Composition, origin and evolution of the terrigenous organic matter in the South Continental margin of Brazil along Holocene: use of molecular markers and 13C in specific organic compounds in high resolution sediment cores

Abstract

The marine environment presents the capacity to record the climatic events that occurred on the planet, making it possible to carry out reconstructions of the environmental conditions during certain geological periods. The sediment present in the continental margins is the destination of most of the autochthonous and allochthonous organic material in the oceans, thereby the use of long, continuous and high-resolution sediment records obtained in marine mud deposits can provide information about the biogeochemical processes occurring in the past and how they responded to environmental changes. The South Brazilian Margin, specifically the Rio Grande Cone region, is influenced by the La Plata River Plume Plata and, to a lesser extent, the Patos Lagoon in the organic matter deposited. Due to their high chemical stability, source specificity and low degradability, the variation and distribution of organic molecular markers and ´13C in specific compounds can serve as tools for paleoceanographic and paleoclimatic reconstructions. Considering the above, the present work aims to evaluate the terrigenous contribution to the organic matter deposited in the South Brazilian Margin along the Holocene, evaluating the regional contributions of continental material deposited and its relation to climatic and hydrodynamic events on a regional and global scale. (AU)