TITANITE OF THE KHIBINY ALKALINE MASSIF (KOLA PENINSULA): NEW DATA
Data on occurrence, morphology and composition of accessory and rock-forming titanite are analyzed in relation to concentrically zoning of the Khibiny massif. The main concentrations of titanite are connected with foidolites of the «Small arch» and the «Main ring» in which titanite is the principal mineral-concentrator of titanium. Chemical composition of titanite varies symmetrically relatively to the massif center. Local maxima (Ca, Sr, Ti) or minima (Ln, Mn, Fe, Zr, Al) concentrations of elements in the mineral composition are connected with foidolites of the Main ring. During formation of the more-and-more lower-temperature parageneses, there was the progress of titanite auto-purification from micro-impurities, which, in their turn, located in composition of numerous secondary titanium-bearing silicates.