stripes
Tikshozerskii is emplaced in Archaean granite gneisses which are altered to form unusual scapolite-microcline fenites. The layered intrusion is formed of two parts: a semi-circular body 5 km in diameter and a northeasterly-trending lens-like body about 3 km long. The complex is composed of olivinite, theralite, gabbro, titanomagnetite clinopyroxenite, nepheline pyroxenite, melteigite-ijolite and numerous dykes of micromelteigite and microijolite. In the northern part of the massif a small area of gabbroic rocks is intersected by veins of trachytic nepheline syenite and dykes of olivine-bearing lamprophyre. In the outer part of the intrusion are developed cancrinite (20-23%), calcite (25-35%), amphibole rocks and carbonatites which form veins and eruptive breccias. The carbonatites are composed of calcite, Mn-calcite, ankerite and dolomite with accessory magnetite, ilmenite, rutile, corundum, sulphides, ancylite and rare-earth phosphates. These rocks are enriched in La, Ce, Ba (up to 0.5%), Sr (up to 0.6%), Mo and V.
BOGACHEV, A.I., VLODAVETS V.I., KLUNIN, S.F. and KIRILLOV, A.I. 1987. Metallogeny of the Tiksheozersky-Elet'ozersky ultrabasic gabbro-alkaline complex. In Magmatism, metamorphism and geochronology of the west-east Precambrian platform. 102-4. Akademii Nauk SSSR, Kola Branch, Petrozavodsk.
SAFRONOVA, G.P. 1982. Perspectives of the Tikshozero massif metallogeny in connection with new types of alkaline and carbonatitic rocks. In Metallogeny of Karelia. 143-60. Nauka,Petrozavodsk.
SAFRONOVA, G.P. and GAVRILOVA, L.M. 1982. On carbonatites of the Tikshozersky massif (data on oxygen isotopes in carbonate). In Metallogeny of Karelia. 161-7. Publishing House of the Geological Institute, Petrozavodsk.
