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Pre-Orogenic Successions and Foreland Basins |
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
The late Neoproterozoic Vendian succession fills a peri- to epicratonic Mezen Basin in front of the Timan Orogen, and is exposed along the northwestern flank of the basin. In the SE White Sea area, the siliciclastic succession demonstrates a wide range of lithofacies that define a transition from a low-energy shallow-marine muddy shelf to a braid-delta plain. Significantly, the prodelta, distributary-mouth bar, and delta plain lithofacies all demonstrate a remarkably tight clustering of palaeocurrent trends suggesting that the sediment was sourced from the NE. This pattern is interpreted as representing deposition in a distal setting in the Timan foreland basin. U-Pb zircon dates of 558 ± 1 Ma and 555.3 ± 0.3 Ma for volcanic tuffs in the Vendian succession provide lower age constraints for the emergence of the Timanian hinterland.
