Arabia-Eurasia Collision and The Geodynamic Models for Plateau Uplift in Turkish-Iranian Plateau

Abstract

<p>Orogenic plateaux, the broad high elevation regions of Earth, are mainly formed by plate convergence/shortening and in some cases, there is (hot) mantle support for their formation. Two major examples at present are the Tibetan and Turkish-Iranian plateaux. For instance, Turkish-Iranian plateau, is a consequence of the continental plate collision between Arabia and Eurasia, which began at ~34-25 Ma and continues to the present day. The plateau can be regarded as two distinct entities, with a boundary at roughly the political border between Turkey and Iran. While there have been studies to explain the uplift history, lithospheric/crustal structure and associated magmatism, currently, the mechanisms behind the plateau growth are not well understood. The western region, also known as the East Anatolian Plateau, has a tectonic plate structure with a near-normal crustal thickness (~35-40 km) and a markedly thinned mantle lithosphere (a few 10s of km in thickness). This suggests that, to achieve its regional elevation of ~2 km there is likely considerable support from the underlying hot asthenospheric mantle. In the east, the crust of most of Iran is thicker, up to ~65 km, and it is underlain by a variable but thicker mantle lithosphere (commonly >100 km thick). It is intriguing why these two regions have similar surface elevations (2-3 km on average) and regional geomorphology, despite predicted lithospheric structures. This study will apply new class of geodynamic models to understand how such plateaux form in response to plate collision/convergence and possible mantle upwelling/support. By comparing models with different setups (varying lithospheric thicknesses, strength profiles etc.) suggested by the natural case studies, this study will provide a more general assessment of controls on plateau growth with 2-D and 3-D perspectives in the context of Arabia-Eurasia collision. Further, the study will also help to explain the role of the forces that generate dynamic topography in the evolution of such geologic structures.</p>