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Перевод: siderite

[существительное]
сидерит

Тезаурус:

1. Nodular concretions of intimately mixed siderite and FeS are growing within sulphide-rich, Recent, salt-marsh sediments on the coast of Norfolk, UK.
2. Mineral cements are mainly ferroan dolomite, siderite, quartz and calcite.
3. This makes them uniquely suitable for investigations into the actual mechanisms of siderite concretion formation.
4. The host mud around the concretions contain FeS but little siderite.
5. However, the siderite concretions in the marsh have C values averaging -5.9 PDB, suggesting that the siderite is not formed under methanogenic conditions.
6. We find that, instead of reducing Fe(III) indirectly through the production of sulphide, some of these bacteria can reduce Fe(III) directly through an enzymatic mechanism, producing siderite rather than iron sulphides.
7. Similarly if haematite or siderite is to be detected the Litho Density Tool (LDT) must be run.
8. Cementing material is described as ferroan dolomite, siderite, ankerite, quartz and calcite (Kelch 1963).
9. The formation of siderite in organic-rich marine mudrocks has previously been associated with the degradation of organic matter by anaerobic, methanogenic bacteria.
10. The presence of siderite (FeCO 3 ) in marine sediments is anomalous, however, as it is unstable in the presence of H 2 S. Previous work has suggested a bacterial origin of siderite.
11. The bulk volume analysis for the fraction larger than 2 m, gave quartz (65-;80%); feldspar (1-;2%); mica (0.5%); kaolinite, well crystallised (0.5-;10%); haematite (1-;3%); siderite (0.5%).
12. Here we describe geochemical and microbiological studies which suggest that contemporary formation of siderite concretions in a salt-marsh sediment results from the activity of sulphate-reducing bacteria.