HR: 1340h
AN: OS23C-1334    [Abstracts]
TI: Results of 2-D backstripping of the Plio-Quaternary sequence of the Golfe du Lion passive margin from the shelf to the basin: insights on the subsidence and paleo-geometries
AU: * Steckler, M S
EM: steckler@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Graindorge, D
EM: graindor@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Baztan, J
EM: Juan.Baztan@ifremer.fr
AF: Ifremer - DRO - G‚osciences marines, B.P. 70, Plouzan‚, 29280 France
AU: Rabineau, M
EM: Marina.Rabineau@ifremer.fr
AF: UBO-IUEM Domaines Oc‚aniques, Place Nicolas Copernic, Plouzan‚, 29280 France
AU: Gorini, C
EM: Christian.Gorini@univ-lille1.fr
AF: Laboratoire de S‚dimentologie et G‚odynamique, Univ. de Lille 1 - SN5, Villeneuve d'Ascq, 59655 France
AU: Olivet, J
EM: jlolivet@ifremer.fr
AF: Ifremer - DRO - G‚osciences marines, B.P. 70, Plouzan‚, 29280 France
AU: Aslanian, D
EM: aslanian@ifremer.fr
AF: Ifremer - DRO - G‚osciences marines, B.P. 70, Plouzan‚, 29280 France
AU: Ryan, W B
EM: billr@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Mountain, G
EM: gmtn@rci.rutgers.edu
AF: Lamont-Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 United States
AU: Mountain, G
EM: gmtn@rci.rutgers.edu
AF: Rutgers, State University of New Jersey, 610 Taylor Rd, Piscataway, NJ 08854 United States
AB: The continental margin of the Golfe du Lion was deeply eroded during the Messinain drawdown of the western Mediterranean Sea, and has subsequently been rebuilt by sediments supplied by the Rhone and adjacent rivers. We are engaged in a study of the evolution of this margin based on sequential backstripping, which accounts for the several processes (thermal subsidence, compaction, sediment loading and tectonics ) that contribute to deformation of the preserved strata and allows us to reconstruct the true stratal geometries at various times throughout the last 5 Ma. We report on our first results of 2-D backstripping as a prelude to a full 3-D treatment that is in progress. Our approach has thus far followed these steps : 1) remove the sedimentary layer above the surface we want to restore, 2) restore offsets along faults (if necessary), 3) allow the sediments to decompact, 4) flexurally unload the underlying crust, 5) remove subsidence, 6) adjust sea level. Using ELF Aquitaine and IFREMER Golfe du Lion seismic data with a consistent interpretation of the main sedimentary units from the shelf to the basin, allows to (1) determine a quantitative estimate of the original morphology, (2) calculate the gradients of continental shelf, shelf clinoforms and continental slopes for each time slice, (3) estimate the sequential locations of the shelf edge and clinoform roll over and their water depths, (4) determine the height of clinoforms, and (5) estimate the volume of Pliocene to Quaternary sediments partitioned between the shelf to the basin, and their possible impact on post-Messinian salt tectonics. These quantitative estimates will help to better understand fundamental processes of margin building.
DE: 9335 Europe
DE: 9604 Cenozoic
DE: 8105 Continental margins and sedimentary basins
DE: 4558 Sediment transport
DE: 3022 Marine sediments--processes and transport
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting