HR: 1340h
AN: PP13B-1268    [Abstracts]
TI: Recent and Late Quaternary sedimentation processes in the area of the SE 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
EM: gerhard.schmiedl@uni-hamburg.de
AF: University of Leipzig, Institute of Geophysics and Geology, Talstrasse 35, Leipzig, 04103, Germany
AU: Schmiedl, G
EM: gerhard.schmiedl@uni-hamburg.de
AF: Institute of Geology and Palaeontology, University of Hamburg, Bundesstrasse 55, Hamburg, 20146, Germany
AU: Dulski, P
EM: dulski@gfz-potsdam.dee
AF: GeoForschungsZentrum Potsdam, Sektion 3.3, Telegrafenberg, Potsdam, 14473, Germany
AU: Kuhnt, T
EM: kuhnt@rz.uni-leipzig.de
AF: University of Leipzig, Institute of Geophysics and Geology, Talstrasse 35, Leipzig, 04103, Germany
AB: The present distribution of clay minerals in the southeastern Levantine Sea reveals a complex pattern of different source areas and dispersions of the main clay minerals smectite, illite, kaolinite, chlorite, and palygorskite. Smectite dominates the suspension load of the Nile River and rivers of the Near East. Sources of illite are dust- bearing winds blowing from the Saharan desert and the northern mainland of the Levantine Sea. Kaolinite is prevalent in the sediment yield of rivers which drain the Sinai, in sediments of wadis which discharge into the Nile River, and in dust loads of African storms. Palygorskite and chlorite are mainly derived from several dust bearing wind systems of the North and Central African continent, whereas chlorite is also provided by dust-bearing winds of the northeastern Mediterranean mainland. The clay mineral distributions and XRF element data of a sediment core from the southeastern Levantine Sea, spanning the last 27,000 years, show that the sediments are mainly affected by the discharge of the Nile River. The provenance of clay minerals provides a sensitive recorder of changes in the Nile River discharge and therefore in the climate conditions in the catchment of its tributaries. The glacial section of the core is characterized by low smectite concentrations, high K/Al ratios and low linear sedimentation rates when compared to the Holocene suggesting a low influence by the Nile outflow. Subsequently, during the early and middle Holocene, when the North African continent was influenced by more humid conditions during the African Humid Period, our record shows high proportions of smectite and low K/Al ratios which likely reflect higher discharge rates of the River Nile. In contrast to the sharp beginning and end of the African Humid Period as recorded in West African records at 15 and 5.5 kyr BP, our record in the southeastern Levantine Sea shows more transitional patterns and trend towards slightly lower Nile discharge rates at about 4 kyr BP. The similarity of the clay mineral pattern, in particular the smectite concentrations, with fluctuations in sea surface temperatures of the tropical western Indian Ocean indicate a tight relationship between the Indian Ocean Dipole and the discharge of the Nile River.
DE: 3022 Marine sediments: processes and transport
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
DE: 4901 Abrupt/rapid climate change (1605)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting