Structural evolution of the Precambrian rocks of the northern part of the Subpolar Urals

In the course of studies of the Lower and Upper Proterozoic formations of the Subpolar Urals, there was a need for a clearer geological interpretation and clarification of their age. This work is intended to offer, at least in part, additional criteria for the dismemberment of the above Precambrian formations. In this article, we present the results of studies, including those obtained from field work in the Subpolar Urals. Using the methods of macrostructure analysis, as well as microstructural analysis, which consisted in determining the orientations of the optical axes of quartz in thin sections, it was shown that for the deposits of the Nyartin complex, the Manhobeu and Shokurya suites, the unifying criterion was the presence of can be that they contain relict isoclinal folds absent in sediments of the Puiva suite and overlying formations. For the complexes and two suites mentioned above, the patterns of the stereographic diagrams of the distributions of optical quartz axes to a certain extent coincide, and the patterns from the diagrams for the Puiva suite are clearly distinguished. All this allows to classify the Nyartin complex, the Manhobeu and Shokurya formations to a structural level separate from the Puiva suite.