Boreskov

BIOGENIC AND ABIOGENIC BIOMORPHIC STRUCTURES IN OCEANICIRON‐MANGANESE CONCRETIONS AND THEIR EVOLUTIONLysyuk G.N.Institute of Geology of Ural Branch of Russian Academy of Sciences54, Pervomaiskaya st., Syktyvkar, 167982, RussiaFax: +7 (8212) 425346, yushkin@geo.komisc.ruPP‐29We investigated two types of the ferromanganese nodules (FMN). Among the first typeare the deep‐see (pelagic) nodules of the Clarion‐Klippertone zone at the Pacific Ocean. Thistype of nodules is known for a long time. The deep‐see nodules have been discovered at1873‐1876 during the expedition on Challenger boat and from that moment they areconstantly investigated. Such a great interest to these natural (native) formations isconnected with the fact that FMN are considered to be a potential source of raw materials(mineral products). Nodule reserves only at the Clarion‐Klippertone zone are about 30milliards of tons and it is very important that these reserves are constantly regenerative. Themain feature of nodules is their enrichment by many ore elements. Concentrations of suchelements in nodules are extensively higher than in continental manganese ores. Forexample, Mn, Co, Mo, Ti are concentrated in pelagic nodules at hundred times more than inores; Ni, Ag, Ir, Pb from fifty to one hundred times more; Cu, Zn, Cd, W, Bi from ten to fiftytimes more and P, V, Fe, Zr – at ten times more than in continental ores.Among the second type of FNM are the nodules of Baltic Sea shelf. This type of FMN hasnever been regarded as the object (material) for industrial using. However recentinvestigations let us to change our attitude to this ore type and (to try) to find it’s worthapplication.There are great differences between the characteristics of these two types of theferromanganese nodules such as:– nodule size– inner structure– chemical and mineral composition.Results of the XRD investigations displayed that the main part of ore matter of theferromanganese nodules is roentgen‐amorphous (uncrystalline). Among the ore mineralssuch phases are determined: 10Å‐phase, 7Å‐phase – birnessite and vernadite. Mineralstability under high‐temperature treatment (heating) was studied for the 10Å‐phasedetermination. The most common 10Å‐phase in our nodules is todorokite. In smallerquantities asbolane and buserite are present. Ferruginous minerals of the nodules areuncrystalline. They were determined with the help of Mossbauer spectroscopy. On the183