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The sea-level highstand correlated to marine isotope stage (MIS) 7 in the coastal plain of the state of Rio Grande do Sul, Brazil
- Source :
- Anais da Academia Brasileira de Ciências, Vol 86, Iss 4, Pp 1573-1595 (2014)
- Publication Year :
- 2014
- Publisher :
- Academia Brasileira de Ciências, 2014.
-
Abstract
- The coastal plain of the state of Rio Grande do Sul, in southern Brazil, includes four barrier-lagoon depositional systems formed by successive Quaternary sea-level highstands that were correlated to marine isotope stages (MIS) 11, 9, 5 and 1, despite the scarcity of absolute ages. This study describes a sea-level highstand older than MIS 5, based on the stratigraphy, ages and fossils of the shallow marine facies found in coastal barrier (Barrier II). This facies outcrops along the banks of Chuí Creek, it is composed of fine, well-sorted quartz sand and contains ichnofossils Ophiomorpha nodosa and Rosselia sp., and molluscan shells. The sedimentary record indicates coastal aggradation followed by sea-level fall and progradation of the coastline. Thermoluminescence (TL) and electron spin resonance (ESR) ages from sediments and fossil shells point to an age of ∼220 ka for the end of this marine transgression, thus correlating it to MIS 7 (substage 7e). Altimetric data point to a maximum amplitude of about 10 meters above present-day mean sea-level, but tectonic processes may be involved. Paleoceanographic conditions at the time of the highstand and correlations with other deposits in the Brazilian coasts are also discussed.
- Subjects :
- Barreira II
Arroio Chuí
MIS 7
Pleistoceno
Paleoceanografia
Science
Subjects
Details
- Language :
- English
- ISSN :
- 16782690 and 00013765
- Volume :
- 86
- Issue :
- 4
- Database :
- Directory of Open Access Journals
- Journal :
- Anais da Academia Brasileira de Ciências
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.746b790cb7c44ecaa22d8c9bebad6f19
- Document Type :
- article
- Full Text :
- https://doi.org/10.1590/0001-3765201420130274