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| Hoffert, Michel; Karpoff, Anne-marie; Clauer, Norbert; Schaaf, André; Courtois, Chantal; Pautot, Guy. |
| A sedimentological, biostratigraphical, mineralogical, geochemical (major and trace elements including rare earths) and isotopic (Rb/Sr) study was made of core samples drilled between the Touamotou Archipelago and the Marquises Islands. This structurally complex region of the South Pacific is characterised by volcanism and deep ocean water circulation. The samples consisted of two 20 cm cores of surface sediment, and a flattened nodule with indurated centre, taken close to the cores. One core sample (T KR 07) is entirely composed of brown, soft sediment. The top part of the second core (T KS 19) is also brown mud but the bottom is indurated. The brown sediment is essentially composed of phillipsite, palagonite. micronodules and nontronite. The indurated... |
| Tipo: Text |
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| Ano: 1978 |
URL: http://archimer.ifremer.fr/doc/1978/publication-5231.pdf |
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| Hoffert, Michel; Karpoff, Anne Marie; Schaaf, André; Pautot, Guy. |
| A sedimentological, mineralogial and geochemical study was made on surface sediment samples associated with nodules in the Tiki Basin (Central South Pacific). The aim of this study was to find variations in the sediment composition with respect to bathymetry and to thus show a relationship between nodule formation and sedimentation. It is now well known that nodules rich, from an economical point of view, are located in this area at a depth more than 4100 meters. The progressive transformation of a carbonate ooze rich in Foraminifera and poor in siliceous biogenic material into a metalifferous sediment has been shown. The CaCO(3), dissolution involves Fe and Mn enrichment of the sediment. The content of these elements becomes stable and independant of... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-5315.pdf |
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| Pautot, Guy; Hoffert, Michel; Karpoff, Anne Marie; Schaaf, André. |
| The Tiki basin is in the south central Pacific, south of the Marquesas Islands and east of the Tuamotu archipelago. It is bounded nothwards by the Marquesas Fracture Zone and divided in two parts by the topographic heights cunstituting the end to the Tuamotu Fracture Zone. One hundred stations with nodule sampling were occupied by the Group CNEXO-SLN in this area (scale 1O X 10 degrees). The nodule abundance at each station is determined from the weight of nodules brought back by free fall grabs. Chemical analysis were made on each sample (three by station) and the values presented here are the mean values. The parameters : abundance, Ni grade, Cu grade and Mn grade are compared with water depth and topographic features of the area. The main results are :... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1981 |
URL: http://archimer.ifremer.fr/doc/1981/publication-5307.pdf |
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