Bunduk

The Bunduk intrusion is situated several kilometres northeast of the Tezhsar complex on the southern slope of the Bazumsky mountain range. This is a dyke-like body expanding at its eastern end to a width of 2 km. There are also several smaller bodies in the vicinity with areas up to 1 km2. The Bunduk intrusion is composed of various textural and mineralogical varieties of peralkaline syenites including leucosyenites, one variety of which is an oligoclase rock with a little arfvedsonite. The principal rock-forming minerals are perthite, oligoclase (An15-30), diopside-augite, arfvedsonite, ferrohastingsite and biotite with accessory zircon, davidite, hellandite, orthite, baddeleyite, titanite, ilmenite and thorite. There is a little nepheline syenite. Various types of secondary alteration, including the development of biotite, amphibole and albite, are manifest.