HR: 08:00h
AN: OS51A-01 INVITED     [PDF]
TI: Ravinement Surfaces And Deglacial Sediments On The Rhone Margin (France)
AU: * Berne, S
EM: sberne@ifremer.fr
AF: IFREMER Geosciences Marines, BP 70, Plouzane, 29280 France
AB: The significance of key surfaces and parasequences on the Rhone margin is investigated by comparing high-, very high-, and ultra-high resolution seismic data to long Calypso cores. Each surface and deposit correspond to typical seismic facies, distinct lithologies and different faunal associations. Radiocarbon datings allow us to tie these surfaces and deposits to the deglacial history of the area. However, it is necessary to consider the Rhone subaqueous delta in three dimensions, in order to decipher the impact of global (sea-level), regional (climate, sediment flux), and local (hydrodynamics, avulsion) processes. The last deglacial sea-level rise is well recorded through surprisingly similar clinoform parasequences, that consist of sand and gravels progressively passing seaward to clayey silts. When these systems have a sufficient lateral extent, they can be utilized as a "dipstick" for sea-levels in the Western Mediterranean Sea. Cemented sands, that formed along the phreatic zone, are also observed at different depths and provide an independent way to constrain paleo-water depths.
DE: 3022 Marine sediments--processes and transport
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting