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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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| Bertrand, P; Pedersen, Tf; Schneider, R; Shimmield, G; Lallier-verges, E; Disnar, Jr; Massias, D; Villanueva, J; Tribovillard, N; Huc, Ay; Giraud, X; Pierre, C; Venec-peyre, Mt. |
| Sediments on the Namibian Margin in the SE Atlantic between water depths of similar to1000 and similar to3600 m are highly enriched in hydrocarbon-prone organic matter. Such sedimentation has occurred for more than 2 million years and is geographically distributed over hundreds of kilometers along the margin, so that the sediments of this region contain a huge concentrated stock of organic carbon. It is shown here that most of the variability in organic content is due to relative dilution by buried carbonates. This reflects both export productivity and diagenetic dissolution, not differences in either water column or bottom water anoxia and related enhanced preservation of organic matter. These observations offer a new mechanism for the formation of... |
| Tipo: Text |
Palavras-chave: Petroleum source rocks; Coastal upwelling; Deep-sea sediments; Quaternary climate; Southwestern African Margin. |
| Ano: 2003 |
URL: https://archimer.ifremer.fr/doc/00224/33553/31977.pdf |
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