Le cône sous-marin du Nil et son réseau de chenaux profonds : nouveaux résultats (campagne Fanil)

Mud volcanoes, gas chimneys, pockmarks and mounds in the Nile deep-sea fan (Eastern Mediterranean): geophysical evidences

“…10A). On detailed bathymetry, this slope area shows rough, chaotic smallscale reliefs, as well as linear furrows, similar to channels, disconnecting individual sedimentary flows (Bellaiche et al, 2001) (Fig. 10B).…”

“…1) where they are in close relationship with active, compressional and transcurrent, tectonic lineaments (Camerlenghi et al, 1995;Dimitrov & Woodside, 2003;Huguen, 2001;Kopf et al, 2000;Woodside & Volgin, 1996). More recently, during two surveys made on the Nile margin (in 1998 and 2000, respectively) (Bellaiche et al, 2001(Bellaiche et al, , 1999Mascle et al, 2000), more than 150 mud cones, and abundant pockmarks and mounds, have also been discovered on the seafloor of the Nile deep turbiditic system or NDSF. In the mean time, Barsoum et al (2000) reported on the discovery of several active gas chimneys along the NDSF upper slope, while Coleman and Ballard (2001) showed evidences, within the very eastern edge of the cone, of cold hydrocarbon seeps, associated with small (less than 10 m in diameter) muddy mounds and authigenic carbonate crusts.…”

“…Finally, an eastermost province, east of Eratosthenes seamount, shows as a gently folded seafloor surface, which still results from progressive gliding of sediments on Messinian evaporites. In this area, salt-bearing sequences are rather thin and only covered by a few hundred meters of Pliocene to Quaternary sediments, only dissected by a few channels, including channels apparently originating from the Levantine coasts (Bellaiche et al, 2001).…”

Multi-scale slope instabilities along the Nile deep-sea fan, Egyptian margin: A general overview

“…The fluvial deltaic system extends offshore from the Rosetta branch across a wide continental shelf (80 km average width). With the exception of the major indentation related to the Rosetta canyon, the Egyptian continental shelf is a flat and undeformed domain, only characterized, particularly in its eastern corner, by gentle, probably sandy, hydraulic dunes, caused by a general east-directed long shore drift (Bellaiche et al, 2001). A major deep-sea fan, covering the continental slope and abyssal plain (down to 3500 m water depth), formed at the foot of this wide platform; it shows a very variable morphology controlled by combined interactions between salt tectonics and various mechanisms of sediment distribution, including turbidite dispersal, giant slumps and debris flows (Gaullier et al, 2000;Loncke, 2002;Loncke et al, 2006).…”

“…This data set has been a very powerful aid in understanding the construction and evolution through time of that deep sedimentary system (Gaullier et al, 2000;Mascle et al, 2000;Bellaiche et al, 2001;Loncke, 2002;Loncke et al, 2002;Loncke and Mascle, 2004;Loncke et al, 2006). Data analysis enhanced in particular the importance of salt-related tectonics on the regional structure of the fan, the existence of numerous seepage structures (gas chimneys, pock-marks, mud volcanoes) and a great variability of sedimentary processes.…”