Beschreibung:
Marine Sedimentology, Palaeoceanography, Shelf dynamics, Shelf export, Northwest Iberia, Southeast South America. - The continental shelf and slope are among the most dynamic sedimentary and oceanographic environments on Earth, strongly influenced by processes within the terrestrial and marine realm. The shelf break, geographically separating the two areas, marks one of the major physiographic transitions on Earth. The oceanographic and sedimentary processes that lead sediments across this boundary represent the dynamic link between both sedimentary systems. With a multi-proxy approach, this thesis tries to elucidate i) how strong sedimentary and (palae)oceanographic processes modify the primary shelf export signal, ii) if sedimentary records from the slope can be used as reliable archives for reconstructing sedimentary and paleoceanographic shelf dynamics, and iii) how important the local morphology is, in influencing shelf sediment export routes, transport process and/or the creation of depocentres on the slope. The key study areas of this thesis cover two different continental slope settings, the lower sloperegion (off Northwest Iberia) and the uppermost slope (off Uruguay). Off Northwest Iberia, based on high frequency sediment echo-sounding profiles and a large sediment core data set the late Pleistocene sedimentary history of the shelf system, as well as the detailed late Holocene evolution of fluviogenic depocentres on the middle shelf was revealed during the beginning of this thesis. Detailed knowledge of the late Pleistocene shelf sedimentary patterns enables the differentiation of local shelf export signals from over-regional palaeoceanographic signals within the sedimentary patterns at the Northwest Iberian slope. Applying this knowledge, multi-proxy investigation of three slope records off Northwest Iberia reveal the interplay of slope morphology as well as palaeoclimatic effects on shelf slope sediment dynamics and depositional patterns during the late Quaternary. At the uppermost slope off Uruguay a small morphologic terrace represents a further type of external archives for the effective and direct recording of shelf sediment export. Contrasting the regional morpho-sedimentary structure of the Southeast South American continental margin, the uppermost slope terrace off Uruguay is not influenced by contouritic sediment transport. Instead, sediment dynamics on the terrace are directly linked to the sedimentary shelf configuration, which is strongly controlled by sea-level rise during the Holocene. Very highsedimentation rates on the terrace (at least approx. 50 cm/kyr) enable the application of ...