The Cadomian Orogen: Neoproterozoic to Early Cambrian Crustal Growth and Orogenic Zoning Along the Northwestern Periphery of the West African Craton

Abstract

The Cadomian Orogen in the NE Bohemian and northern Armorican massifs shows a distinct NW–SE orogenic zoning, consisting of: (1) an outboard-sitting continental crust unit comprising Neoproterozoic rocks associated with ~2.0-Gyr-old Icartian basement; (2) a magmatic arc and a back-arc basin; (3) a foreland or retroarc basin, respectively; and (4) the passive margin of the back-arc basin. New U–Pb zircon ages of detrital zircons of Neoproterozoic to Fortunian siliciclastics from the Schwarzburg Antiform in the Saxo-Thuringian Zone (NE Bohemian Massif) identify the West African Craton as the hinterland for the Cadomian Orogen. U–Pb ages and Hf isotope data constrain the timing of orogenic events and episodes of crustal growth of both the Cadomian Orogen and the cratonic hinterland.