DETRITAL ZIRCONS FROM THE PRECAMBRIAN OF THE IGARKA UPLIFT (NORTHWESTERN SIBERIAN PLATFORM)

Herein we report the results of LA-ICP-MS dating of detrital zircons from eight stratigraphic levels of the Proterozoic section of the Igarka uplift (northwestern Siberian Platform). The age spectra include the Meso- and Neoarchean (3100–2600 Ma), Paleoproterozoic (2100–1700 Ma) and Neoproterozoic (1000–600 Ma) ages. However, the age distribution drastically varies among the samples. The Neoproterozoic zircons, associated with the hypothetic orogenic belt at the platform periphery, dominate in the lowstand system-tract continental and marginal marine strata (Gubinskaya, basal Chernaya Rechka, and Izluchina formations). In contrast, the zircons in the Riphean and Vendian marine strata (Bezymyanny, Ludy, Korablik, and Sukharikha formations) mostly originate from erosion of the crystalline basement of the Siberian Platform. The concordant mafic bodies in the Upper Riphean (Criogenian) Gubinskaya formation contain the concordant cluster of zircons of 835±4 Ma. It contradicts with the maximum deposition age of 716±10 Ma of the host strata, hence the zircons in the mafic bodies supposedly comprise xenocrysts.