On the geochemistry of the ferriginous concretions of the Barents Sea
The contents of Fe, Mn, Al, P, and the rare-earth elements (REE) in ferriginous concretions and enclosing sediments of the eastern part of the Barents Sea were studied. A direct Fe-P correlation in reactive components of the sediments and concretions was found. The concretions were shown to be forme...
| Main Authors: | , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2001
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| Subjects: | |
| Online Access: | http://hdl.handle.net/21.11116/0000-0004-3F8A-B http://hdl.handle.net/21.11116/0000-0004-3F8C-9 |
| Summary: | The contents of Fe, Mn, Al, P, and the rare-earth elements (REE) in ferriginous concretions and enclosing sediments of the eastern part of the Barents Sea were studied. A direct Fe-P correlation in reactive components of the sediments and concretions was found. The concretions were shown to be formed through Fe(II) oxidation in the surface layer of the sediments and cementation of the sediment terrigenous fraction by Fe(III) oxyhydroxides. The latter accumulate phosphorus due to the processes of sorption-coprecipitation, by forming Fe(III) hydrophosphates. The REE composition in sediments and concretions normalized with respect to shale is characterized by an increased proportion of light REE, which may be caused by the regional features of the sources of supply. Due to the significant share of terrigenous matter in the Fe concretions (up to 65% for Nd), the REE composition of the bulk samples is similar to that of enclosing sediments. The negative cerium anomaly in the composition of reactive REE appears as the result of the effect of the REE sorbed from seawater. The ferriginous crust features REE bulk composition closer to that of seawater than the composition of ferriginous concretions from the sediments because of an essentially smaller content of the diluent terrigenous matter. |
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