Recent and active deformation pattern off the easternmost Algerian margin, Western Mediterranean Sea: New evidence for contractional tectonic reactivation
|Author(s)||Kherroubi Abdelaziz2, Deverchere Jacques1, Yelles Abdelkarim2, De Lepinay Bernard Mercier3, Domzig Anne4, Cattaneo Antonio5, Bracene Rabah6, Gaullier Virginie7, Graindorge David1|
|Affiliation(s)||1 : Univ Brest, Inst Univ Europeen Mer, CNRS, UMR Domaines Ocean 6538, F-29280 Plouzane, France.
2 : CRAAG, Algiers 16340, Algeria.
3 : Univ Nice Sophia Antipolis, CNRS, UMR Geosci Azur 6526, F-06560 Valbonne, France.
4 : Univ Nantes, CNRS, Lab Planetol & Geodynam, UMR 6112, F-44322 Nantes, France.
5 : IFREMER, Ctr Brest, Lab Environm Sedimentaires, F-29280 Plouzane, France.
6 : SONATRACH, Boumerdes, Algeria.
7 : Univ Perpignan, LEGEM, EA 3678, F-66860 Perpignan, France.
|Source||Marine Geology (0025-3227) (Elsevier), 2009-06 , Vol. 261 , N. 1-4 , P. 17-32|
|WOS© Times Cited||44|
|Keyword(s)||Subduction inception, Africa Eurasia convergence, Seismic reflection, Seismic hazards, Growth strata, Folding, Active faulting, Annaba, Algerian margin|
|Abstract||We describe for the first time a set of large active thrusts and folds near the foot of the easternmost Algerian margin, Western Mediterranean, from swath bathymetry and high-resolution seismic data acquired in 2005 during the Maradja2/Samra cruise. This active system resumes a previous passive margin and creates growth strata deposition on the limbs of large folds, resulting in the development of perched basins at the foot of the margin since less than similar to 1 Ma. They form a set of overlapping fault segments verging toward the Algerian basin, in a way similar to what has been observed off eastern Algiers on the rupture zone of the 2003 Mw 6.8 Boumerdes earthquake. The horizontal shortening rate across large folds is estimated to be of the order of 1 mm/yr. Although no historical earthquakes are reported here, these fault segments could have been responsible for large (M similar to 7.5) events in the past. This young tectonic system further supports the hypothesis of subduction inception of the Neogene oceanic lithosphere in the context of the Africa-Eurasia convergence.|