They occur along with other types of pyroxene gneiss, hornblende gneiss, amphibolites, etc. It is the principal mineral of amphibolites. Gneisses, schists, quartzites, migmatites, amphibolites and granulite are also found. Early Proterozoic, metamorphic rocks consist of schists and amphibolites. Amphiboles are the primary constituent of amphibolites. This rock unit is formed by quartzites, meta-black shales, amphibolites and skarns. The Okolovo rocks are plagiogneisses, amphibolites, and schists embedded with ferruginous quartzite. BIF is another important rock type occurring in close association with the metapyroxinite and amphibolites. In some places, a Proterozoic basement formed by amphibolites, gneisses and serpentinites crops out. It is also an important constituent of amphibolites formed by metamorphism of basalt. The summit itself is composed of amphibolites. The lherzolites are associated with amphibolites, pyroxenites, and amphibole-bearing peridotites. Their composition includes amphibolites, quartz feldspar, Phyllites and slate. The amphibolites may represent metamorphosed submarine basalt flows. The lithologies of the basement rocks are mainly gneisses, schists and amphibolites.