Data/hora: 09/06/2024 03:37:17

Provedor de dados: | 5
País: | France
Título: | Morphology and sedimentary architecture of a modern volcaniclastic turbidite system: The Cilaos fan, offshore La Reunion Island
Autores: | Sisavath, Emmanuelle; Babonneau, Nathalie; Saint-ange, Francky; Bachelery, Patrick; Jorry, Stephan; Deplus, Christine; De Voogd, Beatrice; Savoye, Bruno.
Data: | 2011-10
Ano: | 2011
Palavras-chave: | Turbidite; Deep-sea fan; Volcaniclastic; La Reunion Island.
Resumo: | 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 coarse-grained turbidites. The distal fan is characterized by elongated structures and fine-grained turbidites. A detailed morphological study of the fan which includes the analysis of swath bathymetry, backscatter, echosounder, and piston core data shows that the Cilaos fan is a complex volcaniclastic deep-sea fan, highly influenced by preexisting seafloor irregularities. The canyons and the slope area show a complex and evolving sediment feeding system with a direct sediment input by the river and irregular sediment supply by submarine landslide. Three main construction stages are identified for this system: (1) an old incision phase of the channels forming wide turbidites extending over the entire distal fan; (2) a period of no or low activity characterized by a thick layer of hemipelagic mud; and (3) a local reactivation of the channel in the proximal fan. Each stage seems to be linked to a different sediment source with a progressively increasing contribution of hemipelagic sediment and mud in younger stages. (C) 2011 Elsevier B.V. All rights reserved.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00056/16704/14203.pdf

DOI:10.1016/j.margeo.2011.06.011

Editor: | Elsevier Science Bv
Relação: | http://archimer.ifremer.fr/doc/00056/16704/
Formato: | application/pdf
Fonte: | Marine Geology (0025-3227) (Elsevier Science Bv), 2011-10 , Vol. 288 , N. 1-4 , P. 1-17
Fonte: | 2011 Elsevier B.V. All rights reserved.