Rapid late Miocene surface uplift of the Central Anatolian Plateau margin

Abstract

The Central Anatolian Plateau (CAP), Turkey, is bordered to its south by a steep mountain belt that emerged ∼8–7 Ma ago from the Mediterranean Sea. Knowledge of the onset, duration and rate of surface uplift and orographic barrier formation along the plateau margin is crucial for understanding the geodynamic drivers of plateau uplift. We present a new comprehensive data set that includes 12 40Ar/39Ar ages and lacustrine carbonate δ18O data (n=637) from 13 sections in upper Oligocene to Pliocene continental basins of the CAP interior. We aim at documenting the development of a rain shadow and therefore the surface uplift history of the CAP and its southern margin (Tauride Mts.).In the rain shadow of the Tauride Mts. we observe a gradual 3.9‰ decrease of δ18O values of lacustrine carbonate between ∼11 and 5 Ma that we interpret to originate from a similar change in δ18O values of precipitation owing to the late Miocene development of an orographic barrier. Our stable isotope paleoaltimetry data show that by 5 Ma the southern CAP margin had reached similar-to-present elevations of ∼2 km. Surface uplift was coeval with ignimbritic magmatism, forearc shortening and distributed compression. We suggest that the removal of lithospheric mantle below Anatolia led to surface uplift of the CAP interior, which was followed by surface uplift of the southern CAP margin due to crustal thickening as a result of northward subduction of the African plate below central Anatolia.