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| Marchand, Cyril; Lallier Verges, E; Baltzer, F; Alberic, P; Cossa, Daniel; Baillif, P. |
| The accumulation of nine heavy metals in fine-grained sediments from the mangrove fringed coast of French Guiana is evaluated. The dynamic features of the South American tropical coastline, from the Amazon to the Orinoco Rivers, result in mangrove sediments being alternately submitted to phases of erosion and net sedimentation a few tens of years long. This process influences the distribution of the heavy metals associated with these frequently re-mobilized deposits. Sedimentary cores and mangrove plant samples were collected, at different seasons, in various swamps characterized by different properties (content of sedimentary organic matter, distance from sea water and fresh water). The ranges of measured concentrations expressed in mu mol g(-1) were the... |
| Tipo: Text |
Palavras-chave: French Guiana; Mangrove; Fe/Mn cycling; Heavy metals. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-1041.pdf |
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| Daumas, R; Alberic, P; Brault, M; Khripounoff, A; Hermin, M-n; Marty, J-c; Saliot, A. |
| Organic matter present in seawater was investigated in various samples collected in an active hydrothermal site of the East Pacific Rise (EPR) near 13 degree N. During three dives of the submersible Cyana, sampling was carried out at the mouth of active chimneys and near animal communities (Alvinellinae, Pogonophora and Serpulidae). The organic C and total N content of particulate material are higher than the mean concentrations of deep water; combined amino-acids do not show a comparative augmentation, but fatty acids and hydrocarbons are higher in the vicinities of Alvinellinae and Pogonophora than in reference samples or near Serpulidae zones. It is suggested that simultaneous determination of the concentrations of organic substances and bacterial... |
| Tipo: Text |
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| Ano: 1988 |
URL: http://archimer.ifremer.fr/doc/00267/37787/35868.pdf |
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| Lallier-verges, E; Alberic, P. |
| Optical (palynofacies) and geochemical (C, N, amino acids) study of surface sediments from the Equatorial North Pacific Ocean, which are deposited in an oxic environment and characterized by ferromanganese nodule occurrence, revealed figured remains of pelagic, benthic and terrestrial organic matter. These organic remains consist of a residual organic fraction, related to alteration phenomena. The scarcity of amorphous organic matter contrasts markedly with anoxic sediments. Amino acid comparison between hand-picked figured organic elements and bulk sediments indicates that coarse components have distinct compositions, some being biologically active sites; the preserved amino acid content of bulk sediments being mostly related to fine fractions as clays. |
| Tipo: Text |
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| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37901/35982.pdf |
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