Tauric subduction (Malatya-Elazıǧ provinces) and its bearing on tectonics of the Tethyan realm in Turkey

Summary In the Eastern Taurus, The Elazıǧ nappes shown an ophiolitic association overlain by andesites and intruded by calc-alkalic granites, both of Late Cretaceous age. The basin was compressed in the Late Cretaceous between two metamorphic massifs each with a sialic basement and platform-type Permian to Mesozoic cover. This history indicates Late Cretaceous subduction under the Taurides and subsequent compression of the basin and arc. Attempts to place this Tauric subduction in the geodynamic history of Turkey lead to conflicting interpretations and two alternative models are presented. The first involves a single Tethyan ocean subducting northwards below the Pontides and southwards below the Taurides. The latter led to the Late Cretaceous opening of back-arc basins which split the formerly continuous Tauric-Arabian platform. Southward subduction ended when the ridge reached the trench, leading to compression of the Elazıǧ back-arc basin, southward obduction and closure of the ocean. The residual, Upper Cretaceous marginal basin controlled the subsequent Tertiary development of the area. The second model involves a northern Tethyan ocean and a southern Mesogean ocean, both subducting northwards. Subduction of the southern ocean generated calc-alkaline magmatism and deformation of the leading edge of the Tauric blocks. The Elazıǧ basin closed as a result, having earlier formed either as a subduction-related marginal basin or as a pre-existing extensional basin. Southward obduction took place from both oceans. After closure of the Tethyan ocean, Tertiary development was controlled by reactivation of Mesogean subduction.