Zwitters are metasomatic rocks associated with rare-metal granites. Petrological, geochemical and mineralogical features of zwitters are given. For dark micas features of chemical composition and type of structure is described. Geochemical specialization of metasomatic solutions is characterized. Data about accessory minerals are given.
Composition of amursk suites metamorphic rocks was reconstructed by geochemical discrimination diagrams (Roser, Neelov). Tectonic settings were studied by REE patterns.
The rock composition was studied, the garnet composition was researched with a X-ray phase analysis, and equilibrium pressures of the garnet crystallization were calculated with the geobarometer GASP, thermal properties of graphite were characterized and polymorphic modification was identified by X-rays diffraction.
