Morphology, structure, and composition of zircon from metasandstones of the Alkesvozhskaya sequence (Polar Urals)

A description of the features of morphology, internal structure, and analysis results of Th/U and Zr/Hf ratios in zircons from sandstones of the gold-bearing Alkesvozhskaya sequence, located at the basement of the Paleozoic section in the Subpolar Urals, is presented. It has been established that most of the studied zircons are primary igneous grains of the first weathering cycle. The detrital zircon source was probably in formations close in age, underlying or located nearby felsic and basic volcanics of igneous complexes of different stages of formation of Timanides-protouralides, associated granitoids, and intrusive mafic formations. Small part of well-rounded zircon Pre-Riphean grains can be redeposited from the Riphean metasedimentary formations, which, in turn, inherited it from the rocks of the ancient basement of the East European Platform.