Thesis objectives 3 Introduction 5 15 43 67 87 Conclusions Bibliography Resumen 121 Conclusiones Appendices Acknowledgements 167 Scientific publications Chapter 1 Evidence of early bottom water current flow after the Messinian Salinity Crisis in the Gulf of Cadiz. Chapter 2 Sedimentary cycles and oceanographic circulation under the influence of MOW over the Miocene-Pliocene boundary in the Gulf of Cadiz. Chapter 3 Controls on authigenic Nd and Pb isotope in Gulf of Cadiz sediments over the Miocene-Pliocene boundary. Chapter 4 Improved biostratigraphic dating of upper Miocene sediments in the western Betics suggests late Tortonian closure of the Guadalhorce Corridor. I. Objectives of MEDGATE. II. Evolution of the Gulf of Cadiz margin and southwest Portugal contourite depositional system: Tectonic, sedimentary and paleoceanographic implications from IODP expedition 339.