Four decades of geochronological work in the Southern and Middle Urals: A review

Abstract

The Uralide Orogen, the geographic and geologic divide between Europe and Asia, has been the subject of geochronological study for more than 40 years. This compilation summarizes age data from the Southern and Middle Urals beginning with Archean to Proterozoic dates from the East European Craton in the west and advancing eastward where progressively younger geological events are recorded. Archean to Proterozoic basement rocks crop out throughout the East European Craton. Neoproterozoic gneisses provide evidence of a Pre-Uralian orogeny that affected large parts of the eastern margin of the East European Craton. Early Paleozoic magmatism related to rifting of the East European Craton in the Middle Urals is recorded by geographically restricted nepheline syenite massifs. The most westerly, and oldest, material accreted during the Paleozoic orogeny is Middle Ordovician to Late Devonian ophiolites and ultramafic/mafic massifs generally associated with the principal suture of the orogen, the Main Uralian fault. Closure of the Uralian paleo-ocean basin led to eastward subduction of the leading edge of the thinned East European Craton generating Late Devonian high pressure complexes now exposed in the Main Uralian fault footwall. East of the Main Uralian fault, Silurian to Early Carboniferous ocean volcanogenic complexes crop out. These accreted island arc terranes are intruded by abundant Late Devonian to Late Carboniferous plutonic complexes with subduction-related characterisitcs. Further to the east, Permian granitoids were generated by melting of orogenically thickened crust. In general, post-Paleozoic magmatism is sparse throughout the Urals.