Linking slab break-off, Hellenic trench retreat, and uplift of the Central and Eastern Anatolian plateaus

The Central and Eastern Anatolian plateaus are integral parts of the world's third largest orogenic plateau. In the past decade, geophysical surveys have provided insights into the crust, lithosphere, and mantle beneath Eastern Anatolia. These observations are now accompanied by recent surveys in Central Anatolia and new data constraining the timing and magnitude of uplift along its northern and southernmargins. Together with predictions from geodynamic models on the effects of various processes on surface deformation and uplift, the observations can be integrated to identify probable mechanisms of Anatolian Plateau growth. A changeover fromshortening to extension along the southern margin of Central Anatolia that is coevalwith the start of uplift can bemost easily associatedwith oceanic slab break-off and tearing. This interpretation is supported by tomography, deep seismicity (or lack thereof), and gravity data. Based on the timing of uplift, geophysical and geochemical observations, and model predictions, slab break-off likely occurred first beneath Eastern Anatolia inmiddle to lateMiocene time, and propagatedwestward toward Cyprus by the latestMiocene. Alternatively, the break-off near Cyprus could have occurred in late Pliocene to early Pleistocene time, in association with collision of the Eratosthenes Seamount (continental fragment) with the subduction zone. Uplift at the northern margin of Central Anatolia appears to result fromcrustal shortening starting in the lateMiocene or early Pliocene, which has been linked to the broad restraining bend of the North Anatolian Fault. The uplift history of the interior of Central Anatolia since the lateMiocene is unclear, although shortening there appears to have ended by the late Miocene, followed by NE–SW extension. This change in the deformation style broadly coincides with faster retreat of the Hellenic trench as well as uplift of the northern and southern margins of Central Anatolia. These different events throughout the plateau may be linked, as faster retreat of the Hellenic trench has been predicted to occur after slab break-off, which could have induced extension of Central Anatolia and helped to form the North Anatolian Fault through accelerated westward movement of Anatolia relative to Eurasia. Correlative geochronologic evidence thatwe summarize here supports the hypothesis that the geodynamic activity throughout the Aegean–Anatolian domain starting in latestMiocene to early Pliocene time defines a series of events that may all be linked to slab break-off.