Éditeur(s) : AGU
Résumé : Submarine canyons are narrow but deep submarine valleys that extend for hundreds of meters. They represent the most impressive structures that shape the present morphology of passive continental margins. They can occur off the mouth of rivers: the Tagus, Zaire, Amazon, and Orinoco in the Atlantic; the Indus in the Indian Ocean; and the Var, Rhone, and Ebro in the Mediterranean. Some are at times disconnected from any stream mouth such as the Nazare canyon, off Portugal, despite the fact that it is close to the coast. Some were connected to a river mouth during lowstands of sea level, such as the Wilmington canyon in the northwest Atlantic, or the Blackmud canyon in the northeast Atlantic.
EOS, Transactions American Geophysical Union (0096-3941) (AGU), 2004-07-06 , Vol. 85 , N. 27 , P. 257

Droits : 2004 AGU
http://archimer.ifremer.fr/doc/00071/18201/15769.pdf
DOI:10.1029/2004EO270001
http://archimer.ifremer.fr/doc/00071/18201/

Éditeur(s) : Gauthier-Villars
Résumé : The continental shelf is very narrow and steep to the north, and broader to the South. This shelf is structuraly influenced by the Andes. This area is mainly covered with terrigenous deposits, i.e. muds and sands which are recent on the internal shelf and relict on the external shelf. The sediments, supplied by rivers, reflect the intense erosion of the Andean backland. This erosion can only be reduced in situ by the vegetation cover. Clays are the main component of the fine fraction reaching the sea. Three different clay assemblages are observed: 1) an Andean (illite-chlorite) assemblage, reflecting the proximity of the cordillera; 2) a mid-American assemblage (smectite), which supplies the North Pacific Margin through the Choco counter-current; 3) an Equatorial assemblage (smectites) which is brought to the South by the Colombian current.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1995 , Vol. 18 , N. 1 , P. 1-18

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00097/20862/18480.pdf
http://archimer.ifremer.fr/doc/00097/20862/