Biriusinskii

a mountain range on the northern slope of the Vostochnyi Saian, in Irkutsk Oblast, RSFSR. It is a watershed for the sources of the Birius River (Angara basin). Maximum elevation, 1,922 m; length, approximately 100 km. Biriusinskii Range is composed mainly of metamorphosed shales and gneisses and effusive-sedimentary deposits shot through by granite intrusions of varying age. Cedar-deciduous mid-mountain taiga predominates; sparse cedar forests grow on the upper part of the slopes. There are deposits of gold and mica.