Magnetic Properties of PT-Bearing Dunite of the Konder Massif (Russian Far East)

The observed gravitational field of the Konder pipe-like dunite-pyroxenite body coincides well with model field designed for a vertical cylinder with radius 2.7 km and density 3.3 g/cm3. It forced its way through crystalline basement and sedimentary cover of the Aldan Shield. Such process is a combination of rolling and hydroextrusion. Magnetic properties of dunite depend on distance from the pyroxenite rim and have a multiextreme character. The distance between extremes is 150-200 m. Magnetic susceptibility χ decreases from value ~ 0,01 unit SI. Variations of residual magnetization Іn are in an antiphase with spatial χ changes. Thermodemagnetization extremes at 310°C are characteristic of maghemite and localize in minimum zones of χ curves. Values, which are characteristic of magnetite are observed in maximum zones. Thus, various redox conditions are characteristic of maximum and minimum zones. Magnetic data explain some features of geochemical structure of the massif generated during emplacement because of localization of shift deformation in accommodation bands.