ИСТИНА

Xenoliths of deep rocks found in kimberlites are a unique source of information on the composition, structure and evolution of the mantle lithosphere of continents and flowing in it processes. The studied structural-textural features, mineral composition and chemistry of rock-forming and accessory minerals, six samples of xenoliths and websterite peridotite-pyroxenite paragenesis of high-diamondiferous pipes in the Mir and not diamondiferous pipes Obnazhennaya (Yakutian kimberlite province). In the garnet websterites (Samples O-281, M-74, M-91) granat varies widely in content pyrope component (from 55 to 71 mol. %) and contains 20 to 28 mol.% almandine component. In the sample O-281 granate is surrounded by a strong kelyphitic rims zonal structure. Garnet from garnet-spinel lherzolites (samples Ob.-125 and Ob-212 from pipe Obnazhennaya) are characterized by lower contents of almandine component (up to 16 mol.%) and higher  pyrope (73 mol %); contains needle inclusions of rutile.