ALBERT

Description: The Mediterranean Sea acts as a miniature ocean with the development of its own conveyor belt. It constitutes an ideal location to study and forecast how the marine environment responds to rapid climatic change. Here we present a palaeoenvironmental study carried out on the sediments of ODP Site 963, recovered in the Sicily Channel, the sill which divides the western from the eastern Mediterranean basin. We focused on the transition between the penultimate glacial (MIS 6) and the last interglacial (MIS 5), between approximately 130 and 115 kyr BP. A novel approach is proposed, taking into account centennial-scale geochemical data on major elements, selected trace elements, and yttrium and REE (YREE). This approach was demonstrated to be suitable to recognize both environmental conditions existing during deposition of the studied sequences and to establish whether diagenetic modifications of the original geochemical signature occurred. Our results highlight the delivery of Fe-rich material to the basin, probably from the arid continental environment of southern Sicily. This phenomenon seems to be interrupted in coincidence with the development of Eemian forests at about 126–127 kyr BP in southern Europe. The deposition of weathered products suggests increate humidity in Sicily between 127 and 124 kyr BP. Less oxidizing/more productive conditions characterized the Sicily Channel sea floor between 124 and 119 kyr BP, while sapropel S5 was depositing in the eastern Mediterranean. They are evidenced by the enrichment of heavy REE, the decrease in positive Ce anomaly, and a slight increase in excess barium. This implies that oceanographic processes which led to bottom anoxia in the eastern Mediterranean might have had an impact even on the Sicily Channel environment.

Description: The AND-2A drillcore (Antarctic Drilling Program-ANDRILL) was successfully completed in late 2007 on the Antarctic continental margin (Southern McMurdo Sound, Ross Sea) with the aim of tracking ice proximal to shallow marine environmental fluctuations and to document the 20-Ma evolution of the Erebus Volcanic Province. Lava clasts and tephra layers from the AND-2A drillcore were investigated from a petrographic and stratigraphic point of view and analyzed by the 40Ar-39Ar laser technique in order to constrain the age model of the core and to gain information on the style and nature of sediment deposition in the Victoria Land Basin since Early Miocene. Ten out of 17 samples yielded statistically robust 40Ar-39Ar ages, indicating that the AND-2A drillcore recovered 〈230 m of Middle Miocene (~128-358 m below sea floor, ~11.5-16.0 Ma) and 〉780 m of Early Miocene (~358-1093 m below sea floor, ~16.0-20.1 Ma). Results also highlight a nearly continuous stratigraphic record from at least 358 m below sea floor down hole, characterized by a mean sedimentation rate of ~19 cm/ka, possible oscillations of no more than a few hundreds of ka and a break within ~17.5-18.1 Ma. Comparison with available data from volcanic deposits on land, suggests that volcanic rocks within the AND-2A core were supplied from the south, possibly with source areas closer to the drill site for the upper core levels, and from 358 m below sea floor down hole, with the 'proto-Mount Morning' as the main source.