Mass Wasting at the Easternmost Cyprus Arc, Off Syria, Eastern Mediterranean

4th International Symposium Submarine Mass Movements and Their Consequences.-- 12 pages, 6 figuresThe seafloor topography at the easternmost deformation front between the African and the Anatolian plate off Syria is dominated by the Latakia Ridge, which obliquely intersects the Syrian margin. In this study, we investigate post-Miocene depositional processes of this topographically intricate area and their relationship with mass-wasting phenomena by means of bathymetric, multi-channel seismic reflection and sediment sub-bottom profiler data. Northward of the Latakia Ridge, the Latakia Slope is characterized by steep scarps of up to 500 m height. The Pliocene-Quaternary strata are truncated by the scarps, which are located in the upward prolongation of normal fault planes. Some scarps are from erosion or non-deposition as a consequence of contour currents. Evidence for recent active tectonics is also present in the Latakia Ridge. A basement outcrop along the crest of the northern Latakia Ridge presumably reflects the transtensional faulting of this easternmost section of the African-Anatolian deformation front. The western side of the northern Latakia Ridge shows evidence of more cohesive slumping, probably owing to the overconsolidated nature of the sediment. Here a potential future slide of 11 km3 associated with a rotational fault has been identified. The sedimentary and tectonic setting has resulted in frequent mass wasting. Abundant scars and debris flow-like deposits have been observed on the flanking slopes of the Latakia canyon and the Syrian Margin. The Latakia canyon is fed by several tributary canyons which are incised into the Syrian Slope. Steep slopes, high sediment accumulation rates and active strike-slip tectonics appear to have a fundamental role in submarine mass-failure initiation. Mass-failure characteristics indicate that geohazards may exist from subsequent potential tsunami generationThis research was supported by a Marie Curie Intra European Fellowship, PIEF-GA-2008–219188, within the 7th European Community Framework ProgrammePeer Reviewe

Tectonique transcurrente éburnéenne au sein du craton ouest-africain: exemple du sillon de Djibo (Burkina Faso).

International audienc

Thermicité et déformation de la Marge continentale dans le sud de la Tasmanie (Australie) : résultats préliminaires d'une analyse par traces de fission et d'une étude microstruturale

Comptes Rendus Géoscience, v. 334, n. 1, p. 59-66, 2002. http://dx.doi.org/10.1016/S1631-0713(02)01725-XInternational audienc

Deformational styles of the eastern Mediterranean Ridge and surroundings from combined swath mapping and seiemic reflection profiling

Recent swath mapping and seismic reflection profiling across the eastern(Levantine) branch of the Mediterranean Ridge (MR), in the eastern Mediterranean Sea, illustrate a strong variability of the deformational styles that characterize this precollisional accretionary prism. Along a north-south cross-section of the MR, a structural analysis, based on surface mapping, combined with vertical seismic reflection data, reveals two main structural domains. A southern Outer Domain consists of a series of three disconnected distinct fold belts. Folding affects a sedimentary cover which includes an approximately 2-km thick Pliocene and Quaternary wedge in this domain, resting on fairly thick Messinian evaporitic sequences that act as probable decollement layers. The MR Inner Domain includes three regions showing evidences of strong internal deformations and of numerous probable mud cones and mud flows, but no seismic evidence of significant underlying Messinian evaporites can be detected. The inner sub-regions are thrusting northwards over an area made of faulted, and locally uplifted, acoustic basement blocks that constitute the southernmost extension of the Crete continental margin, acting as a continental buttress for the MR. This innermost domain is itself structurally disconnected from the Crete continental margin by the en echelon Pliny troughs system that shows evidence of left lateral displacement. Altogether, the different structural and sedimentary cover patterns reveal a strong contrast between both MR Inner and Outer Domains, and important lateral variations within the Inner MR itself. Strike-slip faulting seams to characterizes both areas, and large-scale mud accumulations potentially exist in the northern one. Our results support a model of imbricated accretionary prisms, including, at least, two stages: (1) a pre-Messinian stage during which the Inner MR probably developed in response to northward subduction of the African lithosphere beneath southern Europe, and (2) a Messinian to post-Messinian period, during which the kinematics of the Aegean-Anatolian microplates and the presence of thick Messinian deposits became prevalent and which led to the creation of the Outer MR folded wedge piling against the previous one. In our interpretation, the occurrence of thick Messinian evaporites in this area induces important local and regional modifications of the structural pattern. Strike-slip activities reflect partitioning related to oblique subduction, and likely lateral escape of the sedimentary cover in the whole studied area. ©2001 Elsevier Science B.V. All rights reserved