Komskii

Komskii consists of several small intrusions spread over an area of 3.5 x 1.5 km. It is located between areas of Upper Palaeozoic granite and syenite and consists of two types of nepheline syenite. One is medium-grained and displays a gneissic structure and the other is coarse-grained, leucocratic biotite-hastingsite and aegirine-augite-nepheline syenite with a massive structure. The latter is situated in the central area and covers 1.5 x 0.4 km. Xenoliths of fenitized schist and marble occur in the nepheline syenites but are unknown in outcrop. The youngest rocks of the complex are fine-grained syenites and granosyenites, in some of which aegirine-augite occurs.