Features of chemical and phase compositions of minerals of mantle xenoliths from pipes of Mir and Obnazhennaya (Yakutian kimberlite province)тезисы доклада
Дата последнего поиска статьи во внешних источниках: 22 февраля 2018 г.
Аннотация: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.