This massif is situated in the Krasnomaiskii deep fracture-zone which marks a tectonic contact between Archaean eclogitic formations and Proterozoic schists. The massif takes the form of a curved dyke and is 9x0.3-1.0 km with an area of 6.3 km2. It is composed principally of biotite pyroxenites and nepheline syenites with subordinate malignite, sviatonossite, olivinite, biotite peridotite, zeolite, liebenerite and sodalite syenite and carbonatites. The intrusive sequence is: (1) olivinite and biotite peridotite (2) pyroxenite (3) malignite and syenites (4) syenite porphyry (5) carbonatite. Within the ultrabasic rocks there are veins of syenite pegmatite consisting of orthoclase, albite, apatite, mica and carbonate. In the alkaline and nepheline syenites are found veins of syenite pegmatite and syenite porphyry as well as schlieren, veins and patches of carbonatite and apatite. Hydrothermal veins of zeolite, carbonate and fluorite occur in almost all the rocks of the intrusion but they are most typical of the pyroxenites, alkaline and nepheline syenites. Biotitisation and phlogopitisation (vermiculitisation) of peridotite and pyroxenites and microclinisation and liebeneritisation of alkaline and nepheline syenites are broadly developed within the complex.