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Enviroscan Ukrainian Institute of Speleology and Karstology

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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 root zone is the zone in a soil profile penetrated by plant roots [16].?

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

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What is Karstbase?



Browse Speleogenesis Issues:

KarstBase a bibliography database in karst and cave science.

Featured articles from Cave & Karst Science Journals
Chemistry and Karst, White, William B.
See all featured articles
Featured articles from other Geoscience Journals
Karst environment, Culver D.C.
Mushroom Speleothems: Stromatolites That Formed in the Absence of Phototrophs, Bontognali, Tomaso R.R.; D’Angeli Ilenia M.; Tisato, Nicola; Vasconcelos, Crisogono; Bernasconi, Stefano M.; Gonzales, Esteban R. G.; De Waele, Jo
Calculating flux to predict future cave radon concentrations, Rowberry, Matt; Marti, Xavi; Frontera, Carlos; Van De Wiel, Marco; Briestensky, Milos
Microbial mediation of complex subterranean mineral structures, Tirato, Nicola; Torriano, Stefano F.F;, Monteux, Sylvain; Sauro, Francesco; De Waele, Jo; Lavagna, Maria Luisa; D’Angeli, Ilenia Maria; Chailloux, Daniel; Renda, Michel; Eglinton, Timothy I.; Bontognali, Tomaso Renzo Rezio
Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria), Briestensky, Milos; Rowberry, Matt; Stemberk, Josef; Stefanov, Petar; Vozar, Jozef; Sebela, Stanka; Petro, Lubomir; Bella, Pavel; Gaal, Ludovit; Ormukov, Cholponbek;
See all featured articles from other geoscience journals

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Your search for errors (Keyword) returned 28 results for the whole karstbase:
Showing 1 to 15 of 28
A New Equation Solver for Modeling Turbulent Flow in Coupled Matrix‐Conduit Flow Models, ,
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Karst aquifers represent dual flow systems consisting of a highly conductive conduit system embedded in a less permeable rock matrix. Hybrid models iteratively coupling both flow systems generally consume much time, especially because of the nonlinearity of turbulent conduit flow. To reduce calculation times compared to those of existing approaches, a new iterative equation solver for the conduit system is developed based on an approximated Newton–Raphson expression and a Gauß–Seidel or successive over-relaxation scheme with a single iteration step at the innermost level. It is implemented and tested in the research code CAVE but should be easily adaptable to similar models such as the Conduit Flow Process for MODFLOW-2005. It substantially reduces the computational effort as demonstrated by steady-state benchmark scenarios as well as by transient karst genesis simulations. Water balance errors are found to be acceptable in most of the test cases. However, the performance and accuracy may deteriorate under unfavorable conditions such as sudden, strong changes of the flow field at some stages of the karst genesis simulations.

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Paleohydrology and Streamflow Simulation of three Karst Basins in Southeastern West Virginia, U.S.A., PhD Thesis, 1975,
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Coward, Julian Michael Henry

This study was undertaken to gain a better understanding of karst hydrology. To do this, the present day hydrology and the paleohydrology were determined in three karst basins. The basins chosen were the Swago, Locust and Spring Creek basins in Pocahontas and Greenbrier Counties, West Virginia. A number of conventional field techniques were used successfully in this study, including the following: current meter and dye dilution gauging; dye and lycopodium stream tracing; geological and cave mapping; the setting up of stage recorders; geochemistry; and limestone erosion measurements. The climate of the region was investigated to obtain realistic precipitation, temperature and potential evaporation data over the study basins.
It was found that the mean precipitation over two of the basins was 30% higher than recorded data in the valleys. The karst development of the basins was found to take place in four major stages. These were: A) initial surficial flow, B) strike controlled drainage, C) major piracies from one sub-basin to another, and D) shortening of the flow routes. The major controls on the karst development were found to be: A) the Taggard shale, B) the strike direction, which controlled early basin development, and C) the hydraulic gradient from the sink to rising, which controlled later basin development.
To better assess the quantitative hydrology, and to assist in determining the type of unexplorable flow paths, a watershed model was developed. This modelled the streamflow from known climatic inputs using a number of measured or optimized parameters. The simulation model handled snowmelt, interception, infiltration, interflow, baseflow, overland flow, channel routing, and evaporation from the interception, soil water, ground water, snowpack and channel water. The modelled basin could be split up into 20 segments, each with different hydrological characteristics, but a maximum of 3 segments was used in this study.
A total of 29 parameters was used in the model although only 10 (other than those directly measurable) were found to be sensitive in the three basins. The simulated streamflow did not match the real flows very well due to errors in the data input and due to simplifications in the model. It was found, however, that as the proportion of the limestone in a segment increased the overland flow decreased, the interflow increased, the baseflow and interflow recessions were faster, the soil storages were smaller and the infiltration rate was higher, than in segments with a larger proportion of exposed clastics. The flow characteristics of the inaccessible conduits were inferred from the channel routing parameters and it was postulated that the majority of the underground flow in the karst basins was taking place under vadose conditions.

238U---234U---230Th---232Th systematics and the precise measurement of time over the past 500,000 years, 1987,
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Lawrence Edwards R. , Chen J. H. , Wasserburg G. J. ,
We have developed techniques to measure the 230Th abundance in corals by isotope dilution mass spectrometry. This, coupled with our previous development of mass spectrometric techniques for 234U and 232Th measurement, has allowed us to reduce significantly the analytical errors in 238U---234U---230Th dating and greatly reduce the sample size. We show that 6 x 108 atoms of 230Th can be measured to 30[per mille sign] (2[sigma]) and 2 x 1010 atoms of 230Th to 2[per mille sign]. The time over which useful age data on corals can be obtained ranges from a few years to ~ 500 ky. The uncertainty in age, based on analytical errors, is 5 y (2[sigma]) for a 180 year old coral (3 g), 44 y at 8294 years and 1.1 ky at 123.1 ky (250 mg of coral). We also report 232Th concentrations in corals (0.083-1.57 pmol/g) that are more than two orders of magnitude lower than previous values. Ages with high analytical precision were determined for several corals that grew during high sea level stands ~ 120 ky ago. These ages lie specifically within or slightly postdate the Milankovitch insolation high at 128 ky and support the idea that the dominant cause of Pleistocene climate change is Milankovitch forcing

Quaternary engineering geology, 1991,
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Fookes Pg,
The geological and geomorphological effects on the Earth's surface during the Quaternary have been both extensive and profound. An attempt has been made to simplify and summarize these effects by considering the principal agencies at work during the Quaternary: plate tectonics, rapidly rising sea levels, rapidly falling sea levels, rapidly cooling climates and rapidly warming climates. The resulting series of major glacial and interglacial episodes have had far-reaching consequences for the engineering characteristics of the Earth's surface. In attempting to summarize these major omissions will have been inevitable and errors will have occurred due to compression of the subject and its interpretation in a simplified manner. Table 2 summarizes the approach of the paper in itemising the principal Quaternary events, causes and effects, consequences to landscape and inferences to engineering. Each of the six events has been developed into larger tables and accompanied by some discussion and examples. The principal consequences of the events for engineering have been the production of glacial and periglacial soils,over large areas of the northern and southern hemispheres; changes in the sediment patterns on the coasts, the continental shelves and in river systems; and the development of weathering profiles of very variable type and distribution leading to development of in situ residual soils of many different engineering characteristics. The major shifts in climate associated with these events have led to migration of various surface forms which are now being exposed or covered by the present regime, leading to many active slope processes with potential instability for engineering projects and unexpected distribution of materials. The continuing events of plate tectonics which precedes the Quaternary by a long period of geological time explain the distribution of earthquake systems, growing coastlines and mountains, and the pattern of volcanic areas with their own suites of rock and soil of significance for the engineer. ... This 250-word extract was created in the absence of an abstract

Approche thorique _simplifie de la dissolution karstique, 1994,
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Gombert, P.
The specific behaviour of karsts makes the estimation of karstic denudation very difficult: discharge and water chemical variabili-ties are in fact major characteristics of aquifer karstic systems and cannot be properly estimated by the way of random sampling. The classical empirical methods provide generally high relative errors due to the bad knowledge of the hydrogeological catchment basin and even of the total number of springs. In the case of CORBEL's or WILLIAM's empirical formulas, average relative error can be estimated to about 100 % for a normally known aquifer karstic system : therefore it is impossible to compare different karsts that have not been studied with the same accuracy. The theoretical statisti-cal relationships between karstic denu-dation and a single climatic parameter (rainfall) are open to criticism: main authors tell that effective rainfall and pedological C02 are essential parame-ters of karstic denudation, which are never taken into account. For example, there are different PULINA's formula for different climatic types indicating that it is necessary to use another climatic parameter different from rain-fall! Moreover this way of modelling the data restrains the statistical repre-sentativity of each formula and intro-duces a difficult choice for karsts, which are at the border of two climatic types (or with mountainous parts). Another problem is the case of polar countries karsts where most precipitation is snowy and does not participate in karstic denudation. Therefore a mathematical modelling of carbonate dissolution is shown, based on infiltra-tion rate calculation and knowledge of calco-carbonic equilibrium. Temperature and rainfall are taken into account to determine the efficient part of precipitation, the productivity of pedogenetic C02 and the carbonate solubility constants. This theoretical approach gives the same results but with relative errors under 50 %. Consequently it is easy to compare different karstic countries in the world: hot and wet climates are confirmed to have the main karstogenetic activity but the role of cold countries is rehabilita-ted. Then paleokarstic denudation can be estimated.

Geomagnetic palaeosecular variation recorded in North And Central American speleothems, PhD thesis, 1995,
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Lean, C. M. B.

The aim of this project was to collect samples of stalagmites from Northern and Central America in order to produce records of the palaeosecular variation of the earth's magnetic field. Two stalagmites were sampled from Western Canada and ten from Mexico and Guatemala which could be compared with contemporaneous stalagmite records from these areas (Latham, 1981; Latham et al, 1982; 1986; 1987; 1989).
The stalagmites were generally weakly magnetised but remanence directions were stable upon stepwise thermal and alternating-field demagnetisation. Consistency in directions recorded between central and corresponding lateral sub-samples within two stalagmites (MSC2 from Canada and CP1 from Guatemala) inferred that any depositional errors caused by surface effects were less than the measurement errors. Grain size analysis showed the presence of a fine-grained magnetic fraction (0.01 - 0.1?:m) sourced from the cave drip-waters (either by direct deposition or by chemical precipitation) and a coarser magnetic fraction (0.01 - >10?:m) sourced from the flood-borne detritus. The latter source was dominant in stalagmites which were regularly inundated with water. The type of magnetic mineral present was determined by the geology of the catchment area; magnetite dominated in the Vancouver Island stalagmites, titanomagnetite in the Mexican stalagmites and haematite in the Guatemalan stalagmite.
Uranium-series dating of samples was hindered by the young ages of many of the samples, by low uranium concentrations and by the presence of allogenic thorium. If significant amounts of allogenic thorium were present, a sample age could be calculated based on an estimate of the initial thorium ratio ([230Th/232Th]0). Analysis of samples from Sumidero Recuerdo in Mexico, however, suggested that this ratio is not constant with time and may vary by a factor of two over approximately 1700 years. Due to these imprecisions many dates were out of stratigraphic sequence and age estimates were made assuming constant growth rates, except where growth had ceased for a finite length of time.
Records of sequential change of palaeomagnetic direction were obtained from the Mexican stalagmite SSJ3 and the Canadian stalagmite MSC2. The reliability of the latter record was confirmed by comparison with another Canadian stalagmite record (Latham et al, 1987) and contemporaneous lacustrine records. Other records were disappointing due to poor temporal resolution; each sub-sample represented a period of approximately 1000 years in Mexican stalagmites SSJ2 and SSJ4. Such slow growth rates are insufficient for the resolution of secular variation features with periods of less than 2000 years and are only suitable to gain information about the nature of long-term secular variations, for example the far-sided virtual geomagnetic poles and low inclinations predominant throughout the Holocene in Southern Mexico.
The existence of matching contemporaneous stalagmite records of secular variation together with the demonstrated lack of depositional inclination errors is encouraging, despite the sometimes "hit or miss" aspects of sample selection. Nevertheless it has been proved that speleothem records have the potential to complement the existing archaeomagnetic, lava and lacustrine data.

Palaeosecular variation observed in speleothems from western China and northern Spain, PhD thesis, 1996,
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Openshaw, S. J.

This study has produced records of the palaeosecular variation (PSV) of the earth's magnetic field from Speleothems from China and Spain. The ultimate aim of this project was to produce contemporaneous PSV records which would show that Speleothems accurately record ambient geomagnetic field behaviour. From Sichuan Province, China, five Speleothems were collected of which four were studied for their records of PSV. Eight Spanish Speleothems from the Cantabrian coast were collected but their weak magnetisation allowed only one record of PSV to be produced.
All speleothem sub-samples were weakly magnetised and had, on average, initial intensities of <100 x 10-8 Am2kg-1. Despite this, the majority of sub-samples were stable during stepwise alternating-field and thermal demagnetisation and each displayed a single component of magnetisation after removal of any secondary overprints. Rock magnetic experiments were hampered by low mineral concentrations but suggested that the remanences of each speleothem were carried by a mixture of multi and single-domain (titano-) magnetite and also by haematite present in significant quantities. The primary method of remanence acquisition appeared to be a depositional remanence sourced from flooding. This was corroborated by a linear relationship between sub-sample intensities and weight % acid insoluble detritus.
A selection of sub-samples from each speleothem were dated using uranium-thorium disequilibrium and alpha spectrometry. For the majority of sub-samples the low concentrations of uranium, high levels of detrital contamination and initially low chemical yields raised the associated dating inaccuracies above the quoted level for alpha spectrometry of 5-10%. Two Spanish Speleothems had high uranium concentrations and little, or no, detrital contamination. Percent age errors of these Speleothems ranged from 1 to 6%. Comprehensive experiments on the efficiencies of three electrodeposition methods were also undertaken. The most efficient method was found to be a modified version of the Hallstadius method (Hallstadius, 1984), which consistently achieved chemical yields between 40 and 90% for uranium and thorium.
In order to correct more analytically for the presence of detrital contamination, the leachate/leachate method of Schwarcz and Latham (1989) was tested. The maximum likelihood estimation data treatment technique (Ludwig and Titterington, 1994) was used to calculate dates from these analyses. Tests on Mexican speleothem SSJ2 gave excellent results allowing a revised dating scheme to be adopted. Tests on some sub-samples from Chinese Speleothems were generally unsuccessful due to analytical errors.
The isotope 210Pb was used to date the top surface of one speleothem. A constant growth rate was inferred which was significantly less than that calculated from the 230Th - 234U dating method. This was thought to be due to the former techniques inability to resolve growth rates of periods of less than 200 years.
Despite the dating errors associated with each speleothem the records of PSV compare well with each other and with contemporaneous records from China, Japan and also the UK (for the Spanish record). In addition. agreement with PSV data modelled from observatory records suggested that westward drift of the non-dipole geomagnetic field was predominant during the past 10ka.

Oxidation of organic matter in a karstic hydrologic unit supplied through stream sinks (Loiret, France), 1998,
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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

Simulated effect of vadose infiltration on water levels in the Northern Guam Lens Aquifer, 2000,
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Contractor Dn, Jenson Jw,
Regional-scale hydrology of the fresh water lens in the Northern Guam Lens Aquifer has been simulated in the past using a finite element, sharp interface computer model, SWIG2D. Systematic differences exist between observed and computed water levels. Computed seasonal peak water levels are higher, and the computed seasonal lows are lower than the respective observed levels. It is hypothesized that vadose storage must store a substantial amount of water during the wet season and release it gradually into the lens during the dry season. Flow through the vadose zone was simulated with a one-dimensional finite element, unsaturated flow program UNSATID, in which the van Genuchten model is used to characterize unsaturated diffuse flow through the matrix of the vadose zone. An additional parameter (SINK) was added to the van Genuchten set to account for rapid infiltration down open pathways (fractures) associated with the closed depressions of the karst terrain. A global-optimization technique (Shuffled Complex Evolution or SCE-UA Method) was used to obtain the parameters that minimized the difference between simulated and observed water levels. Simulations incorporating the van Genuchten model were accomplished by combining the two programs, UNSATID and SWIG2D, into a single program. The sum-of-squared-errors (SSE) between computed and observed water levels in four observation wells was minimized using SCE-UA, reducing the arithmetically averaged SSE of the four wells by 30% compared with the SSE obtained when the vadose zone was not modeled. These results suggest that vadose storage is significant. On the other hand, the fact that the best fit obtained with an optimum parameter set was able to reduce the SSE by no more than 30% suggests that additional phenomena have yet to be accounted for to mon fully explain differences between simulated and observed well water levels. (C) 2000 Elsevier Science B.V. All rights reserved

Stable isotope stratigraphy of Holocene speleothems: examples from a cave system in Rana, northern Norway, 2001,
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Linge H. , Lauritzen S. E. , Lundberg J. , Berstad I. M. ,
High-precision TIMS U-series dates and continuous stable oxygen and carbon isotope profiles of a 4000 year stalagmite record from Rana, northern Norway, are presented and compared with data from two other speleothems from the same cave. The dating results yield ages from 387534 to 2963 years before AD2000, with 2[sigma] errors from 0.5 to 1%. The overall growth rate is 35 mm/ka, corresponding to a temporal resolution of 29 years/mm. The stalagmite is tested for isotopic equilibrium conditions, where all `Hendy' tests, except one, indicate isotopic equilibrium or quasi equilibrium deposition. Both the stable oxygen and carbon isotope records reveal a strong and abrupt enrichment in the near-top measurements. This corresponds in time to the opening of a second cave entrance in the late 1960s, which caused changes in the cave air circulation. The stable oxygen isotope signal is enriched compared to the modern value over the last 300 years, indicating a negative response to temperature changes. Likewise, the stable carbon isotope record is enriched in this period. However, both of the stable isotope records are shown to be significantly enriched compared to the isotope ranges displayed by other stalagmites in the same cave, and this questions the reliability of the proxy records derived from the presented stalagmite. Still, a general good correspondence of large scale fluctuations is found between the three stable oxygen isotope records from this cave. The stable carbon isotope records show large variations within the cave and are believed to be governed by soil-zone conditions, percolation pathways and possibly driprates

Simulating time-varying cave flow and water levels using the Storm Water Management Model, 2002,
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Campbell Cw, Sullivan Sm,
The Storm Water Management Model (SWMM) is an Environmental Protection Agency code used to estimate runoff through storm water drainage systems that include channels, pipes, and manholes with storage. SWMM was applied to simulate flow and water level changes with time for a part of Stephens Gap Cave in Jackson County, Alabama. The goal of the simulation was to estimate losses from a surface stream to the cave. The cave has three entrances that can remove water from the surface stream. These entrances connect through several passages to an 8-m (27-ft) high waterfall in a dome room. After a storm, the walls of this dome room had leaves on the wall as high as 4.6 m (15 ft) above the floor. The model showed that the height of the leaves did not represent a water level that could have occurred following any recent storm.Campbell, Livingston and Garza in 1997 developed the CLG model to estimate losses from karst surface streams. This model treats losses as pipe flow from a reservoir and gives the loss flow rate as ~h0.5 where h is the depth of flow in the surface stream. Losses to Stephens Gap Cave calculated with SWMM varied as h1.8. This depth dependence is more characteristic of flow over a weir than of pipe flow.The SWMM-calculated losses to Stephens Gap Cave showed no hysteresis, that is, the rising and falling limbs of the stage-discharge plot followed the same curve. Loss curves with significant hysteresis are difficult to simulate with simple models such as CLG or a weir flow model. However, an SWMM model of a simple hypothetical cave demonstrated that storage in Stephens Gap Cave is far below that required to cause hysteresis. Losses from many karst surface streams can probably be adequately estimated with a calibrated weir flow model. The utility of SWMM for analyzing cave flows was established. SWMM produced stable solutions with very low continuity errors for this cave

Morphometric and spatial distribution prarmeters of karstic depressions, Lower Suwannee River Basin, Florida, 2003,
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Denizman, C.
This study describes an application of Geographic Information Systems (GIS) to examine the morphometric and spatial distribution of karstic depressions in the lower Suwannee River basin. Morphometris analysis of some 25,000 karstic depressions in an area covered by twenty-four 1:24,000 scale standard USGS topographic quadrangles were made possible by the analytical capabilities of the GIS. The parameters calculated for the study area include length, width, orientation, area, depth, circularity index, depression density, pitting index, and nearest neighbor index. Analysis of ~25,000 depressions in the lower Suwannee River basin reveals that the Florida karst is represented by broad, shallow depressions with an average density of 6.07 depressions/km and an average pitting index of 14.5. Morphometric and spatial distribution parameters of karstic depressions within the lower Suwannee River basin show significant variations. The robust GIS methodology used in this study provides not only a rapid analysis of spatial data on a large population of karstic depressions, but also an objective approach with consistent measurement and calculation processes in which human errors and bias were eliminated. In accordance with the increasing use of GIS in analyzing spatial data on diverse applications, this study shows that the GIS environment can also be efficiently used for karst landform studies.

Caves and Karsts of Northeast Africa., 2003,
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Halliday William R.
At least potentially karstifiable rocks cover much of the surface of Egypt and northern Libya. Study of caves and other karstic features of this region has been hampered by lack of roads, rapid disintegration of the surface of friable, poorly consolidated limestone, wind-blown sand and other factors. Interbedding with marly aquicludes hampers speleogenesis locally. Calcareous and evaporite karsts are present, however, and their waters are important albeit generally limited resources. Large quantities of fresh water are lost through submarine springs downslope from Libya's Gebel al Akhdar range; the caves and karst of that range may be among the world's greatest. A recent attempted compendium of caves and karsts of Egypt and Libya contains several important errors; the supposed 5+ km Ain Zayanah Cave does not exist and the Zayanah System includes several smaller caves. The Bir al Ghanam gypsum karst of northwest Libya, however, has caves up to 3.5 km long. In Egypt, the Mokattam, South Galala, Ma'aza, Siwa and Western Desert karsts and the "White Desert" chalk karst of Farafra Depression are especially important. Qattara and nearby depressions may be karstic rather than structural in origin. Unique Wadi Sannur Cave is the world's largest gour and a potential World Heritage site. Little knownsandstone karsts or pseudokarsts in southwestern Egypt may contain analogues of features recently identified on Mars. The well-publicised Uweinat caves of northwestern Sudan are talus caves.

Fallen arches: Dispelling myths concerning Cambrian and Ordovician paleogeography of the Rocky Mountain region, 2003,
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Myrow Paul M. , Taylor John F. , Miller James F. , Ethington Raymond L. , Ripperdan Robert L. , Allen Joseph,
High-resolution sedimentologic, biostratigraphic, and stable isotope data from numerous measured sections across Colorado reveal a complex architecture for lower Paleozoic strata in the central Cordilleran region. A lack of precise age control in previous studies had resulted in misidentification and miscorrelation of units between separate ranges. Corrections of these errors made possible by our improved data set indicate the following depositional history. The quartz-rich sandstone of the Sawatch Formation was deposited during onlap of the Precambrian erosion surface in the early Late Cambrian. The overlying Dotsero Formation, a regionally extensive carbonate- and shale-rich succession records blanket-like deposition with only minor facies changes across the state. An extremely widespread, meter-scale stromatolite bed, the Clinetop Bed, caps the Dotsero Formation in most areas. However, a latest Cambrian erosional episode removed 9-11 m of the upper Dotsero Formation, including the Clinetop Bed, from just east of the Homestake shear zone in the Sawatch Range eastward to the Mosquito Range. The overlying Manitou Formation differs in character, and thus in member stratigraphy, on the east vs. west sides of the state. These differences were previously interpreted as the result of deposition on either side of a basement high that existed within the Central Colorado Embayment or Colorado 'Sag,' a region of major breaching across the Transcontinental Arch. This paleogeographic reconstruction is shown herein to be an artifact of miscorrelation. Biostratigraphic data show that the northwestern members of the Manitou Formation are older than the members exposed in the southeastern part of the state and that there is little or no overlap in age between the two areas. This circumstance is the result of (1) removal of older Manitou Formation strata in the southeast by an unconformity developed during the Rossodus manitouensis conodont Zone, and (2) erosion of younger Manitou strata in central and western Colorado along Middle Ordovician and Devonian unconformities. Deciphering these complex stratal geometries has led to invalidation of long-held views on western Laurentian paleogeography during the Cambrian and earliest Ordovician, specifically the existence of the Colorado Sag and a northeast-trending high within the sag that controlled depositional patterns on either side. The mid- Rossodus uplift and resultant unconformity eliminated any and all Upper Cambrian and Lower Ordovician deposits in southern Colorado and northern New Mexico, and thus their absence should not be misconstrued as evidence for earlier nondeposition in this region. Lithofacies distribution patterns and isopach maps provide no evidence that highlands of the Transcontinental Arch existed in Colorado prior to the mid-Rossodus age uplift event. In fact, regional reconstructions of earliest Paleozoic paleogeography along the entire length of the purported Transcontinental Arch should be reevaluated with similarly precise biostratigraphic data to reconsider all potential causes for missing strata and to eliminate topographic elements not supported by multiple stratigraphic techniques. This study illustrates how seriously paleogeographic reconstructions can be biased by the presumption that missing strata represent periods of nondeposition rather than subsequent episodes of erosion, particularly in thin cratonic successions where stratigraphic gaps are common and often inconspicuous

Composite transfer functions for karst aquifers, 2003,
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Icjukic V. , Jukic D. ,
Linear transfer functions have been extensively used in hydrological studies. Generally, we support this conclusion: rainfall-runoff models based on the convolution between rainfall rates and a nonparametric transfer function (NTF) are not successful at simulating karst spring discharges during long recession periods. The tails of identified transfer functions have irregular shapes and they are not accurate physical representation of the transport through a karst system. Irregularities are the result of unavoidable errors in input and output time series and simplifications made by considering the system as linear and time invariant. This paper deals with a new form of the transfer functions for karst aquifers, the so-called composite transfer function (CTF). The CTF simulates discharges by two transfer functions adapted for the quick flow and the slow flow hydrograph component modeling. NTF is responsible for the quick flow component. The slow flow component is modeled by a parametric transfer function that is an instantaneous unit hydrograph mathematically formulated and defined from a conceptual model. By using the CTF, the irregular shape of the tail of the identified transfer function can be avoided, and the simulation of long recession periods as well as the simulation of a complete hydrograph becomes more successful. The NTF, the Nash model, the Zoch model and other similar conceptual models can be considered separately as simplified forms of the CTF. The rainfall-runoff model based on the convolution between rainfall rates and the CTF was tested on the Jadro Spring in Croatia. The results of the application are compared with the results obtained by applying NTFs independently. (C) 2003 Elsevier Science B.V. All rights reserved

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