Geological position and age of the Shchokurya suite in the Subpolar Urals

The geological position and age of the Shchokurya suite in the Subpolar Urals are considered, which in modern stratigraphic schemes refers to the Lower or Middle Riphean formations. For the first time the U-Pb-dating of zircons indicates the Early Proterozoic time of the early stages of the metamorphism of the rocks of the Shchokurya suite. The upper age limit for the formation of the terrigenous-carbonate substrate of the suite may be previously limited to the minimum age of the main population of terrigenous zircons (about 2.5 Ga). These data confirm the results of previous structural, petrological and mineralogical studies, on the basis of which the idea was formed that the Shchokurya suite with the Manhobeyu suite and the Nyartin complex belonged to the structures of one (Lower Precambrian) structural story, and the Upper Proterozoic section (the Upper Precambrian structural story) in the Subpolar Urals began with the Oisez stratum of the Puyva suite of Middle or Late Riphean age.