
Studies of the geologically young, relatively porous limestones on Tongatapu Island in the Tongan archipelago suggest that the effect of dissolution at the interface between fresh and saline groundwater has been, and continues to be, crucial to the inception and development of underground conduits within young carbonate rock sequences. So far as it is possible to reconstruct the earliest speleogenetic events in the older preserved sequences on the nearby 'Eua Island, it appears that the processes that acted upon young reefal and back-reef carbonates during the Eocene were effectively the same as the processes that have acted on subsequent deposits and are still active today. It is commonly assumed that tectonism promotes the erosional removal of any early speleogenetic activity on carbonate islands and coasts. However, there is evidence on 'Eua to suggest that littoral cave systems and higher level conduits that target upon them, may survive gentle uplift, or even more extreme tectonism. This raises the possibility that some of the caves that can be explored today in both tropical and extra-tropical areas owe their origins to development of cavernous porosity in the littoral zone that was penecontemporaneous with rock formation.

Groundwater pollution by contaminant transport from soil to fractured rock, 2000, Witthü, Ser Kai, Č, Enč, Ur Curk Barbara

Water flow and contaminant transport from soil to underlying fractured rock is mainly controlled by the hydraulic conditions of the soil-bedrock boundary. In respect to the necessary understanding of contaminant transport at the soil-bedrock boundary the identification of flow paths within both the soil cover and the fractured media is decisive on the one side. On the other hand substance-specific behaviour of the often reactive pollutants compared to water flow has to be known in detail. Field scale tracer tests with different tracers (uranine and salts) and a potential pollutant as a reactive tracer (nitrate) were performed at the IRGO field research facility Sinji Vrh (SI). Injection points are located on the surface, in the soil, at the soil-rock interface and in the fractured rock; water is sampled in an underground tunnel with the help of two subhorizontal boreholes equipped with sampling devices and a special construction for collecting water seeping from the ceiling. The goal of these experiments is to identify the flow paths of solutes to the underground tunnel and to estimate their residence time dependent on the injection point. So far only some conclusions regarding the waterflux into the tunnel could be drawn.

Doline morphogenetic processes from global and local viewpoints, 2000, Gams, Ivan

Geomorphogenetical processes of solution dolines are evident from restraints in their global and local distribution: more precipitation than potential evapotranspiration, permeable soil cover, water level and solution front (transition from aggressive to flowstone depositing water) below shallow epikarst, slope inclination below 30°, solid soluble rock. Dolines are an effect of local accelerated solution. In initial phase they are connected with more fractured stone, as the grains have greater specific (surface/volume) surface exposed to soil moisture. Effect of stone fracturing on solution was tested in laboratory. Later growth of basin is based on automatism, as the size of soil/stone interface is increased with deepening of the basin. Funnel-like dolines with growth usually convert in a bowl-like form with greater exceeding. The form is controlled also by water permeability of soil and solifluction. In temperate climate the two million year long Pleistocene offered with more moisture from snow and with intensive fracturing of stone better conditions for doline development than the warmer Neogene and Holocene when man's impact in last centuries essentially redused primary forest environment and thus processes in the basins. Collapse dolines are not taken into account.

Compositional zoning and element partitioning in nickeloan tourmaline from a metamorphosed karstbauxite from Samos, Greece, 2001, Henry Darrell J. , Dutrow Barbara L. ,
Blue-green nickeloan tourmaline from a micaceous enclave of a marble from Samos, Greece, contains unusually high concentrations of Ni (up to 3.5 wt% NiO), Co (up to 1.3 wt% CoO), and Zn (up to 0.8 wt% ZnO). The polymetamorphic karstbauxite sample has an uncommon assemblage of nickeloan tourmaline, calcite, zincian staurolite, gahnite, zincohogbomite, diaspore, muscovite, paragonite, and rutile. The complex geologic history is reflected in multi-staged tourmaline growth, with cores that represent detrital fragments surrounded by two-staged metamorphic overgrowths. Zone-1 metamorphic overgrowths, which nucleated next to detrital cores, are highly asymmetric and exhibit compositional polarity such that narrow overgrowths of brown schorl developed at the (-) c-pole are enriched in Mg, Ti, and F, and depleted in Al, Fe, and X-site vacancies (X{square}) relative to wider, gray-blue schorl-to-foitite overgrowths developed at the () c-pole. Volumetrically dominant Zone-2 overgrowths are strongly zoned nickeloan dravites with a continuous increase in Mg, Co, Ca, and F at the expense of Fe, Zn, Cr, and V from the Zone-1 interface to the outermost rim. Within Zone 2, Ni reaches a maximum of 0.5 apfu before decreasing in the outer 20-40 {micro}m. Zone-2 overgrowths also exhibit compositional polarity such that, at the (-) c-pole, overgrowths are enriched in Mg, F, Na, Ca, and Cr relative to overgrowths at the () c-pole that are, in turn, enriched in Al, Fe, Ni, Co, and X{square}. Element partitioning involving tourmaline rims and coexisting minerals indicates that relative partitioning of Ni is tourmaline >> staurolite > gahnite; Co is tourmaline > staurolite > gahnite; and Zn is gahnite > staurolite >> tourmaline

The occurrence of sinkholes and subsidence depressions in the far west Rand and Gauteng Province, South Africa, and their engineering implications, 2001, De Bruyn Ia, Bell Fg,
Dewatering associated with mining in the gold-bearing reefs of the Far West Rand, which underlie dolomite and unconsolidated deposits, led to the formation of sinkholes and subsidence depressions. Hence, certain areas became unsafe for occupation and were evacuated. Although sinkholes were initially noticed in the 1950s, the seriousness of the situation was highlighted in December 1962 when a sinkhole engulfed a three-story crusher plant at West Driefontein Mine. Consequently, it became a matter of urgency that the areas at risk of subsidence and the occurrence of sinkholes were delineated. Sink-holes formed concurrently with the lowering of the water table in areas which formerly had been relatively free of sinkholes. In addition, subsidence occurred as a consequence of consolidation taking place in the unconsolidated deposits as the water table was lowered. In the latter case, the degree of subsidence which occurred reflected the thickness and original density of the unconsolidated deposits which were consolidated. These deposits vary laterally in thickness and thereby gave rise to differential subsidence. Subsidence also occurred due to the closure of dewatered voids at the rock-soil interface. The risk of sinkhole and subsidence occurrence is increased by urban development, since interrupted natural surface drainage, increased runoff, and leakage from water-bearing utilities can result in the concentrated ingress of water into the ground. Where the surficial deposits are less permeable, the risk of instability is reduced. In the area underlain by dolomite, which extends around Johannesburg and Pretoria, these problem have been more notable in recent years because of housing development, both low-cost and up-market, and the growth of informal settlements. Residential densities may be very high, especially for low-cost housing, the development of which frequently has proceeded without recognition of the risk posed by karst-related ground instability. The appearance of significant numbers of small sinkholes has been associated with dolomite at shallow depth, that is, occurring at less than 15 m beneath the ground surface. The vulnerability of an area overlying dolomite bedrock at shallow depth is largely dependent on the spacing, width and continuity of grikes. When dolomite is located at depths greater than 15 m, the sinkholes which appear at the surface usually are larger in diameter. The risk of sinkhole occurrence in areas of shallow dolomite in general, may be greater, although the hazard itself is less severe. A classification system for the evaluation of dolomitic land based on the risk of formation of certain sized sinkholes has enabled such land to be zoned for appropriate development. Ongoing monitoring and maintenance of water bearing services, and the implementation of precautionary measures relating to drainage and infiltration of surface water are regarded as essential in developed areas underlain by dolomite. Special types of foundation construction for structures are frequently necessary

Geomicrobiology of caves: A review, 2001, Northup D. E. , Lavoie K. H. ,
In this article, we provide a review of geomicrobiological interactions in caves, which are nutrient-limited environments containing a variety of redox interfaces. Interactions of cave microorganisms and mineral environments lead to the dissolution of, or precipitation on, host rock and speleothems (secondary mineral formations). Metabolic processes of sulfur-, iron-, and manganese-oxidizing bacteria can generate considerable acidity, dissolving cave walls and formations. Examples of possible microbially influenced corrosion include corrosion residues (e.g., Lechuguilla and Spider caves, New Mexico, USA), moonmilk from a number of caves (e.g., Spider Cave, New Mexico, and caves in the Italian Alps), and sulfuric acid speleogenesis and cave enlargement (e.g., Movile Cave, Romania, and Cueva de Villa Luz, Mexico). Precipitation processes in caves, as in surface environments, occur through active or passive processes. In caves, microbially induced mineralization is documented in the formation of carbonates, moonmilk, silicates, clays, iron and manganese oxides, sulfur, and saltpeter at scales ranging from the microscopic to landscape biokarst. Suggestions for future research are given to encourage a move from descriptive, qualitative studies to more experimental studies

Physical Mechanisms of River Waterfall Tufa (Travertine) Formation, 2001, Zhang David Dian, Zhang Yingjun, Zhu An, Cheng Xing,
Waterfall tufa is widely distributed around the world, especially in tropical and subtropical karst areas. In these areas river water is generally supersaturated with respect to calcite, and the precipitation occurs mainly at waterfall and cascade sites. Development of waterfall tufa has been described as simply being the result of water turbulence. We believe, however, that three physical effects can lead to tufa deposition at waterfall sites: aeration, jet-flow, and low-pressure effects. The three physical effects are induced by two basic changes in the water: an accelerated flow velocity, and enlargement of the air-water interface area. These two changes increase the rate of CO2 outgassing and the SIc, so that a high degree of supersaturation is achieved, which then induces calcite precipitation. These 'waterfall effects' have been simulated in laboratory and field experiments, and each of them can accelerate, or trigger, calcite precipitation. Field measurements of river water chemistry also show that tufa deposition occurred only at waterfall sites. In these experiments and observations, waterfall effects play the most important role in triggering and accelerating CO2 outgassing rates. Field and laboratory observations indicate that plants and evaporation also play important roles in tufa formation. Growth of algae and mosses on tufa surfaces can provide substrates for calcite nucleation and can trap detrital calcite, accelerating tufa deposition. However, the prerequisite for such deposition at waterfall sites is a high degree of supersaturation in river water, which is mainly caused by waterfall effects. Evaporation can lead to supersaturation in sprays and thin water films at a waterfall site and cause the precipitation of dissolved CaCO3, but the amount of such deposition is relatively small

The Development of a Karst Feature Database for Southeastern Minnesota, 2002, Gao, Y. , Alexander Jr. , E. C. , Tipping, R. G.
A karst feature database of southeastern Minnesota has been developed that allows sinkhole and other karst feature distributions to be displayed and analyzed across existing county boundaries in a geographic information system (GIS) environment. The central Database Management System (DBMS) is a relational GIS-based system interacting with three modules: GIS, statistical, and hydrogeologic modules. Data tables are stored in a Microsoft Access 2000 DBMS and linked to corresponding ArcView shape files. The current Karst Feature Database of Southeastern Minnesota was put on a Windows NT server accessible to researchers and planners through networked interfaces. Initial spatial analyses and visualizations of karst feature distributions in Southeastern Minnesota were conducted using data extracted from the karst feature database. A series of nearest-neighbor analyses indicates that sinkholes in southeastern Minnesota are not evenly distributed (i.e., they tend to be clustered). ArcInfo, ArcView and IRIS ExplorerTM were used to generate a series of 2D and 3D maps depicting karst feature distributions in southeastern Minnesota using data exported from the GIS-based karst feature database. The resulting maps allow regional trends to be visualized and extend county-scale trends to larger state-wide scales.

Eogenetic karst from the perspective of an equivalent porous medium, 2002, Vacher H. L. , Mylroie J. E. ,
The porosity of young limestones experiencing meteoric diagenesis in the vicinity of their deposition (eogenetic karst) is mainly a double porosity consisting of touching-vug channels and preferred passageways lacing through a matrix of interparticle porosity. In contrast, the porosity of limestones experiencing subaerial erosion following burial diagenesis and uplift (telogenetic karst) is mainly a double porosity consisting of conduits within a network of fractures. The stark contrast between these two kinds of karst is illustrated by their position on a graph showing the hydraulic characteristics of an equivalent porous medium consisting of straight, cylindrical tubes (n-D space, where n is porosity, D is the diameter of the tubes, and log n is plotted against log D). Studies of the hydrology of small carbonate islands show that large-scale, horizontal hydraulic conductivity (K) increases by orders of magnitude during the evolution of eogenetic karst. Earlier petrologic studies have shown there is little if any change in the total porosity of the limestone during eogenetic diagenesis. The limestone of eogenetic karst, therefore, tracks horizontally in n-D space. In contrast, the path from initial sedimentary material to telogenetic karst comprises a descent on the graph with reduction of n during burial diagenesis, then a sideways shift with increasing D due to opening of fractures during uplift and exposure, and finally an increase in D and n during development of the conduits along the fractures. Eogenetic caves are mainly limited to boundaries between geologic units and hydrologic zones: stream caves at the contact between carbonates and underlying impermeable rocks (and collapse-origin caves derived therefrom); vertical caves along platform-margin fractures; epikarst; phreatic pockets (banana holes) along the water table; and flank margin caves that form as mixing chambers at the coastal freshwater-saltwater 'interface'. In contrast, the caverns of telogenetic karst are part of a system of interconnected conduits that drain an entire region. The eogenetic caves of small carbonate islands are, for the most part, not significantly involved in the drainage of the island

Variation of delta C-13 in karst soil in Yaji Karst Experiment Site, Guilin, 2002, Pan G. X. , He S. Y. , Cao J. H. , Tao Y. X. , Sun Y. H. ,
This study deals with delta(13)C variation in karst soil system of Yaji Karst Experiment Site, Guilin, a typical region of humid subtropical karst formations. Samples of near ground air, plant tissue, soil and water (soil solution and karst spring) were respectively collected on site in different seasons during 1996-1999. Considerable variation of delta(13)C values are not only found with different carbon pools of soil organic carbon, soil air CO2 and soil water HCO3-, but also with the soil depths and with different seasons during a year. The delta(13)C values Of CO2 both of near ground air and soil air are lower in July than those in April by 1parts per thousand-4parts per thousand PDB. Our results indicate that the delta(13)C values of carbon in the water and air are essentially dependent on interface carbon interaction of air-plant-soil-rock-water governed by soil organic carbon and soil CO2 in the system

Geological and geotechnical context of cover collapse and subsidence in mid-continent US clay-mantled karst, 2002, Cooley T,
This paper presents a synthesis of geologic and geotechnical concepts to present a unified model of conditions controlling The development of cover-collapse sinkholes and associated ground subsidence. Appropriate engineering response to the hazards associated with collapse and subsidence requires a full understanding of the underlying mechanisms that produce such effects. The geotechnical characteristics of the overlying clay mantle and occurrence of the associated cover-collapse features are not random, but rather are directly tied to the underlying water flow routes and their development through time. The clay mantle and underlying epikarst are two components of a single system, each of the components influencing the other. This paper brings together these two aspects in terms of the author's personal experience and observations as a geologist, geotechnical engineer, hydrogeologist, and caver. A summary of the basic model follows. Much of the clay mantle and pinnacled upper surface of the epikarst form while surface drainage still prevails. At this stage, the karst underdrains are insufficiently developed to transport soils, although some subsidence into cutters occurs because of dissolutional rock removal. Soil arches and macropore flow routes associated with cutters have developed by this stage. As competent deep conduits extend into the area by headward linking, the cutters with the most favorable drains are linked to the conduits first and act as attractors for the development of a tributary, laterally integrated drainage system in the epikarst. Once the most efficient cutter drains become competent to transport soils, the depressed top-of-rock and ground surfaces characteristic of dolines develop. A given doline underdrain is likely to have multiple tributary drains from adjacent cutters, which vary in soil transport competence. Soil stiffness in the clay mantle over the limestone varies as a result of the pattern of stresses imposed as the underlying rock surface is lowered by dissolution and later as soil piping locally removes soils. In the absence of karst, these soils would have developed a laterally uniform, stiff to very stiff consistency. Where soil near the soil-bedrock interface is locally removed, however, the weight of the materials overlying this void is transferred to abutment zones on the pinnacles by soil arches. Local soil loading in the abutment areas of these arches would increase at least on the-order of 50% in the case of an isolated cavity. In some cases, multiple closely spaced cutters whose soil arches have narrow, laterally constrained abutment zones bearing on the intervening pinnacles may produce substantially higher soil abutment stresses. If the clays in the abutment zones do not fail, they would respond to this increase in stress by consolidating: stiffening and decreasing in volume. The cutters spanned by the soil arches accumulate raveled soils that are 'under-consolidated', the soft zones noted between pinnacles by Sowers. A simple integral of stresses analysis makes it obvious, however that no continuous soft zone exists. It is the transfer of load to the pinnacles through the stiffened abutment soils that allows these locally soft areas to exist. Soil stiffness profiles from borings substantiate this pattern. Cover-collapse features develop where soil transport through cutter drains is sufficient to remove the soils from beneath these arched areas. Two types of collapse have been observed: type I collapses have an upward-stoping open void whose rubble pile is removed by transport as fast as it is generated, producing a deep, steep-sided final collapses. In some cases, multiple voids in clusters can form with narrow abutments separating them. Large collapses may involve a progressive failure of several members of a cluster, including intervening pillars. Type 2 features are soil-filled voids limited in their rate of upward growth by the rate of soil removal, have little open void space, and migrate to the ground surface as a column of soft soils, finally producing a shallow depression. The type 2 features have geotechnical significance because of their effect on settlement under imposed loads. A single underdrain system may service both types of features, the behavior of particular voids being dependent on the relative efficiencies of their drains. This behavior can also change with time because backfilling of the underdrains with soil or flushing out of the soil filling can occur with changes in hydrologic or erosional regimes

Transport of suspended solids from a karstic to an alluvial aquifer: the role of the karst/alluvium interface., 2002, Massei N. , Lacroix M. , Wang H. Q. , Mahler B. J. , Dupont J. P.

Transport of suspended solids from a karstic to an alluvial aquifer: the role of the karst/alluvium interface, 2002, Massei N. , Lacroix M. , Wang H. Q. , Mahler B. J. , Dupont J. P. ,
This study focuses on the coupled transport of dissolved constituents and particulates, from their infiltration on a Karst plateau to their discharge from a karst spring and their arrival at a well in an alluvial plain, Particulate markers were identified and the transport of solids was characterised in situ in porous and karstic media, based on particle size analyses, SEM, and traces. Transport from the sinkhole to the spring appeared to be dominated by flow through karst: particulate transport was apparently conservative between the two sites, and there was little difference in the overall character of the particle size distribution of the particulates infiltrating the sinkhole and of those discharging from the spring. Qualitatively, the mineralogy of the infiltrating and discharging material was similar, although at the spring an autochthonous contribution from die aquifer was noted (chalk particles eroded from the parent rock by weathering). In contrast, transport between the spring and the well appears to be affected by the overlying alluvium: particles in the water from the well, showed evidence of considerable size-sorting. Additionally, SEM images of the well samples showed the presence of particles originating from the overlying alluvial system; these particles were not found in samples from the sinkhole or the spring. The differences between the particulates discharging from the spring and the well indicate that the water pumped from the alluvial plain is coming from the Karst aquifer via the very transmissive, complex geologic interface between the underlying chalk formation and the gravel at the base of the overlying alluvial system. (C) 2002 Elsevier Science B.V. All rights reserved

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