The effects of subduction termination on the continental lithosphere: Linking volcanism, deformation, surface uplift, and slab tearing in central Anatolia

Subduction beneath central Anatolia represents the transition between continuous subduction along the Aegean trench in the west and slab break-off and/or subduction termination at the Arabian-Eurasian collision zone in the east. Using recently collected seismic data from the Continental Dynamics-Central Anatolian Tectonics project alongside a newly developed approach to the creation of a 3D shear-velocity model from the joint inversion of receiver functions and surface-wave dispersion data, we can gain important insights into the character of the downgoing, segmenting African lithosphere and its relationship with the overriding Central Anatolian plate. These results reveal that the mantle lithosphere of central Anatolia is thin and variable (< 50-80 km) due to the decoupling of the crust of accreted lithospheric blocks from their associated lithospheric mantle, which continued to subduct and was subsequently removed by slab delamination during early-mid Miocene times. The resulting lithospheric thickness variations appear to control deformation as well as the distribution of volcanism throughout the region. In the Central Anatolian Volcanic Province, the uppermost mantle is characterized by very slow shear velocities (< 4.2 km/s) consistent with the presence of melt in the uppermost mantle. The fastest shear velocities observed in this study (> 4.5 km/s) underlie the Central Taurus Mountains, which have experienced ~2 km of uplift in the past ~8 m.y. These velocities are consistent with lithospheric mantle, and we interpret that the recent uplift of these mountains is due to a rebound of the subducting slab after slab break-off and/or fragmentation rather than asthenospheric influx.