AGE AND STRATIGRAPHIC POSITION OF THE SUPRACRUSTAL COMPLEX (THE KASKAMA BLOCK, INARI TERRANE, NORTH-EAST KOLA-NORWEGIAN REGION OF THE FENNOSCANDIAN SHIELD)

New data of U-Th-Pb age (SIMS) of magmatic (T = 730–744°C) zircon from intermediate and acid metavolcanics (1923–1926 Ma) of the supracrustal complex in the Kaskama block of the Inari terrane (north-west of the Kola-Norwegian region of the Fennoscandian shield) were obtained, which makes it possible to attribute them to the Kalevian suprahorizon. The source of primary melts of metariodacites and metabasaltes in the Kaskama block was the paleoproterozoic continental lithosphere not younger than 2390–2384 Ma. It is shown that the age of the tonalites of the Kuroaivi massif (1936 ± 7 Ma, εNd(T) = +0.1) as well as the granitoid massifs of the Southern Pechenga zone (1950–1940 Ma), are older, within the errors of U-Th-Pb age determinations, than the volcano-sedimentary rocks of the Kaskama unit and the Vepsian of the Southern Pechenga zone. This period of granite formation separates the early geodynamic stages of the continental rifting at the Yatulian-Ludikovian time from regimes, similar to the suprasubductional formation of the continental lithosphere, of the Inari terrane (1926–1850 Ma).