Yatsina D. Ore-bearing criteria of dunite-harzburgite formation of the South-Belozersky (Ukrainian Shield) and the Olysya-Musyursky (Circumpolar Urals) massifs

Thesis is related to the solution the actual problem of the ore-forming and ore-controlling factors determining in the history of the ore formation evolution within Ukrainian Shield and Circumpolar Urals layered intrusive complexes, and also to ore-formational analysis of investigated ore occurrences and criteria development of their predictive evaluation. Building features of investigated mafic-ultramafic massifs were uncovered. The South-Belozersky massif were identified as a layered intrusive with mafic-ultramafic composition. It was identified that in contrast to the Olysya-Musyursky massif rocks of the South-Belozersky massif are characterized by the higher degree of metamorphism. Chrysotile-asbestos and talc-magnesite mineralization of the South-Belozersky massif and chromium ores of the Olysya-Musyursky massif are related to the most perspective ore occurrences. Ore occurrences classification of investigated massifs and six formational subtypes allocation were carried out. Intrusive-magmatic genesis and layered structure of the South-Belozersky massif by a number of features were grounded. It was identified that metallogenic specialization and ore formation safety degree within investigated massifs are conditioned by postmagmatic transformation and geotectonic regime. Main regularities of the ore occurrences distribution within investigated massifs are conditioned by tectonic, formational, petrochemical, structural, metamorphic and geochronological factors which in turn represent criteria of predictive evaluation.