HR: 17:00h
AN: GP22B-05    [PDF]
TI: Holocene Geomagnetic Paleointensity Records From Atlantic Ocean and Mediterranean Sea Sediments
AU: * Laj, C
EM: laj@lsce.cnrs-gif.fr
AF: Laboratoire des Sciences du Climat et de l'Environnement, CEA/CNRS, Avenue de la Terrasse, Bat 12,, Gif-sur-Yvette, 91190 France
AU: Vigliotti, L
EM: luigi.vigliotti@bo.ismar.cnr.it
AF: Istituto di Scienze Marine, CNR, Sezione di Geologia Marina di Bologna, Via Gobetti, 101, Bologna, 40129 Italy
AU: Kissel, C
EM: kissel@lsce.cnrs-gif.fr
AF: Laboratoire des Sciences du Climat et de l'Environnement, CEA/CNRS, Avenue de la Terrasse, Bat 12,, Gif-sur-Yvette, 91190 France
AU: Turon, J
EM: jl.turon@epoc.u-bordeaux1.fr
AF: Departement de Geologie et oceanographie, Universite de Bordeaux I, Avenue des Facultes, Talence, 33405 France
AU: Duprat, J
EM: j.duprat@epoc.u-bordeaux1.fr
AF: Departement de Geologie et oceanographie, Universite de Bordeaux I, Avenue des Facultes, Talence, 33405 France
AB: We have obtained new relative geomagnetic paleointensity records from high accumulation rate sediments in the Atlantic Ocean and in the Mediterranean Sea. Measurements were made using either u-channel samples or standard 2x2x2 cm single samples. A minimum of 10 steps of demagnetization was used to characterize the NRM and the ARM. The ratio NRM/ARM after demagnetization at 25 mT was used as a proxy for relative paleointensity changes. The results indicate a large degree of coherency between the different records: from present to past, the geomagnetic intensity increases reaching a maximum of about twice the present value at about 2000 years B.P., then a progressive decrease reaching a minimum with intensity in the order of the present value is observed at about 6500-7000 years BP. There is then an increase of the intensity reaching a maximum at about 8000 years BP, then a decrease lasting at least to 10-11000 years BP. Comparison with published sedimentary data from other environments and also with compilation of archaeomagnetic data will be presented and discussed.
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1503 Archeomagnetism
DE: 1521 Paleointensity
DE: 1522 Paleomagnetic secular variation
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2003 Fall Meeting