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Emil Racovita Institute of Speleology

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January 1998

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Radulescu, C. Editorial. pp. 7-8. TAK Articles: Rowe, P., J., Atkinson, T., J. Dennis, P., F. A stable isotope record from fluid inclusions in a Holocene speleothem from southwest Britain. pp. 9-16. The development of an on-line crushing technique has allowed measurement of both the dD and d18O composition of water from fluid inclusions within speleothems. Preliminary analysis of a Holocene speleothem with an extremely low water content (0.05 wt.%) suggests that the technique enables usefully accurate reconstructions to be made both of the stable isotopic composition of palaeoprecipitation and of cave palaeotemperature. Temperature data scatter can be attributed mainly to non-equilibrium growth of the stalagmite and also to slight isotopic fractionation of the sub-microlitre water volumes during sample handling. Further development of the technique is likely to improve both accuracy and precision. Kostov, K. Data about Quaternary tectonic activity in Labirinta Cave in Stara Planina Iskar Gorge, NW Bulgaria. pp. 17-22. Labirinta Cave is situated in the eastern marginal part of the Stara Planina Iskar Gorge, West Stara Planina Mts. (Balkans). It developed in Upper Cretaceous limestones. A typical maze cave with a total length of 255 m, the object of the study, is a typical example of structural control on the speleogenesis and it provides some interesting data about the Quaternary tectonic activity. According to previous works the relative age of the cave reaches back nearly to the Upper Pleistocene. Indices of neotectonic movements are established: subvertical and subhorizontal normal fault displacements with amplitudes of 14-17 cm, identified on the cave ceiling and walls. The presence of speleothems, covering the displacements favors neotectonic reconstitution. According to these indicators it is supposed that the region of the cave (the SE marginal part of Zgorigrad Anticline) is characterized by a strong Quaternary tectonic activity under the conditions of regional subhorizontal extension mainly along a SW-NE direction. The latter is possibly reflected on Labirinta Cave configuration also. Holmgren, K. Shaw, P. Paleoenvironmental interpretation of cores from large stalagmites: an example from Lobatse II Cave, Botswana. pp. 23-34. A large stalagmite, LII2, from Lobatse II Cave in southeast Botswana, was sampled by coring. Two vertical cores (V1, V2) and two horizontal cores (H1, H2) were subject to a total of 17 U-series alpha spectometry age determinations, 225 stable isotope measurements and 102 XRD analyses for mineralogical composition. The results are compared with previously reported similar analyses performed on a small, complete stalagmite (LII4), which cover the age range 50 kyr to 20 kyr. The results suggest that LII2 grew rapidly and asymmetrically between 26 kyr and 22 kyr, with an isotopic signature that does not match LII4. The ambiguous nature of the data implies a need for caution in the use of large stalagmite formations, which tend towards concentric asymmetry and variable mineralogy, the latter being probably a function of non-equilibrium conditions. It is also obvious that for large stalagmites coring is more appropriate than removal of the whole sample, but imposes limitations on both analysis and interpretation. Constantin, S. Lauritzen, S.-E. Speleothem datings in SW Romania. Part 1: Evidence for a continuous speleothem growth in Pestera Closani during Oxygen isotope stages 5-3 and its paleoclimatic significance. pp. 35-46. Two stalagmites and five pool-spar crystals from Closani cave (Southern Carpathians, Romania) were dated by U-series method. The 17 dates obtained show that the speleothem growth was slightly inhibited, yet not halted during the cold Oxygen Isotope stage 4. Although both stalagmites were located within a zone of currently stable meroclimate, their growth rates were very different. Sample C6 showed a remarkable constant and low growth rate between the Eemian and the last glacial maximum, while sample C8 grew fast, mostly within OI substage 3.3. This contrast enables us to assume that the eastern end of the Crystals Passage was still linked to the entrance area some 40 ka ago. On the other hand, since the slow-growth of C6 is indicative for a stable meroclimate, its initiation postdates the total clogging of the link between the paleo-ponor of Cioaca cu Brebenei and Crystals Passage. This gives a minimum estimate of the underground stream deepening/capture time. Diaconu, G. Lascu, C. Preliminary data about nitrates in "Pe?tera Mare de la ??litrari", Cerna Mountains, Romania. pp. 47-52. Sodium saltpetre (NaNO3) and darapskite [Na3 (NO3)(SO4).H2O] were identified for the first time in Romania by means of XR-analysis. The factors that favoured the genesis of these minerals are further discussed. Papadopoulou-Vrinioti, K. Karst landsform of Lichas Peninsula (NW of Euboea Island-Greece). pp. 53-56. This paper deals with the karst landforms of Lichas peninsula, situated in the north-western part of Euboea Island, which being developed on dolomitic limestone, is full of karst landforms. They are represented by a typical "dolomite tower karst", as well as by small 'polje' and 'ouvalas', the genesis and development of which are strongly related to the geotectonic structure of the area. Their filling material derives from corrosion and erosion processes; despite the significant thickness of the deposits, a simultaneous 'lateral corrosion' and 'linear erosion' occur as well. Stojiljkovic, D., Pavlovic, P. Sekularak, G. Risks of mine water in flow due to tectonics. pp. 57-60. The isolated Neogene coal basins formed by or exposed to the action of radial tectonics often keep a latent danger of mine waters inflow into the pit rooms. This is especially the case when the Pre-Neogene base is composed of karstified limestone and fissured rocks, divided into tectonic blocks brought to the same level with the coal horizon. The southern field of the brown coal mine Vranik was totally flooded by a catastrophic inflow of thermal water. The risks could be avoided by an accurate knowledge of the geologic-tectonic relationships. In the Vranik valley there have been drilled a number of exploratory boreholes but only few of them reached down to the coal basin base. By drilling a borehole into this formation it would be possible to establish the position of the tectonic blocks and the nature of the rocks in the basement, which would eliminate all the risks. Racovita, G. Moldovan, O. Rajka, G. Données préliminaires sur l'environnement de la Grotte des Ours en régime d'exploitation touristique. pp. 61-74. Des mesurages mensuels effectués dans le secteur touristique de la Grotte des Ours durant le cycle avril l997 - mai 1998 montrent que le topoclimat souterrain reste contrôlé en premier lieu par la météorologie externe même après deux décennies d'exploitation touristique plus ou moins intensive de la cavité. Néanmoins, des effets à long terme de cette exploitation ont pu être décelés. Ils se traduisent par une augmentation de l'humidité atmosphérique jusqu'à l'état de saturation et, de ce fait, par une condensation plus importante que d'ordinaire en régime estival. Une diminution sévère des effectifs de la population spéléicole de Coléoptères Bathysciinae a pu être mise également en évidence. Benderev, A. Angelova, D. Evolution of karst in the southern part of Vitosha Mountain, Bulgaria. pp. 75-82. The object of this investigation is karst and its morphogenesis in the region of the Bosnek village, where the 17 000 m- long cave system "Duhlata" (the longest in Bulgaria ) is situated. The initial stage of karstification is closely connected to the overthrust of Golo Burdo. Later stages are controlled by the evolution of Pernic fault zone and of the Struma river. Contemporary development of the cave system is controlled by underground streams, which occurred below the present-day bed of the Struma river. There are some older floors within this system and other large caves, which outline karst stages in the area. Silvestru, E. Perennial ice in caves in temperate climate and its significance. pp. 83-94. Ice is relatively frequent in caves. However, perennial accumulations of ice in caves in temperate climate are a rare feature. Little is presented in the karstological literature about the mechanisms that trigger and control cave glaciation in temperate climate. The same about the most important caves with ice deposits. After presenting several such caves, we present the most typical case that we know of - Ghetarul de la Scarisoara - and sum up the results of over 40 years of research in this cave. Perennial ice only accumulates nowadays in static caves (also called cold-air traps), while dynamic caves rapidly lose their ice, unless gated. There seems to be a cyclical increase and decrease of the overall volume of ice (75,000 m3) due to cave morphology rather than to climate oscillations. There seems to exist a "cold halo" in the Scarisoara cave, which explains why the temperature in the temperate meroclimate of the cave is below the regional multiannual mean temperature. This is considered to be a sign of maturity of the ice deposit. Mijatovic, B., F. The optimization of groundwater exploitation regime by regulation and control of karst reservoirs system. pp. 95-100. The basic and most difficult problem in supplying water from karst areas derives from considerable fluctuations in the quantity of water discharged from a large number of springs and other stream flows. This fact continually forces us to face the question if, and in what manner, we can use technical control facilities to regulate flows of karst water for a more efficient exploitation. Several case studies throughout karst regions worldwide are described, representing examples of circumstances favorable for the application of artificial improvements. Methods for increasing the volume of stored water and for controlling discharge, with better yields, involve such facilities as wells, dams, grout curtains and drainage galleries. It is emphasized that detailed preliminary hydrogeological research is essential to the success of the designed control facilities. Ivanov, I., I. Relationship between geological, tectonic, climatic, and hydrogeological conditions in the karst region Boga-Kozhnia, Albania. pp. 101-108. The expedition "Albania '96" of the Bulgarian Federation of Speleology was carried out between 20.08.96 and 05.09.96. It continued the series of Bulgarian expeditions in Albania, that started in 1992. The investigated region is situated in the north-western part of Albania, north-east of Skodra, and belongs to the western part of the Dinarides (called Albanian Alps). The area investigated during the expedition covers about 10 km2 and is situated at 1600-1800 m altitude, north of Boga village. The investigated area includes mainly carbonate rocks of Jurassic-Cretaceous age. From a tectonic point a view it is an uplifted block, delimited by faults striking SW-NE and NW-SE. Rocks display a high degree of tectonic fracturing. Karst is typically alpine, uncovered, with a large aeration zone. During the expedition hydrogeological, tectonic and climatological investigations were performed. Water and rock samples were taken and analysed in the Laboratory of the Institute of the Bulgarian Academy of Science. Preliminary conclusions are forwarded concerning the relative part of water of different origins in the karst processes. An attempt is made to provide forecasts on karst processes that occur deep in the rock massif. The main indications that need to be detected in the search for large vertical caves in the region are determined. Raeisi, E., Zareh, M. Eftekhari, P. Application of dye tracing for determining the characteristics of Shespeer karst spring. pp. 109-118. The water supply management requires fully understanding of the aquifer geographic extent, the hydraulic behavior and the characterization of karst conduit system in order to provide a safe and reliable supply of water. Dye tracing is generally the most practical and satisfactory method to provide information for management and protection of karst aquifer. The study area is a part of the Zagros Thrust Zone. The Sheshpeer aquifer is mainly composed of karstic Sarvak Formation. The main karst feature of the area is the presence of 259 sinkholes which direct rain and snowmelt water into the aquifer. The main discharge point is the Sheshpeer spring with a mean annual discharge of 3200 l/s. Thirty kilograms of sodium fluorescein where injected into the sinking stream and sampled at 33 springs, for a period of 287 days. Florescent dyes were detected in the spring water by means of a Shimadzu RF 5000 spectro-fluorophotometer with a sensitivity of 0.001 ppb. The dye was only detected in the Sheshpeer spring. The mass of dye recovered was estimated to be 10.11 kg. Three experiments were conducted in the laboratory to evaluate the dye loss of. The first experiment showed that at low concentration, 13 % of the dye decayed in darkness after 100 hours. The second experiment (batch method) and the third experiment (column method) revealed that from 8 to 40 % of the dye was adsorbed by limestone, marl and clay after 24 hours. The low recovery is due to the adsorption and the processes that induce colour loss. The geological setting, water balance, and dye tracing indicated that the catchment area of the Sheshpeer spring is limited to major parts of the Barm-Firooz anticline and the northern flank of the Gar anticline. The flow velocity in the Sheshpeer aquifer is 51.3 m/hr, 15.2 m/hr and 7.2 m/hr based on the time of the first appearance of the dye, time to peak concentration, and the centroid time respectively. The obtuse peak and long tail of the dye recovery curve, as well as the huge volume of diluting water indicate the existence of an extensive underground reservoir in the catchment area of the Sheshpeer spring. Pavlovic, P., Stojiljkovic, D. Rajic, M. Determination of karst aquifers recharge area in a terrain of complex geology and tectonic composition. pp. 119-124. In some instances, it is difficult to determine the directions of water circulation in a limestone aquifer, especially if the limestones are included in a terrain characterized by a complex geology and tectonics. A good example are the karst thermal springs of Rgoska Banjica near Knjazevac. The source of thermal water is situated in the western limb of the Tupiznica-Knjazevac syncline, hence it was supposed that its recharge zone was located in its hinterland. However, by discovering magnetite sand in a limestone cavern in an exploratory bore drilled near the thermal spring, it was concluded that the recharge zone is on the opposite eastern limb, where the karstified limestones are in contact with the gabbroid massif of Zaglavak, the only one from where only the association of fragments of the microscopically investigated magnetite sand could originate. Jemcov, I., Ristic, V., Stefanovic, Z. Prohaska, S. Application of auto-cross regression model to the analysis and discharge simulation of some karst springs. pp. 125-134. The drainage of karst aquifers mostly occurs by karst spring discharge. The karst hydrogeological system is characterized by a great complexity, as a result of which we lack sufficient information about the system. We can obtain significant information about the system by monitoring quantitative characteristics of the springs. With that goal in mind a stochastic model was taken into consideration; one which simulates daily discharge rate oscillations of karst spring and the influence of climatic factors (rainfall and air temperature) on the springflow regime. Bandrabur, G., Slavoac?, D., Bandrabur, R. Slavoac?, R. Considérations hydrodynamiques sur le système karstique de Bârza (Monts et Plateau de Mehedin?i, Roumanie). pp. 135-139. Le comportement du système karstique dont les sources de Bârza en sont l'exutoire a fait l'objet de recherches qui ont pris en compte les résultats fournis par le dernier essai de traçage (19.08.1998) et l'analyse systémique appliquée aux données pluie - débit. Les particularités du système incluent une réponse rapide à la pluie, suivie ultérieurement par une forte inertie en ce que concerne la variabilité des débits. La zone d'alimentation comprend les Monts ainsi que le Plateau de Mehedinti. Le comportement hydrodynamique apparemment contradictoire est dû à l'interaction entre les zones karstiques bien organisées au long des principales directions de drainage et les systèmes annexes qui renferment un volume d'eau considérable. Stojiljkovic, D. Pavlovic, P., Neskovic-Zdravic, V. The occurrence conditions of aquifers in Permo-Carboniferous limestones in Western Serbia. pp. 139-144. Permo-Carboniferous limestone in the northern part of western Serbia, between the rivers Drina and Jadar, has no visible continuous extension. A large part of the limestone is covered with cultivated sandy-clay strata or with Miocene sands and clays. In mountain areas the limestone is karstified and fissured. In the hills area and the plateaus with burried limestone, an interesting phenomenon of incipient karstification occurs. In "Lelic karst" karst forms such as sinkholes and valley, have been found. The karst aquifer that was formed in Triassic limestone discharges through several strong springs with a flow rate of 0.95 m3/s. The Permo-Carboniferous limestone is practically devoid of water, as compared to "Lelic Karst" with spring flow rates of about 2-8 l/s. Since the average annual rainfall amounts to 800-1100 mm, the aridity assumption is questionable. Papic, P., Ristic, V., Golubovic, R. Damnjanovic, V. Influence of the physico-chemical properties of rainfall on karst groundwater quality. pp. 145-148. During complex hydrogeological and hydrochemical investigations on karst groundwater in Valjevo town (Western Serbia), increased concentrations of nitrates have been identified. Daily regime observations on groundwater quality and quantity, as well as on atmospheric precipitations started in 1991. The hydrochemical determinations were performed in situ with standard methods. Bassed on 600 atmospheric precipitation and some 2,000 groundwater samples, a positive trend of nitrate ions concentration in karst groundwaters was noticed. Anthropogenic processes range among the basic ones that determine the chemical composition of precipitation and groundwater. The results of statistical analyses have shown a negative, as well as a positive influence of anthropogenic factors (which include the reduction of industrial activities due to Bosnia war actions and to the beginning of international unjust sanctions). Oraseanu, I. Contributions to the Poieni Plateau hydrogeology investigation (Metaliferi Mountains, Romania). pp. 149-158. The Poieni Plateau is located in the Metaliferi Mountains, to the south of the Ariesul Mic river, and it occurs as a virtually horizontal surface, perched some 300-500 m above the surrounding rivers. It is shaped in massive crystalline limestone included in a monoclinal structure, that gently dips southward, underlain by crystalline schists and overlain by flysh-like deposits. The water accumulations in the plateau, supplied almost exclusively by rainfall, discharge mainly to the north, through gravitational springs located at the contact of the crystalline limestone with the crystalline schists. The springs in the southern section of the plateau include on the one hand overflow type outlets that discharge the water of the karst aquifer at its contact with the overlying flysch-like deposits, and on the other hand the outlets in the Crisul Alb river valley, an area where the karst aquifer is dissected by this river course. To the east, the karst aquifer cover is locally eroded next to the village of Sohodol, the aquifer water emerging through the spring Feredeu. The cumulated flow rate of the main springs by which the karst aquifer discharges amounts to some 800 l/s. In hydro-chemical terms, the water is generally over-saturated with respect to calcite, many outlets exhibiting extended deposits of travertine. Radulescu, C., Samson, P., M. Petculescu, A. Remarques sur la dentition de Allactaga orghidani Radulescu Samson, 1976 du Pléistocène moyen de la Dobrogea centrale (Roumanie). pp. 159-168. On précise les aspects morphologiques de la dernière molaire supérieure (M3) chez Allactaga orghidani Rådulescu Samson, du Pléistocène moyen de la Grotte des Chauves-Souris (Pestera Liliecilor) de Gura Dobrogei (phase de Gura Dobrogei-2). L'analyse morphologique des M3 de plusieurs espèces du genre Allactaga a montré que A. orghidani diffère nettement par rapport au groupe de A. major Kerr dont M3 a conservé une structure plus primitive. La régression graduelle du mésolophe et sa soudure au paracône est une particularité de A. orghidani. Une réduction plus forte du mésolophe est présente chez A. severzovi Vinogradov dont la structure d'ensemble reste, toutefois, plus proche de A. major. La fusion du paracône et du mésolophe, caractéristique de A. orghidani suggère un rapprochement de A. euphratica Thomas qui présente une structure similaire. Teodorescu, M.-A. Mitrofan, H. An alpine karst occurrence: G?uri Cirque (Parâng Mountains, Romania). pp. 169-176. As a part of Lotru glacial complex, "Gauri" cirque represents an area on which limestones outcrop over 1.25 sq. km. The position of the crystalline limestone layer reveals the existence of a perched syncline whose axis plunges northward. The two limbs of this structure act as a substratum for a petrographic topography occurring in two different drainage basins (Lotru and Jiet) with distinct karst features. A 'mature' karstic area situated in Gauri Cirque between 1920 and 2020 m elevation can be associated, at least in part, with a drainage system corresponding to the shaping of Borascu platform (Danian-Eocene). The surface karst consists in grikes, sinkholes, swallets, as well as a sinking creek. The abandoned channel situated beyond the swallets was left as a dry valley (Gauri dry valley). At least five small caves were found within the area. They are predominantly horizontal, and some display more than one level. Both the surface topography and the caves were affected by glacial processes, during the Pleistocene epoch. Subsequently, during the Holocene epoch, the underground dissolution was re-activated and the caves were enlarged, while on the surface a less mature relief developed. Due to its high-altitude location, Gauri cirque can be considered an alpine karst area. In Memoriam Emilian Gaspar, 1932-1999. pp. 177-178. Open Access - Permission by Publisher Vol. 11-12 (1998-1999) See Extended description for more information.

Keywords

Romania, Geology

Subject: topical

Geology

Subject: geographic

Romania

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Article

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serial

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K26-04803

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