EGU24-12731, updated on 09 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The Seismic Expression and Tectonomagmatic Evolution of Subduction Termination along the Anatolian Margin 

Jonathan Delph1, Mary Reid2, Daniel Portner3, Susan Beck4, A. Arda Ozacar5, W. Kirk Schleiffarth6, Michael Darin7, Donna Whitney8, Michael Cosca9, Christian Teyssier8, Nuretdin Kaymakci5, and Eric Sandvol10
Jonathan Delph et al.
  • 1Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, Indiana, USA (
  • 2School of Earth & Sustainability, Northern Arizona University, Flagstaff, Arizona, USA
  • 3Department of Earth and Environmental Science, Socorro, New Mexico, USA
  • 4Department of Geosciences, University of Arizona, Tucson, Arizona, USA
  • 5Department of Geological Engineering, Middle East Technical University, Ankara, Turkey
  • 6Rio Tinto
  • 7Oregon Department of Geology & Mineral Industries, Portland, Oregon, USA
  • 8Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, Minnesota, USA
  • 9Denver Federal Center, U.S. Geological Survey, Denver, Colorado, USA
  • 10Department of Geological Sciences, University of Missouri, Columbia, Missouri, USA

The geological expression of subduction termination is poorly understood due to overprinting during the collisional stage of the Wilson Cycle. The Anatolian domain of the eastern Mediterranean represents a modern system where spatial variability can be interpreted in terms of the transition from subduction to collision. Convergence in the west is accommodated by the subduction of the last remnants of Neotethyan oceanic lithosphere, while in the east, the margin has transitioned to complete continent-continent collision. In central Anatolia, however, the expression of convergence is complicated by the underthrusting of small continental fragments and attenuated continental lithosphere. By investigating variations in the geological expression of convergence across this system, we can investigate the processes that accompany the transition from subduction to collision.

Spatially variable tectonomagmatic and seismic characteristics along the Anatolian margin reflect this transition. Seismic images reveal a disjointed and disaggregating subducting slab beneath central Anatolia that interacts with, and in some cases induces, mantle flow. This spatially corresponds with Miocene-to-recent volcanism that is sourced from very shallow depths (<60 km) and has a southwestward younging pattern to the initiation of magmatism. Primitive melts in the region contain metasomatized lithospheric mantle and asthenosphere signatures resulting from the long-lived subduction history of the margin combined with recent slab rollback and mantle upwelling around the subducting slab edge based on seismic images. Superimposed on regional magmatic trends, local spatiotemporal patterns show subtle southward and westward younging and/or broadening, perhaps associated with thermomagmatic erosion of the lithosphere along relict structures and/or slab edge-induced flow. Conversely, seismic images in eastern Anatolia reveal a nearly uniform mantle flow and no discernable evidence for subduction. Interestingly, magmatic patterns in central and eastern Anatolia bifurcate in the early to mid-Miocene, interpreted as the time when a vertical slab tear developed along the once continuous Tethyan slab. These results indicate that expressions of subduction termination can be very heterogenous along the strike of a margin.

How to cite: Delph, J., Reid, M., Portner, D., Beck, S., Ozacar, A. A., Schleiffarth, W. K., Darin, M., Whitney, D., Cosca, M., Teyssier, C., Kaymakci, N., and Sandvol, E.: The Seismic Expression and Tectonomagmatic Evolution of Subduction Termination along the Anatolian Margin , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12731,, 2024.