PROVENANCE AND AGE CONSTRAINTS OF THE RIPHEAN SANDSTONES FROM THE IVANOVSKY GRABEN (THE KOLA PENINSULA) BASED ON THE U-Pb LA-ICP-MS DATING AND RAMAN SPECTROSCOPY OF DETRITAL ZIRCON

The results of U-Pb LA-ICP-MS dating 150 detrital zircon grains from the Precambrian (Riphean?) sandstones Kildin group on coast Ivanovka Bay (northeastern Kola Peninsula) are presented. A three youngest yielded constraint sandstone maximum depositional age 1179±45 Ma. Detrital distribution is dominated by maximums 1.9, 2.4 and 2.7 Ga. authors consider two complementary scenarios interpretation data obtained. first scenario involves contribution distant provenance out granitoids in Lapland-Kola orogen (~1.9 Ga) adjacent areas Kola-Karelia region (~2.7 Ga), Imandra-Varzuga structure (~2.4 Sveconorwegian belt (~1.2 Ga); off-Baltic (Greenland?) sources also cannot be excluded. According to second scenario, Ivanovsky graben received zircons proximal – sialic complexes formed upon melting granite-gneiss substratum upper crust Murmansk craton during largescale episodic mafic magmatism 1.86, 2.50 2.68 Raman spectroscopy showed that about 25 % analyzed experienced a 1.4-Ga-old thermal effect which did not lead Pb losses but partially restored crystalline zircon. This result can used as an additional detailed analysis northeastern East European Platform sedimentary basins indicative large-scale magmatic events related breakup supercontinent Nuna.