An analysis of U-Pb datings of detrital zircons from Upper Precambrian basal deposits of the Subpolar and Polar Urals is given. The presented material, taking into account the available data for other regions of the north of the Urals, as well as Timan, indicates that, in contrast to the Southern Urals, where the complete Riphean section is known, the Timan-North Urals Upper Precambrian begins with deposits bordering in age between the Middle and Late Riphean, most likely Late Riphean. This indicates the Late Riphean time of the Timan passive margin. It has been suggested that in Pre-Late Riphean times, the northeast of Baltica was located in the inner part of the fragment of Columbia, which avoided destruction until the entry of Baltica into Rodinia.