Plio-Quaternary extensional tectonics of the Central Anatolian Plateau: a case study from the Tuz Gölü Basin, Turkey

Abstract

The Tuz Gölü Basin is the largest sedimentary depression located at the center of the Central Anatolian Plateau, an extensive, low-relief region with elevations of ca. 1 km located between the Pontide and Tauride mountains. Presently, the basin morphology and sedimentation processes are mainly controlled by the extensional Tuz Gölü Fault Zone in the east and the transtensional İnönü–Eskişehir Fault System in the west. The purpose of this study is to contribute to the understanding of the Plio-Quaternary deformation history and to refine the timing of the latest extensional phase of the Tuz Gölü Basin. Field observations, kinematic analyses, interpretations of seismic reflection lines, and 40Ar/39Ar dating of a key ignimbrite layer suggest that a regional phase of NNW–SSE to NE–SW contraction ended by 6.81 ± 0.24 Ma and was followed by N–S to NE–SW extension during the Pliocene–Quaternary periods. Based on sedimentological and chronostratigraphic markers, the average vertical displacement rates over the past 5 or 3 Ma with respect to the central part of Tuz Gölü Lake are 0.03 to 0.05 mm/year for the fault system at the western flank of the basin and 0.08 to 0.13 mm/year at the eastern flank. Paleo-shorelines of the Tuz Gölü Lake, vestiges of higher lake levels related to Quaternary climate change, are important strain markers and were formed during Last Glacial Maximum conditions as indicated by a radiocarbon age of 21.8 ± 0.4 ka BP obtained from a stromatolitic crust. Geomorphic observations and deformed lacustrine shorelines suggest that the main strand of the Tuz Gölü Fault Zone straddling the foothills of the Şereflikoçhisar–Aksaray range has not been active during the Holocene. Instead, deformation appears to have migrated towards the interior of the basin along an offshore fault that runs immediately west of Şereflikoçhisar Peninsula. This basinward migration of deformation is probably associated with various processes acting at the lithospheric scale, such as plateau uplift and/or microplate extrusion.

Palaeoenvironmental reconstruction of the eastern part of the Karapınar-Ayrancı coal deposit (Central Turkey)

“…The Konya Graben, which hosts the Karapınar-Ayrancı coal deposit, is one of them (Göncüoğlu and Toprak, 1992;Dirik and Göncüoğlu, 1996;Fernández-Blanco et al, 2013). Typically for these Central Anatolian sedimentary basins, the basinal infilling commenced with the deposition of fluvio-lacustrine deposits in the study area during Middle to Late Miocene (Toprak and Göncüoğlu, 1993).…”

“…8c). Similar alluvial and slope deposits are also widely developed around the Ereğli and Ayrancı towns (Özsayın et al, 2013;Temiz and Savaş, 2014). Drier climate conditions were developed during the Middle…”

Contributions of biogeographical functions to species accumulation may change over time in refugial regions

“…Increased precipitation sustained a high diversity of freshwater environments until the earliest Pleistocene (Alçiçek, 2010). Additionally, ongoing tectonic activity at that time strongly affected the physiography of some of the basins (Brocard, Meijers, Willenbring, Kaymakci, & Whitney, 2015; Gürbüz & Kazancı, 2015;Özsayin et al, 2014). For example, basin fragmentation probably led to divergence differences in the mollusc assemblages of two adjacent basins of Denizli and Baklan (Wesselingh & Alçiçek, 2010).…”

Shallow melting of MORB‐like mantle under hot continental lithosphere, Central Anatolia

“…East of the Cyprean slab edge, the Arabian slab is at much greater depth (>440 km) [ Biryol et al ., ], having likely detached 11 Ma ago [ Keskin , ]. A N–S to NE–SW extensional tectonic regime, characterized by normal faults with a minor strike‐slip component, has persisted along the Tuz Golu Fault Zone of Central Anatolia since at least 7 Ma [ Özsayın et al ., ].…”