Abstract:
5 representatives of corundum mineral group have been established in Khibiny massif with certainty. The mere corundum and karelianite occur only within hornfels of volcanic-sedimentary rocks, which xenoliths are tracking ring faults filled with foidalites, inside the field of foyaites. Hematite is connected with hydrothermally altered nepheline syenites and crossing them hydrothermal veins surrounding the ring faults. Minerals of the il-menitc-pyrophanite series are present in all rocks of the massif, veins including. Accessory ilmenite in foyaites is regularly changing its composition from the manganese ilmenite and pyrophanite, in central and outer parts of the massif, down to manganese-free ilmenite - in zone of the Main ring fault; in xenoliths of volcanic-sedimentary rocks, and alkaline-ultramafic rocks, it is enriched in magnesium. Revealed zoning in distribution of the above mentioned mineral species and the character of changes in their compositions from edges of the massif to its center are well connecting with data on the massif petrochemical zonality, which forming is related, in its turn, with processes differentiating foyaites around the ring faults.