GHOST-ROCK KARSTIFICATION IN «ENTRE-DEUX-MERS» (GIRONDE, FRANCE), IMPLICATIONS FOR KARSTOGENESIS AND KARSTIC MORPHOLOGY, , Dubois Caroline, Lans Benjamin, Kaufmann Olivier, Maire Richard, Quinif Yves

The formation of the Oligocene « calcaires à Astéries » in the region of « Entre-deux-Mers » is affected by a karstification with subhorizontal caves that drained rivers from swallow-holes to resurgences. Observations in quarries show that ghost-rock alterites are present. This paper describes the ghost-rocks in the quarry of Piquepoche exploiting the Frontenac stone. We have studied horizontally developed ghost-rocks with vertical extensions still containing the residual alterite. They can be badly consolidated calcarenites up to soft material which has been sampled. Speleogenesis is reviewed in the frame of the mechanical erosion of the alterite of a horizontal ghost-rock followed by an incision by free-flowing waters which form a passage with promontories and potholes. Finally, we show that ceiling anastomoses can form by ghost-rock karstification.

Le système souterrain du Sornin (Berger-Fromagère, Vercors, Isère), 1983, Delannoy, J. J.

THE UNDERGROUND SYSTEM OF PLATEAU DU SORNIN (VERCORS, FRANCE): THE GOUFFRE BERGER AND THE SCIALET DE LA FROMAGERE - Gouffre Berger (-1198m) and Scialet de La Fromagère (-902m) are the two main drains of an important underground complex, which develops 26 km inside Sornin table-land, massif du Vercors, Isère. The glaciers have left deep prints in the surface morphology (Schichttreppenkarst) and have played an important role in the genesis of the underground complex of Sornin. Most of morphological elements and dated witnesses (speleothems) testify to the primacy of this morphoclimatic term. Under present bioclimatic conditions (discontinuous forest - Raw weather climate, T? = 4?C, P = 1700mm), the specific dissolution is estimated to 120mm/ky. This dissolution is important in winter (2,5 times more than in summer). Sornin plateau belongs to an intermediary case between forests mountainous karsts and high karsts regarding the spatial distribution of the dissolution.

Le système souterrain de la Dent de Crolles, Isère, 1985, Marchand, Th.

THE UNDERGROUND SYSTEM OF DENT DE CROLLES (ISERE, FRANCE) - The Dent de Crolles plateau (highest point: 2062m asl.) is the southermost part of the great syncline of the eastern Chartreuse. This syncline stretches from Grenoble to Mont Granier, above Chambery. The karst of Dent de Crolles develops in urgonian limestone, and in spite of little surface (2km2), it contains the most important underground system of the French Alps (about 52km). In spite of important oceanic rainfall, underground flows only drain some small galleries. Karst genesis is related to the glaciers.

Apports des datations U/Th dans la karstogenèse de la Grande Moucherolle-Rochers de la Balme (Vercors), 1986, Delannoy J. J. , Holliger Ph.

234 U - 230 Th DATING OF SPELEOTHEMS AND KARSTOGENESIS OF THE "GRANDE MOUCHEROLLE-ROCHERS DE LA BALME" (VERCORS) - In this article, is presented a first geomorphological and speleological synthesis of the subalpine karst of the Grande Moucherolle (2285 m) - Rochers de Ia Balme. This area of Vercors (Alps), which has 8 caves deeper than 300m (Antre des Damnés -720m; Clos de La Fure -580m...) is surely the most promising sector from a speleological point of view. Through the study of the glacio-karstic landforms and the distri-bution of the great caves, it seems that there is a real relation between these two parameters. In order to evaluate the contribution of quaternary glaciations in the genesis of caves, isotopic dating (234U-230Th) have been performed on underground carbonated deposits. After a presentation of the chronometric method 234U-230Th, the results are analysed according to their speleological environment. A paleogeographic reconstitution through the middle and recent Quaternary is proposed for the geosystem of the Grande Moucherolle - Rochers de la Balme.

Néotectonique dans les massifs karstiques, un exemple dans les Préalpes de Nice : la grotte des Deux Gourdes, 1986, Gilli, E.

NEOTECTONICS IN KARST REGION (EXAMPLE IN THE NICE PREALPS) - Speleothem observations may give interesting information about neotectonic phenomena in karstic areas. It is also possible with calcite dating to give an age to these phenomena. An example in Nice Prealps (France), the Deux Gourdes Cave, shows some data about this type of research.

La morphologie karstique souterraine du Pozo Azul (''Puits Bleu'') de Burgos (Espagne), 1986, Sanz Perez E. , Medina Ferrer J.

SPELEOMORPHOLOGY OF POZO AZUL ("BLUE POOL") (BURGOS, SPAIN) - The present paper gives a morphological description of the Pozo Azul, which is the longest known submerged cave in Spain. It is associated with a karstic spring (x flow = 1m3/sec.) that drains an Upper Cretaceous aquifer situated in a syncline. Different morphological observations made on the section and orientation to the gallery, together with data concerning erosive and sedimentary phenomena, confirm a phreatic type of circulation.

Les cavités de la Sierra d'Aralar (Pays Basque espagnol), 1986, Ugarte, F. M.

CAVES OF THE SIERRA OF ARALAR (NAVARRA-GUIPUZCOA, SPAIN). CORRELATION BETWEEN UNDERGROUND FORMATIONS AND GEOLOGICAL STRUCTURES - The study of numerous cavities of the Sierra of Aralar permits to give importance to: 1/ the relations between the subterranean morphology and the structural network; 2/ the relations with the actual morphoclimatic conditions of the middle-mountain exokarst; 3/ the part of the heritages of the Quaternary cold-periods. Following important speleological research carried out by the Aranzadi Society of Science (San Sebastian) in the central mountains of the sierra d'Aralar the majority of the PKH (“Karst phenomenons”) have been located and mapped (PKH = 2,78 km2). As a result of this work, we have attempted to correlate endokarstic landscape with geological structure

Premières observations morphologiques et spéléologiques sur le karst haut-alpin du Tennengebirge (Salzburg, Autriche), 1987, Audra, Ph.

THE MASSIF OF TENNENGEBIRGE (SALZBURG, AUSTRIA) - The Tennengebirge, in the Salzburg limestone Alps, are characterised by an important high alpine karst, containing some of the deepest austrian caves (Batman Höhle: -1219m, Schneeloch: 1086m, Platteneck: -937m, Gipfel Loch: -852m…). The phreatic zone locates at 720m asl. The main springs are situated on the northern side of the mountain. A description of the Vordere Pitschenberg Valley has been sketched illustrating a large diversity and underground, of actual or inherited character.

La tanne des Biolles, un axe de drainage majeur sous le massif du Margériaz (Bauges, Savoie, France), 1996, Hoblea F. , Dodelin C. , Lasserre D. , Bottazzi J. , Maniez P.

The entrance of the Tanne des Biolles is located 1670 m high in the Mount Margeriaz. Urgonian limestones are inclined towards the east. This moun-tain is well known for its numerous, very long and narrow meanders, espe-cially the Tanne aux Cochons - Tanne Froide system which is the deepest cave in Savoie F825 m, 17km). The Tanne des Biolles was discovered in 1985, but an obstruction near the entrance was cleared only in 1993, thus opening the way to several kilo-metres of wide galleries (20 m x 20 m). Such a large size, exceptional for the Margeriaz can be explained by the fact that the cave has developed in a little faulted transverse syncline which leads the underground stream directly to the Pissieu vauclusian spring, 1000 m lower. The stream is strong enough to score the marl--limestones of the hauterivian level which is usually the watertight floor. The biggest volumes are thus dug into the Hauterivian. This paper presents the special speleomorphology of the Tanne des Biolles, and a water tracing test made in May 1995. The existence of another exsurgence, situated downstream the Pissieu at the base level of the main valley in the Bauges, and obstructed by alluvial deposits, is thus confirmed by this experience.

Speleomorphology of dry passage in Provala cave (Croatia), 1998, Boč, Ič, Neven, Buzjak Nenad

Provala cave is located in the fluviokarst area of Žumberačka gora mountain (NW Croatia). This two-level cave is 1687 m long and 55 m deep. In the lower level there is a permanent water stream. The upper level, according to its hydrological characteristics, can be divided into three parts: 1. the southern part with permanent water stream, 2. the part with periodical water stream, and 3. dry part. The last two parts called "Dry passage" were speleomorphologically observed.

Speleological Features in the Mountainous Karst of Risnjak Mountain (Croatia), 1999, Buzjak Nenad, Fiedler Suzana

Risnjak mountain is located in western Croatia. Its central area is, together with the nearby Snjećnik mountain and the upper part of the Kupa river valley, a part of Risnjak National Park. Since it is mostly built of heavy broken Jurassic carbonate rocks (limestones predominate), all kinds of karst features are well developed. Among exokarst forms dolines predominate. Among speleological features shafts are the most frequent forms. There are several morphological types of these in the altitude range between 680 and 1520 m. Although the deepest shaft explored to date is 180 m deep, the rest of the shafts are mostly up to 50 m deep. Consistent with high altitude and a severe climate thick beds of snow and ice were found in a few shafts. Near the southeastern border of the National Park area there are a few streams which flow over the less permeable Triassic dolomite beds and impermeable Triassic and Permian clastic beds. They sink at the contact with permeable carbonate beds. Among their ponors the largest is Vele Vode ponor cave which is 1495 m long.

On the genetic conditions of black manganese deposits from two caves of Eastern Serbia., 2001, Ljubojevic V. , Pafevski A. , Calicljubojevic J.

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 prolusions, 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. manganese deposits, chemical analysis, speleomorphology

Observations morphologiques dans l’abîme de Maramoye (Le Beausset, Var), 2003, Bigot, Jeanyves

Morphological observations in the Maramoye pit (Le Beausset, Var) - Maramoye pit is a two-levels cave around the Beausset Clay, and near to a 6 Ma old lava flow. On one hand, the description of the deposit’s cuts, and of galleries features, on the other hand, show a run of events whose relative chronology can be recreated. The siliceous cover, developed by the crypto-corrosion, then the volcanic event and at last, the “red event” showing limestones out of their siliceous toping, stand for the great phase inferred from observations in the cave. The upper level galleries morphology shows a connection between lower and upper levels linked by a “puits-cheminée” (phreatic lift). The corroded speleothems and partly removed fillings point out a flooding of the upper level. It has not been possible to show obviously that one or other levels of Maramoye is formed before the other. In compensation, the observations suggest that the lower level after the basaltic event have been picked up, so that the paleogeographic precing back get complicated.