DATE2016-05-30 11:12:25
IDABSTRACT20160530111225-1050
CONTACTrousakis@hcmr.gr
PRESENTATIONPOSTER
INVITED0
IDSESSION3
TITLEPALEOCEANOGRAPHIC-PALEOCLIMATIC RECORDS OF MIS 5E INTERGLACIAL DEPOSITS: FIRST EVIDENCE OF SAPROPEL S5 IN THE AEGEAN SEA (SW CYCLADES PLATEAU, GREECE)
AUTHORSG Rousakis (1), M Ratopoulou (2), M V Triantaphyllou (2), A Gogou (1), I Bouloubassi (3), M D Dimiza (2), K Kouli (2), K Parinos (1), S Kyrikou (2), V Lykousis (1)
AFFILIATIONS
  1. Hellenic Centre For Marine Research, Institute Of Oceanography 190 13 Anavyssos (Greece)
  2. Faculty Of Geology And Geoenvironment, National And Kapodistrian University Of Athens Panepistimioupolis, 157 84 Athens (Greece)
  3. 3laboratoire D’océanographie Et Du Climat, Expérimentation Et Approche Numérique, Université Pierre Et Marie Curie Paris Cedex 05 (Greece)
ABSTRACTCombined sedimentological, micropaleontological, geochemical and pollen analyses have been performed on core SK-3 (R/V Aegaeo, 2010; 249 m water depth), aiming to determine the paleoceanographic-paleoclimatic changes during the last interglacial in the SW Aegean Sea. The grain-size data of SΚ-3 sediment record show a high percentage of sand that was prominently decreased within two distinct sapropelic layers. The first sapropelic layer (24-37 cm) corresponds to sapropel S1. The second sapropelic layer (OC ~2-5 %) appears in-between 178-200 cm, corresponding to the high sea-level warm Eemian MIS5e associated with sapropel S5 deposition. Alkenone SSTs within this interval exceed 23oC and δ18ΟG. ruber appears strongly depleted, pointing to warm surface waters with decreased salinity, also supported by the dominant planktonic foraminifera Globigerinoides ruber (white and pink) and Orbulina universa. The presence of benthic infaunal taxa Chilostomella mediterranensis, Globobulimina affinis and Bulimina spp. imply oxygen deficiency conditions at bottom waters. The contemporaneous absence of Globorotalia inflata indicates a highly stratified water column. Pollen flora within S5 depositional interval is characterized by high arboreal abundances; mainly deciduous Quercus, together with Pinus and Juniperus. The succession of deciduous oak forest-dominated vegetation; firstly marked by increased Mediterranean elements, followed afterwards by Pinus and Abies, complies with synchronous terrestrial deposits of southern Balkans. The later phase of Abies expansion features the vegetation instability at the onset of the climatic deterioration towards the end of MIS5e. A cooling event is assumed at 189-192cm, where the OC content is decreased well compared with SST trend, heavier δ18O G. ruber values and rapid decrease of deciduous trees coupled with expansion of Chenopodiaceae, interpreted as a disruption of the African monsoonal forcing.
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