TAK-Online
Contents and Abstracts
TAK Reviews
Tenu, A. & Davidescu, F., D. La datation par radiocarbone dans la recherche spéléologique, pp. 7–16.
La mise au point de la datation par radiocarbone, réalisée par Libby en 1955, a permis d’établir des chronologies absolutes et efficaces pour la période des dernières 40 milles ans.
Malgré le fait qu’en Roumanie la méthode fût signalée en 1956, la datation proprement dite par radiocarbone a été réalisée seulement en 1977, à l’Institut de Météorologie et Hydrologie de Bucarest. Depuis cette année, les applications au radiocarbone en Roumanie ont visé exclusivement la datation des eaux souterraines.
Ce rapport, par la présentation succuncte des bases théoriques, expérimentales et méthodologiques et des déterminations préliminaires, effectuées sur des spéléothèms, voudrait être une tentative pour l’extrapolation de cette méthode dans la recherche spéleologique.
Le travail expose, d’une façon succinte, les bases théoriques, expérimentales et méthodologiques de la datation par radiocarbone dans la recherche spéologique et présente aussi, pour illustrer la méthode, trois déterminations d’âge pour des spéléothèms de Roumanie.
TAK Articles
Ungureanu, C. Mineralogic and geochemical research of the Tecuri Cave (Romania) red clay, pp. 17–32.
Le travail tente de tirer au clair la genèse des dépôts argileux se trouvant dans la zone Bojita-Tecuri-Rachiteaua du Sud-Ouest des monts de Sebes.
Après un aperçu historique sur les recherches effectuées dans la zone, on y trouve présentées des données orohydrographiques, la géologie de la région et la pétro-chimie des roches.
La comparison des paramètres géochimiques des roches se trouvant dans cette zone – c’est-à-dire des schistes cristallins du domaine Gétique, des calcaires du Jurasien et des argiles rouges (qui abondent dans la grotte de Tecuri) – a porté aux conclusions suivantes:
1.La composition granulométrique des échantillons d’argile indique une fraction pélitique d’environ 50%.
2.La composition chimique des argiles indique des taux de Al2O3 et Fe2O3 élévés, qui les approchent des argiles bauxitiques (Suliman, 1976).
3.Les minéraux argileux déterminés ont été: le kaolinite, le gibbsite, le diaspore, l’illite et le halloysite.
4.La genèse des argiles est liée à l’altération des métamorphites appartenant au domaine gétique, sourtout l’altération des micaschistes et des amphibolites.
5.Il y a égalment la possibilité de la formation des minéraux argileux par l’altération des bauxites à un pH acide (5.5–6.4).
6.L’apparition de ce genre d’argiles saulement sur substrat de calcaires peut être due aussi au phénomène de piézo-électricité du calcite (Diaconu, 1986).
Ionescu, G. & Ionescu, C. Considerations on the morphology and genesis of the Jurassic paleokarst in Farcu Hill area (Southern Padurea Craiului Mountains, Romania), pp. 33–40.
Based on surface data and more than 300 boreholes investigations in Farcu Hill area, in the Southern part of Padurea Craiului Mountains, the present paper deals with some features of the Jurassic fossil karst relief sunk now under limy Cretaceous deposits. Our purpose is both theoretical: to enrich the image about some factors and their evolution in modelating this paleorelief and practical: to detect bauxite bodies in this region by use of reconstructing methods, as is the isobathic map and geostatistical analysis of these data, in correlation with geological and geomorphological observations.
Constantin, S. & Rotaru, A. Considérations génétiques sur la grotte “Pestera cu Lacuri din Valea Seaca” (Monts Locvei, Roumanie), pp. 41–49.
Les auteurs présentent une hypothèse sur la genèse d’une cavité de dimensions moyennes, située dans le Bassin Valea Mare (Monts Locvei). La grotte est ascendante, disposée sur deux étages et elle présente sur son parcours une suite de lacs situés à des cotes croissantes par rapport à l’entrée. Compte tendu de la morphologie d’ensemble et de détail de la cavité on advance l’hypothèse que son creusement a eu lieu regime noyé après lequel, consécutivement à un abaissement relativement rapide du niveau phréatique, les galeries ont restées fossiles. Le niveau hydrostatique actuel est marqué par le niveau de l’eau dans les lacs. Le mécanisme de constitution du réseau karstique est analysé en tentant compte des similitudes entre la situation présentée et celle de certaines cavités de la zone de Mendip (Angleterie). Etant donné que l’alimentation de l’acquifère est due exclusivement aux infiltrations on considère que dans l’abaissement brusque du niveau phréatique un rôle primordial serait revenu à couverture argileuse imperméable qui a couvert, à partir du Pléistocène supérieur, les plateaux calcaires sommitaux. Cette couverture aurait eu un rôle de “tampon”, diminuant la quantite d’eau écoulée vers l’acquifère. On apprécie ainsi que l’âge de l’abaissement du niveau phréatique, et donc de la “fossilisation” des galeries, pourrait être situé le plus tôt, à la fin du Pléistocène supérieur.
Serban, M. & Racovita, G. L’extension de la zone glacée dans la Grotte de Scarisoara (Roumanie) – effet des oscilations météorologiques multiannuelles, pp. 51–64.
La limite des formations stalagmitiques de glace qui se développent dans la zone périglaciaire de la Grotte de Scarisoara (Monts du Bihor) présente des variations saisonnères dues aux changements périodiques qui lieu dans le régime de ventilation de la cavité. Ces variations ont été suivies par des mensuelles effectuées durant l’intervalle 1983-1988. L’analyse stastique des données primaires, basée sur la méthode de Ballot-Besson d’adjustement d’une suite chronologique de valeurs, mpntre que cette limite comporte aussi des oscillations d’ordre supérieur, correspondant à des tendances multiannuelles d’extension ou de restriction de la zone glacée. Leur cause réside dans des fluctuations thermométriques analogues qui se produisent au niveau de l’atmosphère souterraine et qui peuvent être mises en corrélation avec les tendances de long terme liées à l’évolution météorologique de l’extérieur.
Mafteiu, M. Contributions to the investigation of the Padis karst area (Bihor Mountains, Romania) by means of resistivity measurements, pp. 65–76.
Geological measurements are frequently used in karst investigation for the identification of underground cavities, of tectonic fractures which may favour the development of karst phenomena and for establishing the flow directions of corresponding groundwater bodies.
Taking into account the strong control that the dimension and burial depth of a certain anomalous body exert on the electrometric methods applicability, arrays with various depths of investigation were used.
The present paper included the results of a survey performed above a known anomalous body, the cave of Padis, as well as that of a subsequent extended application of the methods over a wider area. The data interpretation resulted in maps of the karst drainage areas and in establishing flow directions of the groundwater bodies.
The water-table level and the flow directions indicated by the soundings were adjusted according to the information derived from boreholes and from tracing experiments.
Davidescu, F., D., Tenu, A. & Slavescu, A. Environmental isotopes in karst hydrology. A lay-out of problems with exemplifications in Romania, pp. 77–86.
The paper provides actual examples of the possibilities to apply environmental isotopes in determinating certain hydrogeological characteristics and parameters in carbon-matrix aquifers of economic importance in Romania.
Iordache, O., Isopescu, R., Gaspar, E. & Isopescu, A. Interpretation of tracer experiments. Multi-cell of imperfect mixing, pp. 87–92.
A new model is put forward for the dispersion processes in hydrokarstic systems exhibiting more scales of mixing.
An expansion using Laguerre polynomials is obtained for the residence time distribution. The first term in expansion corresponds to the standard multi-cell model while the following are corrections for imperfect mixing.
The results are applied to interpret tracer research on the dynamics of underground waters in the Cerna Valley.
Slavoaca, D., C. & Slavoaca, R. The karstic water participation in the genesis of the thermomineral water reservoir of the spa complex Calimanesti-Caciulata-Cozia (Romania), pp. 93–96.
The paper sets in evidence the karstic waters participation at the genesis of the thermomineral water reservoir exploited in the spas: Calimanesti, Caciulata, Cozia. The water-inflow zone is situated in the northern part of the thermomineral reservoir, at the base of the senonian sedimentary deposits. The karstic water proceeds from jurassic carbonate rocks, which outcrop in the Vinturarita zone.
Oraseanu, I. Hydrogeological map of the Padurea Craiului Mountains (Romania), pp. 97–127.
The hydrogeological map shown herein covers an area of 670 sq. km. In the Padurea Craiului, a massif that makes the North-western termination of the Apuseni Mountains. Owing to a varied geologic structure, with Mesozoic limestones and dolomites outcropping on 330 sq. km, the relief boasts a great variety of features, noteworthy among which are the karst plateaus and valleys, as well as the caves and the potholes.
The numerous karst catchment processes, of which some are in full progress at present, disorganized the surface hydrographic network, leading to the formation of an endoreic zone of roughly 224 sq. km and of a diffluence area extending on 94 sq. km. The hydrologic links between these areas and the zones bordering the massif is secured by surface and underground flows.
The great lithologic diversity and the different tectonization indices of the deposits in the lithologic structure of the Padurea Craiului Mountains led to the individualization of five groups that boast distinct models of underground water supply, circulation, storage and discharge. In the hydrogeological map, the five types are separated cartographically and characterized hydrogeologically; the map also gives their detailed lithologic description.
International conventional signs show various models whereby the water penetrates the carbonate massif (diffusely, ponors and caves, a.o.), as well as different types of karst exurgences, all while pinpointing the permanent or temporary hydrologic character of the flow and the speleologists’ access – or lack of it – to the underground realm through these points.
The precipitations that fell in October 1982-September 1983 hydrologic year on the non-karst area of the massif generated a specific annual mean runoff ranging from 3 to 20 l/s sq. km, with its vertical gradient standing at 3.3 l/s sq. km. The value of that index is strongly influenced by the presence of the areal carbonate rocks wherein the karst-catchment processes substantially diminish the discharge.
The 78 tracer labellings performed by various authors pinpointed the general directions of flow of underground waters and the comparison between those data and the results of the hydrometeorogical observations and measurements provided for a hydrogeologic characterization of the major hydrogeological karst systems. The discharge, variability indices and the recession curve discharge coefficients for 13 of the major karst sources of the massif, as well as the distribution in time of underground flow of that area were shown.
The overall hydrogeological picture of the Padurea Craiului Mountains, without Remeti graben, is characterized by the presence of an unitary karstic aquifer in which there is a deep circulation from the East to the West overlay by numerous underground “surficial” (shallow) ones which discharge at the periphery of the massif, by sources with overflow meaning, the water excess resulting from the rainfall on its surface and which can’t be involved in deep circulation.
Ponta, G., Terteleac, N. & Gaspar, E. Three karstic systems (Rosia, Toplita de Rosia and Vadu Crisului) in the Padurea Craiului Mountains (Romania), pp. 129–142.
The paper presents data regarding three karstic aquifers: Rosia, Toplita de Rosia and Vadul Crisului, whose hydrogeological basins were outlined by surveying the subterranean cavities and the tracers experiments. Complete informations are given concerning the experiments with In-EDTA, La-EDTA and Rhodamine B, carried out in Valea Perjii, Birtin and Pintiuca sinkholes. These tracers appeared in Rosia Spring respectively Vadul Crisului. There is also a presentation of the Ciur Ponor cave and a structural characterization of the three karstic systems.
Feru, M., U. & Capota, A. Les eaux thermominérales karstiques de la zone de Mangalia (Roumanie), pp. 143–157.
Oraseanu, I., Gaspar, E., Pop, I. & Tanase, T. Tracers experiments in the karst area of Bihor Mountains (Romania), pp. 159–172.
The complex geological evolution of Bihor Mountains led to the grooth of karstifiable and unkarstifiable rocks mosaic. This evolution is hydrogeologically reflected by the presence of numerous karstic aquifers having different extensions and being charged by precipitations and surface streams, karstically trapped either total or partial.
In order to find out the main running water directions of some karstic aquifers, the authors carried out a number of 36 labellings with rhodamine, fluoresceine, stralex, radioactive tracers (I-131, Br-82) and activable tracers (In-EDTA, Dy-EDTA, I–).
On the whole, the tracers labellings accomplished up to now in the karst area of Bihor Mountains showed an average running speed of the underground waters of 45 m/hour.
The longest course was found between the pothole of Hoanca Urzicarului and Pauleasa spring (4,800 m), while the maximum level difference was between the Muncelu cave and Blidaru spring (665 m).
Pirvanescu, E. & Pirvanescu, A. Overall water balance computation in the karst zone “Sapte Izvoare Reci”, Scropoasa (Romania), pp. 173–181.
The paper presents the manner of balance elements assessment and the computation of the overall water balance in the karst area “7 Izvoare Reci” Scropoasa proposed for valorization as export “flat waters”.
The main purpose of this computation was to establish the feed zones of the source with a view to implement protection systems against polluting agents.
Ionescu, G. & Ionescu, C. Considerations concerning the gyps occurrence in the Ciur-Izbuc Cave (Padurea Craiului Mountains, Romania), pp. 183–187.
Nedopaca, M. La pyrite bactérienne de Risculita – Département de Hunedoara, Roumanie, pp. 189–191.
Fratila, R. & Constantin, S. Aspects of the karstification in the Cornilor Spring area (Padurea Craiului Mountains, Romania), pp. 193–203.
The paper presents the researches accomplished in a karst area with a small surface (2.6 sq. km) which hide a great cave, Cornilor Cave, with a length of 10.14 km. The karst morphology study, together with the geological and tectonical observations are used for realizing the karst map of this area. The factors that conditioned the genesis of the cavity are analyzed: lithology, tectonics and hydrochemical conditioning. Finally, based on this analysis, the authors propose a hypothesis on the endokarstic drainages succession and the genesis of the cavern.
Defleur, A., Crégut-Bonnoure, E. & Radulescu, C. Excavation at the Grotte des Cèdes (Le Plan d’Aups, Var, France), 1987. Evidence for a Late Rissian episode, pp. 205–210.
A brief account is given of recent excavation at the Grotte des Cèdres (Le Plan d’Aups, Var, France). Pleistocene deposits yielded lithic assemblages associated with abundant mammalian remains indicative of a Late Rissian age (isotopic stage 6 of deep-sea cores).
Oraseanu, I., Ventel, R. & Gaspar, E. Tracers investigations in Poiana-Tecuri area (Sureanu Mountains, Romania), pp. 211–212.