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	Provedor de dados OMA (3) Autor Chesselet, R. (3) Dehairs, F.A. (3) Bernard, P. (1) Goeyens, L. (1) Goyet, C. (1) Jedwab, J. (1) Lambert, C.E. (1) Poisson, A. (1) Risler, N. (1) Stroobants, N. (1) Mais... Palavra-chave Barite (1) Barite Barium Suspended inorganic matter MED (1) Barite Oxygen PS (1) Barium (1) Southern Ocean (1) Western Mediterranean (1) Mais... Tipo do documento Info:eu-repo/semantics/article (3) Ano 1990 (1) 1987 (1) 1980 (1) País Belgium (3) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última Discrete suspended particles of barite and the barium cycle in the open ocean OMA Dehairs, F.A.; Chesselet, R.; Jedwab, J.. Barite particles are a universal component of suspended matter in the Atlantic and Pacific Oceans. This is demonstrated by scanning electron microscope and electron microprobe analyses of samples collected during the GEOSECS program. These discrete particles, about 1 µm in diameter, account for by far the greatest part of the total particulate barium of most of the filters collected at different depths. Total particulate barium (mean value: 20 ng/kg seawater) was measured on the same filters by instrumental neutron activation analysis.Several observations indicate that biochemical, rather than purely chemical, processes are involved in the formation of the BaSO4 mineral in the water column. Sr/Ba molar ratios among the individual barite grains,... Tipo: Info:eu-repo/semantics/article Palavras-chave: Barite; Barium. Ano: 1980 URL: http://www.vliz.be/imisdocs/publications/228699.pdf On suspended barite and the oxygen minimum in the Southern Ocean OMA Dehairs, F.A.; Goeyens, L.; Stroobants, N.; Bernard, P.; Goyet, C.; Poisson, A.; Chesselet, R.. Particulate Ba profiles were measured in the Indian sector of the southern ocean. The largest fraction (>80%) of this barium is present as barite microcrystals. The profiles of total barium are characterized by a subsurface maximum between 200 and 500 m depth in the vicinity of the oxygen minimum. Highest barium values are found just south of the Polar Front, while lowest values occur close to the Antarctic Divergence. Between the divergence and the Polar front a tight inverse relationship is observed between oxygen in the oxygen minimum and barium in the barium maximum. This relationship disappears north of the Polar Front. Since suspended barite is known to be of biological origin, the correlation of barite with oxygen suggests that the observed... Tipo: Info:eu-repo/semantics/article Palavras-chave: Barite Oxygen PS; Southern Ocean. Ano: 1990 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3076 The biological production of marine suspended barite and the barium cycle in the Western Mediterranean Sea OMA Dehairs, F.A.; Lambert, C.E.; Chesselet, R.; Risler, N.. Suspended particulate barium was measured in the Western Mediterranean along 4 profiles sampled during the PHYCEMED 1 cruise in 1981. The non-terrigenous fraction of particulate barium (i.e. excess Ba; Ba<sub>xs</sub>) can account for up to 96 % of the total barium. This fraction follows the barite settling and dissolution rate model we described earlier for the Atlantic Ocean, conforming barite as the carrier of excess barium. We propose that these Ba<sub>xs</sub> concentrations, which are higher in the Western Mediterranean than in the overall Atlantic, may represent an adaptation of the microplankton to the high densities and density gradients of surface Mediterranean waters. A mass-balance for Ba in the Mediterranean Sea shows:... Tipo: Info:eu-repo/semantics/article Palavras-chave: Barite Barium Suspended inorganic matter MED; Western Mediterranean. Ano: 1987 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3253 Registros recuperados: 3 Primeira ... 1 ... Última

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