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| Registros recuperados: 10 | |
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| Pujos, M; Griboulard, R; Latouche, C; Meidinger, P. |
| The continental shelf is very narrow and steep to the north, and broader to the South. This shelf is structuraly influenced by the Andes. This area is mainly covered with terrigenous deposits, i.e. muds and sands which are recent on the internal shelf and relict on the external shelf. The sediments, supplied by rivers, reflect the intense erosion of the Andean backland. This erosion can only be reduced in situ by the vegetation cover. Clays are the main component of the fine fraction reaching the sea. Three different clay assemblages are observed: 1) an Andean (illite-chlorite) assemblage, reflecting the proximity of the cordillera; 2) a mid-American assemblage (smectite), which supplies the North Pacific Margin through the Choco counter-current; 3) an... |
| Tipo: Text |
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| Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00097/20862/18480.pdf |
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| Pujos, M; Latouche, C; Maillet, N. |
| Marine muds deposited on the French Guiana coast mostly originate in the Amazon. Recent sediments are composed of (a) illite (33 %) and chlorite (13 %) of Andean mountain origin; and (b) kaolinite (28 %) and smectite (26 %), principally from the Amazonian lowlands but also from the Guiana Shield. In the coastal mud prism, high-resolution seismic profiles, together with sedimentological, micropaleontological and soil engineering studies, supplemented by C-14 dates, permitted a stratigraphic interpretation of eight cores. Three episodes have been determined on the basis of clay-mineral variations related to Amazonian lowland, Andean and Guiana shield sources. The older episodes 3 (3000-1700 y BP) and 2 (1700-1000 y BP) are predominantly characterized by... |
| Tipo: Text |
Palavras-chave: Late quaternary; French Guiana; Shelf; Clay minerals; ENSO. |
| Ano: 1996 |
URL: http://archimer.ifremer.fr/doc/00094/20506/18175.pdf |
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| El Ghobary, H; Latouche, C. |
| The study of metal partition patterns in the tidal flats of the Marennes Oleron Bay shows that the metal partition patterns in the superficial sediments indicate that the major part of the mobile fraction of metals is associated with Fe-Mn oxides. The metal fractions associated with organic matter are relatively small. As depth increases, the decrease of metal reducible fraction is evidence of oxide dissolution under reducing conditions. The increase of metal sulfide-organic fraction with an increasing depth of burial, supports the idea of metal sulfide formations. Calculations show that the total sulfur in the sediments is in excess with respect to iron extracted by the hydrogen peroxide treatment. This assumes the existence of Fe fraction as FeS sub(2)... |
| Tipo: Text |
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| Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/00246/35718/34227.pdf |
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| Latouche, C; Moyes, J. |
| D'un point de vue historique, la distribution des pollutions chimiques dans le milieu marin a été en premier lieu envisagée au niveau des eaux marines. Par la suite, les recherches se sont orientées vers le passage de ces pollutions dans l'échelon biologique. A partir de 1965, le rôle essentiel des matières solides inertes comme support préférentiel de ces composés et notamment des oligo-éléments métalliques dans les milieux fluviatiles estuariens et marins retient l'attention des chercheurs et constitue maintenant un fait universellement reconnu. Par matières solides, il faut entendre aussi bien les dépôts sédimentaires que les matières en suspension. Ainsi, la connaissance de la distribution des oligo-éléments métalliques dans ces environnements implique... |
| Tipo: Text |
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| Ano: 1977 |
URL: http://archimer.ifremer.fr/doc/00066/17692/15197.pdf |
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| Pujos, M; Monente, J; Latouche, C; Maillet, N. |
| The suspended matter transported by the Orinoco to the Orinoco delta originates mainly in the Colombian Andes. The four clayey minerals (kaolinite, chlorite, illite and smectite) are always present in the deltaic suspensions, the delta deposits and the gulf of Paria. Illite contents are always dominant except in those regions of the gulf of Paria situated far from the mouths of the Orinoco tributaries characterized by smectites. In the delta, illite contents which are minimal during the dry season increase noticeably during the wet season which is marked by a high Liquid and particulate matter discharge. In the delta, the clay mineralogy of the substrate is comparable to that of dry season suspensions (February), thus showing a sedimentation composed of... |
| Tipo: Text |
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| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20435/18102.pdf |
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| Latouche, C; Jouanneau, J M; Lapaquellerie, Y; Maillet, N; Weber, O. |
| The southern Biscay shelf is a typical example of a continental margin submitted to a macrotidal regime and the heavy sedimentary fluxes of continental provenance. The aim of this study was to determine the manner in which clay sedimentation is organized on the margin and to evaluate the impact of both river-borne inputs and marine hydrodynamic activity. It was established that the distribution of clay minerals (in the order of frequence: micas, chlorites, illites and smectites) is upset by the interconnection of several sedimentary processes: discontinuous river-borne discharges (richer in smectites); the mixture of newly-arrived material with fine fractions (rich in micas and chlorites) resulting from the reworking of remnant material that represents the... |
| Tipo: Text |
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| Ano: 1991 |
URL: http://archimer.ifremer.fr/doc/00268/37889/35970.pdf |
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| Faugeres, J-c; Gayet, J; Gonthier, E; Latouche, C; Maillet, N. |
| Mineralogical analyses of sediments from the Makassar Strait, collected during the Corindon and Misedor cruises (dredges, piston and box cores) show the existing differences between sediments supplied from Kalimantan in the West and sediments supplied from Sulawesi in the East. The Kalimantan source is characterized by quartzitic sand, with rare feldspars, heavy minerals consisting mainly of pyroxene (hypersthene) and amphibole and predominant illite-kaolinite in the clay mineral assemblage. In contrast, the Sulawesi source differs by a great abundance of feldspars, lithoclasts and micas with predominant amphibole and pyroxene (augite) and major illite-chlorite clay minerals. |
| Tipo: Text |
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| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/00268/37924/36005.pdf |
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| Registros recuperados: 10 | |
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