Arctic Zone of the Eastern Siberia: Geology and Mineral Resources

The world's largest continental Siberian trap province is an example of a combination of a huge volume of basic rocks with Pt-Cu-Ni ores. Deposits of the Noril'sk area provide 90% of the PGE and Ni in Russia. Their high economic value raises the question on a possibility of discovering rich ores in other parts of the Siberian province and around the world. The Taimyr peninsula in Arctic zone comprises economic sulfide mineralization as well. Geochemistry of intrusive and effusive rocks of this region demonstrates their difference from rocks of the southern part of the trap province. They are characterized by maximal compositional diversity and have both mantle and crustal characteristics: (i) trace element patterns without Ta-Nb and Pb anomalies, with ɛ_Nd ranging from+3 to +5, and ⁸⁷Sr/⁸⁶Sr within 0.703 - 0.704; (ii) patterns with distinct Ta-Nb and Pb anomalies, ɛ_Nd varies from -9 to +2, ⁸⁷Sr/⁸⁶Sr from 0.705 to 0.711. The difference in the rock compositions of northern and southern parts of the province is explained by the difference in their tectonic position: within paleorift zone and platform. The PGE-Cu-Ni deposits are concentrated within the first tectonic structures characterized by long-lasted development.

This study was supported by RFBR (project No18-05-70094).