Miocene decoupling of surface uplift of the Central Anatolian Plateau interior (Türkiye) and its modern mountainous margins

The Central Anatolian Plateau (CAP) forms the western portion of the Turkish-Iranian plateau and has mostly remained above sea level since ca. 41 Ma. However, the current topography of the CAP has predominantly developed since the Late Miocene, with mean elevations of ca. 1.0–1.5 km and northern and southern mountainous margins with peak elevations that locally exceed 3 km. To clarify patterns of surface uplift, we present paleoelevation estimates for the past 10 Ma by applying stable isotope paleoaltimetry on soil carbonates from the CAP and nearby coastal regions, as well as dual clumped isotope paleothermometry.

The compiled datasets from the Aegean-Anatolian region display a sustained increase in δ¹⁸O values of soil carbonates after the Miocene, in response to increased regional aridification. Our paleoaltimetry and dual clumped isotope results indicate that the CAP has been at higher elevations than the modern coastal regions since 10 Ma. By ca. 8 − 6 Ma, our refined paleoaltimetry estimates indicate the presence of a ca. 1.5 km-high orographic barrier. However, surface uplift of the Tauride and Pontide mountains on the southern and northern plateau margin postdate surface uplift of the CAP. Therefore, surface uplift of the CAP and its mountainous margins were decoupled during the Late Miocene, implying distinct geodynamic drivers for their asynchronous formation. Given that the Tauride Mts. emerged from the Mediterranean after 7 Ma, we document outward growth of the southern plateau margin since the Late Miocene.