Structure and geodynamics of the Uralian orogen

Abstract

The Urals are a Late Palaeozoic orogenic belt. The relicts of earlier orogens are traced in its basement. In particular, the Late Vendian pre-Uralian orogen is reconstructed and identified as a part of the Late Precambrian Cadomian orogen. The Uralian orogeny was preceded by Late Cambrian–Early Ordovician epicontinental rifting and formation of the Paleo-Uralian ocean whose remnants are Palaeozoic ophiolites. Calc-alkaline volcanites and plutons, typical of active margins, are widely developed in the eastern Urals. The Uralian foldbelt results from oblique collision between the East European (Laurussia) passive margin and the active margin on the Kazakhstanian continent. Collision began in the south of the Urals and moved, wave-like, to the north. The eastern and northern parts of the Urals have been affected by the Middle Jurassic Cimmerian intracontinental (intra-Pangaea) shortening. The Uralian–Cimmerian mountain belt was eroded and partially inundated by seas in the Late Jurassic—Early Cretaceous times and has been reactivated since the Oligocene in response to a recent intracontinental shortening.