Community news

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 epsomite is a cave mineral - mgso4.7h2o [11].?

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

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

Search in KarstBase

Your search for scale (Keyword) returned 511 results for the whole karstbase:
Showing 1 to 15 of 511
Controversy over the great flood hypotheses in the Black Sea in light of geological, paleontological, and archaeological evidence, , Yankohombach Valentina, Gilbert Allan S. , Dolukhanov Pavel,
Legends describing a Great Flood are found in the narratives of several world religions, and the biblical account of Noah's Flood is the surviving heir to several versions of the ancient Mesopotamian Flood Myth. Recently, the story of the biblical deluge was connected to the Black Sea, together with the suggestion that the story's pre-Mesopotamian origins might be found in the Pontic basin [Ryan, W.B.F., Pitman, III, W.C., 1998. Noah's Flood: The New Scientific Discoveries About the Event That Changed History. Simon and Schuster, New York]. Based on the significance of this flood epic in the Judeo-Christian tradition, popular interest surged following publication of the idea.Currently, two Great Flood scenarios have been proposed for the Black Sea: (1) an Early Holocene event caused by catastrophic Mediterranean inflow at 7.2 ky BP (initial hypothesis of [Ryan et al., 1997. An abrupt drowning of the Black Sea shelf. Marine Geology 138, 119-126]) or 8.4 ky BP (modified hypothesis of [Ryan et al., 2003. Catastrophic flooding of the Black Sea. Annual Review of Earth and Planetary Science 31, 525-554.); and (2) a Late Pleistocene event brought on by Caspian influx between 16 and 13 ky BP [Chepalyga, A.L., 2003. Late glacial Great Flood in the Black Sea and Caspian Sea. GSA Annual Meeting and Exposition, 2-5 November 2003, Seattle, USA, p. 460]. Both hypotheses claim that the massive inundations of the Black Sea basin and ensuing large-scale environmental changes had a profound impact on prehistoric human societies of the surrounding areas, and both propose that the event formed the basis for the biblical Great Flood legend.This paper attempts to determine whether the preponderance of existing evidence sustains support for these Great Floods in the evolution of the Black Sea. Based upon established geological and paleontological data, it finds that the Late Pleistocene inundation was intense and substantial whereas the Early Holocene sea-level rise was not. Between 16 and 13 ky BP, the Late Neoeuxinian lake (the Late Pleistocene water body in the Pontic basin pre-dating the Black Sea) increased rapidly from ~-14 to -50 m (below the present level of the Black Sea), then rose gradually to ~-20 m by about 11 ky BP. At 11-10 ky BP (the Younger Dryas), it dropped to ~-50 m. When the Black Sea re-connected with the Sea of Marmara at about 9.5 ky BP, inflowing Mediterranean water increased the Black Sea level very gradually up to ~-20 m, and in so doing, it raised the salinity of the basin and brought in the first wave of Mediterranean immigrants. These data indicate no major drawdown of the Black Sea after the Younger Dryas, and they do not provide evidence for any catastrophic flooding of the Black Sea in the Early Holocene.In addition, available archaeological and paleoenvironmental evidence from the Pontic region reveal no recognizable changes in population dynamics between 14 and 6 ky BP that could be linked to an inundation of large magnitude [Dolukhanov, P., Shilik, K., 2006. Environment, sea-level changes, and human migrations in the northern Pontic area during late Pleistocene and Holocene times. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 297-318; Stanko, V.N., 2006. Fluctuations in the level of the Black Sea and Mesolithic settlement of the northern Pontic area. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 371-385]. More specifically, Mesolithic and early Neolithic archaeological data in southeastern Europe and Ukraine give no indications of shifts in human subsistence or other behavior at the time of the proposed catastrophic flood in the Early Holocene [Anthony, D., 2006. Pontic-Caspian Mesolithic and Early Neolithic societies at the time of the Black Sea Flood: A small audience and small effects. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 345-370; Dergachev and Dolukhanov, 2006. The Neolithization of the North Pontic area and the Balkans in the context of the Black Sea Floods. In: Yanko-Hombach, V., Gilbert, A.S., Panin, N., Dolukhanov, P.M. (Eds.), The Black Sea Flood Question: Changes in Coastline, Climate, and Human Settlement. Springer, Dordrecht, pp. 489-514]

Fungal communities on speleothem surfaces in Kartchner Caverns, Arizona, USA, , Vaughan Michael J. , Maier Raina M. , Pryor Barry M.

Kartchner Caverns, located near Benson, Arizona, USA, is an active carbonate cave that serves as the major attraction for Kartchner Caverns State Park. Low-impact development and maintenance have preserved prediscovery macroscopic cavern features and minimized disturbances to biological communities within the cave.. The goal of this study was to examine fungal diversity in Kartchner Caverns on actively-forming speleothem surfaces. Fifteen formations were sampled from five sites across the cave. Richness was assessed using standard culture-based fungal isolation techniques. A culture-independent analysis using denaturing gradient gel electrophoresis (DGGE) was used to assay evidence of community homogeneity across the cave through the separation of 18S rDNA amplicons from speleothem community DNA. The culturing effort recovered 53 distinct morphological taxonomic units (MTUs), corresponding to 43 genetic taxonomic units (GTUs) that represented 21 genera. From the observed MTU accumulation curve and the projected total MTU richness curve, it is estimated that 51 percent of the actual MTU richness was recovered. The most commonly isolated fungi belonged to the genera Penicillium, Paecilomyces, Phialophora, and Aspergillus. This culturebased analysis did not reveal significant differences in fungal richness or number of fungi recovered across sites. Cluster analysis using DGGE band profiles did not reveal distinctive groupings of speleothems by sample site. However, canonical correspondence analysis (CCA) analysis of culture-independent DGGE profiles showed a significant effect of sampling site and formation type on fungal community structure. Taken together, these results reveal that diverse fungal communities exist on speleothem surfaces in Kartchner Caverns, and that these communities are not uniformly distributed spatially. Analysis of sample saturation indicated that more sampling depth is required to uncover the full scale of mycological richness across spelothem surfaces.

Caves of the Coastal Areas of South Australia, 1965, Sexton, R. T.

The majority of South Australian caves occur in the Tertiary and Quaternary limestones of the coastal areas. Their distribution is discussed here on a geological rather than a geographical basis. The most significant caves are briefly described and illustrated to indicate different types and related developments in the coastal limestones. The most notable feature of the limestones is their soft, porous nature. Caves also occur in South Australia in hard, massively bedded Cambrian and Pre-Cambrian limestones and dolomites. These are not discussed in the present paper. To facilitate recording, South Australia has been divided into six zones as shown in Figure 1, and the caves numbered in order of discovery in each area. In general, both the name and the number of the cave have been given, but unnamed caves are specified by number only. The cave maps have been chosen to give as wide a coverage as possible of the various types, or to illustrate points of particular interest. The arrows on the section lines show the direction of viewing, and the sections are numbered to relate them to the plans. Where a cross-section and longitudinal section intersect, the common line has been drawn to relate the sections. The same scale has been used throughout for ease of comparison.

The cuticular surfaces of the gnathopods of two Amphipod Crustaceans: Niphargus (hypogean Gammarid) and Gammarus (epigean Gammarid)., 1972, Sellem Evelyne
Niphargus virei and N. schellenbergi (hypogean Gammarids) as also Gammarus pulex pulex (epigean Gammarid) show on the Gn1 and Gn2 of both sexes ornamented areas which were studied with a scanning electron microscope. The ornamentations are built up of teeth. These are simple in Gammarus pulex pulex and present a sexual dimorphism on the meropodite. In N. schellenbergi and N. virei they are as often as not grouped by three. In Orchestia (Talitrid) the teeth have their bases fusioned which forms pectinate scales showing a sexual dimorphism. Outside these areas, the gnathopod cuticle of N. virei, N. schellenbergi and Gammarus pulex pulex is ornamented with ovoid papilla, each of them surmounted by a finger-like process covering over a depression.

The cuticular surfaces of the gnathopods of two Amphipod Crustaceans: Niphargus (hypogean Gammarid) and Gammarus (epigean Gammarid)., 1972, Sellem Evelyne
Niphargus virei and N. schellenbergi (hypogean Gammarids) as also Gammarus pulex pulex (epigean Gammarid) show on the Gn1 and Gn2 of both sexes ornamented areas which were studied with a scanning electron microscope. The ornamentations are built up of teeth. These are simple in Gammarus pulex pulex and present a sexual dimorphism on the meropodite. In N. schellenbergi and N. virei they are as often as not grouped by three. In Orchestia (Talitrid) the teeth have their bases fusioned which forms pectinate scales showing a sexual dimorphism. Outside these areas, the gnathopod cuticle of N. virei, N. schellenbergi and Gammarus pulex pulex is ornamented with ovoid papilla, each of them surmounted by a finger-like process covering over a depression.

Geology and hydrogeology of the El Convento cave-spring system, Southwestern Puerto Rico., 1974, Beck Barry F.
Whereas the North Coast Tertiary Limestones of Puerto Rico are classic karst locales, their southern counterparts are almost devoid of karst development. The El Convento Cave-Spring System is the most prominent feature of the only large scale karst area developed on the South Coast Tertiary limestones. The karst topography is localized on the middle Juana Diaz Formation, which is a reef facies limestone, apparently because of the high density and low permeability of this zone as compared to the surrounding chalks and marls. In the El Convento System a sinking ephemeral stream combines with the flow from two perennial springs inside the cave. The surface drainage has been pirated from the Rio Tallaboa to the east into El Convento's subterranean course. The climate is generally semi-arid with 125-150 cm of rain falling principally as short, intense showers during Sept., Oct., and Nov. Sinking flood waters are absorbed by a small sinkhole and appear two to three hours later in the cave. In the dry season this input is absent. The two springs within the cave have a combined inflow to the system of 1.0 m3/min at low flow but half of this leaks back to the groundwater before it reaches the resurgence. The spring waters are saturated with CaCO3 and high in CO2 (26.4 ppm). As the water flows through the open cave it first becomes supersaturated by losing CO2 and then trends back toward saturation by precipitating CaCO3.

Karst Geomorphology of the Bruce Peninsula, Ontario, PhD Thesis, 1976, Cowell, Daryl William

This is the first detailed examination of the karst geomorphology of the Bruce Peninsula. It attempts to review all aspects including pavement phenomena and formation (microkarst features), surface and subsurface karst hydrology (meso to macro scale) and water chemistry. The latter is based on over 250 samples collected in 1973 and 1974.
The dolomite pavement is the best example of its kind that has been described in the literature. It covers much of the northern and eastern parts of the peninsula and can be differentiated into three types based on karren assemblages. Two of these are a product of lithology and the third reflects local environmental controls. The Amabel Formation produces characteristic karren such as rundkarren, hohlkarren, meanderkarren, clint and grike, kamentizas and rillenkarren on glacially abraded biohermal structures. The Guelph Formation develops into a very irregular, often cavernous surface with clint and grike and pitkarren as the only common recognizable karren. The third assemblage is characterized by pitkarren and is found only in the Lake Huron littoral zone. Biological factors are believed to have played a major role in the formation of the pavement. Vegetation supplies humic acids which help boost the solution process and helps to maintain a wet surface. This tends to prolong solution and permit the development of karren with rounded lips and bottoms.
Three types of drainage other than normal surface runoff are found on the Bruce. These are partial underground capture of surface streams, complete underground capture (fluvio-karst), and wholly vertical drainage without stream action (holokarst). Holokarst covers most of the northern and eastern edge of the peninsula along the top of the escarpment. Inland it is replaced by fluvial drainage, some of which has been, or is in the process of being captured. Four perennial streams and one lake disappear into sinkholes. These range from very simple channel capture and resurgence, as shown by a creek east of Wiarton, to more mature and complex cave development of the St. Edmunds cave near Tobermory. Partial underground capture represents the first stage of karst drainage. This was found to occur in one major river well inland of the fluvio-karst and probably occurs in other streams as well. This chapter also examines the possible future karst development of the Bruce and other karst feature such as isolated sinks and sea caves.
The water chemistry presented in Chapter 5 represents the most complete data set from southern Ontario. It is examined on a seasonal basis as well as grouped into classes representing water types (streams, Lake Huron and Georgian Bay, inland lakes, swamps, diffuse springs and conduit springs). The spring analyses are also fitted into climatic models of limestone solution based on data from other regions of North America. It was found that solution rates in southern Ontario are very substantial. Total hardness ranges from 150 to 250 ppm (expressed as CaCO3) in most lakes and streams and up to 326 ppm in springs. These rates compare with more southerly latitudes. The theoretical equilibrium partial pressure of CO2 was found to be the most significant chemical variable for comparing solution on different kinds of carbonates and between glaciated and non-glaciated regions. Expect for diffuse flow springs and Lake Huron, the Bruce data do not separate easily into water types using either graphical or statistical (i.e. Linear Discriminant Analysis) analyses. This is partly because of the seasonality of the data and because of the intimate contact all waters have with bedrock.

Geomorphology of the North Karst, South Nahanni River Region, Northwest Territories, Canada, PhD Thesis, 1976, Brook, George Albert,

First investigated on the ground in June 1972, the Nahanni karst of northern Canada is the most complex karst terrain yet reported from high latitudes. It is centered at 61°28' N, longitude 124°05' W and lies within the zone of discontinuous permafrost. Mean annual temperature is 24°F and mean total precipitation 22.3 inches. Principal karst forms are fracture-located karst streets and irregularly-shaped closed depression called karst platea which may be up to 600 feet in depth. Platea often contain karst towers which are residuals of wall recession. Vertical-walled pond dolines up to 120 feet deep are common in bare karst areas while subjacent karst collapse, subsidence and suffosion depressions occur on marginal shale- and drift-mantled surfaces. Three small poljes have been identified, two produced entirely by solution, the other a structural form. These are periodically inundated. There are several peripheral fluvial canyons up to 3,000 feet deep that are blocked by glacial drift and which presently drain underground. Similarity in the hydrogeological properties of Nahanni Formation limestones at a variety of scales has led to the development of morphologically-identical karst forms which range in size from inches up to hundreds of feet. Furthermore, many of these landforms are part of a developmental sequence that at one scale links vertical-walled dolines, karst streets, platea and poljes; and at another links solution pits, grikes and joint hollows on limestone pavements. The evidence suggests that poljes form by the coalescence of dolines and uvalas just as Cvijic suggested in 1918. In attempting to explain the almost "tropical" nature of the sub-arctic Nahanni karst landform assemblage, a number of facts are of importance.
(a) The Nahanni Formation limestones have been highly warped and intensively fractures during the past one million years. Open fractures have encouraged karstification by allowing easy movement of water underground. Warping has provided the relief necessary for the development of solutional forms with a distinct vertical component.
(b) The karst can not be considered relict because it was glaciated during the Pleistocene. In addition the hydrological activity in it today is comparable with that in many humid tropical karst areas.
(c) Solutional denudation rates governed by aspects of surficial and bedrock geology may in some localized areas be equivalent to rates in humid tropical carbonate regions.
(d) At present rates, the most highly developed forms could have been produced within the last 200,000 years and because there is evidence to indicate that the karst may not have been glaciated for up to 250,000 years, such a period has been available for solutional development.
Because the Nahanni region has not been glaciated for an extremely long period, it may be one of only a few high-latitude carbonate terrains that have had time to develop fully. Its very existence questions the validity of the concept that the intensity and direction of karst development is climate-controlled. In the Nahanni at least, the structural and lithological properties of the host limestone appear to have been of greater importance. The labyrinth karst type present in regions of humid-tropical to sub-arctic climate, is an outstanding example of a structurally-controlled karst landscape. It may well be that the same controls also influence the distributions of other karst types.

Geodetic measurements of the Bear-Cave (Jaskinia Nied?wiedzia). [in Polish], 1977, Caco? Stefan, G?zikiewicz Roman

Identification of the origin of oreforming solutions by the use of stable isotopes, 1977, Sheppard S. M. F. ,
SynopsisThe four major different types of water -- magmatic, metamorphic, sea water and/or connate, and meteoric water -- have characteristic hydrogen (D/H) and oxygen (18O/16O) isotope ratios. Applied to the analysis of isotopic data on hydrothermal minerals, fluid inclusions and waters from active geothermal systems, these ratios indicate that waters of several origins are involved with ore deposition in the volcanic and epizonal intrusive environment. Water of a single origin dominates main-stage mineralization in some deposits: magmatic -- Casapalca, Peru (Ag-Pb-Zn-Cu); meteoric -- Butte, Montana (Cu-Zn-Mn), epithermal deposits, e.g. Goldfield, Tonopah, Nevada (Ag-Au), Pachuca, Mexico (Ag-Au), San Juan Mountains District, Colorado (Ag-Au-Pb-Zn); sea water -- Troodos, Cyprus (Fe-Cu), Kuroko, Japan (Fe-Cu-Pb-Zn). Solutions of more than one origin are important in certain deposits (magmatic and meteoric -- porphyry copper and molybdenum deposits) and are present in many. In the porphyry Cu-Mo deposits the initial major ore transportation and alteration processes (K-feldspar-biotite alteration) are magmatic-hydrothermal events that occur at 750-500{degrees}C. These fluids are typically highly saline Na-K-Ca-Cl-rich brines (more than 15 wt % equivalent NaCl). The convecting meteoric-hydrothermal system that develops in the surrounding country rocks with relatively low integrated water/rock ratios (less than 0.5 atom % oxygen) subsequently collapses in on a waning magmatic-hydrothermal system at about 350-200{degrees}C. These fluids generally have moderate to low salinities (less than 15 wt % equivalent NaCl). Differences among these deposits are probably in part related to variations in the relative importance of the meteoric-hydrothermal versus the magmatic-hydrothermal events. The sulphur comes from the intrusion and possibly also from the country rocks. Deposits in which meteoric or sea water is the dominant constituent of the hydrothermal fluids come from epizonal intrusive and sub-oceanic environments where the volcanic country rocks are fractured or well jointed and highly permeable. Integrated water/rock ratios are typically high, with minimum values of 0.5 or higher (atom % oxygen) -- the magmatic water contribution is often drowned out'. Salinities are low to very low (less than 10 wt % equivalent NaCl), and temperatures are usually in the range 350-150{degrees}C. The intrusion supplies the energy to drive the large-scale convective circulation system. The sulphur comes from the intrusion, the country rocks and/or the sea water. Argillic alteration, which occurs to depths of several hundred metres, generated during supergene weathering in many of these deposits is isotopically distinguishable from hydrothermal clays

A New Development in Solving Problems of Large Scale Speleophotography "Diprotodon Poulter", 1977, Poulter, Norman

A discussion of the special requirements of photography in large caverns is followed by a history of the "Diprotodon" magnesium flare as a lighting source. A new model, Diprotodon poulter is described in detail.

A Model for the development of broad scale networks of groundwater flow in steeply dipping carbonate aquifers, 1978, Ewers Ralph O.

Small-scale spatial variations in the Chemistry of diffuse-flow seepages in Gua Anak Takun, West Malaysia, 1981, Crowther J.

Hydrogeological conditions in the Middle East, 1982, Burdon Dj,
The geology of Middle East is summarized under the subheadings: Precambrian basement, epicontinental sediments, geosynclinal and shelf deposits, Tertiary volcanics and Quaternary cover. The main tectonic episodes including epeirogenic movements, rifting and the Tertiary orogeny, are reviewed. The imposition of hydrometeorolocal and climatic conditions upon the regional geology provides the setting for the hydrogeological discussion. Five factors which influence infiltration to aquifers under conditions of low precipitation and high potential evaportranspiration are discussed. The predominance of fossil groundwater is the most striking hydrogeological phenomenon occurring on a regional scale in the Middle East. Its mode of formation during the pluvials is outlined and the isotopic evidence is reviewed. The main physical and chemical characteristics of fossil ground-waters are described. It is conservatively estimated that some 65 000 km3 of good- to medium-quality groundwater are stored in the great artesian basins of the Near East. These fossil ground-waters are a non-renewable natural resource. Current annual abstraction is, as yet, a small percentage of the total reserves but economic factors rather than the volume of reserves will determine the ultimate extent of their exploitation. The renewable groundwater resources of the Middle East tend, by comparison, to be of local rather than regional significance. Some originate outside the Middle East, coming in as surface flows in the Nile and Tigris-Euphrates and infiltrating into the sediments in and adjacent to the flood plains. Other renewable resources accumulate within the region where high precipitation and mountainous relief are associated. Such areas include the Djebel Akhdar of Cyrenacia, the Tertiary fold mountains from the Taurus through the Zagros to the Oman ranges, and the volcanic and basement highlands of Yemen, Asir and Ethiopa. Locally, in areas of lower precipitation, lenses of recent fresh groundwater float on regional more saline groundwater. In some areas subsurface flows towards and through wadi systems are also of importance

Hydrogeology of the Great Nubian Sandstone basin, Egypt, 1982, Shata A. A. ,
In Egypt, the strata of major hydrogeological interest are composed of a sandstone complex ranging from Cambrian to Upper Cretaceous in age. This sandstone complex, commonly known as the Nubian Sandstone, has a thickness varying from less than 500 m to more than 3000 m and rests directly on Precambrian basement. This simple picture is complicated by a number of major structural fault and fold axes which traverse the region in a north-easterly direction. The sandstones reach their max-imum development in the Ain Dalla basin, a downthrown structural block SW of Bahariya oasis. Basement features exercise a dominant control on the structural and sedimentological form of the sandstone complex. In spite of the structural complications, the Nubian sand-stone, underlying an extensive area of Egypt, probably con-stitutes a single hydrogeological system to the W of the Gulf of Suez. To the E, on the Sinai peninsula, a second system may exist with some connection to the main western system in the N. The main western system, which extends into Libya and Sudan, comprises a multi-layered artesian basin where huge groundwater storage reserves were accumulated, principally during the pluvials of the Quaternary. The carbonate rocks overlying the Nubian Sandstone complex display karst features locally and are recharged by upwards leakage from the underlying major aquifer. Large-scale development of the Nubian Sandstone aquifer in Egypt has been under consideration since 1960. Latest proposals for the New Valley development project involve exploitation at the annual rate of 156.2 x l06m3 at El-Kharga, 509.2 at

Results 1 to 15 of 511
You probably didn't submit anything to search for