Sortable silt particle-size data and stable isotope analyses from the Corsica Trough, western Mediterranean Sea, provide a continuous palaeoceanographic record of the inflow, ventilation and vertical fluctuations of the Levantine Intermediate Water (LIW) in the northern Tyrrhenian Sea for the last 130,000 years. The results presented herein reveal that climate changes drive the Mediterranean intermediate circulation on Milankovitch to millennial timescales. Intensified intermediate inflow and ventilation in the Corsica Trough occurred throughout the last glacial interval, with a cold/fasterwarm/slower pattern existing between the Dansgaard-Oeschger climatic oscillations (including Heinrich events) and the LIW variability. By contrast, a weak intermediate ventilation characterised the Holocene and the Last Interglacial period, especially during insolation maxima and the sapropel deposition in the eastern Mediterranean. This variability probably reflects the changes of the eastern Mediterranean net evaporation, as well as the propagation to the western Mediterranean of the profound hydrographic adjustments of the Levantine Sea and adjacent areas to climate forcing. The implications for the formation and ventilation of the Western Mediterranean Deep Water (WMDW) in the northwestern Mediterranean basin, as well as for Mediterranean-Atlantic exchange through the Strait of Gibraltar are discussed. Highlights ► The LIW dynamics in the Corsica Trough is reconstructed for the last 130,000 years. ► Climate changes drive the LIW dynamics on Milankovitch to millennial timescales. ► A cold/fasterwarm/slower pattern exists between climate and the LIW variability. ► Role of LIW in deep-water formation and Mediterranean-Atlantic exchange is examined.

International audienceThe role of mid-latitude precipitation in the hydrological forcing leading to the deposition of sapropels in the Mediterranean Sea remains unclear. The new GDEC-4-2 borehole, East Corsica margin (northern Tyrrhenian Sea), provides the first precisely dated evidence for enhanced rainfall in the Western Mediterranean during warm intervals of interglacial periods over the last 547 kyr. Comparison of GDEC-4-2 proxy records with pollen sequences and speleothems from the central and eastern Mediterranean reveals that these pluvial events were regional in character and occurred probably in response to the intensification of the Mediterranean storm track along the northern Mediterranean borderlands in autumn/winter. Our dataset suggests that the timing of maxima of the Mediterranean autumn/winter storm track precipitation coincide with that of the North African summer monsoon and sapropel deposition. Besides highlighting a close coupling between mid- and low-latitude hydrological changes, our findings suggest that during warm intervals of interglacial periods the reduced sea-surface water salinities, together with the high flux of nutrient and organic matter, produced by the monsoonal Nile (and wadi-systems) floods, were maintained throughout the winter by the Mediterranean rainfall. This provides an important additional constraint on the hydrological perturbation causing sapropel formation

Foraminifera and ostracods have been quantitatively studied in core MD01-2472, from the upper continental\ud slope (at water depth of 501 m), to evaluate their relationship with bottom water condition\ud variability and decipher the control of the Levantine IntermediateWater (LIW) current on benthic faunas.\ud The occurrence of reworked ostracod species (originating from the continental shelf) and, the presence of\ud shallow water Elphidium/Ammonia benthic foraminifera are used to estimate the degree of along-slope\ud transport at the core site. This has revealed two intervals of along-slope transport also associated with\ud coarse-grained contourite deposits, deposited during the YD and HS2 episodes. Planktonic-benthic\ud foraminiferal and ostracod assemblages reflect climate oscillations. Peaks of the polar planktonic Neogloboquadrina\ud pachyderma (left-coiling S) may be used to identify Heinrich Events. Interstadials are\ud marked by abundant ostracod species such as Paracypris sp., Argilloecia acuminata, and Cytheropteron\ud alatum and the presence of benthic foraminifera like Bulimina marginata, Bulimina costata and Gyroidina\ud altiformis. The BeA and Holocene are characterized by abundant warm water species of planktonic\ud foraminifera and by the ostracod species Polycope sp. We hypothesize that there is relationship between\ud LIW intensification during cold rapid climate events and benthic fauna assemblage variations due to\ud changes in: 1) bottom water ventilation; and 2) the export of nutrients and/or sediment particles by\ud bottom currents

The study of Quaternary sediments covering the last 550 kyr from the borehole GDEC-4-2, East-Corsica basin, was performed through the study of benthic meiofaunal assemblages (ostracoda and benthic foraminifera) whose distribution responds to climate changes, and glacial-interglacial variability in particular. The interglacial ostracod group is mainly composed of the Argilloecia acuminata, Cytheropteron alatum, Henryhowella sp., Polycope sp. and Cytherella sp., which indicate an enhanced surface productivity and possibly high bottom water temperature during these warm intervals. Benthic foraminifera, such as Hoeglundina elegans, Sigmoilopsis schlumbergeri, Bigenerina nodosaria and Hyalinea balthica are predominant during interglacial periods and also show an increasing surface productivity associated to warm intervals. Increase in surface productivity would contribute to an enhanced export of organic matter to sea floor at the GDEC-4-2 site during interglacial periods. The bottom temperature drop coupled with the important sedimentary inputs (associated to a significant quantity of refractory organic matter) during glacial periods was highlighted by the predominance of ostracoda, such as Paradoxostoma sp., Cytheropteron testudo, Bathycythere vanstraateni, Macrocypris sp., Echinocythereis echinata and benthic foraminifera as Bolivina spathulata, Bulimina costata, and Bulimina marginata. The distribution of some benthic foraminifera species describing a turnover system allowed the characterization of the last three climate cycles (MIS 8-9, MIS 6-7, MIS 1-5) probably Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site. marked by changes of bottom water paleoceanographic conditions in terms of temperature, salinity, bottom current intensity and surface productivity. The cyclic variations of the allochthonous group recorded over the last 550 kyr suggest a major role played by the eustatic factor, with the latter possibly favouring down slope transport. The distribution of this group allowed thus establishing a link between shelf-basin sediment transfer and climate, with enhanced shelf-basin sediment transfer during glacial low stands.

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