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Emil Racovita Institute of Speleology

Publication Date

January 2001

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Contents and Abstracts: Constantin, S. Editorial. p. 4. TAK Meetings:White, W.B. The Friends of Karst. pp. 5-6. TAK Anniversaries: Onac, B.P. Iosif Viehmann - a life for karst, p. 7. TAK Articles: White, W.B., White, E.L. - Conduit fragmentation, cave patterns, and the localization of karst ground water basins: the Appalachians as a test case. pp. 9-23. Because conduit systems in maturely developed karst aquifers have a low hydraulic resistance, aquifers drain easily and karst aquifers are subdivided into well-defined ground water basins. Ground water elevations are highest at basin boundaries; lowest at the spring where the ground water is discharged. Parameters that control the type of conduit development are (1) the effective hydraulic gradient, (2) the focus of the drainage basin, and (3) the karstifiability of the bedrock. Moderate to highly effective hydraulic gradients permit the runaway process that leads to single conduit caves and well ordered branchwork systems. Low hydraulic gradients allow many alternate flow paths and thus a large degree of fuzziness in the basin boundaries. Low gradient ground water basins also tend to merge due to rising water tables during periods of high discharge. Focus is provided by geological constraints that optimize discharge at specific locations that can evolve into karst springs. Karstifiability is a measure of the bulk rate at which aquifer rocks will dissolve. Fine grained, pure limestones and shaley dolomites mark the opposite ends of the range. The cave surveys of the Appalachian Highlands provide a data base that can be used to classify the lateral arrangements of conduit systems and thus determine the relative importance of the factors defined above. Tamas, T., Causse, C. - U-Th TIMS chronology of two stalagmites from V11 Cave (Bihor Mountains, Romania). pp. 25-32. Two stalagmites (S22, S117) from V11 Cave (Bihor Mountains, Romania) were dated by thermal ionisation mass-spectrometry (TIMS). The 40 subsamples dated had uranium contents between 0.229 and 0.676 ppm, a 234U/238U actual ?1 and generally low detrital contamination. Ages obtained range between 138.3 ± 1.6 ka and 5.6 ± 0.1 ka and are distributed in six growth periods separated by hiatuses. Growth rates calculated show that calcite deposition was slow in both stalagmites for most of the depositional periods recorded during oxygen isotope (OI) stage 5 (1.3-3 mm/ka), with the exception of the OI substage 5e, when S117 experienced fast growth (50 mm/ka). After an interruption of 22 ka, calcite deposition in S22 resumed during OI stage 3 (2.5 mm/ka). The age of 23.4 ± 0.12 ka recorded in S117 confirms previous evidence for a short depositional period during OI stage 2. Termination I was determined in S117 at 16.08 ka. The last growth interval during OI stage 1 is marked by a strong increase in growth rates of both stalagmites, determined by warming and by a significant increase in precipitation. The presented dataset frames the main climatic events that occurred in the last 140 ka and brings a precise chronology in this time span, in good agreement with previous studies from Europe and NW Romania. Onac, B.P. - Mineralogical studies and Uranium-series dating of speleothems from Scarisoara Glacier Cave (Bihor Mountains, Romania). pp. 33-38 Recent mineralogical investigations carried out in Scarisoara Glacier Cave pointed out the presence of speleothems made up of monohydrocalcite and hydromagnesite. Although both minerals were documented earlier from other Romanian caves this is for the first time when a speleothem is described as being entirely composed of monohydrocalcite. Crocoite, a rare mineral was also identified; however, this is not a real cave mineral being transported into the cave by the percolating waters. U-Th dating of some speleothems from Scarisoara Glacier Cave enabled us to draw some considerations concerning the palaeoclimate changes and the age of the cave. Constantin, S., Lauritzen, S.-E., Stiuca, E., Petculescu, A. - Karst evolution in the Danube Gorge from U-series dating of a cave bear skull and calcite speleothems from Pestera de la Gura Ponicovei (Romania). pp. 39-50. Two bone samples taken from a cave-bear skull discovered in Pestera de la Gura Ponicovei (Danube Gorge, Romania) have been dated by U-series liquid-liquid extraction procedure. They allowed the determination of a minimum age of the cave as well as the minimum age of Danube's fourth terrace at c. 277 ka. This age has been also used to ascertain the paleontologic determination of the bear species as Ursus deningeri v. Reichenau. Datings on speleothem calcite indicate that the minimum age of the active level of the cave is ~30 ka and enabled rough estimations of the incision rate of the underground river and of the fluvial erosion rate of the Danube at 0.05 m/ka and 0.67 m/ka, respectively. Mylroie, J., Jenson, J. - The Carbonate Island Karst Model applied to Guam. pp. 51-56. The karst of tropical carbonate islands is unique because: 1) fresh water-salt water mixing occurs at the base and margin of the fresh-water lens; 2) glacioeustasy has moved the freshwater lens up and down through a vertical range of over 100 m; and 3) the karst is eogenetic, i.e., it has developed in young carbonate rocks that have never been buried beyond the range of meteoric diagenesis. Carbonate islands can be divided into three categories based on basement-sea level relationships: simple carbonate islands (no non-carbonate rocks), carbonate cover islands (non-carbonate rocks beneath a carbonate veneer), and composite islands (carbonate and non-carbonate rocks exposed on the surface). These ideas form the Carbonate Island Karst Model (CIKM) which can be visualized in terms of a three-dimensional framework, with island size on the x-axis, sea-level change on the y-axis, and bedrock relationships on the z-axis. On Guam, tectonic uplift and glacio-eustatic sea level change have produced a complex history on this composite island. The aquifer is partitioned in the subsurface by the antecedent topography of the volcanic core of the island, and lens discharge is both diffuse and conduit controlled. Florea, L., Mylroie, J., Carew, J. - Karst genetic model for the French Bay Breccia deposits, San Salvador, Bahamas. pp. 57-65. the Island of San Salvador in the Bahama archipelago 30 breccia deposits can be found along the French Bay sea cliffs on the southeastern coast of the island. Breccia deposits of this type have not been observed on any other location on the island. These deposits have traditionally been interpreted as paleo-talus deposits from an eroding sea cliff formed on a transgressive eolianite deposited at the start of the oxygen isotope substage 5e sea-level highstand (ca. 125,000 years before present). New evidence supports a karst genesis. A survey of several deposits revealed a vertical restriction of +2 to +7 meters above sea level consistent with flank margin caves developed during the substage 5e still-stand. The morphologies of the features were found to be globular and contain distinct caliche boundaries, overhung lips, and smooth undulating bases. Petrographic results support a model in which voids are created and then infilled with a soil breccia. It can be concluded from these results that the deposits reflect qualities of a lithified soil breccia filling in breached flank margin caves. Diaconu, G., Dumitras, D. - Sur la présence de l'ardéalite dans la Grotte de Topolnita (Plateau de Mehedinti, Roumanie). pp. 67-73. Il y à 70 années, dans la Grotte de Cioclovina (Monts Sebes, Roumanie) un nouveau minéral - l'ardéalite - a été découvert en association avec le gypse et la broushite (HALLA, 1931; SCHADLER, 1932). Les auteurs ont identifié la même association minéralogique dans la Galerie Suspendue de la Grotte de Topolnita (Plateau de Mehedinti). L'échantillon prélevé a été analysé en RX, IR, TDA et chimiquement. Les données obtenues, comparées avec les données standard, ont mis en évidence l'ardéalite, le gypse et la broushite. Le travail présente de même un point de vue original sur les conditions du milieu spéléique qui ont facilité la genèse de cette association minéralogique. Ljubojevic, V., Pacevski, A., Calic-Ljubojevic, J. - On the genetic conditions of black manganese deposits from two caves of Eastern Serbia. pp. 75-79. Portions of cave passages often have a black colour due to manganese deposits that occur as coatings on cave walls and ceilings, on clastic sediments, as well as on speleothems. On samples from the cave Buronov Ponor chemical analysis, infrared spectroscopy, X-ray diffraction and DTA analysis confirmed the presence of birnessite. In cave Cerjanska Pecina, the presence of manganese compounds in the black coating has been confirmed by chemical tests. In both caves it has been noted that cave passages with black coating have a distinct morphology. They are highly weathered showing an abundance of sharp protusions, potholes in the streambed and scallops. The paper studies these occurrences and the possible link between the manganese deposition, hydrology and morphology of the passages and petrologic composition. Although this link was not identified, some interesting questions regarding manganese deposition arose. It remains unclear why manganese deposition is limited only to a certain part of cave Cerjanska Pecina, and what caused the cyclicity in manganese deposition in the cave Buronov ponor. Feier, N., Munteanu, G., Onac, B. P. - Mineralogy and speleogenesis of the Ice-Cave from Poiana Vârtop (Bihor Mountains, Romania). pp. 81-85. The cave of Poiana Vârtop in the NW Bihor Mountains hosts the fourth largest underground perennial glacier in Romania with a volume estimated to 12,000 m 3 . The ice accumulated within the cave as a result of trapping of subzero winter air through its single entrance near the top of the cave. The speleothem mineralogy is dominated by calcite, with minor amounts of included aragonite. Crusts of carbonate-hydroxylapatite (associated with bat guano) and goethite (associated with pyrite in the host limestone) are found at a few locations. Based on structural observations, dye traces, and cave galleries orientations, it is inferred that the cave is part of a much larger hydrologic karst system that also includes the nearby Humpleu-Poienita cave network. Constantinescu, T., Constantin, S. - La genèse et l'évolution des grandes dolines (obans) de la zone karstique de Mangalia (Dobroudja du Sud, Roumanie). pp. 87-92. Pour expliquer la genèse et l'évolution des grandes dolines ou obanes de la zone karstique de Mangalia, Obanul Mare est le plus représentatif, du fait qu'ici ont été effectués de nombreux forages et qu'à son bord s'ouvre la célèbre Grotte de Movilé. Les sédiments accumulés dans l'oban sont des repères pertinents qui argumentent la genèse du celui-ci par effondrement karstique. Au cours de leur évolution, ces grandes dolines ont connu trois phases principales : de doline-lac, de doline-marécage et de doline-sèche. Ross, J.-H., Serefiddin, F., Hauns, M., Smart, C.C. - 24 h Tracer Tests on Diurnal Parameter Variability in a Subglacial Karst Conduit: Small River Valley, Canada. pp. 93-99. Repeated dye tracer tests were undertaken for two complete diurnal discharge cycles at Small River Glacier, British Columbia. The injection site is a well developed glacier moulin. Monitoring was done at a karst spring in a cave entrance 1530 m down valley. The spring is the major outlet of glacial meltwater and also drains karstified glacier forefields. High flow velocities and low dispersivities indicate a very well developed conduit flow system. Discharge and velocity show strong diurnal cycles and are controlled by the amount of meltwater. The relationship of increasing velocity with discharge is approximately linear. Dispersivity values do not show any significant variation under diurnal discharge cycles. These results show the importance of diurnal variation in a transient groundwater system. Vesper, D.J., Loop, C.M., White, W.B. - Contaminant transport in karst aquifers. pp. 101-111. Contaminants are easily injected into karst aquifers through sinking streams, sinkholes, or through open fractures and shafts in the carbonate rock. Transport of the contaminants through the aquifer is by a variety of mechanisms depending on the physical and chemical properties of the contaminant. Contaminants consist of (1) water soluble compounds, both organic and inorganic, (2) slightly soluble organic com-pounds, less dense than water (LNAPLs), (3) slightly soluble organic compounds, more dense than water (DNAPLs), (4) pathogens, (5) metals, and (6) trash. Water soluble compounds (e.g. nitrates, cyanides, carboxylic acids, phenols) move with the water. But rather than forming a plume spreading from the input point, the contaminated water forms linear stringers migrating down the conduit system toward the discharge point. LNAPLs (e.g. petroleum hydrocarbons) float on the water table and can migrate down the water table gradient to cave streams where they tend to pond behind obstructions. DNAPLs (e.g. chlorinated hydrocarbons), in contrast, sink to the bottom of the aquifer. In the conduit system, DNAPLs pond in low spots at the bottom of the conduit and infiltrate sediment piles. Transport of both LNAPL and DNAPL is dependent on storm flow which can force LNAPL through the system as plug flow and can move DNAPLs by mobilizing the sediment piles. Pathogens (viruses, bacteria, parasites) are transported through the karstic drainage system because of the absence of filtration and retain their activity for long distances. Metals (e.g. chromium, nickel, cadmium, mercury, and lead) tend to precipitate as hydroxides and carbonates in the neutral pH, carbonate rich water of the karst aquifer. Metal transport is mainly as particulates and as metal adsorbed onto small particulates such as clays and colloids. Metal transport is also episodic. Metals migrate down the flow path under flow conditions that take small particulates into suspension. Trash is carried into karst aquifers through sinkholes and sinking streams. It is, in effect, a form of clastic sediment, and can be carried deep into the conduit system where it can act as a source term for other contaminants leached from the trash. Brunet-Lecomte, P., Paunesco, A.-C. - Microtus (Terricola) grafi miciaensis (Rodentia, Mammalia), une nouvelle sous-espèce du site moustérien de Gaura Lupului (Craciunesti, Roumanie). pp. 113-117. Les particularités morphométriques de la population de M. (Terricola) grafi du site moustérien de Gaura Lupului (village de Craciunesti, département de Hunedoara, Roumanie), nous a incités à lui donner un rang sub-spécifique. Elle est décrite sous le nom de Microtus (Terricola) grafi miciaensis. Book Reviews Constantin, S. - Speleological Atlas of Serbia. p. 119. Onac, B. P. - Speleogenesis. Evolution of karst aquifers. p. 120. Racovita, G. - Précis de Karstologie. pp. 121-122. Roata, S. - Geologia regiunilor carstice. p. 122. Constantinescu, T. - Scarisoara Glacier Cave. Monographic study. p. 123. Iurkiewicz, A. - Geological engineering in karst. p. 124. Constantin, S. - Caves Beyond Time. p. 125. Moldovan, O. - The protection of the subterrannean environment.p. 126. In Memoriam Petre-Mihai Samson, 1930-2001. Open Access - Permission by Publisher Vol. 13-14 (2000-2001) See Extended description for more information.

Keywords

Romania, Geology

Subject: topical

Geology

Subject: geographic

Romania

Type

Article

Genre

serial

Identifier

K26-04804

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