U–Th–Pb Age of Detrital Zircon from the Riphean Sandstones of the Volyn-Orsha Paleotrough, Belarus

Abstract

Geochronological U–Th–Pb LA-ICP-MS study of detrital zircon grains from Riphean sandstones of the Sherovichi and Belarus series of the Orsha part of the Volyn-Orsha paleotrough (boreholes Korma and By-khov, Belarus) was carried out. The received U–Th–Pb geochronological data indicate that the primary provenance of zircon was crystalline rocks of predominantly Early and Middle Riphean, as well as Early Proterozoic and Archean age. The presence of detrital zircon grains with an age of 1 Ga in the sandstones of the Sherovichi and Belarus series, which were previously considered Middle Riphean, evidences that these sequences are of Late Riphean age. A representative population of grains with an age of about 1 Ga was detected only in the rocks of the Korma borehole, whereas in sandstones from other boreholes located within the Voly-n-Orsha trough (borehole 70, borehole Vilchitsy 1 and borehole Bykhovskaya), it is absent. This indicates that a possible primary provenance of zircon could be located both within the paleotrough and at a considerable distance, within the Grenville Sweconorwegian orogen.