The influence of tectonic, climate and ocean circulation on sediment transport and deposition in the western South Atlantic during the past 60 mill years

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Tectonic events and modifications in climate have a direct (e.g. supply of sediment via erosion, increase of primary production) and indirect (e.g. opening/closure of gateways and hence modification of oceanic circulation, feedback on climate via uplift/subsidence) influence on sediment deposition. The study of sedimentary features at the continental margin thus provides valuable information on the regional tectonic and climatic evolution. We aim at resolving modifications in climate and oceanographic circulation at the Argentine continental margin, which result from variations in both climatic (e.g. Antarctic ice sheet formation, Mid Miocene Climate Optimum MMCO, etc.) and tectonic (rise of the Andes with its feedback on climate, emplacement of the Rio Grande Rise, opening of Drake Passage, closure of Central American Seaway CAS) processes. Sedimentary material provided amongst others by the rising Andes is deposited partly in the South Atlantic basins formed on the shelf and partly directly on the slope, rise and in the deep sea, where it is picked-up by oceanic currents, which represent an important element of the global thermohaline circulation. The deposited material represents an archive of the interplay of down-slope and along-slope sediment transport. Via the analysis of seismic data we will gain information on sediment flux from the continent into the ocean and variations in the oceanic circulation allowing conclusions on modifications in climate.The project proposed here forms a strong link to proposal 'Long-term evolution of northern Argentine-Uruguay continental margin: implications on the sediment input history of Rio de la Plata River and hydrocarbon generation and leakage' by Anka et al., which will tackle questions related to onshore-offshore basin dynamics.