Tectono-stratigraphy of the Neogene basins in Western Turkey: Implications for tectonic evolution of the Aegean Extended Region

- New field data and radiometric age data are presented.
- Stratigraphy of the Neogene basins in western Anatolia is reviewed.
- Temporal variation of the basin formation is discussed.
- A tectonic model for the extensional tectonics in the Aegean is presented.

The western part of the Aegean region includes several Neogene basins containing volcano-sedimentary successions. The Neogene basins, located along the northern Menderes Extensional Metamorphic Complex (MEMC) were developed during the Miocene as supra-detachment basins. They contain two distinct volcano-sedimentary successions, separated by a regional unconformity. The basins located to the west of the MEMC were developed as strike-slip basins and contain volcanic and sedimentary units getting younger from NE to SW with no remarkable unconformity.Available paleomagnetic studies in the Aegean Region suggest to us that, the basins to the west of the MEMC were developed in response to southward clockwise rotational roll-back of the Aegean subduction zone. The eastern margin of this rotational deformation is characterized on the surface by a large strike-slip zone, which is known as Ä°zmir-Balıkesir Transfer Zone (Ä°BTZ). The sedimentary successions in the basins along the northern MEMC do not show southward younging and are interpreted to be developed in response to exhumation of the MEMC. During the Pliocene to Quaternary, ~ E-W-trending grabens such as the Gediz (Alaşehir), Büyük and Küçük Menderes Grabens were developed in response to tectonic escape accompanying the slab-roll back process. These grabens truncate the MEMC basins. During this time, strike-slip deformation and associated sedimentation continued along the Ä°BTZ.