944 resultados para Underwater archaeology
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n.s. no.4(1981)
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no.34(1940)
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n.s. no.6(1983)
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no.36(1945)
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n.s. no.5(1982)
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v.36:no.5(1950)
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Mineralogy and geochemistry of low-temperature hydrothermal manifestations occurring on the surface of basalts and in their cracks within a submarine volcano in the north-eastern part of the Kuril deep-sea basin have been studied. The following order of isolation of mineral phases has been found out: Fe-rich sulphides (pyrite) - Fe-rich layered silicates (hydromica of celadonite-nontronite type) - amorphous silica (opal) - Fe-oxyhydroxides (goethite) - Mn-oxyhydroxides (vernadite). Sulphide mineralization is of the phenocryst-stockwork type. Finding of pure barite fragments does not exclude presence of hydrothermal exhalations (smokers) on this volcanic structure.