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Babonneau, Nathalie; Delacourt, Christophe; Cancouet, R.; Sisavath, Emmanuelle; Bachelery, Patrick; Mazuel, Aude; Jorry, Stephan; Deschamps, Anne; Ammann, Jerome; Villeneuve, N.. |
Submarine canyon heads are key areas for understanding the triggering factors of gravity currents responsible for the transfer of detrital sediment to the deep basins. This contribution offers a detailed picture of canyon heads off La Réunion Island, with high-resolution multibeam bathymetry in the water depth range of 4–220 m. The present feeding of the Cilaos turbidite system, one of the largest modern volcaniclastic systems in the world, is deduced from morphological and sedimentological interpretations of newly acquired data. The study highlights small-scale sedimentary features indicating hydrodynamic and sedimentary processes. A direct connexion between the Saint-Etienne river mouth and submarine canyons is evidenced by the complete incision of the... |
Tipo: Text |
Palavras-chave: Submarine canyon; Canyon head; Turbidity current; Hyperpycnal flow; Coastal instability. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00156/26697/24790.pdf |
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Sisavath, Emmanuelle; Babonneau, Nathalie; Saint-ange, Francky; Bachelery, Patrick; Jorry, Stephan; Deplus, Christine; De Voogd, Beatrice; Savoye, Bruno. |
Recent oceanographic surveys revealed the existence of five volcaniclastic deep-sea fans off La Reunion Island. The Cilaos fan is a large volcaniclastic submarine fan, connected to rivers that episodically experience torrential floods through a narrow and steep shelf-slope system. New piston cores presented in this study together with echosounder profiles give new insight into the evolution, of this extensive and sand-rich turbidite system. The Cilaos fan extends over 15,000 km(2) on an abyssal plain and is compartmentalized by topographic highs. Located southwest of the island, the sedimentary system consists of a canyon area and a deep sea fan divided into a proximal and a distal fan. The proximal fan is characterized by its wide extent and... |
Tipo: Text |
Palavras-chave: Turbidite; Deep-sea fan; Volcaniclastic; La Reunion Island. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00056/16704/14203.pdf |
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Sisavath, Emmanuelle; Mazuel, Aude; Jorry, Stephan; Babonneau, Nathalie; Bachelery, Patrick; De Voogd, Beatrice; Salpin, Marie; Emmanuel, Laurent; Beaufort, Luc; Toucanne, Samuel. |
The present study focused on turbidite sedimentation in the Cilaos turbidite system, a volcaniclastic deep-sea fan recently recognized offshore La Réunion Island. A set of piston cores was collected in order to establish the stratigraphy of this fan and to examine the processes controlling the turbidite sedimentation off the Cilaos cirque (Piton des Neiges volcanic massif) over the last climatic cycle. Two main phases of turbidite activity were identified, during the ca 140–127 ka and 30–0 ka periods, coinciding with the two last glacial–interglacial transitions (i.e., Terminations II and I). In addition to changes in climate and eustatic sea-level, these periods coincide with a low effusive volcanic activity of the Piton des Neiges volcano. The high... |
Tipo: Text |
Palavras-chave: Turbidites; La Reunion Island; Indian Ocean; Late Quaternary; Volcaniclastic system. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00105/21659/19383.pdf |
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Sisavath, Emmanuelle. |
Even if deep-water turbidite systems have been widely studied throughout the world ocean, volcaniclastic deep-sea fans are little known compared to silicoclastic systems. Numerous studies dedicated to the Canary or the Hawaii Islands have never revealed the presence of well-developed turbidite system (with canyons, lobes and levees). Nevertheless, turbidite deposits and sedimentary structures like canyons or channels are visible off these volcanic islands suggesting that other processes than large mass wasting processes (flank landslides, debris avalanches) also played an important role in the erosion and transport of sediments in the deep marine environment adjacent to volcanic islands. The new dataset collected off La Réunion Island, during the 2006... |
Tipo: Text |
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Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00075/18617/16171.pdf |
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Mazuel, Aude; Sisavath, Emmanuelle; Babonneau, Nathalie; Jorry, Stephan; Bachelery, Patrick; Delacourt, Christophe. |
Recent marine geophysical surveys reveal the existence of well-developed volcaniclastic deep-sea fans around La Réunion Island, Indian Ocean. The Mafate turbidite complex, located in the northwestern part of the island, is a large sedimentary system formed by two coalescent-like volcaniclastic deep-sea fans: the Mafate fan and the Saint-Denis fan. They are both connected to terrestrial rivers supplying sediment produced by erosion on the island, particularly during austral summer cyclonic floods. Through the integration of marine geophysical data (including bathymetry, backscatter multibeam sounder images, TOBI side-scan sonar images and seismic reflection profiles) and piston cores, a submarine morpho-sedimentary map of the surface architecture of the... |
Tipo: Text |
Palavras-chave: Deep-sea fan; Turbidite; Volcaniclastic; Land-to-sea transfer; La Reunion Island; Late Quaternary. |
Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00312/42273/41597.pdf |
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