FEATURES OF THE COMPOSITION AND STRUCTURAL TRANSFORMATIONS OF MANGANESE MINERALS OF THE BOL’SHOE MIASSOVO LAKE (SOUTH URAL)
N.A. Palchik, T.N. Moroz, T.N. Grigorieva
Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: структура, химический состав, свойства, марганцевые минералы, воздействие температур, рентгенография, ИК спектроскопия, structure, chemical composition, properties, manganese minerals, temperature effect, X-ray diffraction, IR spectroscopy
Abstract
The mineral and microelement composition of natural manganese minerals from iron-manganese concretions of the Bol’shoe Miassovo lake (South Ural) is investigated. The structural transformations of the samples under the effect of different temperatures are studied. Apart from layered 9.6 Å and 7.2 Å structures of manganese minerals the lake samples often contain various manganese-containing carbonates. For carbonate minerals by IR spectroscopy the dependence of the wavenumbers of n
2 and n
4 vibrations of the СО
3 group on the mineral composition is analyzed. The composition of macro- and microelements of iron-manganese concretions of Bol’shoe Miassovo lake varies in wide ranges not only in different samples, but also in different parts of the same sample. An analysis of the microstructure of lake manganese concretions revealed their biomorphic nature that is exhibited in globe-shaped to filament organic bacterial forms.
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