U-Pb (SIMS) zircon chronology of intrusive magmatism of the south-eastern part of the Izhma zone (basement of Pechora Basin)

The results of local U-Pb (SIMS) zircon analysis indicate that plutonic rocks drilled by five boreholes in the Izhma zone of the Timan megablock of the Pechora Basin basement were not intruded simultaneously in the Late Precambrian. The first episode of magmatic activity took place at c. 600 Ma (at the Riphean — Vendian boundary), while the second one is confined to the Late Vendian. The ages of the granites from the 1-Nizhnyaya Omra and 1-Prilukskaya boreholes are 602 ± 2 and 593 ± 14 Ma, respectively. The granites from the 11-Malaya Pera and 1-South Djer boreholes and diorites from the 21-Palyu borehole are 557—536 Ma old, being well correlated to the 555—544 Ma old orogenic granitoids of the Pripechora fault zone (the supposed suture of the Timanides orogen).