Paleo-oceanographic follow-up of a Younger Dryas contourite in the North and South of the Gulf of Cadiz

Abstract: How much paleoceanographic information can a single contourite unit comprise is a matter for debate. Focusing on two contourite units sitting in the North and South of the Gulf of Cadiz, on the Iberian (GC-01A) and the Moroccan (TG-2) margins, we examine their synchronous sedimentological evolution during the Younger Dryas (YD). We apply a detailed multi-proxy analysis, which includes physical properties, sediment composition, O and C stable isotopes in foraminifera, and both planktonic and benthic foraminifera species and ecological assemblages. We seek to bound the ecological and environmental conditions playing during the YD´ formation of these specific contouritic sediments by relating geochemistry, biology and water dynamics in order to define a pattern of deposition. In the end, we trace in common water masses involved in the formation of the YD contourites in either sides of the Gulf of Cadiz. While the northern branch of the Mediterranean Outflow Water (MOW) is widely assumed to be responsible for the thick contourite depositional systems found along the Iberian margin, the currents originating the contouritic drifts found in the Moroccan margin are less established. A conceptual model of the detailed characterization of a single contourite is proposed here, contributing to interpret contourite depositional systems.