Petrogeochemisy of Granites of the Badiayu Massif (the Subpolar Urals)

Abstract

Magmatic formations of various ages are developed within the northern part of the Circumpolar Urals, the oldest peripheral part of the Ural belt. Including the Late-Riphean-Vendian granitoids of the salner-mankhambov intrusive complex, which includes the Badiayu granite massif. The conducted research allowed us to identify a number of petrographic and petrogeochemical features of the granites under consideration. The analysis of rock-forming minerals, which are a typical set for granites, with the help of a polarization microscope allowed us to determine the characteristic structures of the rock, to identify the presence of plagioclases and biotites of two generations, to detect partial substitution of quartz with a granular variety. The data of the silicate method allowed us to establish that the studied rock is characterized by an increased content of silica, the main alkali metals, and a very high alumina content. ICP-MS method data and their normalization with respect to S. S. San chondrite and the hypothetical plagiogranite COX showed that the rocks were formed from crustal-type melts saturated with rare-earth, as well as individual lithophilic elements (rubidium, barium). According to the diagnostic diagrams of J. A. Pierce, D. Papu, N. B. Harris, the formation of the studied massif occurred in the conditions of an intraplate geodynamic situation.