Data/hora: 12/06/2024 13:50:18

Provedor de dados: | Institutional Archive of Ifreme (ArchiMer)
País: | France

Título:

Transformation de la phase solide à travers l’estuaire de la Loire en relation avec son environnement chimique et biologique

Solid phase transformations through Loire Estuary in relations to chemical and biological environment

Autores: | Thibault De Chanvalon, Aubin.
Data: | 2016-03-25
Ano: | 2016
Palavras-chave: | Estuaire; Fer; Phosphore; Nitrate; Foraminifère benthique; Diagenèse précoce; Loire; Bioturbation; Estuary; Iron; Phosphorus; Nitrate; Benthic foraminifera; Precocious diagenesis; Loire; Bioturbation.
Resumo: | Before reaching the ocean, riverine particles from the Loire watershed undergo important chemical transformations in the estuary. This study aims to identify and characterize main processes involving iron (and to a lesser extent Al, Mn, PO4 3- and rare earths elements). Suspended particulate matter data show that 15% of their iron is lost through the estuary. Reductive iron dissolution during deposition periods is likely to explain most of this loss. However, estuarine sediments are characterized by high spatial heterogeneity due to macrofaunal activities. To overcome this difficulty, new methodologies of high resolution and two-dimensional analyses and calculation of pore water, sediment and benthic meiofauna were developed. These developments enable to estimate the impact of macrofaunal activity to 80% of dissolved iron export from sediment towards water column, and a total flux of 0.5 mmol m-2 d-1. Such kinetics requires a 10-year of residence time of particles within the sediment in order to match to observed iron loss on suspended particles. This time is much longer than the mean particle residence time in the estuary. Therefore, sediment reactivity over a larger surface that stretches to the external mudflats has to be taken into account to explain transformation of solid iron through the estuary.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00498/60932/64325.pdf

https://archimer.ifremer.fr/doc/00498/60932/

Editor: | Université de Nantes
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

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