Data/hora: 16/06/2024 19:37:08

Provedor de dados: | 5
País: | France
Título: | Stable isotopes in deep-sea living (stained) foraminifera from the Mozambique Channel (eastern Africa): multispecies signatures and paleoenvironmental application
Autores: | Fontanier, Christophe; Sakai, Saburo; Toyofuku, Takashi; Garnier, Eline; Brandily, Christophe; Eugene, Thibaut; Deflandre, Bruno.
Data: | 2017-04
Ano: | 2017
Palavras-chave: | Oxygen and carbon isotopes; Deep-sea foraminifera; Organic matter; Oxygenation; Microhabitat.
Resumo: | Oxygen and carbon isotopes (δ18O and δ13C) have been investigated in carbonate tests of deep-sea foraminifera living in the Mozambique Channel (eastern Africa) to understand how environmental constraints (e.g., organic matter, oxygenation) control the intra- and interspecific variability of isotopic signatures. 197 living individuals, including eight different species, from various microhabitats within the sediment were sorted from sediment samples gathered at two stations on the Malagasy upper slope. Results show that the δ18O values of foraminiferal taxa were not controlled by microhabitat pattern. They presented tremendous and intriguing intraspecific variability that is not explained by the classical ontogenetic effect. The δ13C values of infaunal foraminiferal taxa do not show a 1:1 relationship with the bottom water δ13C DIC and do not present a constant offset from it; instead, they appear to be mainly controlled by a microhabitat effect. The lower δ13C values of shallow, intermediate, and deep infaunal taxa at the deeper station compared to those seen at the shallower station reflect the enhanced exportation of sedimentary organic matter at the sediment–water interface, and its related mineralization within the upper sediments. The ∆δ13C between shallow/very shallow infaunal species (i.e., Hoeglundina elegans, Uvigerina hispida) and intermediate/deep infaunal species (i.e., Melonis barleeanus, Globobulimina barbata) permits insight into (1) the exportation of organic matter to the seafloor and (2) the various degradation pathways for organic detritus in the benthic environments off NW Madagascar.
Tipo: | Text
Idioma: | Inglês

Identificador:

http://archimer.ifremer.fr/doc/00357/46831/46979.pdf

DOI:10.1007/s10872-016-0401-1

http://archimer.ifremer.fr/doc/00357/46831/

Editor: | Springer
Formato: | application/pdf
Fonte: | Journal Of Oceanography (0916-8370) (Springer), 2017-04 , Vol. 73 , N. 2 , P. 259-275

Fonte:

The Oceanographic Society of Japan and Springer Japan 2016

info:eu-repo/semantics/openAccess

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