EGU21-13757, updated on 04 Mar 2021
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Closing the Neotethys Ocean in western Anatolia: Insights from forearc and foreland sedimentary basin records

Megan Mueller1, Alexis Licht2, Clay Campbell3, Faruk Ocakoğlu4, Gui Akşit5, Grégoire Métais6, Pauline Coster7, K. Christopher Beard8,9, and Michael Taylor3
Megan Mueller et al.
  • 1University of Washington, Department of Earth and Space Sciences, Seattle, United States of America (
  • 2Aix-Marseille Université, CNRS, Centre de Recherche et d’Enseignement de Géosciences de l’Environnement (CEREGE), Aix-en-Provence, France
  • 3Department of Geology, University of Kansas, Lawrence, Kansas 66045, USA
  • 4Department of Geological Engineering, Eskişehir Osmangazi University, 26040 Eskişehir, Turkey
  • 5Department of Earth Sciences, University of Oregon, Eugene, Oregon 97403, USA
  • 6Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements, Muséum National d'Histoire Naturelle, 75005 Paris, France
  • 7Réserve naturelle nationale géologique du Luberon, Apt, France
  • 8Biodiversity Institute, University of Kansas, Lawrence, Kansas 66045, USA
  • 9Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045, USA

Across the Tethyan realm, subduction zones are characterized by phases of forearc and backarc extension, and subsequent collisions are protracted and polygenetic, often resulting in significant discrepancies among proxies of collision age. The closure of the northern branch of the Neotethys Ocean along the İzmir-Ankara-Erzincan suture in Anatolia has been variously estimated from the Late Cretaceous to Eocene. It remains unclear whether this age range results from a protracted, multi-phase collision or disparities between proxies and geographic location. Near-continuous Jurassic through Eocene deposition in the forearc-to-foreland Central Sakarya Basin system in western Anatolia makes it an ideal location to integrate pre-collisional extension and multi-stage collision into a holistic reconstruction of subduction through collision. The Central Sakarya Basin system is located north of the Izmir-Ankara-Erzincan suture, where the Gondwanan-derived Anatolide and Tauride terranes to the south collided with the Laurasian-derived Pontide terrane in the north. By integrating new sandstone petrography and detrital zircon U-Pb and Hf isotopes with other geologic proxies, we demonstrate four phases of evolution of subduction and collision. (1) Magmatism began on the Pontides at 110 Ma, potentially the signal of subduction (re-)initiation, and is coincident with extension in the forearc. (2) Forearc obduction began around 94 Ma with initial subduction of lower plate continental lithosphere. Extension migrated to the backarc and opened the Black Sea. (3) The onset of intercontinental collision at 76 Ma is marked by gradual arc shutdown, basement exhumation, and uplift of the suture zone. (4) This first contractional phase is followed by thick-skinned deformation and basin partitioning starting around 54 Ma, coeval with regional syn-collisional magmatism. The 20-Myr protracted collision in western Anatolia could be explained by three non-exclusive mechanisms that produced a change in plate coupling: relict basin closure, progressive underthrusting of thicker lithosphere, and slab breakoff.

How to cite: Mueller, M., Licht, A., Campbell, C., Ocakoğlu, F., Akşit, G., Métais, G., Coster, P., Beard, K. C., and Taylor, M.: Closing the Neotethys Ocean in western Anatolia: Insights from forearc and foreland sedimentary basin records, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13757,, 2021.


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