HR: 1340h
AN: PP43A-0663    [Abstracts]
TI: Holocene Sedimentary Processes in the Eastern Mediterranean Sea
AU: * Hamann, Y
EM: yhamann@rz.uni-leipzig.de
AF: University of Leipzig, Institute of Geophysics and Geology, Talstrasse 35, Leipzig, 04103 Germany
AU: Ehrmann, W
EM: ehrmann@rz.uni-leipzig.de
AF: University of Leipzig, Institute of Geophysics and Geology, Talstrasse 35, Leipzig, 04103 Germany
AU: Schmiedl, G H
EM: schmiedl@rz.uni-leipzig.de
AF: University of Leipzig, Institute of Geophysics and Geology, Talstrasse 35, Leipzig, 04103 Germany
AU: Kuhnt, T
EM: tkuhnt@rz.uni-leipzig.de
AF: University of Leipzig, Institute of Geophysics and Geology, Talstrasse 35, Leipzig, 04103 Germany
AB: High-resolution sedimentological proxy records of different cores from the Aegean Sea and Levantine Sea allow the reconstruction of spatial and temporal patterns of riverine and eolian sediment input and dispersal in the eastern Mediterranean Sea during the late glacial and Holocene. In the North Aegean Sea, sedimentation processes are basically controlled by the sea-level evolution, discharge of terrigenous particles from rivers and fluxes of biogenic carbonate. Short-term fluctuations in grain size and sediment mineralogy indicate millennial-scale changes in river discharge and, thus, humidity of the catchment area. In addition, middle to late Holocene sedimentation processes are likely influenced by the influx of suspension material from the Black Sea and Marmara Sea. In the South Aegean Sea and at the Israeli continental margin, sedimentation processes are dominated by suspension load of the River Nile and eolian influx of dust from the Saharan desert and local sources. Between approximately 12.5 and 5 kyr, sediments of the Israeli continental margin are characterized by generally high clay to silt ratios. During this time interval, pluvial conditions in East and North Africa resulted in extensive vegetation cover, low eolian influx and high Nile discharge. The riverine suspension load is transferred to the different sites following the anti-clockwise circulation of surface waters. A drastic decrease of Nile discharge is observed during the last 2 kyr and may be linked to agricultural changes in Egypt. All investigated sediment successions include the sapropel layer S1 that formed between approximately 9.6 and 7 kyr during warmest and most humid conditions. The sapropels display several phases of elevated organic carbon content indicating repeated intervals of increased productivity and organic carbon preservation. Spatial and temporal differences in the organic carbon nitrogen ratio suggest variable contribution of organic material from marine and terrestrial sources. In the Aegean Sea, a North-South transfer of organic material with bottom currents is suggested.
DE: 4901 Abrupt/rapid climate change (1605)
DE: 4902 Anthropogenic effects (1803, 4802)
DE: 4936 Interglacial
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005