Nuretdin Kaymakcı

and 5 more

Convergence between the Eurasian and the African plates in the West Anatolian-Aegean region results in a trench retreat due to slab roll-back and tearing of the subducted African lithosphere. The upper plate response of this process gave way to back-arc extension in the region. In this context, we have conducted a very rigorous AMS study on the Neogene units in SW Anatolia to unravel the style and amounts of deformation. For this purpose, from 83 sites in 11 structurally homogeneous domains, 1680 paleomagnetic samples were analyzed. Obtained results are used to determine principal strain directions to unravel overall deformation styles and amounts in the region. The results have shown that AMS is related to the tectonic deformation, which facilitated that the AMS directions correspond to cumulative principal strains. Maximum susceptibility is parallel to the major extension (k), minimum susceptibility (k) corresponds to compaction after deposition, almost always normal to the bedding plane. The intermediate axis (k) found to be parallel to a second extension direction that the region has been under the control of multi-directional extension during Neogene. Two mean anisotropy directions are identified. These are Oligocene-Middle Miocene NW-SE, and Late Miocene-Pliocene NE-SW directed extension. The mean anisotropy directions are generally parallel or perpendicular to the general strikes of the normal faults. The results have shown that the deformation in the region resembles to differentially stretched rubber sheet under the influence of SW directed extension exerted by the southwards retreating Eastern Mediterranean subduction system.

Murat Özkaptan

and 3 more

The demise and closure of the Neotethyan Ocean gave way to the collision and finally amalgamation of various continental fragments in Turkey along the Izmir-Ankara-Erzincan and Intra-Tauride suture zones. These continental fragments include Pontides in the north and Menderes-Tauride , and Kırşehir Block in the south. This study aims to the restoration of these suture zones in central Anatolia using paleomagnetic tools during Neogene. Most of the paleomagnetic studies carried out in the region consider the deformation of Anatolian Block as a monolithic block rotated counter-clockwise due to escape tectonics since the Miocene. We introduce new paleomagnetic evidence obtained from Neogene sedimentary successions and few volcanic suits. Our results point out five distinct tectonic domains with distinct rotation patterns that indicate the rotational deformation of Central Anatolia is far more complex than generally presumed. Among these, 1) Kırıkkale-Bala Domain (KB) is rotated ~18° clockwise, 2) the Tuz Gölü Domain (TG) underwent ~15° counter-clockwise rotation, 3) the Alcı-Orhaniye Domain (AO) rotated ~25° counter-clockwise sense, 4) the Haymana Basin is divided into two different domains, (4) the Northern Haymana Domain (NHY) underwent ~17° counter-clockwise rotation while (5) the Southern Haymana Domain (SHY) underwent barely no net rotation (~5° clockwise) since the early Miocene. The Kırşehir Block was proposed to be an NNE-SSW striking tectonic block that broken into three fragments. These fragments underwent clockwise, in the north, and counterclockwise rotations in the south, respectively, during early Tertiary due to collision and N-S shortening of the Kırşehir Block between Taurides and the Pontides.