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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 Kannelierungen is (german.) see rillenkarren.?

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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 dilution (Keyword) returned 44 results for the whole karstbase:
Showing 1 to 15 of 44
Spatial variability in cave drip water hydrochemistry: Implications for stalagmite paleoclimate records, , Baldini Jul, Mcdermott F, Fairchild Ij,
The identification of vadose zone hydrological pathways that most accurately transmit climate signals through karst aquifers to stalagmites is critical for accurately interpreting climate proxies contained within individual stalagmites. A three-year cave drip hydrochemical study across a spectrum of drip types in Crag Cave, SW Ireland, reveals substantial variability in drip hydrochemical behaviour. Stalagmites fed by very slow drips ( 2[no-break space]ml/min) sites, apparently unconnected with local meteorological events. Water from these drips was typically undersaturated with respect to calcite, and thus did not result in calcite deposition. Data presented here suggest that drips in this flow regime also experience flow re-routing and blocking, and that any stalagmites developed under such drips are unsuitable as mid- to high-resolution paleoclimate proxies. Most drip sites demonstrated seasonal [Ca2] and [Mg2] variability that was probably linked to water excess. Prior calcite precipitation along the flowpath affected the chemistry of slowly dripping sites, while dilution predominantly controlled the water chemistry of the more rapidly dripping sites. This research underscores the importance of understanding drip hydrology prior to selecting stalagmites for paleoclimate analysis and before interpreting any subsequent proxy data

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

Groundwater chemistry and cation budgets of tropical karst outcrops, Peninsular Malaysia, I. Calcium and magnesium, 1989, Crowther J,
The discharge and chemical properties of 217 autogenic groundwaters were monitored over a 1-yr period in the tower karsts of central Selangor and the Kinta Valley, and in the Setul Boundary Range. Because of differences in soil PCO2, calcium concentrations are significantly higher in the Boundary Range (mean, 82.5 mg l-1) than in the tower karst terrain (44.6 mg l-1). Local differences in both source area PCO2 and amounts of secondary deposition underground cause marked intersite variability, particularly in the tower karst. Dilution occurs during flood peaks in certain conduit and cave stream waters. Generally, however, calcium correlates positively with discharge, since the amount of secondary deposition per unit volume of water decreases at higher flows. Magnesium concentrations and Mg:Ca Mg ratios of groundwaters are strongly influenced by bedrock composition, though bedrock heterogeneity and the kinetics and equilibria of carbonate dissolution reactions preclude extremely low or high Mg:Ca Mg values. Net chemical denudation rates range from 56.6 to 70.9 m3km2yr-1.The results are considered in relation to cation fluxes in surface runoff, soil throughflow and nutrient cycling. Preliminary calcium and magnesium budgets show that (1) dissolutional activity is largely confined to the near-surface zone; and (2) the annual uptake of calcium and magnesium by tropical limestone forests is similar in magnitude to the net solute output in groundwaters

FLOW PARAMETERS IN A SHALLOW CONDUIT-FLOW CARBONATE AQUIFER, INNER BLUEGRASS KARST REGION, KENTUCKY, USA, 1991, Thrailkill J. , Sullivan S. B. , Gouzie D. R. ,
In the carbonate aquifers which underlie most karst terrains, groundwater flow is through a dendritic system of solution conduits. In such aquifers, termed shallow conduit-flow aquifers. the methods used to mode) granular and fracture aquifers are not generally applicable. Investigations were conducted in the Inner Bluegrass Karst Region of central Kentucky with the objective of developing methods of modeling shallow conduit-flow aquifers as well as obtaining quantitative information on a specific portion of the aquifer to assist in its management for water supply purposes. In the Inner Bluegrass Karst Region, groundwater basins are developed. in each of which there is an integrated system of solution conduits which conducts recharge to a major spring. One of the largest of these groundwater basins feeds Royal Spring, which serves as the principal water supply for the town of Georgetown. The basin extends over 15 km to the southeast and most of its flow is furnished by underground diversions of Cane Run, a surface stream with headwaters near the center of the City of Lexington. The principal objectives of the field investigation were to determine discharges at the spring and travel times to the spring from discrete recharge points within the basin, termed swallets. The spring is ungaged. and an attempt was made to obtain a continuous discharge record by the dilution of dye introduced at a swallet. Comparison of the dye-dilution discharge record with stage discharges at the spring revealed substantial discrepancies which are believed to be caused by as much as five-sixths of the low-flow discharge from the upper portion of the basin bypassing the spring. The dye-dilution method, therefore, provided significant insights into the geometry of the conduit system of the groundwater basin although it proved unsatisfactory as a method of determining discharges at the spring. Analysis of the travel times and stage discharges provided information on the conduit geometry by modeling the flow as open-channel flow in a rectangular channel. Flow in the system is rapid, ranging from 140 to 590 m h-1. Although the flow rate increases with discharge, the relationship is not simple owing to substantial increases in conduit cross-sectional area at higher discharges. Flow is turbulent and subcritical under all conditions. The most surprising result was the very low depth of flow calculated; less than 17 cm at even the highest discharge. Although this must be considered an 'equivalent' depth, it is believed to indicate that active flow in shallow conduit-flow aquifers is generally in a thin zone just beneath the water table

GROUNDWATER GEOCHEMISTRY OF THE CARBONATE KARST AQUIFER, SOUTH-CENTRAL KENTUCKY, USA, 1993, Hess J. W. , White W. B. ,
Analyses of 441 water samples from 15 sample sites, mainly springs and sinking creeks in the southcentral Kentucky karst, were used to determine hardness, P(CO2), and state of saturation with respect to calcite and dolomite. Most of the waters are undersaturated with respect to calcite and more undersaturated with respect to dolomite, in agreement with recent kinetic models. Time series data revealed chemical fluctuations on both weekly and seasonal time scales. Much of the short-term variation and some of the seasonal variation in the hardness and saturation index parameters can be accounted for by dilution effects from storm and seasonal runoff. Seasonal cycles in CO2 partial pressure arise from a dependence of soil CO2 on temperature and the growing season. Waters from different locations in the aquifer system are chemically distinct and fit into the concept of a hydrochemical facies

MICROBIOLOGICAL ACTIVITY IN THERMOGLACIAL KARST SPRINGS, SOUTH SPITSBERGEN, 1994, Lauritzen S. E. , Bottrell S. ,
Along the Hornsund fault zone, South Spitsbergen (76-degrees-60'N), thermokarstic springs smell of H2S and display either growth of, or eject fragments of, organic slime. The temperature in individual springs varies between 4 and 15-degrees-C. Their rate of discharge is approximately 1 L s-1 to 18 m3 s-1, corresponding to a minimum temperature of 30-degrees-C within the base of the aquifer. The water, which contains a few ppm SO4(2-), 0.5 ppm S2-, and several thousand ppm NaCl, appears to be a mixture of turbid glacial meltwater and hot brine. Water chemistry and stable isotopes indicate that the salinity is not the result of simple dilution of modern seawater from the brackish zone beneath the coastal karst aquifer, but rather originates from a deep thermal brine component where concentrations and isotopic composition of various species are controlled by water-rock interaction in the source area of the brine. A value of DELTAdeltaS-34 of up to about 30 parts per thousand indicates that sulfide is a bioreduction product of sulfate. Scanning electron microscope (SEM) studies revealed bacteria and fungal hypha in the organic slime, and larger spherical particles (approximately 3.8 mum diameter) that display high concentrations of Fe and S. These findings demonstrate the presence of sulfate-reducing bacteria within the subpermafrost aquifer

Geochemistry of submarine warm springs in the limestone cavern of Grotta Azzurra, Capo Palinuro, Italy: evidence for mixing-zone dolomitisation, 1996, Stuben Doris, Sedwick Peter, Colantoni Paolo,
Subtidal springs in and around the submarine limestone cavern of Grotta Azzurra, at Capo Palinuro, Italy, discharge fluids which are warm (-, Na and Mg2, and enriched in Si, alkalinity, Ca2, Sr2, Mn, NH4, PO43- and H2S, relative to surrounding seawater. The compositions of the warm fluid samples collected in and around the cave define mixing lines which suggest dilution of a single thermal fluid (T >= 23[deg]C) by cool overlying seawater (T= 17-17.6[deg]C). The chemical data suggest that the proposed thermal fluid contains two components, one derived from seawater ( 10%). Excess Si, alkalinity, Ca2, Sr2 and Mn relative to seawater are likely derived from the groundwater component or dissolution/hydrothermal alteration of the host rocks. Magnesium has been removed from the seawater component in exchange for Ca2, due to dolomitisation of the limestone and/or hydrothermal alteration reactions. Saturation-state calculations suggest that the vented fluids are near saturation with respect to calcite and supersaturated with respect to dolomite. This and the presence of dolomite in the host rocks and cave-floor sediments suggest that 'mixing-zone' dolomitisation of the limestones is occurring, perhaps kinetically assisted by elevated temperature and/or bacterial mediation in the reducing subseafloor zone. One possible 'end-member' condition is considered for the thermal fluid -- zero-Mg -- which suggests an end-member temperature of 50.5[deg]C and a fluid composition derived from ~ 38% seawater and ~ 62% groundwater. The heat source for the circulating fluids is uncertain, but may involve warm underlying igneous rocks or heating via the geothermal gradient. A continuous in-situ record of vent-fluid temperature, salinity, pH and O2 concentration collected within the cavern is consistent with our interpretation of the fluid origin, and suggests that tidal forcing affects circulation and venting of the warm fluids

Microorganisms as tracers in groundwater injection and recovery experiments: a review, 1997, Harvey R. W. ,
Modern day injection and recovery techniques designed to examine the transport behavior of microorganisms in groundwater have evolved from experiments conducted in the late 1800s, in which bacteria that form red or yellow pigments were used to trace flow paths through karst and fractured-rock aquifers. A number of subsequent groundwater hydrology studies employed bacteriophage that can be injected into aquifers at very high concentrations (e.g., 10(13) phage ml(-1)) and monitored through many log units of dilution to follow groundwater flow paths for great distances, particularly in karst terrain. Starting in the 1930s, microbial indicators of fecal contamination (particularly coliform bacteria and their coliphages) were employed as tracers to determine potential migration of pathogens in groundwater. Several injection and recovery experiments performed in the 1990s employed indigenous groundwater microorganisms (both cultured and uncultured) that are better able to survive under in situ conditions. Better methods for labeling native bacteria (e.g. by stable isotope labeling or inserting genetic markers, such as the ability to cause ice nucleation) are being developed that will not compromise the organisms' viability during the experimental time course

Geochemistry of Carlsbad Cavern Pool Waters, Guadalupe Mountains, New Mexico, 2000, Forbes, J. R.
Water samples collected from 13 pools in Carlsbad Cavern were analyzed to determine the concentrations of major ions. Air temperature, relative humidity, and carbon dioxide concentration of the cave atmosphere were also measured. Large differences in water quality exist among different cave pools, with some pools containing very fresh water, while others are brackish, with total dissolved solids concentrations up to 5000 mg/L. Brackish water pools appear to be associated with those portions of the cave where evaporation rates are high and/or soluble minerals are present. Geochemical speciation modeling showed that some pools are close to saturation with respect to the common cave minerals aragonite, calcite, gypsum, and hydromagnesite. A tracer test was performed using a non-toxic bromide salt to estimate the leakage rates of selected pools. Pool volumes calculated based on dilution of the bromide tracer were up to 550 m. The tracer test results were used to calculate mean residence times for the water in each pool. Calculated mean residence times based on bromide tracer loss rates ranged from less than a year for Rookery Pool and Devils Spring to 16 years for Lake of the Clouds. Calculated pool leakage rates ranged from 2 L/day to over 100 L/day. The pools with the highest leakage rates appear to be Rookery Pool, Green Lake, and Lake of the Clouds. The long residence times indicated by the tracer tests suggest that the pools evaporate more water than they leak. However, evaporation should result in an accumulation of dissolved chloride and other solutes in the pools, which for most pools does not appear to be the case. Taken together, these observations suggest that the pools are recharged primarily by infrequent precipitation events, separated by long periods of slow evaporation and minimal leakage.

The catchment of the Brassus karst spring (Swiss Jura): a synthesis of the tracer tests, 2000, Perrin J. , Jeannin P. Y. , Lavanchy Y. ,
Two successive tracer tests were carried out in the Pleine Lune cave which is located in the central part of the Brassus karstic spring catchment area (South-western Jura, Switzerland). During both experiments, the tracers were not recovered neither. at the Brassus spring nor at the secondary springs. Following this amazing result, the available data on this spring have been studied and a synthesis is proposed in this paper. The Brassus karstic spring, situated in the south-western part of Vallee de Joux, is an important resurgence from this part of the folded Jura. The water emerges from Cretaceous limestones covered by a thin layer of moraine: the main alimentation comes however from the underlying Maim limestone aquifer, Cretaceous limestones bring only a limited part of the total discharge. Within the supposed Brassus spring catchment areal 18 tracer tests were realised, but only half of them gave positive results. Positive tracer rests show low velocities and poor restitution percentage, particularly during low water periods. Such peculiarities are attributed to an important saturated zone, favouring dilution and dispersion of the tracers. The average discharge at the: spring is assumed to be less than 500 l/s and the average specific discharge is about 40 l/s/km(2), following previous data on other springs of the area. A calculated catchment area with such values would have a surface of 13,5 km(2); but the catchment area derived from the topography of the base of the Maim aquifer (top of the argovian marls considered as an aquitard) covers 56 km(2). This important difference as well as the negative results obtained from the Pleine Lune cave tracer tests show how difficult it is to define a catchment area for limestone aquifers: on one hand a delimitation based on water balance calculations tends to underestimate the catchment area by neglecting outlets as direct infiltration in the alluviums and secondary springs. On the other hand a delimitation based on geological considerations seems to overestimate the surface; this is illustrated by negative tracer tests results with injection points situated well inside the catchment area

Influence of contaminated Vistula River water on the groundwater entering the Zakrzowek limestone quarry, Cracow region, Poland, 2000, Motyka J. , Postawa A. ,
Chemical composition of water inflows in the Zakrzowek quarry, developed in fractured and karstified Upper Jurassic limestones, is controlled by infiltration of polluted water from the Vistula River and by infiltrating meteoric water. The river water TDS value is 2.5 g/dm(3). The quarry waters have 0.6-2.0 g/dm(3) TDS. Highly mineralised waters belong to Cl-Na type. With decreasing TDS the percentage of sulphates, calcium, magnesium and hydrocarbonates increases. This seems to result from various processes including dilution of polluted river water, leaching of aquifer rocks, and ion exchange. The transfer time of river water to the quarry is about 100-120 days. Concentration of contaminants contained in the river water declines during the migration through limestones to the quarry

Groundwater protection zone delineation at a large karst spring in western Ireland, 2000, Deakin J,
Pouladower Spring is a large karst spring in County Clare, Ireland which is being considered for use as a public supply. Groundwater protection zones have been delineated as a water quality management strategy for the spring. The Irish national groundwater protection scheme methodology is adapted to take account of the hydrological and hydrogeological complexities of the karst regime. The catchment area for the spring is large (approximately 380 km2) and comprises the zones of contribution for two major outlets of water, the spring and the River Fergus. The actual zone of contribution to the spring varies with different water level conditions and the risk to the source from any point within the catchment, at any given time, is less than that for a conventional groundwater source. The catchment area is highly vulnerable, but dilution and sedimentation occurring in the lakes up gradient of the source, the high throughput, and the contribution from fissures outside the main flow conduits have helped maintain good water quality at the spring. The source is considered to be a combination of both groundwater and surface water as they are intricately inter-linked throughout the catchment. An Inner Protection Area is delineated which does not provide the 100-days travel time to the source required by the national scheme, as this would be impractically large and over-protective. Rather, it delineates the area of highest hydrogeological risk to the source and should allow the local authority sufficient time to act in the event of an accidental spill. A certain degree of microbial contamination is inevitable in a karst regime and treatment is essential, as it would be for a surface water source. The remainder of the catchment is classed as an Outer Protection Area. These protection areas are then combined with the vulnerability in a GIS to give groundwater protection zones which will be used by the planners, in conjunction with groundwater protection responses, to control potentially contaminating activities

Controls on the geochemistry of speleothem-forming karstic drip waters, PhD thesis, 2000, Tooth, A.

Research was performed at Crag Cave, Castleisland, southwest Ireland, and P8 Cave, Castleton, Derbyshire, in order to determine the main factors responsible for modifying rainwater geochemistry during flow through soil and karstic aquifer zones. Monitoring was performed on a daily basis in summer and winter at Crag Cave, and on a monthly basis over one year at P8 Cave. At both sites, biannual peaks in karst system Ca2+ concentrations occurred due to: (i) promotion of microbial CO2 production by increased summer temperatures, and (ii) retardation of gaseous exchange by ponding of elevated winter rainfall input leading to an unseasonable build up in soil zone CO2. Therefore, speleothems at both sites may form biannual bands in hydrological years subject to elevated winter rainfall input.

In addition to variations in carbonate weathering due to fluctuations in CO2 levels, cation yields in Crag Cave matrix soil water were controlled by dolomite dissolution (Mg2+), plant uptake (K+), and evapotranspiration balanced by enhanced winter marine aerosol input (Na+). Strontium isotope analysis indicates that Sr2+ was derived from a 50:50 silicate/carbonate mixture, whereas the relatively light ?13C signal was related to direct evolution of CO2 into the aqueous phase in water-logged pores.

Within the Crag Cave aquifer variations in karst water geochemistry were controlled by dilution, flow switching, prior precipitation of calcite, and dolomite dissolution along the flow path. Strontium isotope analysis indicates that dissolution in the aquifer dominated, with Sr2+ being sourced from a 25:75 silicate/carbonate mixture. Light karst water 13C values were constrained by the supply of light soil gas to the aquifer.

Elevation in the Mg/Ca and Sr/Ca ratios in the Crag Cave speleothem record compared to present day analogues indicates that the former Holocene climate was drier, whereas heavier 87Sr/86Sr ratios and 13C values suggest variation in soil hydrology over time.


Chemical and physical controls on waters discharged from abandoned underground coal mines, 2001, Lopez D. L. , Stoertz M. W. ,
Abandoned up-dip drift mines in high-sulphur coal are a major source of acid mine drainage (AMD) in Appalachia. Studies of mines in the Monday Creek watershed of southeastern Ohio show that mines are recharged by surface runoff into subsidence features that dilate the natural stress-relief fracture system. The direct connection between the ground surface and the mines leads to a rapid response in the hydrograph, with a one- to four-day lag between precipitation and corresponding peak mine discharge. Subsidence occurs in topographic depressions where overburden is presumably relatively thin. Subsidence features drain 20-36% of the surface area. Unsaturated storage appears to be volumetrically insignificant, so that far more recharge occurs than the 5% often assumed for this region. Mine storage can change rapidly due to subsidence recharge. Hydrologically, mines with subsidence features behave like karst systems, with meteoric quickflow' representing more than 50% of the total flow. Mine discharge concentrations are relatively uniform through time, suggesting either equilibrium controls on chemistry or drainage of a well-mixed pool, or both. Evidence of dilution by high flows is slight. The first high flows after a baseflow period show only a slight increase in concentrations, attributed to flushing of stored reaction products. Loadings (concentrations x flow) depend on volumetric discharge and as a consequence are highly variable. The Eh/pH environment in up-dip drift mines indicates that mine waters are in contact with the atmosphere at least part of the time, unlike a true groundwater. Iron buffering partly controls pH, which clusters around values of 3.6-5.0

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