HR: 1340h
AN: T13C-0485    [Abstracts]
TI: Geodynamic Evolution of the Southern Flank of the Corinth Rift
AU: * JOUSSELIN, D
EM: jousse@crpg.cnrs-nancy.fr
AF: ENSG-INPL, Centre de Recherches Petrographiques et Geochimiques 15 Rue Notre Dame des Pauvres, B.P. 20, , Vandoeuvre-les-Nancy, 54501 France
AU: Bourlange, S
EM: bourlang@crpg.cnrs-nancy.fr
AF: ENSG-INPL, Centre de Recherches Petrographiques et Geochimiques 15 Rue Notre Dame des Pauvres, B.P. 20, , Vandoeuvre-les-Nancy, 54501 France
AU: Ford, M
EM: Mary.Ford@ensg.inpl-nancy.fr
AF: ENSG-INPL, Centre de Recherches Petrographiques et Geochimiques 15 Rue Notre Dame des Pauvres, B.P. 20, , Vandoeuvre-les-Nancy, 54501 France
AU: LE CARLIER, C
EM: Christian.Le-Carlier@ensg.inpl-nancy.fr
AF: ENSG-INPL, Centre de Recherches Petrographiques et Geochimiques 15 Rue Notre Dame des Pauvres, B.P. 20, , Vandoeuvre-les-Nancy, 54501 France
AU: ROHAIS, S
EM: sebastien.rohais@ifp.fr
AF: Institut Francais du Petrole, Geology and Geochemistry department 1-4, avenue de Bois Pr‚au, Rueil-Malmaison, 92852 France
AB: The Gulf of Corinth is the most seismically active area of Europe extending in a N-S direction at a rate of 12mm/yr. Many studies have focused on currently active normal faults, which bound the southern flank of the Corinth rift. However, many prominent faults, that are considered no longer active, outcrop over a broader area along with their syn-rift sedimentary sequence. The normal fault network and related synrift succession have been mapped and studied at a scale of 1:25,000. The geometry of the fault network in 3D has been reconstructed in the gOcad 3D geomodelling package. Based on these detailed field data we propose a geodynamic model for the evolution of the region in three steps over the last two million years. From 2 to 1 Ma, extension affected a broad area at least twenty kilometers wide. Alluvial conglomerates and sandstones, deposited in grabens and half grabens, were derived from erosion of the pre-existing (Hellenic) high relief to the south in the Peloponnese massif. Around 1Ma, a regional uplift led to the migration of the depocenter to the north. New faults are activated closer to the coast, in places generating forced folds that tilted synrift fluvial formations northward over a 2-3 kilometers wide area. Considerable accommodation space was generated by these faults and, with an increased sediment supply from the south, a series of giant marine Gilbert deltas developed in their hangingwalls. Finally, from 0.5 Ma to present, the activation of a series of major new faults further to the north (near the current coastline) coincided with regional uplift of the south coastal belt, and initiated the formation of a second generation of Gilbert delta, currently building out into the gulf. The faults can be divided into three families. The main one (74 data) is oriented N110, dipping 45 to 60° to the north. It includes 5 major faults spaced 3 to 5 km from south to north, with a throw larger than 1000m. A secondary set (41 data) strikes N60, dipping to the NW, it includes only one fault with a throw larger than 500m; the other secondary set (43 data) is antithetic to the two first ones as it strikes N60 to N110, dipping to the south, the largest fault it includes has a throw of about 400m. Most faults are planar and the importance of listric faults seems minor in the rift history.
DE: 8000 STRUCTURAL GEOLOGY
DE: 8010 Fractures and faults
DE: 8109 Continental tectonics: extensional (0905)
DE: 8169 Sedimentary basin processes
DE: 8175 Tectonics and landscape evolution
SC: Tectonophysics [T]
MN: Fall Meeting 2005