Séminaire ISTeP - Ramadan Ghalayini

Rôle de la limite de plaque transformante du Levant sur la structuration cénozoïque du bassin Est-Méditerranéen

Sedimentary basins adjacent to plate boundaries contain key tectonic and stratigraphic elements to understand how stress is transmitted through plates. The Levant basin is a place of choice to study such elements because it flanks the Levant Fracture System and the Africa/Anatolia boundary. New high quality 3D seismic reflection data is used to unravel the tectonic evolution of the margin of this basin during the Cenozoic, the period corresponding to the formation of the Levant Fracture System, part of the Africa/Arabia plate boundary. Four major groups of structures are identified in the interpreted Cenozoic units: NW-SE striking normal faults, NNE-SSW striking thrust-faults, ENE-WSW striking dextral strike-slip faults, and NNE trending anticlines. All structures, apart of the NW-SE striking normal faults, are inherited from Mesozoic faults. Their reactivation and associated folding started during the Late Miocene prior to the Messinian Salinity Crisis due to a NW-SE compressional stress field. No clear evidence of shortening at present day offshore Lebanon and no large NNE-SSW strike-slip faults parallel to the restraining bend are found indicating that the Levant Fracture System is mainly contained onshore at present day. The intermittent activity of the interpreted structures correlates with the two stages of LFS movement during Late Miocene and Pliocene. The seismic interpretation results are validated by analogue modelling of the Levant margin to test the reactivation of pre-existing faults.

21/11/2014 à 12h30, Salle Fourcade (Tour 55/56, 4ème étage)