Vanishing World Heritage in Central Anatolia: The Tuz Gölü

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

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

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

The Tuz Golu 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 Golu Fault Zone in the east and the transtensional Inonu-Eskisehir 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 Golu Basin. Field observations, kinematic analyses, interpretations of seismic reflection lines, and Ar-40/Ar-39 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 Golu 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 Golu 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 Golu Fault Zone straddling the foothills of the Sereflikochisar-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 Sereflikochisar 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

The Role Of Oroclinal Bending In The Structural Evolution Of The Central Anatolian Plateau: Evidence Of A Regional Changeover From Shortening To Extension

The NW-SE striking extensional Inonu-Eskisehir Fault System is one of the most important active shear zones in Central Anatolia. This shear zone is comprised of semi-independent fault segments that constitute an integral array of crustal-scale faults that transverse the interior of the Anatolian plateau region. The WNW striking Eskisehir Fault Zone constitutes the western to central part of the system. Toward the southeast, this system splays into three fault zones. The NW striking Ilica Fault Zone defines the northern branch of this splay. The middle and southern branches are the Yeniceoba and Cihanbeyli Fault Zones, which also constitute the western boundary of the tectonically active extensional Tuzgolu Basin. The Sultanhani Fault Zone is the southeastern part of the system and also controls the southewestern margin of the Tuzgolu Basin. Structural observations and kinematic analysis of mesoscale faults in the Yeniceoba and Cihanbeyli Fault Zones clearly indicate a two-stage deformation history and kinematic changeover from contraction to extension. N-S compression was responsible for the development of the dextral Yeniceoba Fault Zone. Activity along this structure was superseded by normal faulting driven by NNE-SSW oriented tension that was accompanied by the reactivation of the Yeniceoba Fault Zone and the formation of the Cihanbeyli Fault Zone. The branching of the Inonu-Eskisehir Fault System into three fault zones (aligned with the apex of the Isparta Angle) and the formation of graben and halfgraben in the southeastern part of this system suggest ongoing asymmetric extension in the Anatolian Plateau. This extension is compatible with a clockwise rotation of the area, which may be associated with the eastern sector of the Isparta Angle, an oroclinal structure in the western central part of the plateau. As the initiation of extension in the central to southeastern part of the Inonu-Eskisehir Fault System has similarities with structures associated with the Isparta Angle, there may be a possible relationship between the active deformation and bending of the orocline and adjacent areas.WoSScopu