FN Archimer Export Format
PT J
TI The Kramis fan offshore western Algeria: the role of sediment waves in turbiditic levee growth
BT 
AF BABONNEAU, Nathalie
   CATTANEO, Antonio
   SAVOYE, Bruno
   BARJAVEL, Guy
   DEVERCHERE, Jacques
   YELLES, karim
AS 1:1;2:2;3:3;4:3;5:4;6:5;
FF 1:;2:PDG-REM-GM-LES;3:;4:;5:;6:;
C1 Université de Brest, IUEM, UMR CNRS 6538 Domaines Océaniques, Place Nicolas Copernic, 29280 Plouzané, France
   IFREMER, Géosciences Marines, Laboratoire Environnements Sédimentaires, BP70, 29280 Plouzané, France
   IFREMER, Géosciences Marines, Laboratoire Environnements Sédimentaires, BP70, 29280 Plouzané, France
   Université de Brest, IUEM, UMR CNRS 6538 Domaines Océaniques, Place Nicolas Copernic, 29280 Plouzané, France
   CRAAG, BP 63, Route de l’Observatoire, Bouzareah, 16340 Alger, Algeria
C2 UBO, FRANCE
   IFREMER, FRANCE
   IFREMER, FRANCE
   UBO, FRANCE
   CRAAG, ALGERIA
SI BREST
SE PDG-REM-GM
   PDG-REM-GM-LES
   IUEM
TC 0
UR https://archimer.ifremer.fr/doc/00129/24021/21978.pdf
LA English
DT Article
CR MARADJA
   MD 140 / PRIVILEGE
   PRISME
   PROGRAMME PRISMA
BO Le Suroît
   Marion Dufresne
   L'Atalante
DE ;Algerian margin;turbidity currents;sediment waves;scours
AB The Kramis deep-sea fan extends over 45 km at the base of the western Algerian continental slope between 2000 and 2550 m water depth and covers an area of approximately 1200 km2. The Kramis Fan was initiated after Messinian time, evolved during the Plio-Quaternary, and, is still active, as proved by submarine cable breaks during the 1954 Orléansville earthquake. The Kramis Fan is fed by two perpendicular canyons: the Kramis Canyon and the Khadra Canyon, merging in a single E–W-oriented channel confined at the foot of the slope. It is strongly asymmetric with a super-developed levee on the right-hand side of the channel, the Kramis Ridge.  Based on recent multibeam, side-scan sonar, and sediment core data (Maradja, 2003 and 2005, Prisma, 2004, and Prisme, 2007 cruises), we describe the morphology and internal structure of the fan and particularly the sediment ridge, showing marked lateral changes in the sediment-wave morphology and their association with a series of large scours in the intermediate part of the ridge aligned in the continuity of the Khadra Canyon direction. Overall, the Kramis Ridge is formed by turbidity currents overspilling the ridge crest, which is 100 m above the channel floor, with two exceptions. In the distal part of the ridge the subdued ridge-crest height probably causes continuous overspill, testified by sediment waves migrating parallel to the channel. The scours occur in the intermediate part of the ridge where the ridge height is only 50–60 m; scours are interpreted as the result of cyclic steps due to flow stripping of currents provided by the intersection of the Khadra Canyon with the Kramis Canyon and Channel system. The scours probably postdate the main growth of the Kramis Ridge and induce the local erosion of the ridge, which could correspond to a new channel initiation cutting the ridge. The superposition or the interaction of flows with different directions is responsible of the amplification of the size of the sediment waves with erosional downside flanks and their transformation in scours. The Kramis Fan provides a clear example of flow interaction to explain the presence of large sediment waves and scours on modern submarine fans.
PY 2012
SO SEPM Special Publication
SN 1060-071X
PU Society for Sedimentary Geology
VL 99
BP 293
EP 308
ID 24021
ER

EF