Title
Mineral and elemental indicators of post-glacial changes in sediment delivery and deposition under a western boundary upwelling system (Cabo Frio, southeastern Brazil)
Date Issued
01 March 2016
Access level
metadata only access
Resource Type
journal article
Author(s)
Albuquerque A.L.
Meyers P.
Belem A.L.
Siffedine A.
Capilla R.
Research Institute Development
Universidad Federal Fluminense
Publisher(s)
Elsevier B.V.
Abstract
Minerals and elements are important proxies that can provide information about variations in the delivery and deposition of coastal ocean sediments associated with past climate changes. In this study, postglacial changes in the accumulation of sediments on the upper shelf of southeastern Brazil are linked to the evolution of regional paleoceanographic and continental paleoclimatic conditions during the last 14.4kyr CAL BP. Mineralogical and major and trace element analyses of a 14C-dated sediment core identify three main lithostratigraphic units of this core that reveal a succession of changes in sediment delivery and accumulation as postglacial sea level rose and Holocene climate on land evolved. The depositional setting has transitioned in response to the large sea level rise prior to 9.9kyr CAL BP from being a shallow water high energy environment to a deeper water one. This location has since then been a lower energy environment that has persisted into modern times. Due to the high marine productivity associated with the Cabo Frio upwelling system in an oxygenated water column, the sediments have shown a complex and dynamic redox condition, making variations in redox-sensitive trace elements indicative of changes in primary production and organic matter diagenesis at this location. After sea level stabilized ~9kyr CAL BP, variations in fluxes of Al, Fe, Ca, and minerals were small, indicating that climate driven changes had only secondary controls on delivery of detrital sediment components to the Cabo Frio shelf. Modern coastal upwelling conditions and the onset of mid-shelf organic-rich sediment deposition were established after 9.9CAL kyr BP.
Start page
72
End page
82
Volume
445
Language
English
OCDE Knowledge area
Mineralogía Oceanografía, Hidrología, Recursos hídricos
Scopus EID
2-s2.0-84954478344
Source
Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN of the container
00310182
Sponsor(s)
This study was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico ( CNPq ) and the “Institut de Recherche pour le Développement ( IRD France)” — LMI-PALEOTRACES, the Geochemistry Network of PETROBRAS/CENPES and the Brazilian National Petroleum and the Biofuels Agency ( ANP ) (Grant 0050.004388.08.9 ). Albuquerque is senior scholar from CNPq (Grant 306385/2013-9 ). We thank Prof. Joel Blum for his thoughtful comments on an earlier version of this contribution. We are also grateful to two anonymous reviewers for their helpful suggestions that helped us to further improve this paper.
Sources of information: Directorio de Producción Científica Scopus