New data on mineralogy and petrogeochemistry of alkaline rocks of the Kozlinogorsk complex: Ufaley block, Middle Urals

Rare metals bearing alkaline complexes are quite uncommon on the western slope of the Urals. The Kozlinogorskiy complex is situated in the Ufaley block related to the junction zone of the Urals and the East European Platform. Gabbro, syenites, granosyenites and granites comprise the complex. Their alkaline nature is proved by the presence of aegirine, riebeckite, astrophyllite, enigmatite. Rocks are characterized by the ratio of rare elements and fluid regime features indicating the participation of the mantle plume in their genesis. The plume formation could be an energy and material source that initiated the process of reopening of the ancient rift structure. Alkaline plume-dependent series on the western slope of the Urals have been recorded more frequently last time, indicating the significant role of plume tectonics in the geodynamics of the early stages of the structure evolution.