Gouffre de la Sambuy is an alpine cave, located in the French northern Western Alps, in the Bauge... more Gouffre de la Sambuy is an alpine cave, located in the French northern Western Alps, in the Bauges massif. This subalpine massif is included in the "delphinohelvetic" domain of the external Alps, drifted over the foreland (jurassian and molassic domains). Bauges massif presents with these folded structures a medium altitude (< 2 500 m asl) and mountainous relief built with only sedimentary rocks. To the east of the massif, the Sambuy summit is 2198 m asl, the main entrance of the cave (SB9) is open at 1 820 m asl. The average of temperature in this area is 1.6°C. The precipitations are over 2 100 mm/year. The cave is approximately 900 m development and 120m depth. The final part of the cave is on the top of the Hauterivian marls. During speleogenesis studies on 2012, speleologists have founded bacterial mats and gypsum in the marly parts of the cave. Upper, in the middle part, the Barremian limestone wall of a 25 m shaft was covered by unusual fine and white deposits looking like lichen. To understand these ecosystems, climate aerologic measurements like air temperature, pressure, and wind speed were realized during each visit in winter, spring and summer. Due to the difficulties to access to the cave with no possibilities to get electrical power, no monitoring was realized for the climate parameters. In spring, the wall deposits have been sampled with swab and store in sterile tube for laboratory molecular analysis. DNA was extracted, PCR amplifications and cloning-sequencing were performed targeting bacterial 16SrRNA and eukaryotic 18SrRNA genes. For the bacterial community, we identified 29 different OTUs and the richness estimator (Schao) showed a global richness of 65 OTUs. The bacterial community was mainly composed by Proteobacteria, Acidobacteria, Actinobacteria, Nitrospirae and an important part of uncultured bacteria. Some of these bacterial taxa are known to be involved in nitrogen cycling. For the eukaryotic community, 32 OTUs were identified from our clones library, and the Schao index showed a global richness of 86 OTUs. Rhizaria (with mostly Cercozoa, genus Cermononas) was a dominant group, followed by Fungi (mostly Dikaria). Some Alveolata belonging to Ciliophora were also detected, as well as an important part of uncultured fungi and others. Additional sequencing analyses should be performed to depict in depth the taxonomic composition in these microbial mats. Our preliminary results showed that these microbial mats comprised a rather high diversity of prokaryotic and eukaryotic taxa, which physiological/biochemical characteristics and biotic interactions have still to be described.
The earliest European carvings, made of mammoth ivory, depict animals, humans, and anthropomorphs... more The earliest European carvings, made of mammoth ivory, depict animals, humans, and anthropomorphs. They are found at Early Aurignacian sites of the Swabian Jura in Germany. Despite the wide geographical spread of the Aurignacian across Europe, these carvings have no contemporaneous counterparts. Here, we document a small, intriguing object, that sheds light on this uniqueness. Found at the Grotte des Gorges (Jura, France), in a layer sandwiched between Aurignacian contexts and dated to c. 36.2 ka, the object bears traces of anthropogenic modifications indicating intentional carving. Microtomographic, microscopic, three-dimensional roughness and residues analyses reveal the carving is a fragment of a large ammonite, which was modified to represent a caniformia head decorated with notches and probably transported for long time in a container stained with ochre. While achieving Swabian Jura-like miniaturization, the Grotte des Gorges specimen displays original features, indicating the ...
The Camou springs (Arbailles Massif, French Western Pyrenees) display an unusual close associatio... more The Camou springs (Arbailles Massif, French Western Pyrenees) display an unusual close association of a typically cold karstic spring that drains the Urgonian western limb of the Arbailles, and a thermo-mineral spring (33.5°C; salinity 17.7 g/L). The latter gains its mineralization at the contact of Triassic evaporites mainly through a deep loop in the Apanicé syncline. The fast upflow of this deep water occurs at the cross of large active lines (the North-Pyrenean thrust located at depth, and the Saison transverse fault). Cave diving in the nearby Maddalen Cave allowed reaching the phreatic passage at the origin of the cold spring, which however also crosses the thermal body in the third sump (S3). Both water bodies are separated by a sharp thermocline. 6 pressure-temperature dataloggers were placed in both water bodies along the thermocline for 6 months. The dataloggers located downstream on either side of the thermocline show at the beginning of flood first a rise of the thermal ...
Several sinkhole collapses were occurred in the many sites in urban areas and/or their rural peri... more Several sinkhole collapses were occurred in the many sites in urban areas and/or their rural periphery; in NE Algeria, in the last few years. The abrupt collapse causes damages to properties, infra-structures, and even lives. The most spectacular oneoccurred in February 2009 inside the Cheria city, Northwest of Tebessa department, with a diameter of more than a hundred meters. This abrupt collapse is due to a sudden rupture of the roof of a large underground karst cavity. It caused panic-stricken among the population living near the crater. In order to investigate the origin of this phenomenon, we combine several geophysical and geotechnical methods, such as Ground Penetrating Radar, Electrical Resistivity Tomography, Standard Penetration Test, Mechanical Drill Core, Cave Survey Photogrammetry, etc. It appears that each method may provide specific information. Their comparison allows to precise the results itself, the limits and the application field of each. Consequently a number o...
Gouffre de la Sambuy is an alpine cave, located in the French northern Western Alps, in the Bauge... more Gouffre de la Sambuy is an alpine cave, located in the French northern Western Alps, in the Bauges massif. This subalpine massif is included in the "delphinohelvetic" domain of the external Alps, drifted over the foreland (jurassian and molassic domains). Bauges massif presents with these folded structures a medium altitude (< 2 500 m asl) and mountainous relief built with only sedimentary rocks. To the east of the massif, the Sambuy summit is 2198 m asl, the main entrance of the cave (SB9) is open at 1 820 m asl. The average of temperature in this area is 1.6°C. The precipitations are over 2 100 mm/year. The cave is approximately 900 m development and 120m depth. The final part of the cave is on the top of the Hauterivian marls. During speleogenesis studies on 2012, speleologists have founded bacterial mats and gypsum in the marly parts of the cave. Upper, in the middle part, the Barremian limestone wall of a 25 m shaft was covered by unusual fine and white deposits looking like lichen. To understand these ecosystems, climate aerologic measurements like air temperature, pressure, and wind speed were realized during each visit in winter, spring and summer. Due to the difficulties to access to the cave with no possibilities to get electrical power, no monitoring was realized for the climate parameters. In spring, the wall deposits have been sampled with swab and store in sterile tube for laboratory molecular analysis. DNA was extracted, PCR amplifications and cloning-sequencing were performed targeting bacterial 16SrRNA and eukaryotic 18SrRNA genes. For the bacterial community, we identified 29 different OTUs and the richness estimator (Schao) showed a global richness of 65 OTUs. The bacterial community was mainly composed by Proteobacteria, Acidobacteria, Actinobacteria, Nitrospirae and an important part of uncultured bacteria. Some of these bacterial taxa are known to be involved in nitrogen cycling. For the eukaryotic community, 32 OTUs were identified from our clones library, and the Schao index showed a global richness of 86 OTUs. Rhizaria (with mostly Cercozoa, genus Cermononas) was a dominant group, followed by Fungi (mostly Dikaria). Some Alveolata belonging to Ciliophora were also detected, as well as an important part of uncultured fungi and others. Additional sequencing analyses should be performed to depict in depth the taxonomic composition in these microbial mats. Our preliminary results showed that these microbial mats comprised a rather high diversity of prokaryotic and eukaryotic taxa, which physiological/biochemical characteristics and biotic interactions have still to be described.
The earliest European carvings, made of mammoth ivory, depict animals, humans, and anthropomorphs... more The earliest European carvings, made of mammoth ivory, depict animals, humans, and anthropomorphs. They are found at Early Aurignacian sites of the Swabian Jura in Germany. Despite the wide geographical spread of the Aurignacian across Europe, these carvings have no contemporaneous counterparts. Here, we document a small, intriguing object, that sheds light on this uniqueness. Found at the Grotte des Gorges (Jura, France), in a layer sandwiched between Aurignacian contexts and dated to c. 36.2 ka, the object bears traces of anthropogenic modifications indicating intentional carving. Microtomographic, microscopic, three-dimensional roughness and residues analyses reveal the carving is a fragment of a large ammonite, which was modified to represent a caniformia head decorated with notches and probably transported for long time in a container stained with ochre. While achieving Swabian Jura-like miniaturization, the Grotte des Gorges specimen displays original features, indicating the ...
The Camou springs (Arbailles Massif, French Western Pyrenees) display an unusual close associatio... more The Camou springs (Arbailles Massif, French Western Pyrenees) display an unusual close association of a typically cold karstic spring that drains the Urgonian western limb of the Arbailles, and a thermo-mineral spring (33.5°C; salinity 17.7 g/L). The latter gains its mineralization at the contact of Triassic evaporites mainly through a deep loop in the Apanicé syncline. The fast upflow of this deep water occurs at the cross of large active lines (the North-Pyrenean thrust located at depth, and the Saison transverse fault). Cave diving in the nearby Maddalen Cave allowed reaching the phreatic passage at the origin of the cold spring, which however also crosses the thermal body in the third sump (S3). Both water bodies are separated by a sharp thermocline. 6 pressure-temperature dataloggers were placed in both water bodies along the thermocline for 6 months. The dataloggers located downstream on either side of the thermocline show at the beginning of flood first a rise of the thermal ...
Several sinkhole collapses were occurred in the many sites in urban areas and/or their rural peri... more Several sinkhole collapses were occurred in the many sites in urban areas and/or their rural periphery; in NE Algeria, in the last few years. The abrupt collapse causes damages to properties, infra-structures, and even lives. The most spectacular oneoccurred in February 2009 inside the Cheria city, Northwest of Tebessa department, with a diameter of more than a hundred meters. This abrupt collapse is due to a sudden rupture of the roof of a large underground karst cavity. It caused panic-stricken among the population living near the crater. In order to investigate the origin of this phenomenon, we combine several geophysical and geotechnical methods, such as Ground Penetrating Radar, Electrical Resistivity Tomography, Standard Penetration Test, Mechanical Drill Core, Cave Survey Photogrammetry, etc. It appears that each method may provide specific information. Their comparison allows to precise the results itself, the limits and the application field of each. Consequently a number o...
Uploads
Papers