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. ...
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,
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. ...
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 solution breccia is a mass of rock composed of angular to rounded fragments of rock that have accumulated by solution of surrounding or underlying carbonate. see also collapse breccia.?
SummaryKarst aquifers are the main groundwater resource in Lebanon as well as in most Mediterranean countries. Most of them are not exploited in a sustainable way, partly because their characteristics remain unknown. Karst aquifers are so complex that the assessment of their resource and their exploitable storage requires an analysis of their whole functioning, particularly by analysing the spring hydrograph. Among all various methods, the method proposed by Mangin aims to characterize at the same time the recharge conditions and the storage and recession of the saturated zone by analyzing the spring hydrograph. This method defines two parameters, the infiltration delay i, and the regulating power k which are the roots of a classification of karst systems. This classification makes the distinction between karst and porous aquifers considering the value of the regulating power. k is assumed to be lower than 0.5 in karst, and between 0.5 and 1 for all other aquifers, 1 being the upper limit.The study of karst aquifers in Lebanon shows values of k > 0.5, and even 1; former data from the literature show that other karst springs in Middle East have comparable characteristics. In fact, what is not considered by Mangin and others, k is equivalent to a mean residence time in years of water in the saturated zone. So long residence times are normally observed in poorly karstified aquifers, or containing abandoned, not functioning karstification. The geological framework in which the studied springs are located in fact shows that these aquifers have been subject to a long, complex evolution, as a consequence of the base level rising. This rising produced the flooding of the successive karst drainage network, which does not really function anymore and provides a large storage capacity to the aquifer. The very interesting properties of these aquifers make them prime targets for fulfilling the increasing needs of water
Clastic sedimentary rocks are generally considered non-karstifiable and thus less vulnerable to pathogen contamination than karst aquifers. However, dissolution phenomena have been observed in clastic carbonate conglomerates of the Subalpine Molasse zone of the northern Alps and other regions of Europe, indicating karstification and high vulnerability, which is currently not considered for source protection zoning. Therefore, a research program was established at the Hochgrat site (Austria/Germany), as a demonstration that karst-like characteristics, flow behavior and high vulnerability to microbial contamination are possible in this type of aquifer. The study included geomorphologic mapping, comparative multi-tracer tests with fluorescent dyes and bacteria-sized fluorescent microspheres, and analyses of fecal indicator bacteria (FIB) in spring waters during different seasons. Results demonstrate that (i) flow velocities in carbonate conglomerates are similar as in typical karst aquifers, often exceeding 100 m/h; (ii) microbial contaminants are rapidly transported towards springs; and (iii) the magnitude and seasonal pattern of FIB variability depends on the land use in the spring catchment and its altitude. Different ground water protection strategies than currently applied are consequently required in regions formed by karstified carbonatic clastic rocks, taking into account their high degree of heterogeneity and vulnerability.
Anomalous behaviour of specific electrical conductivity (SEC) was observed at a karst spring in Slovenia during 26 high-flow events in an 18-month monitoring period. A conceptual model explaining this anomalous SEC variability is presented and reproduced by numerical modelling, and the practical relevance for source protection zoning is discussed. After storm rainfall, discharge increases rapidly, which is typical for karst springs. SEC displays a first maximum during the rising limb of the spring hydrograph, followed by a minimum indicating the arrival of freshly infiltrated water, often confirmed by increased levels of total organic carbon (TOC). The anomalous behaviour starts after this SEC minimum, when SEC rises again and remains elevated during the entire high-flow period, typically 20–40 µS/cm above the baseflow value. This is explained by variable catchment boundaries: When the water level in the aquifer rises, the catchment expands, incorporating zones of groundwater with higher SEC, caused by higher unsaturated zone thickness and subtle lithologic changes. This conceptual model has been checked by numerical investigations. A generalized finite-difference model including high-conductivity cells representing the conduit network (“discrete-continuum approach”) was set up to simulate the observed behaviour of the karst system. The model reproduces the shifting groundwater divide and the nearly simultaneous increase of discharge and SEC during high-flow periods. The observed behaviour is relevant for groundwater source protection zoning, which requires reliable delineation of catchment areas. Anomalous behaviour of SEC can point to variable catchment boundaries that can be checked by tracer tests during different hydrologic conditions.
Arranged by geologist Dr. Temucin Aygen, the International Conference of Speleology and Karstology at Istanbul, with the participation of about twenty foreign scholars, opened first at Beyazit de Stamboul University. For three days papers and discussions enlivened the sessions, broken by tours around the Bosporus. During the following two weeks the members of the Conference took a field trip across Anatolia, through Ankara, Konya, Mersin, Antalya, Burdur, Izmir, Bursa, and Istanbul. They thus had the opportunity to investigate the principal karstic phenomena of Turkey; the Konya obrouks, travertines of' Yerkòpru and Antalya, caves of the Mersin region, vauclusian springs of Irviz and Manavgat, and so forth. The interest of these occurrences of Anatolian karst is unquestionable; in addition to the scientific problems they pose, they represent a great economic value either as tourist centres or as producers of electric energy and sources of water for irrigation.
Arranged by geologist Dr. Temucin Aygen, the International Conference of Speleology and Karstology at Istanbul, with the participation of about twenty foreign scholars, opened first at Beyazit de Stamboul University. For three days papers and discussions enlivened the sessions, broken by tours around the Bosporus. During the following two weeks the members of the Conference took a field trip across Anatolia, through Ankara, Konya, Mersin, Antalya, Burdur, Izmir, Bursa, and Istanbul. They thus had the opportunity to investigate the principal karstic phenomena of Turkey; the Konya obrouks, travertines of' Yerkòpru and Antalya, caves of the Mersin region, vauclusian springs of Irviz and Manavgat, and so forth. The interest of these occurrences of Anatolian karst is unquestionable; in addition to the scientific problems they pose, they represent a great economic value either as tourist centres or as producers of electric energy and sources of water for irrigation.
The new subspecies Stenasellus skopljensis thermalis, from Banja Luka (Bosnie, Yugoslavia) is described. From the ecological point of view this form differs from the others because it inhabits underground waters of elevated temperature (240°C). Another constantly abundant species, St. hungaricus thermalis Mestrov, also occurs in Yugoslavia under the same ecological conditions, in the warm springs of Podsused near Zagreb. This indicates that these underground waters at elevated temperature are not accidental but preferred habitats for these forms, and confirms once again that thermal waters of this type are the biotopes-refuges in which certain relic forms are retained.
The new subspecies Stenasellus skopljensis thermalis, from Banja Luka (Bosnie, Yugoslavia) is described. From the ecological point of view this form differs from the others because it inhabits underground waters of elevated temperature (240°C). Another constantly abundant species, St. hungaricus thermalis Mestrov, also occurs in Yugoslavia under the same ecological conditions, in the warm springs of Podsused near Zagreb. This indicates that these underground waters at elevated temperature are not accidental but preferred habitats for these forms, and confirms once again that thermal waters of this type are the biotopes-refuges in which certain relic forms are retained.
After brief descriptions of the geomorphology of the Cooleman Plain karst and in particular of the Blue Waterholes, the methods adopted to analyse the functioning of these major risings are detailed. The discharge regime of Cave Creek below them is oceanic pluvial in type perturbed by drought and snow. There is much annual variation both in seasonal incidence and total amount, with catchment efficiency correspondingly variable. Suspended sediment concentration is even more erratic and monthly determinations are inadequate for calculating corrasional denudation rates. Mean concentrations of suspended solids are about 1/18th of solute load. Total dissolved salts have a strong inverse relationship with discharge, and mean values are high compared with those for other catchments in eastern Australia but none of these determinations are from limestone catchments. Sodium, potassium, and chlorine contents are low compared with the same catchments but silica is relatively high. The ratio of alkaline earths to alkalis indicate that Cave Creek carries carbonate waters and there is an inverse regression of the ratio on discharge. There is inverse correlation of total hardness on discharge likewise due to concentration of surface waters by evaporation in dry periods, together with reduced underground solution rate at times of large, rapid flow. The spring waters remain aggressive. Close regressions of hardness on specific conductivity now permit the latter to be determined in the place of the former. Much evidence converges to indicate that all the springs at the Blue Waterholes are fed from the same conduit. The intermittent flow which comes down the North Branch on the surface to the Blue Waterholes differs significantly in many characters from the spring waters. Rates of Ca + M carbonate equivalent removal vary directly with discharge since hardness varies much less than does water volume. These gross rates have to be adjusted for (a) atmospheric salts entering the karst directly, (b) peripheral solute inputs from the non-karst two-thirds of the catchment and (c) subjacent karst solution before they can be taken as a measure of exposed karst denudation. The methods for achieving this are set out. The total corrections amount to about one third of the total hardness, though the correction for subjacent karst on its own lies within the experimental error of the investigation. The residual rate of limestone removal from the exposed karst also shows a winter/spring high rate and a summer/autumn low rate but the seasonal incidence and annual total varied very much from year to year. In comparison with results from karsts in broadly similar climate, the seasonal rhythm conforms and so does the high proportion (78%) of the solution taking place at or close to the surface. This reduces the importance of the impounded condition of this small karst but supports the use of karst denudation rate as a measure of surface lowering. Cave passage solution may however be more important in impounded karst than its absolute contribution might suggest, by promoting rapid development of underground circulation. The mean value of limestone removal is low for the climatic type and this is probably due to high evapotranspirational loss as well as to the process of eliminating atmospheric, peripheral non-karst and subjacent karst contributions. The difficulties of applying modern solution removal rate to the historical geomorphology of this karst are made evident; at the same time even crude extrapolations are shown to isolate problems valuably.
A preliminary inquiry to the extent and boundaries of subterranean waterways within the Mystery Cave System was explored. Rhodamine WT dye in 500 ml quantities was used in fluormetry determinations of surface flow to ground water basins. A Turner Model 111 fluorometer was utilized for detection purposes powered by a portable 12 volt, 220 amp hour battery-inverter system. It was shown that water entered underground passageways through sinkholes or highly creviced limestone/dolomite rock strata and reappeared several kilometres downstream. The outflow appears in the form of "springs". The possibility exists that contaminated surface water may seep through the soil for long distances. It is obvious there is acute danger of underground contamination of municipal and private water supplies situated in this area.
A preliminary inquiry to the extent and boundaries of subterranean waterways within the Mystery Cave System was explored. Rhodamine WT dye in 500 ml quantities was used in fluormetry determinations of surface flow to ground water basins. A Turner Model 111 fluorometer was utilized for detection purposes powered by a portable 12 volt, 220 amp hour battery-inverter system. It was shown that water entered underground passageways through sinkholes or highly creviced limestone/dolomite rock strata and reappeared several kilometres downstream. The outflow appears in the form of "springs". The possibility exists that contaminated surface water may seep through the soil for long distances. It is obvious there is acute danger of underground contamination of municipal and private water supplies situated in this area.
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.
