Chemical composition of Fe-Mn manifestations from the Laptev Sea

• Main Authors: Kalyagin, A N, Tishchenko, P Ya, Gukov, Aleksander Yu, Volkova, T L, Kurilenko, L N, Chichkin, R V
• Format: Dataset
• Language: English
• Published: PANGAEA 2001
• Subjects: Aluminium oxide; Archive of Ocean Data; ARCOD; Atomic absorption spectrometry (AAS); Calcium oxide; Chromium; Cobalt; Copper; Dunay-97-01; Dunay-97-02; Dunay-97-03; Dunay-97-04; Dunay-97-05; Dunay-97-06; Dunay-97-07; Dunay-97-08; Dunay-97-09; Dunay-97-10; Dunay-97-11; Dunay-97-12; Dunay-97-13; Dunay-97-14; Dunay-97-15; Dunay-97-16; Dunay-97-17; Dunay-97-18; Dunay-97-19; Dunay-97-20; Dunay-97-21; Dunay-97-22; Dunay-97-23; Dunay-97-24; Dunay-97-25; Dunay-97-26; Dunay-97-27; Event label; Flame emission spectrometer Nippon Jarrell ASH AA-780; Grab; Iron oxide; Fe2O3; Laptev Sea; Latitude of event; Longitude of event; Magnesium oxide; Manganese dioxide; Nickel; Potassium oxide; Sample code/label; Sample type; laptev
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.783313; https://doi.org/10.1594/PANGAEA.783313

In sediments of the Laptev Sea unknown earlier ferromanganese manifestations have been found. On the basis of structural-textural external signs they have been divided to five groups: 1) tube- and spindle-shaped pseudomorphs after and within invertebrates; 2) nuclear and non-nuclear nodules; 3) flagellum- and tube-like skeletons of polychaetes; 4) flat and flattened crustate nodules and crusts; 5) micronodules. All types of ferromanganese manifestations have been sorted in three main genetic series: eigenferrous formations of autochthonous (polychaetes, goethite micronodules) and allochthonous (nuclear nodules) nature; ferromanganese nodules formed under mild hydro-geodynamic conditions at the sediment-seawater geochemical barrier; and ferromanganese manifestations formed under conditions of the variable physico-chemical environment. Ferromanganese manifestations of allochthonous type have signs of littoral zones. They contain both ferrous and ferric iron and have low oxidation degree of manganese in comparison with the autochthonous type manifestations. Manganese minerals with moderate oxidation degree are represented by vernadite and buserite. Such features of iron and manganese indicate different conditions of their formation and occurrence. The main distinctive feature of ferromanganese mineralisation in the Laptev Sea is the redox barrier: the oxidized water layer enriched in oxygen and reduced sediments. This barrier provides favorable conditions for bacterial formation of ferromanganese ores. Understanding of the genesis of ferromanganese manifestations should be found in a study of organic matter reworking by bacteria.