The Permian emplacement of granite–gneiss complexes in the East Uralian Zone and implications on the geodynamics of the Uralides

Abstract

In the southern Uralides, Permian magmatism, tectonism and metamorphism concentrate in the East Uralian Zone, such that this zone provides the key for understanding of the late phase of the Uralian orogeny. Carboniferous distal marine sediments and lenses of amphibolite–serpentinite associations show that the lithospheric precursor of the East Uralian Zone was largely oceanic. In the Latest Carboniferous, the Kazakhstanides collided with the Uralides, but relics of the oceanic basin between both units were conserved and accommodated a large part of Permian deformation. Structural data provide evidence that a NW-directed plate convergence was partitioned in W-directed compression and N-directed strike-slip. Additionally, they show that granitic melts, which had formed in the thickened crust of the Uralides, migrated eastward into the strike-slip belt of the East Uralian Zone. Also the exhumation of the plutonic rocks occurred eastward, oblique to the direction of regional extension, indicating that upper crust and lower crust deformed mainly decoupled from one another. We suggest that the emplacement of the granite–gneiss complexes contributed significantly to the consolidation of the orogenic crust in the eastern Urals.