HR: 1340h
AN: PP43A-0664    [Abstracts]
TI: Benthic Foraminifera as Sensitive Recorders of Climate and Environmental Variability in the SE and NE Mediterranean During the Holocene
AU: Avnaim-Katab, S
EM: simona100@bezeqint.net
AF: Recanati Institute for Maritime Studies, Haifa University, Mt. Carmel, Haifa, 31905 Israel
AU: * Almogi-Labin, A
EM: almogi@gsi.gov.il
AF: Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501 Israel
AU: Bar-Matthews, M
EM: matthews@gsi.gov.il
AF: Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501 Israel
AU: Schilman, B
EM: shilman@gsi.gov.il
AF: Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501 Israel
AU: Ayalon, A
EM: ayalon@gsi.gov.il
AF: Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501 Israel
AU: Suvan, D
EM: dsivan@research.haifa.ac.il
AF: Recanati Institute for Maritime Studies, Haifa University, Mt. Carmel, Haifa, 31905 Israel
AU: Paterne, M
EM: Martine.Paterne@cfr.cnrs-gif.fr
AF: LSCE Laboratoire mixte CNRS-CEA, Domaine du CNRS, Avenue de la Terrasse, Gif sur Yvette, 91198 France
AB: Benthic foraminifera are sensitive recorders of environmental variability,reflecting climatically induced changes related to environment stability, variations in food flux and sea floor ventilation. In order to reconstruct the oceanographic/climate variability in the Levantine basin during the Holocene we studied two cores recovered by R/V Marion Dufresnae: Core MDVAL95-01 taken SE of Cyprus (980 m) represent the NE Levantine basin, and core MDVAL95-09 taken at the distal parts of the Nile delta (884 m) represent the SE Levantine basin. d18O stratigraphy was established using G. ruber, AMS 14C dating and correlating this record with well-dated (U/Th) speleothem records of Soreq Cave. The deep-sea benthic foraminiferal assemblages reveal a complex picture of lateral variations in numerical abundance, species richness and assemblage composition during the Holocene. This complexity reflects fluctuation in African monsoon system as recorded by Nile River discharge, and north Atlantic climate system controlling deep-water formation rates. The early Holocene (12-9.5 kyr) was characterized by well-ventilated and oligotrophic bottom water all over the Levant. The onset of the sapropel event (9.5 kyrBP) is characterized by gradual decrease in oxygenation and increase in trophic level in SE Levant and abrupt depletion in bottom water oxygenation in NE Levant. During the sapropel event anoxic conditions were shortly interrupted 8.1 kyrBP at the SE Levant whereas in the NE Levant dysaerobic conditions prevailed continuously as indicated by the occurrence of specialized deep infaunal taxa. The end of the sapropel event is marked by gradual increase in deep-water oxygenation in the SE Levant concomitantly with a more sharp change in oxygenation in NE Levant. During the last 5.5 kyr the dominance of shallow infaunal species at the SE Levant indicate more mesotrophic Nile controlled regime whereas in the NE Levant opportunistic taxa indicate environmental instability and low, fluctuating nutrient input and seasonality that is more pronounced.
DE: 0473 Paleoclimatology and paleoceanography (3344, 4900)
DE: 1637 Regional climate change
DE: 4944 Micropaleontology (0459, 3030)
DE: 4950 Paleoecology
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005