Detrital zircon provenance of early Palaeozoic sediments at the southwestern margin of the Siberian Craton: Insights from U-Pb geochronology

Detrital zircons from the Ordovician and Devonian sedimentary cover of the Siberian Craton were analyzed for U/Pb geochronology to understand their sediment provenances. Five main age-peaks were identified in the zircon U/Pb age-spectra: (1) Neoarchaean - early Palaeoproterozoic (2.7-2.4 Ga); (2) late Palaeoproterozoic (2.0-1.65 Ga); (3) minor early Neoproterozoic (1.0-0.75 Ga); (4) Ediacaran (0.650.60 Ga) and (5) Cambrian - Early Ordovician (0.54-0.47 Ga), reflecting the main magmatic events in the sediment source regions. The oldest zircons (groups I and 2) are derived from the Siberian Craton which amalgamated during the Neoarchean - Palaeoproterozoic. The Neoproterozoic zircons (groups 3 and 4) likely sourced from southwestern basement uplifts and Neoproterozoic belts of the Siberian margin such as the Yenisey Ridge and Baikal-Muya region. The provenance of the youngest zircons (group 5) can be traced to the Altai-Sayan fold-belt, where peri-Gondwanan microcontinents and island-arcs accreted to Siberia during late Neoproterozoic - early Palaeozoic progressive consumption of the Palaeo-Asian Ocean. (C)2013 Elsevier Ltd. All rights reserved.