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Studies on Baltik Sea manganese nodules have been a subject of great interest to mineralogists, sedimentalogists and metallurgists. These shallow sea iron- manganese nodules are potentially a promising source of many useful metals such as manganese and iron and specially Ni, Co, Cu, etc.
Manganous oxide is one of the most widespread and practically important objects, in formation and transformation of which microorganisms play an active role. Manganous oxide is characterized by the joint presence of both well crystallize modifications, and fine phases with the lowest order strength (with the contents of roehtgenoamorphous component till 50 - 60% at significant concentration of ore component). This fact till now has no enough strict scientific explanation. We examined formation of roehtgenoamorphous nano-dimensional manganous oxide from positions of biogenic mineral formation. Objects of our researches were nano-dimensional phases of the iron-mangsnous nodules and manganous residual soil. Electronic-microscopic investigations showed a great expansion of mineralized biofilms on the studied samples. The content of the bacterial mass make (%): MnO - 28.34; Fe2O3 - 17.14; SiO2 - 7.11; CaO - 2.41; TiO2 - 1.90; Na2O - 1.74; Al2O3 - 1.73; MgO - 1.30; P2O5 - 1.25; SO3 - 1.25; CoO - 0.68; CuO - 0.54; NiO - 0.53; K2O - 0.50.
Another development of a bacteria factor during formation of manganous oxide is occurrence of fossilized cyanobacterial mat with the content (%): MnO - 48.35; Fe2O3 - 6.23; MgO - 8.76; Al2O3 - 5.05; SiO2 - 4.45; NiO - 3.63; Na2O - 2.30; CuO - 2.19; CaO - 1.31; K2O - 0.68. The use atomic-force microscopy method allows determining size of some cells of cyanobacteria with the 200nm at length and about 70nm across diameter. Electronic- microscopic investigations showed that the phase data is a mineralized glycocalix, composed of nanodimensional flakes of todorokite.
Inclusions of native metals (copper, iron, zinc) with the size from 10 to 20 n were found in the ore areas of ferromanganese nodules as well as manganese-bearing crusts of weathering. Formation of the native metals can be explained by an accumulation of organic matter as a result of formation of microscopic areas with abrupt recovery conditions.
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