Browsing by Author "Gülyüz, E."

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Late Cretaceous To Recent Kinematic History of the Tuzgölü Basin, Central Anatolia, Turkey: a Paleostress Study
(Hacettepe Universitesi Yerbilmleri, 2020) Gülyüz, E.
Traces of deformation events related to the Neotethyan and post-Neotethyan evolution of the Central Anatolia is well recorded in Upper Cretaceous to recent deposits of the Tuzgölü basin. In this regard, kinematic traces with age controls are crucial for differentiating and characterizing deformation phases that prevailed in the region. This study presents 57 paleostress inverse analysis based on more than 500 fault slip measurements collected from 41 different locations in the basin. The temporal distribution of the data sets indicates three different phases of deformation. The first one is represented by an almost E-Wdirected compressional setting, which might be related to the late-stage closure of the Neo Tethys Ocean and continental collision events along the Intra-Tauride Suture Zone during late Cretaceous to Oligocene time interval. The second phase is attributed to the segmentation of the Kırşehir block under NNW-SSE-directed compressional setting in the basin after the indentation of the Kırşehir block into the Pontide block along the İzmir Ankara-Erzincan Suture Zone. The last phase is represented by the transtensional regime, which might be related to uplift of the entire Central Anatolian Plateau since ~ 10 Ma. © 2020, Hacettepe Universitesi Yerbilmleri. All rights reserved.
Paleomagnetic Constraints on the Early Miocene Closure of the Southern Neo-Tethys (Van Region; East Anatolia): Inferences for the Timing of Eurasia-Arabia Collision
(Elsevier B.V., 2020) Gülyüz, E.; Durak, H.; Özkaptan, M.; Krijgsman, W.
Oligocene-Miocene convergence of the Eurasian and Arabian plates resulted in (i) the gradual closure of the Neo-Tethys Ocean that formed an open marine connection between the Indian Ocean and the proto-Mediterranean until the early Miocene and (ii) Eurasia-Arabia continental collision. Remnants of the Neo-Tethys basin are found scattered over eastern Anatolia. The Van region of SE Anatolia contains a unique stratigraphic succession (Van Formation) of this ancient marine corridor, showing a gradual transition from deep-marine marls to continental clastics and shallow marine deposits. This formation is considered a key unit for the late stage evolution of the Neo-Tethys Ocean as it contains one of the youngest marine deposits of the southern Neo-Tethys branch in SE Anatolia. Here, we present new magnetostratigraphic and Anisotropy of Magnetic Susceptibility (AMS) data to better constrain the timing of the marine-continental transition and the style of deformation in the Van region. The Van Formation was sampled in ~2-m stratigraphic resolution, with ~350 paleomagnetic cores drilled in stratigraphic order. These cores were analyzed with thermal and alternating field demagnetization, resulting in a magnetic polarity pattern that could straightforwardly be correlated to the standard Geomagnetic Polarity Time Scale (GPTS). The base of the section has an age of ~19.5 Ma, the marine-continental transition is dated at 18.8 Ma, and the top of the succession has an age of ~16.8 Ma. The AMS data show a conspicuous change from extensional to contractional patterns, coinciding with the end of open marine environments, at an age of ~19 Ma. We hypothesize that the closure of the marine basin and the concomitant change in stress regime in the Van region are related to the onset of Eurasia-Arabia collision and the terminal subduction of the Neo-Tethys oceanic lithosphere. © 2019 Elsevier B.V.