The discovery of a level of lithophaga in the entrance of the karstic spring of the 'Fontaine... more The discovery of a level of lithophaga in the entrance of the karstic spring of the 'Fontaine de Vaucluse'indicates a pre-Pliocene age and supports a Messinian origin for the present spring. To cite this article: É. Gilli, P. Audra, CR Geoscience 336 (2004).
Caves formed by rising sulfuric waters have been described from all over the world in a wide vari... more Caves formed by rising sulfuric waters have been described from all over the world in a wide variety of climate settings, from arid regions to mid-latitude and alpine areas. H 2 S is generally formed at depth by reduction of sulfates in the presence of hydrocarbons and is transported in solution through the deep aquifers. In tectonically disturbed areas major fractures eventually allow these H 2 S-bearing fluids to rise to the surface where oxidation processes can become active producing sulfuric acid. This extremely strong acid reacts with the carbonate bedrock creating caves, some of which are among the largest and most spectacular in the world. Production of sulfuric acid mostly occurs at or close to the water table but also in subaerial conditions in moisture films and droplets in the cave environment. These caves are generated at or immediately above the water table, where condensation–corrosion processes are dominant, creating a set of characteristic meso-and micromorphologies. Due to their close connection to the base level, these caves can also precisely record past hydrological and geomorphological settings. Certain authigenic cave minerals, produced during the sulfuric acid speleogenesis (SAS) phase, allow determination of the exact timing of speleogenesis. This paper deals with the morphological, geochemical and mineralogical description of four very typical sulfuric acid water table caves in Europe: the Grotte du Chat in the southern French Alps, the Acqua Fitusa Cave in Sicily (Italy), and the Bad Deutsch Altenburg and Kraushöhle caves in Austria.
It is difficult to explain the position and behaviour of the main karst springs of southern Franc... more It is difficult to explain the position and behaviour of the main karst springs of southern France without calling on a drop in the water table below those encountered at the lowest levels of Pleistocene glacio-eustatic fluctuations. The principal karst features around the Mediterranean are probably inherited from the Messinian period (“Salinity crisis”) when sea level dropped dramatically due to the closing of the Straight of Gibraltar and desiccation of the Mediterranean Sea. Important deep karst systems were formed because the regional ground water dropped and the main valleys were entrenched as canyons. Sea level rise during the Pliocene caused sedimentation in the Messinian canyons and water, under a low hydraulic head, entered the upper cave levels. The powerful submarine spring of Port-Miou is located south of Marseille in a drowned canyon of the Calanques massif. The main water flow comes from a vertical shaft that extends to a depth of more than 147 m bsl. The close shelf margin comprises a submarine karst plateau cut by a deep canyon whose bottom reaches 1,000 m bsl. The canyon ends upstream in a pocket valley without relation to any important continental valley. This canyon was probably excavated by the underground paleoriver of Port-Miou during the Messinian Salinity Crisis. Currently, seawater mixes with karst water at depth. The crisis also affected inland karst aquifers. The famous spring of Fontaine de Vaucluse was explored by a ROV (remote observation vehicle) to a depth of 308 m, 224 m below current sea level. Flutes observed on the wall of the shaft indicate the spring was formerly an air-filled shaft connected to a deep underground river flowing towards a deep valley. Outcroppings and seismic data confirm the presence of deep paleo-valleys filled with Pliocene sediments in the current Rhône and Durance valleys. In the Ardèche, several vauclusian springs may also be related to the Messinian Rhône canyon, located at about 200 m below present sea level. A Pliocene base level rise resulted in horizontal dry cave levels. In the hinterland of Gulf of Lion, the Cévennes karst margin was drained toward the hydrologic window opened by the Messinian erosional surface on the continental shelf.
The discovery of a level of lithophaga in the entrance of the karstic spring of the 'Fontaine... more The discovery of a level of lithophaga in the entrance of the karstic spring of the 'Fontaine de Vaucluse'indicates a pre-Pliocene age and supports a Messinian origin for the present spring. To cite this article: É. Gilli, P. Audra, CR Geoscience 336 (2004).
Caves formed by rising sulfuric waters have been described from all over the world in a wide vari... more Caves formed by rising sulfuric waters have been described from all over the world in a wide variety of climate settings, from arid regions to mid-latitude and alpine areas. H 2 S is generally formed at depth by reduction of sulfates in the presence of hydrocarbons and is transported in solution through the deep aquifers. In tectonically disturbed areas major fractures eventually allow these H 2 S-bearing fluids to rise to the surface where oxidation processes can become active producing sulfuric acid. This extremely strong acid reacts with the carbonate bedrock creating caves, some of which are among the largest and most spectacular in the world. Production of sulfuric acid mostly occurs at or close to the water table but also in subaerial conditions in moisture films and droplets in the cave environment. These caves are generated at or immediately above the water table, where condensation–corrosion processes are dominant, creating a set of characteristic meso-and micromorphologies. Due to their close connection to the base level, these caves can also precisely record past hydrological and geomorphological settings. Certain authigenic cave minerals, produced during the sulfuric acid speleogenesis (SAS) phase, allow determination of the exact timing of speleogenesis. This paper deals with the morphological, geochemical and mineralogical description of four very typical sulfuric acid water table caves in Europe: the Grotte du Chat in the southern French Alps, the Acqua Fitusa Cave in Sicily (Italy), and the Bad Deutsch Altenburg and Kraushöhle caves in Austria.
It is difficult to explain the position and behaviour of the main karst springs of southern Franc... more It is difficult to explain the position and behaviour of the main karst springs of southern France without calling on a drop in the water table below those encountered at the lowest levels of Pleistocene glacio-eustatic fluctuations. The principal karst features around the Mediterranean are probably inherited from the Messinian period (“Salinity crisis”) when sea level dropped dramatically due to the closing of the Straight of Gibraltar and desiccation of the Mediterranean Sea. Important deep karst systems were formed because the regional ground water dropped and the main valleys were entrenched as canyons. Sea level rise during the Pliocene caused sedimentation in the Messinian canyons and water, under a low hydraulic head, entered the upper cave levels. The powerful submarine spring of Port-Miou is located south of Marseille in a drowned canyon of the Calanques massif. The main water flow comes from a vertical shaft that extends to a depth of more than 147 m bsl. The close shelf margin comprises a submarine karst plateau cut by a deep canyon whose bottom reaches 1,000 m bsl. The canyon ends upstream in a pocket valley without relation to any important continental valley. This canyon was probably excavated by the underground paleoriver of Port-Miou during the Messinian Salinity Crisis. Currently, seawater mixes with karst water at depth. The crisis also affected inland karst aquifers. The famous spring of Fontaine de Vaucluse was explored by a ROV (remote observation vehicle) to a depth of 308 m, 224 m below current sea level. Flutes observed on the wall of the shaft indicate the spring was formerly an air-filled shaft connected to a deep underground river flowing towards a deep valley. Outcroppings and seismic data confirm the presence of deep paleo-valleys filled with Pliocene sediments in the current Rhône and Durance valleys. In the Ardèche, several vauclusian springs may also be related to the Messinian Rhône canyon, located at about 200 m below present sea level. A Pliocene base level rise resulted in horizontal dry cave levels. In the hinterland of Gulf of Lion, the Cévennes karst margin was drained toward the hydrologic window opened by the Messinian erosional surface on the continental shelf.
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table below those encountered at the lowest levels of Pleistocene glacio-eustatic fluctuations. The principal karst features around the
Mediterranean are probably inherited from the Messinian period (“Salinity crisis”) when sea level dropped dramatically due to the closing
of the Straight of Gibraltar and desiccation of the Mediterranean Sea. Important deep karst systems were formed because the regional
ground water dropped and the main valleys were entrenched as canyons. Sea level rise during the Pliocene caused sedimentation in the
Messinian canyons and water, under a low hydraulic head, entered the upper cave levels.
The powerful submarine spring of Port-Miou is located south of Marseille in a drowned canyon of the Calanques massif. The main
water flow comes from a vertical shaft that extends to a depth of more than 147 m bsl. The close shelf margin comprises a submarine
karst plateau cut by a deep canyon whose bottom reaches 1,000 m bsl. The canyon ends upstream in a pocket valley without relation to
any important continental valley. This canyon was probably excavated by the underground paleoriver of Port-Miou during the Messinian
Salinity Crisis. Currently, seawater mixes with karst water at depth. The crisis also affected inland karst aquifers. The famous spring of
Fontaine de Vaucluse was explored by a ROV (remote observation vehicle) to a depth of 308 m, 224 m below current sea level. Flutes
observed on the wall of the shaft indicate the spring was formerly an air-filled shaft connected to a deep underground river flowing
towards a deep valley. Outcroppings and seismic data confirm the presence of deep paleo-valleys filled with Pliocene sediments in the
current Rhône and Durance valleys. In the Ardèche, several vauclusian springs may also be related to the Messinian Rhône canyon,
located at about 200 m below present sea level. A Pliocene base level rise resulted in horizontal dry cave levels. In the hinterland of Gulf
of Lion, the Cévennes karst margin was drained toward the hydrologic window opened by the Messinian erosional surface on the continental
shelf.
table below those encountered at the lowest levels of Pleistocene glacio-eustatic fluctuations. The principal karst features around the
Mediterranean are probably inherited from the Messinian period (“Salinity crisis”) when sea level dropped dramatically due to the closing
of the Straight of Gibraltar and desiccation of the Mediterranean Sea. Important deep karst systems were formed because the regional
ground water dropped and the main valleys were entrenched as canyons. Sea level rise during the Pliocene caused sedimentation in the
Messinian canyons and water, under a low hydraulic head, entered the upper cave levels.
The powerful submarine spring of Port-Miou is located south of Marseille in a drowned canyon of the Calanques massif. The main
water flow comes from a vertical shaft that extends to a depth of more than 147 m bsl. The close shelf margin comprises a submarine
karst plateau cut by a deep canyon whose bottom reaches 1,000 m bsl. The canyon ends upstream in a pocket valley without relation to
any important continental valley. This canyon was probably excavated by the underground paleoriver of Port-Miou during the Messinian
Salinity Crisis. Currently, seawater mixes with karst water at depth. The crisis also affected inland karst aquifers. The famous spring of
Fontaine de Vaucluse was explored by a ROV (remote observation vehicle) to a depth of 308 m, 224 m below current sea level. Flutes
observed on the wall of the shaft indicate the spring was formerly an air-filled shaft connected to a deep underground river flowing
towards a deep valley. Outcroppings and seismic data confirm the presence of deep paleo-valleys filled with Pliocene sediments in the
current Rhône and Durance valleys. In the Ardèche, several vauclusian springs may also be related to the Messinian Rhône canyon,
located at about 200 m below present sea level. A Pliocene base level rise resulted in horizontal dry cave levels. In the hinterland of Gulf
of Lion, the Cévennes karst margin was drained toward the hydrologic window opened by the Messinian erosional surface on the continental
shelf.