Surface and deep water conditions in the Sicily channel (central Mediterranean) at the time of sapropel S5 deposition
Abstract New centennial-scale data of benthic foraminifera assemblages and of stable isotopes of foraminifera shells from the Sicily Channel, representative of surface and bottom waters, over the interval between about 140 and 110 kyr BP, are presented. During this period anoxia developed on the eastern Mediterranean basin and sapropel S5 deposited. Although anoxic sediments have not been deposited in the Sicily Channel, this area is strategic to study the character of intermediate waters, whose chemical–physical properties strongly precondition the eastern Mediterranean deep water formation. So far, no data from these water masses have been obtained, apart from the isotopic composition of shells of the planktonic foraminifera species Neogloboquadrina pachyderma which lives at about 200 m depth, thus quite far from the intermediate water core. We conclude that, although with a reduced rate, the flowing of intermediate waters coming from the eastern basin, together with the surface water masses with a clear western affinity, implies the maintenance of an anti-estuarine circulation pattern across the Sicily Channel and in the Mediterranean Sea, also during one of the most severe episodes of anoxia of the Late Pleistocene.