The high-supply, current-dominated continental margin of southeastern South America during the late Quaternary

Autor(es)

Lantzsch, Hendrik ^{[1, 2]} ; Hanebuth, Till J. J. ^[1] ; Chiessi, Cristiano M. ^[3] ; Schwenk, Tilmann ^{[1, 2]} ; Violante, Roberto A. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Bremen, MARUM Ctr Marine Environm Sci, D-28334 Bremen - Germany

^[2] Univ Bremen, Fac Geosci, D-28334 Bremen - Germany

^[3] Univ Sao Paulo, Sch Arts Sci & Humanities, BR-05508 Sao Paulo - Brazil

^[4] Serv Hidrog Naval, Buenos Aires, DF - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Quaternary Research; v. 81, n. 2, p. 339-354, MAR 2014.
• Citações Web of Science: 23

Resumo

The continental margin off the La Plata Estuary (SE South America) is characterized by high fluvial sediment supply and strong ocean currents. High-resolution sediment-acoustic data combined with sedimentary facies analysis, AMS-C-14 ages, and neodymium isotopic data allowed us to reconstruct late Quaternary sedimentary dynamics in relation to the two major sediment sources, the La Plata Estuary and the Argentine margin. Sediments from these two provinces show completely different dispersal patterns. We show that the northward-trending La Plata paleo-valley was the sole transit path for the huge volumes of fluvial material during lower sea levels. In contrast, material from the Argentine margin sector was transported northwards by the strong current system. Despite the large sediment volumes supplied by both sources, wide parts of the shelf were characterized by either persistent non-deposition or local short-term depocenter formation. The location and formation history of these depocenters were primarily controlled by the interplay of sea level with current strength and local morphology. The high sediment supply was of secondary importance to the stratigraphic construction, though locally resulting in high sedimentation rates. Thus, the shelf system off the La Plata Estuary can be considered as a hydrodynamic-controlled end-member. (c) 2014 University of Washington. Published by Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 12/17517-3 - Resposta da porção oeste do Oceano Atlântico às mudanças na circulação meridional do Atlântico: variabilidade milenar a sazonal
• Beneficiário: Cristiano Mazur Chiessi
• Linha de fomento: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Jovens Pesquisadores
• Processo FAPESP: 10/09983-9 - Mudanças na temperatura da superfície do mar no oeste do Atlântico Sul e variabilidade na precipitação no sudeste da América do Sul desde o Último Máximo Glacial
• Beneficiário: Cristiano Mazur Chiessi
• Linha de fomento: Auxílio à Pesquisa - Regular