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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Paleoproductivity changes during the Late Quaternary in the southeastern Brazilian upper continental margin of the Southwestern Atlantic

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Author(s):
Renata Hanae Nagai [1] ; Silvia Helena de Mello e Sousa [2] ; Rafael André Lourenço [3] ; Márcia Caruso Bícego [4] ; Michel Michaelovitch de Mahiques [5]
Total Authors: 5
Affiliation:
[1] Universidade de São Paulo. Instituto Oceanográfico. Programa de Pós-graduação em Oceanografia Química e Geológica - Brasil
[2] Universidade de São Paulo. Instituto Oceanográfico. Departamento de Oceanografia Física, Química e Geológica - Brasil
[3] Universidade de São Paulo. Instituto Oceanográfico. Programa de Pós-graduação em Oceanografia Química e Geológica - Brasil
[4] Universidade de São Paulo. Instituto Oceanográfico. Departamento de Oceanografia Física, Química e Geológica - Brasil
[5] Universidade de São Paulo. Instituto Oceanográfico. Departamento de Oceanografia Física, Química e Geológica - Brasil
Total Affiliations: 5
Document type: Journal article
Source: Brazilian Journal of Oceanography; v. 58, p. 31-41, 2010-00-00.
Abstract

Changes in the Brazilian continental margins oceanic productivity and circulation over the last 27,000 years were reconstructed based on sedimentological and microfaunal analyses. Our results suggest that oceanic paleoproductivity and the supply of terrigenous sediments to the Brazilian continental margin were higher during the Last Glacial Maximum (LGM) than during the Holocene. These changes may have been primarily influenced by significant sea level fluctuations that have occurred since the late Pleistocene. During the LGM, the lower sea level, higher productivity and lower sea-surface paleotemperatures may have been the result of the offshore displacement of the main flow of the Brazil Current. However, during the Holocene, the warm waters of the Brazil Current were displaced toward the coast. This displacement contributed to the increase in water temperature and prevented an increase in oceanic productivity. The decrease in terrigenous supply since the LGM could be related to the increase of the extension of the continental shelf and/or drier climatic conditions. (AU)