(Table 1) Mn, Fe, TOC and CaCO3 concentrations in bottom sediments and silt waters of Kandalaksha Bay, White Sea ...

• Main Authors: Rozanov, Alexander G, Volkov, Igor I
• Format: Dataset
• Language: English
• Published: PANGAEA 2009
• Subjects: Event label; Method comment; DEPTH, sediment/rock; Depth, top/min; Depth, bottom/max; Lithology/composition/facies; Iron; Iron II, ferrous iron; Iron III, ferric iron; Iron 2+; Iron, total; Manganese; Carbon, organic, total; Calcium carbonate; Water content, wet mass; Grab; Multiple investigations; Carbon analyser AN-7529, 7560; Ekolog-2002; PSh55; Ekolog; Professor Shtokman; Archive of Ocean Data ARCOD; White Sea
• Online Access: https://dx.doi.org/10.1594/pangaea.792621; https://doi.pangaea.de/10.1594/PANGAEA.792621

The redox stratification of bottom sediments in Kandalaksha Bay, White Sea, is characterized by elevated concentrations of Mn (3-5%) and Fe (7.5%) in the uppermost layer, which is two orders of magnitude and one and a half times, respectively, higher than the average concentrations of these elements in the Earth's crust. The high concentrations of organic matter (Corg = 1-2%) in these sediments cannot maintain (because of its low reaction activity) the sulfate-reducing process (the concentration of sulfide Fe is no higher than 0.6%). The clearest manifestation of diagenesis is the extremely high Mn2+ concentration in the silt water (>500 µM), which causes its flux into the bottom water, oxidation in contact with oxygen, and the synthesis of MnO2 oxy-hydroxide enriching the surface layer of the sediments. Such migrations are much less typical of Fe. Upon oxygen exhaustion in the uppermost layer of the sediments, the synthesized oxyhydroxides (MnO2 and FeOOH) serve as oxidizers of organic matter during ... : Supplement to: Rozanov, Alexander G; Volkov, Igor I (2009): Bottom sediments of Kandalaksha Bay in the White Sea: the phenomenon of Mn. Geochemistry International, 47(10), 1004-1020 ...