Geological structure and magmatism of the Shchuchinsky megablock (Polar Urals)
Purpose of the work: determination of the geological structure, occurences of magmatism and geodynamics of the northernmost isolated segment of the paleooceanic sector of the Ural mobile belt - the Shchuchinsky megablock. Geographic disconnection with the southern structures of the Ural mobile belt and sub-ring structure have led to both a suspended interest and conflicting ideas about its geology, the composition of the host rock complexes, their age, genesis, and mineragenic specialization. Methodology of the work: generalization, analysis and synthesis of materials of long-term study of geology and magmatism of the region, including the conducted GDP-200/2 sheets Q-42-VII, VIII and GMK-200 sheets Q-42-I- II with extensive literary sources and creator-owned mineralogical-petrographic and petro-geochemical studies, including isotope-geochronological ones. Results. For the first time, the internal geological structure of the Shchuchinsky megablock, its magmatism, geodynamic conditions of formation and metallogeny are shown on the basis of the created geological map of pre-Mesozoic deposits and the developed author's legend of the territory. Magmatic, metamorphic and sedimentary formations are combined into pre-Paleozoic (Archean-Proterozoic), Paleozoic and Mesozoic megacomplexes, characterized by specific formational-geodynamic parameters and ore content of their occurences at certain stages of the development of the region. Analytical information on the breed associations of the structure under consideration is given in a concise form. Conclusions. The results obtained indicate a probable polygenic-polychronous structure of the ophiolite association and subsequent island-arc-collisional complexes, including the so-called “femic” (AR - PR) base, involved in the vortex interplate system, which caused the annular structure of the Shchuchinsky ridge.