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Contents and Abstracts
TAK Articles
Onac, B., P. & Lauritzen, S.-E. The climate of last 150,000 years recorded in speleothems: preliminary results from north-western Romania. pp. 9–22.
Seventy-four 230Th/234U dates on speleothems enable preliminary estimates to be made of the palaeoclimatic evolution of the north-western part of Romania. The growth frequency of speleothems was examined using the cumulative distributed error frequency method (Gordon, 1989). The climatic oscillations that are suggested by our curve correlate tentatively with known climatic events provided by pollen analysis, coral growth frequency and oxygen isotope records from both deep sea sediments and ice cores during the same timespan (the last 150,000 years).
Pourchet, M., Mélieres, M., A., Silvestru, E., Rajka, G., Candaudap, F. & Carbonnel, J.-P. Radionuclides in a caves lake sediment core from Ghetarul de sub Zgurasti (Romania). pp. 23–28.
Some 250 m from the entrance of the cave Ghetarul de sub Zgurasti, on the bottom of a lake exclusively charged per ascensum, at 12 m depth, a 41 cm core of fine sediment had been taken for radionuclide investigation. The following have been identified: 210Pb—a natural radionuclide originating from atmospheric Radon decay, 134Cs and 137Cs—artificial radionuclides derived from the thermonuclear tests in the early sixties and the Chernobyl accident in the mid-eighties. Deposition fluxes of these elements at the water/sediment boundary have been found to be of the same order of magnitude as the ones at the surface, which shows a very effective transmission of pollution from the surface to remote cave environment. This is, to our knowledge, the first time such a substantial contamination has been measured. Coherent results were yielded by the profiles, especially in terms of sedimentation processes, allowing estimates of sedimentation rates, diffusion coefficients and the recent history of the sediment. The latter proved to be in perfect agreement with the climate recorded through the last decades.
Labau, V., Gaspar, E. & Paunica, T. Speleothems dating using the thermoluminiscence method. pp. 29–34.
The age of a stalagmite fragment collected from Pestera Vântului (Wind Cave), Romania, was estimated using the thermoluminescence method. The natural dose accumulated by the calcite during the geological age was established. Using the relationship between the calcite thermoluminescence sensitivity and the applied pre-dose, an age of 59,052 years has been established.
Carlier, E. Effet d’échelle de la dispersion dans un conduit karstique. Hypothèse linéaire et hypothese fractale. pp. 35–44.
Les variations du coefficient de dispersion sont étudiées dans un conduit rectiligne et dans un conduit présentant une tortuosité à géométrie fractale. Dans le cas d’un conduit rectiligne, nous montrons que le coefficient de dispersion est sujet à un effet d’échelle, jusqu’à une certaine distance au?delà de laquelle on retrouve le processus classique fickien de dispersion, caractérisé par un coefficient constant. En revanche, dans un conduit à tortuosité fractale, nous montrons qu’il n’existe pas de valeur asymptotique du coefficient de dispersion apparent. La détermination du coefficient de dispersion par la variance est discutée.
Carlier, E. Influence de la structure sur la variabilité spatio-temporelle du coefficient de dispersion. Cas théorique d’un faisceau de conduits karstiques soumis à une injection continue en absence de diffusion moléculaire (écoulement rapide). pp. 45–50.
De nombreux modèles de simulation du transfert de masse en karst et milieu fissuré reposent sur l’hypothèse d’un coefficient de dispersion invariant dans le temps et l’espace pour une vitesse moyenne d’écoulement constante. A partir d’un ensemble de conduits cylindriques horizontaux, on montre que le coefficient de dispersion est, généralement, une fonction du temps, de la distance et de la structure du milieu karstique ou fissuré. Lorsque la fréquence de répartition des sections obéit à une loi exponentielle particulière, le coefficient de dispersion n’est plus fonction que de la distance.
Miatovic, B., F. Relation entre les caractères physiques et les champs de leur distribution dans les roches karstiques. pp. 51–62.
Dans les roches karstiques la structure des champs de distribution spatiale des majeurs paramètres physiques, tels la perméabilité et la porosité peut être caractérisée par: (1) la distribution statistique dans les blocs-matrices, (2) la distribution ponctuelle dans le réseau d’écoulement, et (3) l’effet d’échelle sur ces champs. Ces considérations demandent à être bien expliquées, notamment dans le domaine de la fracturation des massifs calcaires, dont les caractères physiques et hydrauliques sont sous l’influence de l’effet d’échelle. On constate souvent en terrains karstiques une coexistence de deux types bien distincts d’écoulements: l’un, correspondant aux classiques rivières souterraines, lié aux collecteurs des grandes dimensions du réseau karstique, l’autre, conforme à une variété de circulation plus ou moins lente, dans les blocs-matrices volumineux mais relativement peu perméables. Il se pose alors la question de la répartition des valeurs de perméabilité et de porosité efficace dans un réseau de conduits connectés et des blocs-matrices lorsque l’échelle varie.
Papadopoulou, K., A. Comparative observations in karst formations of Parnass and Arcadia Mountains (Greece). pp. 63–68.
The paper deals with the study of two great karst areas in Greece. The first one belongs to the Parnass Mountain (Central Greece) while the other one to the Arcadia Mountain (South Greece). A large number of dolines (300) have been studied in order to identify their common characteristics, differences, and the rules that control their development. The final purpose of the paper is to emphasize the rules that control the genesis of those areas.
Papadopoulou, K., A. & Gournellos, T. A study of the subsurface karst of Kopais (Central Greece). pp. 69–76.
In this article we attempt to perform a quantitative analysis of the swallets (“katavothres”) of the former lake of Kopais (Central Greece). These are situated at different altitudes around the former lake. The principal outcrops are various limestones, flysch and schists. We investigate the relationships between various variables such as lithology, altitude, horizontal development and geographical position of these karst forms. We proceed to a statistical analysis of the above variables and we study the spatial distributions of the swallets. The final results are indicative of the development of these karstic forms and their dependence on the various parameters.
Zlokolica, M., Mandic, M. & Ljubojevic, V. Some significant caves at the western rim of the Miro? karst (Yugoslavia). pp. 77–88.
The western rim of the Miro¹ karst oasis is composed of Lower Cretaceous sandstone, marl, mudstone and limestone (K1,2), and Upper Jurassic limestone (J33), and it abounds with rivers which sink into caves of considerable dimensions. The deepest of them is the pothole Jama u Laniëtu (–272 m), while the longest is the cave Buronov Ponor (1950 m). The caves abound with diverse forms of passages — ranging from almost unaltered fissures to well-rounded phreatic tubes. The phases of fluvial sedimentation, of rock collapses, of formation of travertine coating, and of hydrologic reactivation and emptying of the cavities, can be distinguished as well.
Stevanovic, Z., Dragisic, V., Dokmanovic, P. & Mandic, M. Hydrogeology of Miro? karst massif, eastern Serbia, Yugoslavia, pp. 89–96.
The karst massif of Miro? mountain is one of the national parks of Yugoslavia, situated in the northern extremity of the Carpatho-Balkanides of eastern Serbia and extending to the Danube and the Romanian border. The area of the calcareous massif, composed mainly of Tithonic limestones, exceeds 120 km2. Four karst springs used to drain a karst aquifer located in the north and the west of the massif, along the Danube, before being submerged by the reservoir behind the dam at Portile de Fier (The Iron Gates). To the south, the massif is drained by Blederija spring (Qav. about 30 l/s). The massif has a multitude of active concentrated swallets. Several deep caves (e.g. Rakin Ponor, 278 m deep, the deepest in Serbia) were recently investigated by speleologists. Explorations have been undertaken in Miro? area for karst ground water intake aiming at the water supply of Donji Milanovac resort center.
Samani, N. & Ebrahimi, B. Analysis of spring hydrographs for hydrogeological evaluation of a karst aquifer system. pp. 97–112.
Karst aquifers are, in general, extremely heterogeneous in character. As a result, quantitative data obtained from selected points in the system, either by pumping or by using marker dyes, can be rarely extrapolated to evaluate the average function of the system as a whole. In contrast, recession curves of spring hydrographs show the overall response of the aquifer to precipitation events and help evaluating aquifer storage and drainage potentials. In this study, three analytic equations are used for estimating hydrogeological characteristics of a karst aquifer: Mangin’s equations, a newly proposed equation that assumes that the recession curve is composed of both quickflow and baseflow, and Coutagne’s equation, which considers the recession curve to be the response of a single reservoir. The hydrographs of three springs draining Sabzpooshan and Beaza aquifers in Fars Province, Iran, are analyzed. From the analysis, it is apparent that the saturated zone accounts for 99%, 91% and 99%, respectively for Pirbanoo, Polberengi and Ghorehdan springs.
Iurkiewicz, A., Voica, M. & Bulgar, A. Indirect evaluation of the Izvarna karst system discharge trend (Romania). pp. 113–120.
The importance of Izvarna karst system stems from the fact that its water is being tapped for the supply of the city of Craiova. The hydrodynamic behavior of the aquifer under natural conditions has been investigated based on records from 1957–1965. The development of the Cerna-Motru-Tismana hydropower system has induced changes in the surface streams discharge regime and hence possible consequences on the karst aquifer supply. Compared to an accurate water budget evaluation, the correlative and spectral analysis of the discharge is a cost?effective method for the identification of the subsurface flow evolution trend induced by human activity. The paper illustrates the ability of the method to provide a quantitative evaluation of the water resource reduction as well as the limits of the adopted approach.
Iurkiewicz, A., Dragomir, G., Rotaru, A. & Badescu, B. Karst systems in Banat Mountains (Resita–Nera zone). pp. 121–140.
The Banat Mountains area, located in the south-west of Romania includes more than 800 sq. km of karst zones belonging to the Resita - Moldova Noua large synclinorium. Although scientific karst investigations were initiated at the beginning of the century, the previously collected hydrogeological data were rather local and contradictory. Taking into account groundwater resources that karst areas should normally contain, “Prospectiuni” company has recently started a complex research program, in order to evaluate the amount of groundwater resources of this particular area.
The karst territory was divided as a result into three distinct zones, which correspond roughly to the Caras, Minis–Nera and Nera–Danube catchment areas. The hydrologic, hydrodynamic and hydrochemical characteristics of the karst systems included within the first two zones are discussed. The water budget completed based on 1992–1995 data provides information on underground hydrologic connections between small catchment basins, and eventually for each of the above mentioned areas as a whole.
Ristic, V., Prohaska, S. & Stevanovic, Z. Some examples of karst springflow regime simulation and prediction for water management balance analyses. pp. 141–148.
Karst occurrences in stream basins have not been given adequate consideration in the applied hydrology. As a consequence, water table and discharge of karst springs are not measured at stations of the official hydrometeorological network. For a proper assessment of the karst water regime, under the given study conditions, indirect methods and computation procedures have to be used. One of these is MNC (Multiple Nonlinear Correlation) model, used for filling-in, extending and three-dimensional interpolation of the hydrometeorological data. Based on this model, in the general areas of the karst springs (Izvor-Sveta Petka, Mlava, Grza, Nemanja, Mrljis with Groznicevac) on Kucaj and Beljanica mountains, eastern Serbia, this paper presents filled-in (where data are lacking) and extended series, which are essential for the investigation of the karst springflow regime, or for a water budget analysis that extends over several years.
Stevanovic, Z., Markovic, M., Pavlovic, R., Jemcov, I., Dragisisic, V. & Cupkovic, T. Correlation between regional fault pattern and karst water flow directions based on examples from Eastern Serbia (Yugoslavia). pp. 149–154.
The analysis of the fault pattern of eastern Serbia was made as a part of the basic and purpose detailed hydrogeological investigations in some localities. By correlating the observed regional features with the point elements of the principal drainage systems, a significant coincidence of positions has been noticed. The strikes of the main faults, longitudinal NW–SE and younger NE–SW (W–E), largely coincide with the principal, general directions of karst ground water flows. Subjects of particular analysis were the calcareous massifs corresponding to the anticlinoria of Ku?aj and Beljanica, and of Rtanj and Ozren in central Carpatho-Balkan mountain range of eastern Serbia.
Filipovic, B., Lazic, M., Vidovic, M. & Sekulovic, B. Tapping and protection of Maljen Spring, on Mount Durmitor, Yugoslavia. pp. 155–164.
Karst springs Veliki and Mali Maljen emerge, 30–35 m apart at the foot of one of the slopes of the mountain Durmitor at the altitude of 1320 m, approximately 15 km south of ?abljak, one of the largest winter resorts in Montenegro and Yugoslavia. The springs drain a vast karst reservoir consisting of Triassic carbonate rocks: they are of ascending type with the outflow zones masked by moraine material. The spring Veliki Maljen is tapped, whereas Mali Maljen still runs through glacial material. The discharge of the spring varies between a maximum of 150–200 l/s and 35–40 l/s indicating a characteristic karst regime. According to their physical and chemical properties, the waters are of exquisite quality and therefore they absolutely meet any norms or regulations for bottling, that is foreseen in the future. In order to determine the conditions of exploitation and of preservation of the water qualities, a necessary hydrogeological research has been carried out. It has been performed according to the regulations for establishing the boundaries of the sanitary protection zones for maintaining the necessary continuity during the building and the operation of the plant for bottling the natural drinking waters that flow through Veliki Maljen spring.
Raeisi, E., Jehbez, O. & Moore, F. Hydrochemical behavior of karstic and evaporitic formations surrounding Sarvestan Plain, Iran. pp. 165–174.
The Sarvestan Plain is located in the central-southern Iran. The plain is surrounded by extensive karst carbonate deposits with minor amounts of evaporitic-argillitic sediments. These Mesozoic and Cenozoic formations are intruded by two Precambrian salt domes to the northeast and southeast of the plain. Despite the presence of karstic formations in the drainage basin of the plain, the quality of the ground water is very poor.
In this study the lithological characteristics and mineral constituents of the surrounding formations are investigated by optical and chemical methods. During the summer 1992, the electrical conductivities of 500 operational wells, 15 springs, and 4 qanats were measured. Furthermore, 128 representative samples were analyzed for major ions including calcium, magnesium, sodium, potassium, chloride, bicarbonate, and sulfate using standard wet chemical methods. Temperature and pH of all the sampling sites were also measured. Using the WATQEF computer program, the saturation indices in various minerals were calculated.
Results indicate that although the drainage basin of the plain consists mostly of carbonate formations, except for a narrow band in the south and a small region in the northeast of the plain where the type of water is bicarbonate, the rest of the aquifer exhibits a chloride-sulfate type water. The main sources of the chlorine and sodium ions are shown to be the exposed salt domes, and the sources of the sulfate are the dissolution of gypsum and anhydrite along with the oxidation of pyrite in the argillaceous formations. The reason for varying ionic compositions in different parts of the aquifer is discussed. The main reason for the poor quality of groundwater is apparently the mixing of the karstic water with water expelled mainly from salt domes and to a lesser extent from evaporitic and argillitic units. The higher solubility of halite minerals compared with that of carbonates, contributes to the poor quality of the groundwater.
Gaspar, R. Pulse temperature and conductivity analysis in pseudo-karst structure investigation. pp. 175–184.
The permeable zones and associated leakage through the pseudokarstic structure of Racova reservoir were determined by using natural tracers: electrical conductivity, TDS and water temperature. The variation of these parameters was measured in piezometers, boreholes, subaerial and underwater springs. To check the flow paths determined by natural tracers, artificial labelings were performed.
Oraseanu, I. Contributions to the hydrogeology of the karstic areas of the Bihor Vladeasa Mountains (Romania). pp. 185–214.
The Bihor Vladeasa Mountains are ones of the most important karst regions in Romania. They have important groundwater resources, unexploited till now. On the hydrogeological map there are pointed the main karst springs with their magnitude of discharges and the directions of the groundwater flows. More than 45 tracers labellings were performed and an average of 45 m/hour of flow velocity was recorded in 42 of these.
As a consequence of the great diversity of the geological constitution and intense fracturation of the rocks, the karst systems are of binary type, with a large variety in size and hydrological parameters distribution. Due to the consistent observations and the hydro-meteorological measurements, the groundwater resources were evaluated and the processing of the flow rates series outlined a great diversity of the karstic systems.
The quality of the groundwater is very good as indicate the results of the chemical and bacteriological analysis and the potential sources of pollution are leaks.
Diaconu, G. Points de vue concernant le clivage de la calcite. pp. 215–218.
A l’aide des quelques images obtenues au microscope électronique en balayage, l’auteur exprime un point de vue original concernant le clivage de la calcite.
Iurkiewicz, A., Badescu, B. & Marinica, E. Intensity of karst processes as a function of the carbonate formations in the north Resita–Moldova Noua Synclinorium. pp. 219–222.
The exploration of the karst cavities in the Resita–Anina area led to the identification of a significant amount of "karst entrances", consisting mainly of caves and potholes, swallets and springs. The study of the characteristics of the karst cavities, as well as of their distribution with respect to the different types of carbonate deposits, has resulted in a qualitative evaluation of the karstification processes that have occurred in this specific area.
