Browsing by Author "Ozkaptan, Murat"

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Age and Kinematics of the Burdur Basin: Inferences for the Existence of the Fethiye Burdur Fault Zone in Sw Anatolia (Turkey)
(Elsevier, 2018) Ozkaptan, Murat; Kaymakci, Nuretdin; Langereis, Cor G.; Gulyuz, Erhan; Ozacar, A. Arda; Uzel, Bora; Sozbilir, Hasan
The Burdur Basin is a late Miocene to Pliocene fluvio-lacustrine basin in SW Anatolia. It is developed within the postulated Fethiye-Burdur Fault Zone, which was argued to be a sinistral strike-slip fault zone developed in response to propagation of the Pliny-Strabo STEP fault into SW Anatolia (Turkey). In order to assess the presence and tectonic characteristics of the fault zone, we conducted a paleomagnetic study in the Burdur basin that involved rock magnetic experiments, Anisotropy of Magnetic Susceptibility (AMS) measurements and developing a magnetostratigraphy for dating purposes. The obtained age model constrains most part of the tectonic evolution of the basin. The well exposed (similar to 270 m thick) Burdur section revealed 3 normal and 2 reverse polarity magnetozones. We propose that the Burdur Formation spans most of the Gauss Chron (similar to 3.4-2.5 Ma) which implies a sedimentation rate of > 18 cm/kyr. The AMS results in the section indicate NW-SE directed extension. In addition, we have also conducted kinematic analyses from 1790 fault slip data collected at 44 sites distributed within the supposed Fethiye Burdur Fault Zone in the region. The results indicate that the region has been developed under a NW-SE directed extensional deformation regime and was dominated by NE-SW striking normal faults from late Miocene to recent. Few NW-SE striking normal faults with strike-slip components are categorized as transfer faults, which accommodated differential stretching between the Burdur and Cameli basins. Stretching amounts increase southwards demonstrating a dextral transtensional character of the transfer faults. We have not observed any significant strike-slip motion along the NE-SW striking faults, which challenges the presence and sinistral transcurrent nature of the supposed Fethiye Burdur Fault Zone.
Deformation in Sw Anatolia (Turkey) Documented by Anisotropy of Magnetic Susceptibility Data
(Amer Geophysical Union, 2021) Ozkaptan, Murat; Gulyuz, Erhan; Uzel, Bora; Langereis, Cor G.; Ozacar, A. Arda; Kaymakci, Nuretdin
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. We have conducted a very detailed anisotropy of magnetic susceptibility (AMS) study on the Neogene rocks in SW Anatolia to unravel the style and magnitudes of deformation. For this purpose, from 83 sites in 11 structurally homogeneous domains, 1,680 paleomagnetic samples were analyzed. The results show that AMS fabrics are related to the tectonic deformation and that the magnetic lineation (maximum susceptibility axis, k(1)) is parallel to inferred maximum extension, while minimum susceptibility (k(3)) is typically normal to the bedding plane, corresponding to a preserved compaction associated with deposition fabric. The intermediate axis (k(2)) is parallel to a second extension direction and indicates that the region has been under the control of multi-directional extension during the Neogene. Two main magnetic lineation directions are identified and represent Oligocene to middle Miocene E-W, and late Miocene to Pliocene NW-SE oriented extension. The magnetic lineation directions are dominantly parallel or perpendicular to the general strikes of the normal faults. The results show that the deformation in the region resembles two differentially stretched rubber sheets under the influence of SW oriented extension, exerted by the southward retreating Eastern Mediterranean subduction system.
Kinematic and Thermal Evolution of the Haymana Basin, a Fore-Arc To Foreland Basin in Central Anatolia (Turkey)
(Elsevier, 2019) Gulyuz, Erhan; Ozkaptan, Murat; Kaymakci, Nuretdin; Persano, Cristina; Stuart, Finlay M.
Gondwana (Tauride/kirsehir blocks) and Eurasia (Pontides) derived continental blocks delimit the Haymana basin, central Turkey, to the south and the north, respectively. The boundaries of these blocks define the IzmirAnkara-Erzincan and Intra-Tauride Suture zones which are straddled by a number of Late Cretaceous to Oligocene marine to continental basins. The Haymana Basin is located at the junction of the IAESZ and ITSZ and comprises Upper Cretaceous to Middle Eocene basin infill deposited in response to the interaction of these blocks. The basin provides a unique opportunity to unravel spatio-temporal relationships related to the timing of late stage subduction history of Neo-Tethys Ocean and subsequent collision of the intervening continental blocks. We have conducted a multidisciplinary study in the region that includes mapping of major structures combined with fault kinematic analyses. E-W striking folds dominate the basin, cross-section balancing of these structures indicates around 25% roughly N-S shortening in the region. Paleostress studies indicate that the basin was initially subjected to N-S to NNE-SSW extension until the middle Paleocene (phase 1) and then N-S directed syn-depositional compression and coeval E-W directed extension until the middle Miocene (phase 2) implying strike-slip deformation and pure shear shortening in the basin. These different deformation phases are attributed to first fore-arc (subduction) basin development then foreland (collision) stages of the basin. Apatite (U-Th)/He dating of 5 samples indicate that exhumation of the SE segment of the basin started in early Oligocene, whereas the NW segment of the basin exhumed in the early Miocene. The differential uplift is possibly related to progressive north-westwards movement of Derekby basin bounding fault at the north. We propose that the Haymana basin evolved from extensional forearc basin during the late Cretaceous to early Paleocene and foreland basin after the terminal subduction and subsequent collision of Tauride and Pontide blocks.
New Insights on the Neogene Tectonic Evolution of the Aksu Basin (Se Turkey) From the Anisotropy of Magnetic Susceptibility (Ams) and Paleostress Data
(Pergamon-elsevier Science Ltd, 2020) Wasoo, Muhammad Harbi; Ozkaptan, Murat; Koc, Ayten
The junction between the Aegean and Cyprus arc in the southern Turkey forms a triangular-shaped morphological structure so-called Isparta Angle (IA). In Neogene time, the inner part of the Isparta Angle became overlain by sedimentary basins including Manavgat, Koprucay and Aksu, characterized by marine clastics and carbonates. Aksu Basin, one of these marine basins, provides geological records about the Neogene crustal deformation and stress field in the Eastern Mediterranean region. Therefore, we kinematically assess if and when tectonic stress fields affected the Aksu basin in early Miocene to recent times. For this purpose, Anisotropy of Magnetic Susceptibility (AMS) data (AMS) of cored samples and fault-slip data from the brittle mesoscopic faults were collected. The similar to 490 oriented samples for Anisotropy of Magnetic Susceptibility measurements were analyzed and two different maximum magnetic lineation's directions are recognized; 1) N-S magnetic lineation in Pliocene and 2) from N-S to NW-SE magnetic lineation in the Miocene. The results inferred from more than 1000 fault-slip data collected from 83 different sites combined with AMS results demonstrate that the Aksu Basin developed under four different tectonic phases; 1) similar to E-W extensional phase (related to basin formation), 2) similar to N-S compressional (Lycian) phase, 3) similar to(N)E-(S)W compressional (Aksu) phase and 4) N-S extensional (Recent) phase.
Paleomagnetic Evidence for Upper Plate Response To a Step Fault, Sw Anatolia
(Elsevier Science Bv, 2018) Kaymakci, Nuretdin; Langereis, Cor; Ozkaptan, Murat; Ozacar, A. Arda; Gulyuz, Erhan; Uzel, Bora; Sozbilir, Hasan
Pliny-Strabo Trench is a Subduction Transform-Edge Propagator (STEP) Fault developed on the northern edge of the subducted African Oceanic Lithosphere. It connects the Aegean and Cyprian trenches in the Eastern Mediterranean convergent system. Although, deep geometry of the STEP fault and associated slab tear in mantle are imaged, its shallow vertical and lateral continuation in the crust and impact on the over-riding plate are still unknown. Thus, we have studied SW Anatolia, the candidate site where this structure could propagate laterally and vertically, for its vertical axis rotations using paleomagnetic tools. In this study, more than 2000 paleomagnetic samples were collected and analysed from 86 different sites which were later classified into 11 separate geographic domains displaying similar tectonic characteristics. Moreover, available paleomagnetic data in the literature were parametrically resampled, analysed and combined with our data. In the region, there is a positive correlation between rotation amounts and sample ages supporting continuous deformation throughout the Neogene period. The spatial variations of results indicated that the study area can be divided into three main domains based on vertical axis rotations. From the south to the north these domains include SW Anatolian domain with similar to 20 degrees counter-clockwise rotation, Burdur-Dinar-Ulubey domain with similar to 4 degrees counter-clockwise rotation and northern areas characterized by clockwise rotations. The identified domains of counter-clockwise rotation are separated by a well-defined NW-SE striking Acipayam Transfer Zone and there is no differential rotation in agreement with the presence of NE-SW striking shear zone in the region. Therefore, we concluded that the Pliny-Strabo STEP Fault have not propagated into the over-riding plate as a shear zone. This implies that there is no evidence to support the presence of alleged Fethiye-Burdur Fault Zone as suggested, and its existence is dubious. (C) 2018 Elsevier B.V. All rights reserved.
Relationship Between the Anisotropy of Magnetic Susceptibility and Development of the Haymana Anticline, Central Anatolia (Turkey)
(Tubitak Scientific & Technological Research Council Turkey, 2019) Ozkaptan, Murat; Gulyuz, Erhan
Integrated structural and anisotropy of magnetic susceptibility (AMS) analyses were carried out on the Campanian-Maastrichtian shale-mudstone dominated sedimentary sequences (Haymana Formation) cropping out within the doubly plunging Haymana Anticline in Central Anatolia (Turkey). In order to understand the relationship between the development of magnetofabrics and the tectonic processes, six sites from different parts of the anticline were sampled and analyzed. AMS lineations from 634 cylindrical samples and structural data were collected in the field. The results show very high correlation with the structural trend of the region and indicate that the maximum susceptibility vector (k(1)) is almost parallel to the Haymana Anticline fold axis (similar to E-W) and the trace of the Derekoy Thrust Fault, which is the basin-bounding fault at the northern margin of the Haymana Basin. In order to assess the relationship between shortening ratios and obtained AMS vectors, a number of balanced cross-sections are constructed along five traverses almost perpendicular to the axis of the anticline. Results from both the AMS and the balanced cross-sections yielded similar shortening ratios (similar to 18%-32%) that decrease towards the eastern closure of the anticline from its culmination. In a regional sense, we related these results to compressional/transpressional deformation that formed during the Eocene to Early Miocene period. Differential shortening ratios calculated from AMS and restored balanced cross-sections indicate that the shortening is associated with the transcurrent tectonics, possibly in relation with rotational convergence of the Pontides and the Taurides and/or the oblique indentation of the Kirsehir Block into the Pontides during or subsequent to the collision.