Paleoceanographic and paleoclimatic variability in the Western Mediterranean during the last 25 cal. kyr BP. New insights from contourite drifts

The Western Mediterranean Deep Water (WMDW), on its way out toward the Atlantic Ocean, has favored formation of contourite drifts in Alboran Sea (SW Mediterranean) since opening Strait Gibraltar. Resolving nature these deposits is crucial for reconstructing WMDW variability at a millennial scale, deciphering bottom current paleo-velocity, and establishing paleoclimatic implications over last 25 cal. kyr BP. Two sediment cores retrieved from elongated separated plastered formed along path are investigated by means multi-sedimentological data (terrigenous grain-size, sortable silt, terrigenous carbonate fluxes, bioturbation ichnofabric changes), geochemical (Zr/Al Si/(Si + Al) ratios), chronostratigraphic (?18O, 14C data) as well statistical analyses (grain-size end-member modelling spectral analysis). Integration confirms contouritic drift deposits. high-resolution paleocurrent records inferred silt sequences led us to define two regimes terms flow energy. Regime 1 (weak moderate velocity) defined paleo-velocities ?4 23 cm s?1 dominant during 24 cal 2 (strong characterized estimated about ?36 Heinrich Stadial 2. analysis proxies (sortable Zr/Al ratio) matches four cyclic climatic signals (1900 yr, 2300 4000 ye 6100 yr), corroborating occurrence millennial-scale cyclicity. These cycles related atmospheric climate variability, turn linked variations solar activity. Our results, when combined with published neighboring NW drift, provide better regional understanding dynamics.