U-Pb (LA-ICP-MS) isotopic ages and probable sources of detrital zircon in quartzite sandstone of the Khobeyu formation (the Subpolar Urals)

The article presents the first U-Pb data on the age of detrital zircon from clastic sediments of Khobeyu Formation in the Subpolar Urals. Age data for 102 zircon grains (LA-ICP-MS) cover the range of 862-2656 Ma. Weighted average age of the three youngest grains yields the age of 927 ± 54 Ma which provides grounds to assume that sediment deposition took place in Late Riphean. Significant similarity of the ages of detrital zircon grains from the terrigenous rocks of the Khobeyu Formation and underlying Puyva Formation indicates that the rocks were formed in the same sedimentary basin, and the detrital material came from source areas similar in age. In terms of the prevalence of zircon grains of Middle-Late Riphean age, the Khobeyu and Puyva Formations are comparable to the Upper Precambrian sandstones and siltstones of the Barmin Group of the Northern Timan, and Chetlas and Vym Groups of the Middle Timan. It is assumed that the sources of detrital zircon in all these stratigraphic units were igneous and metamorphic rocks of Fennoscandia and the Central Russian Belt.