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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Late Pleistocene-Holocene evolution of the Doce River delta, southeastern Brazil: Implications for the understanding of wave-influenced deltas

Texto completo
Rossetti, Dilce de Fatima [1] ; Polizel, Silvia Palloti [1] ; Lisboa Cohen, Marcelo Cancela [2] ; Ruiz Pessenda, Luiz Carlos [3]
Número total de Autores: 4
Afiliação do(s) autor(es):
[1] Brazilian Inst Space Res INPE, Div Remote Sensing, BR-12245970 Sao Jose Dos Campos, SP - Brazil
[2] Fed Univ Para, Fac Oceanog, BR-66075110 Belem, Para - Brazil
[3] Univ Sao Paulo, Lab 14C, BR-05508 Sao Paulo - Brazil
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: MARINE GEOLOGY; v. 367, p. 171-190, SEP 1 2015.
Citações Web of Science: 16

Brazil's coast displays many wave-influenced deltas that are still incompletely understood, despite their significance for reconstructing the history of Late Pleistocene-Holocene sea-level changes in this region and the potential to advance in the knowledge of wave-influenced deltas. Among them, the Doce River delta is the most expressive, given its larger geographic extension. The present work shows that this is a wave-influenced delta that evolved within the context of Late Pleistocene-Holocene sea-level fluctuations, rather than a mid-Holocene lagoonal delta as proposed elsewhere. The delta had an initial progradation at an OSL age of 132.7 (+/- 9.1) ka after the Marine Isotope Stage (MIS) 5e, which was followed by major progradation between 45,775-49,391 and 29,678-29,226 cal yr BP. Beach ridges/spits formed during these phases were in part destroyed during an ensuing transgression between 8161-7933 and 4974-4850 cal yr BP. The central delta remained dominated by fluvial processes, which kept pace with the rising sea level due to relatively high rainfall in the Doce River drainage basin. The Doce River delta started to grow again after the late-Holocene transgression, a process still on-going at the present time. During this evolution, the Doce River was deflected northward and then southward, a process that did not result in any significant facies change when the updrift and downdrift sides of the river's mouth are compared. Such a pattern is in disagreement with previously proposed asymmetry index models for wave-influenced deltas, which predict an uneven distribution of sandy- or muddy-rich deposits in the updrift and downdrift sides of the river's mouth, respectively. Several other deltas along the Brazilian coast also display facies configuration similar to the Doce River delta or have patterns opposed to those proposed by the asymmetry index models. Based on these analogs, it can be stated that the geometries and fades patterns of wave-dominated deltas are not determined simply by the interplay of fluvial and marine processes. Instead, they can be strongly influenced by the fluvial influx, sea-level changes and/or tectonic reactivations, as it appears to be the case of Brazilian wave-influenced deltas, including the Doce River delta. Such a conclusion calls for a word of caution when applying processes-based facies models to reconstruct wave-influenced deltas in the sedimentary record. (C) 2015 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 09/53988-8 - EMU: aquisição de sistema de datação por luminescência e de microamostrador de precisão, para o estudo de mudanças ambientais no Quaternário
Beneficiário:Paulo César Fonseca Giannini
Linha de fomento: Auxílio à Pesquisa - Programa Equipamentos Multiusuários
Processo FAPESP: 11/00995-7 - Estudos paleoambientais interdisciplinares na costa do Espírito Santo
Beneficiário:Luiz Carlos Ruiz Pessenda
Linha de fomento: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
Processo FAPESP: 07/03615-5 - Reconstrução da vegetação e clima desde o Holoceno médio no Brasil
Beneficiário:Luiz Carlos Ruiz Pessenda
Linha de fomento: Auxílio à Pesquisa - Regular