ALKALI CARBONATE VEIN MINERALIZATION IN THE CENTRAL ARC OF THE KHIBINY PLUTON

Alkali carbonates, including natron, trona, thermonatrite, pirssonite, shor-tite, burbankite, donnayite etc., are abundant in veins cutting rischorrite and ijolite-urtite of the central arc of the Khibiny pluton and in the Kukis-vumchorr deep fault zone. Thre are indications of a genetic relationship with carbonatite complex penetrated by drilling in the eastern part of pluton (see International Geology Review, Vol. 33, No. 4, pp. 375-384, 1991). Besides being of possible economic significance, these new findings are of importance in understanding the petrogenesis of alkaline complexes.