Structural and magnetic microinhomogeneities in accessory spinel of the system Fe2+(Cr2–xFex3+)O4 from the Kytlym massif (Urals platinum-bearing belt)

The microstructure and magnetic properties of accessory Fe–Cr-spinels from the Kytlym massif of the Urals platinum-bearing belt were studied. Atypical Fe–Cr-spinels in the form of magnetic microareas in grains of primary nonmagnetic Fe–Cr-spinel have been revealed for the first time in the bed dunites of the Kytlym multiphase concentrically zoned massif, North Urals. These spinels are responsible for the magnetic properties of the dunites. It has been established that the microareas are separations in solid solution Fe²⁺(Cr_2–xFe_x³⁺)O₄, which are enriched in Fe^3 + and are probably an intermediate product of the transformation of primary accessory Fe-Cr-spinel during the formation of the dunite massif. These are magnetic microphases with particular chemical composition, cation distribution, and corresponding reversed crystal lattice, which determine the main magnetic properties of the microarea: the magnitude and direction of magnetization vector and Curie temperature. The formation of this earlier unknown type of magnetic Fe–Cr-spinel is probably conjugate with the formation and concentration of PGE mineralization in the bed dunites of the Kytlym platinum-bearing massif. The presence of such magnetization carriers in rocks and ores must be taken into account in geophysical research at the Urals chromite and platinum–chromite deposits.     

Assessing the possible effect of developing the Zelenodol’skoe groundwater deposit on the ecosystems of the Volzhsko–Kamskii Reserve: Contradictions and compromises

The effect of maximal design water extraction on groundwater levels, lake budgets, and vegetation in the Volzhsko–Kamskii Reserve was assessed with the use of a hydrodynamic scheme of interaction between groundwater and surface water, specially developed for the territory of the Zelenodol’skoe Fresh Groundwater Deposit and mathematical simulation. The first stage of deposit development was proved to have no such effect. A scheme of the further development of the deposit by the results of environmental monitoring is recommended.     

Formation Conditions of Ferromagnesian Metasomatic Carbonates in the Lower Riphean Terrigenous–Carbonate Rocks of the Southern Urals

Lithology and Mineral Resources - Ferromagnesian carbonate metasomatites in limestones of the Lower Riphean Suran Formation in the Avzyan ore region (Bashkir meganticlinorium) are represented by...