Tectonic control on the stratigraphic framework of Late Pleistocene and Holocene deposits in Marajó Island, State of Pará, eastern Amazonia

Autor(es)

Rossetti, Dilce F. ^[1]

Afiliação do(s) autor(es)

^[1] Inst Nacl Pesquisas Espaciais, OBT DSR, BR-12245970 Sao Jose Dos Campos - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Anais da Academia Brasileira de Ciências; v. 82, n. 2, p. 439-449, JUN 2010.
• Citações Web of Science: 9

Resumo

The traditional view that the Brazilian Amazonia is located in a tectonically stable area since the Cretaceous is changing in front of the increasing documentation of fault reactivations even during the Holocene. How the sedimentary record has responded to these events is an issue that remains to be approached with basis on field data. This work focuses on the stratigraphic correlation of late Quaternary deposits from eastern Marajó Island, with the goal of demonstrating the role of fault reactivation on the origin and preservation of these deposits. Despite the location in a stable platform of a continental passive margin, three studied stratigraphic units display significant vertical offsets that define two depocenters that are better explained through tectonic displacements. This interpretation is reinforced by several morphostructural features related to faults that occur between the studied drills. Without the influence of tectonics, sediment preservation in this characteristically low-lying terrain would have been negligible. The results of the present work motivate to look for other tectonically-influenced areas in Amazonia, which similarly might have acted as sites for sediment accommodation during the late Quaternary. These sedimentary records have great potential to be the source of valuable information for reconstructing Quaternary geological events in Northern Brazil. (AU)

• Processo FAPESP: 04/15518-6 - Integração de dados biológicos e geológicos no Baixo Tocantins-Ilha do Marajó: chave na análise da biodiversidade
• Beneficiário: Dilce de Fátima Rossetti
• Modalidade de apoio: Auxílio à Pesquisa - Regular