Материалы по геологии и полезным ископаемым Карело-Финской, Ленинградской и Мурманской областей. Сб. № 6 / Ком. по делам геологии при СНК СССР, Ленингр. геол. упр. – Москва ; Ленинград : Гос. науч.-техн. изд-во нефтяной и горнотоплив. литературы, 1941.

The garnet problem of the USSR and the garnet-almandine deposits of the Kola peninsula М . V agapova-Kadyrova S u m m a r y The Garnet-almandine deposits in the central p a rt of the Kola peninsula arn rather large. They are located in the western p a rt of the Bolshikh Keiv Ridge oe 67°50' north latitude and between 36° and 37° east longitude. Alkaline granites play the main p a rt in the geological structure of this region, forming an enormous massif stretched out in a latitud ina l direction on a distance of 180—200 km. The age of these granites by analogy to the rocks of the Khibine and Lovo- zero massifs is determined by Prof. A. Polkanov as Devonian. In the massif of a l kaline granites there are large xenoliths of the Proterozoic metamorphic gneisso- schist series of sedimentary origin. This series, called Keivian is presented in the form of a band of a latitud ina l strike on a distance of 180—200 km (from 0,5 to 8 km thick), pressed in from the north and south along its whole length between alkaline granites. Besides th a t there are a number of small xenoliths of this series. In the alkaline granites as well as in the Keivian series small bodies of diabases are inclosed, which are the youngest formations and also a number of older horn blende rocks, presented by amphibolites and metadiabases belonging to the Protero zoic. In Keivian series and p a rtly in the alkaline granites pegmatite and quartz veins are abundan tly developed. The pegmatites in the shists contain much indu- strially-importan t muscovite. The Keivian schists in the eastern p a rt of the plateau are intensely enriched in cyanite, where there are large deposits of this mineral. The garnet almandine deposits are confined to the western p a rt of the Kei vian series. The mineralogical composition of our alkaline granites is as follows: micro- cline, albite, quartz, aegerine, alkaline amphibole of the arfvedsonite group. Acces sories: apatite, sphene, zircon, fluorite, an ore mineral and a mineral of the astro- phyllite group. The texture is granitic and granoblastic. The composition of the gneisses: plagioclase, microcline, quartz, biotite, garnet, hornblende, muscovite. Accessories: apatite, sphene, zircon, an ore mineral. The texture of the rock: granoblastic, porphyroblastic and lepidoblastic. The composition of the crystalline schists: quartz, muscovite, garnet, silli- manite, disthene, staurolite, biotite, sericite, chlorite. Accessories: apatite, sphene, zircon, graphite, ore mineral. Texture: lepidoblastic, porphyroblastic. The silli- manite and disthene in schists of our region are not always present and in small quantities. Garnet-almandine as a rock-forming mineral in scattered form is present in gneisses and different schists of the Keivian series. The concentration of garnet in schists in the form of group accumulations of crystals so as to form a garnet ore, is confined to bodies of schists, which branch out into the alkaline granite massif from the main zone. There are two such branching outs: 1) on the Mount Makzabak, and 2) to the north of Mount Berezovaya. In the first muscovite-quartz shists were enriched in garnet. Nearing the granite massif the enrichment in garnet becomes noticeably more intense and in places we have nests and vein-like accumulations of garnet crystals. The ore zone extends out on a distance of 2 km. According to prelim inary esti mates the resources of garnet-almandine on the Makzabak are about 300.000 tons. The almandine deposits to the north of Mount Berezovaya are composed of several regions a t a distance of 1—2 km from each other. In the main region there 69