Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2025Scopus SJRQ2/r/munzur/2123
  Geochronological and isotopic data from the adakitic Dodurga Pluton (Central Pontides, N Türkiye): new insights for the geodynamic evolution of the northern Neotethys

  Çimen, Okay; Gücer, Mehmet Ali; Simonetti, Antonio; Karaoğlan, Fatih

  The Dodurga Pluton is located within the Central Pontides (northern Türkiye), has a SW–NE elongation, and consists of granodiorite and dacite porphyry. Previous studies have suggested that this pluton is Triassic in age, and its whole-rock geochemical systematics is consistent with that from adakitic magmatic occurrences rather than the classic arc granitoid suite. This study reports for the first time in situ/whole-rock radiogenic isotopic (Sr, Nd, and Pb) and mica/amphibole Ar–Ar age data to evaluate better its petrogenetic/geodynamic evolution and the chemical nature of mantle source(s). Unlike previous data, combined new in situ zircon U–Pb yield Late Cretaceous crystallization ages of 84.2 ± 0.9 Ma and 86.9 ± 0.9 Ma, and the Ar–Ar age data along with apatite fission track measurements suggest magma cooling extending to 82.3 ± 0.4 Ma and 85.4 ± 0.4 Ma, respectively. The apatite fission track (AFT) dating results also reveal that this pluton was buried at a depth of 2.5–3 km following a fast-cooling period during the Late Cretaceous and cooled/exhumed over ~2 km during the Middle–Late Miocene (15–10 Ma) in a slow cooling phase. The overall data reported here suggest that the Dodurga Pluton represents melts derived from an enriched/metasomatized mantle source that interacted with lower crustal mafic rocks in an active continental margin as a result of northward subduction of the northern branch of the Neotethys Ocean.

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• MakaleAçık Erişim2023Scopus SJRQ2/r/munzur/2727
  Paleoseismology of the Ganos segment; the western extend of the North Anatolian Fault (Turkey)

  Aksoy, Murat Ersen; Meghraoui, Mustapha; Ferry, Matthieu; Çakir, Ziyadin; Uçarkuş, Gülsen; Sançar, Taylan; Altin, Mehmet Uğur

  The Ganos fault that ruptured on 9 August 1912 (Mw: 7.4) is the westernmost inland segment of the North Anatolian fault (NAF). Here, the Ganos fault is bounded at its two tips with offshore faults segments, in the Sea of Marmara to the east and the Gulf of Saros to the west in the North Aegean Trough. Therefore, the paleoseismology of the 45-km-long inland fault is of importance to the seismic hazard analysis related to offshore active faults and in particular for the seismic gap in the Marmara Region. Earlier studies have established an earthquake chronology for the western and eastern inland tips of the Ganos fault. Here, we extend the paleoseismic studies toward the central segment. Three trenches at Yörgüç have revealed evidence for two faulting events, possibly post-1669 CE ±30 years, which can be correlated to the 1659 or 1766, and the 1912 historical earthquakes. At Yeniköy, we determined an offset of 46 ± 1 m and 47 ± 1 m on a stream channel and a ridge-crest, respectively. In two trenches we determined two faulting events for the last 1000 years and seven events for the last 3500 years. In trench T5, the base of the displaced stream channel provides a calibrated date of 829–591 BCE. Using the 46 ± 1 m right-lateral displacement, we calculate a slip rate of 16.9 ± 0.7 mm/year for the last 2732 ± 119 years. A combined analysis with earlier paleoseismic studies on the Ganos fault suggests that the historical earthquakes of 1912, 1766b or 1659, 1354 or 1343a, and 1063 ruptured the entire inland fault section. In such a case, the recurrence interval for this section of the NAF corresponds to 283 ± 81 years. Combining earlier estimations, we suggest an average slip rate of 17.1 ± 0.9 mm/year for the last 2700 years and observe a characteristic slip behavior of 4.5 to 5 m per event for this section of the North Anatolian plate boundary fault.

  AtıfScopus1·OpenAlex2

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• MakaleAçık Erişim2023Scopus SJRQ2/r/munzur/2408
  Internal deformation of continental blocks within converging plates: insights from the Ovacık Fault (Anatolia, Türkiye)

  Zabci, Cengiz; Sançar, Taylan; Tikhomirov, Dmitry; Ivy-Ochs, Susan; Vockenhuber, Christof; Friedrich, Anke M.; Yazici, Müge; Akçar, Naki

  The active tectonics of Anatolia is mostly characterized by its westward motion with respect to Eurasia between the Hellenic subduction in the west and Arabia-Eurasia continental collision in the east. Although most of the deformation is suggested to be confined along Anatolia’s boundary elements, viz. the North and East Anatolian shear zones, recent studies indicate a higher magnitude of internal strain accumulation, especially along the parallel/subparallel strike-slip faults of its central province. We present the first morphochronology-based slip rate estimate for one of these strike-slip structures, the Ovacık Fault, by using cosmogenic36Cl dating of offset fluvial deposits. At the Köseler Site (39.3643°N, 39.1688°E), two faulted risers, bounding the alluvial fan with its subplanar surface (NF1/NF1’) and the inset terrace tread (NF1/T2), are offset 19–24 and 15–22 m, respectively. The scattered surface ages and variability of 36 Cl concentrations in depth profiles suggest strong evidence for inheritance in alluvial fan and terrace deposits; thus, we used modelled depth-profile ages for both surfaces. The modelled ages 8–10 ka for NF1 and 6–8 ka for T2 yield slip-rate estimates 2.4 +0.5/–0.4 mm/a and 2.8 +0.7/–0.7 mm/a, respectively, for the upper-tread reconstruction of the NF1/NF1’and the lower-tread reconstruction of the NF1/T2. Our results together with previous slip-rate estimates for other structures show a significant internal deformation for Anatolia, especially along its subparallel strike-slip faults. These secondary faults slice Anatolia into several pieces giving rise to the formation of the Malatya-Erzincan, Cappadocian, and Central Anatolian slices, where the geometry is strongly controlled by the distribution of the Tethyan accretionary complexes.

  AtıfScopus3·OpenAlex3·TR Dizin1

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• MakaleAçık Erişim2021Scopus SJRQ2/r/munzur/2435
  Tectonic geomorphology of the yatağan fault (Muğla, sw turkey): Implications for quantifying vertical slip rates along active normal faults

  Basmenji, Mehran; Sançar, Taylan; Dikbaş, Aynur; Boulton, Sarah J.; Akyüz, Hüsnü Serdar

  South Western Anatolia is dominated by E-W and NW-SE trending active faults. The dip-slip Yatağan Fault is one of these active structures that trends in a NW direction for ~30 km. To assess the relative tectonic activity of the Yatağan Fault, two geomorphic segments were defined along the fault: the FS-1 (northern segment) and the FS-2 (southern segment). The vertical slip rate pattern of the fault was analyzed using steepness indexes, chi (χ) plots, and log-log slope area graphs. Results of the analyses indicate that the steepness of the streams draining the footwall reveal increasingly higher values downstream along the fault. All of the main basins contain at least one slope-break knickpoint associated with tectonic uplift. Facet morphology-based investigations using empirical methods along faceted spurs of the Yatağan Fault indicate vertical slip rates of 0.16 ± 0.05 mm/year and 0.3 ± 0.05 mm/year for the FS-1 and the FS-2, according to relationship of facet slope angle (Rsa ). Additionally, using the facet basal height relationship (Rbh ) we calculated slip rates of 0.24 mm/year and 0.36 mm/year for the FS-1 and the FS-2 segments, respectively. Mountain front sinuosity analysis yields values of 1.34 and 1.2, while the ratio of valley-floor width to valley height gives values of 0.64 and 0.24 for the FS-1 and the FS-2 respectively, indicating typical active mountain front where the uplift rates are ≥ 0.5 mm/year. Hypsometric analysis suggest a transition from mature to older stage for catchments along the Yatağan Fault. Comprehensive interpretation of the results from morphometric analysis, vertical slip rate calculations, and data based on field observations suggest preponderance of tectonic activity over erosional process along the Yatağan Fault. Our analyses reveal that the rate of the tectonic activity gradually increases from the FS-1 to the FS-2 along the fault.

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• MakaleAçık Erişim2020Scopus SJRQ3/r/munzur/3145
  3d surface modeling of late pleistocene glaciers in the Munzur mountains (Eastern Turkey) and its paleoclimatic implications

  Çilğin, Zeynel

  Located in the Eastern Anatolian Region in Turkey, the Munzur Mountains (Munzurs; 3463 m above sea level) are one of the most important glacial landscapes in Turkey, with evidence for extensive glaciations in the past and small-scale glaciation at present. As Turkey’s second-largest glaciated region, these mountains include various glacial landforms, primarily glacial valleys, hanging valleys, cirques, and moraines. However, only limited data are available on the extent and chronology of former glaciations in the Munzur Mountains. This study produced data on the extent of paleoglaciers, calculated their equilibrium line altitudes (ELAs), revealed paleoclimate conditions, and modeled paleo temperatures during maximum ice extent using numerically derived reconstruction methods (GlaRe and ELA calculation tools) based on geomorphic evidence. The major glacial landforms were first mapped in detail before the reconstruction. Six hundred and eighty cirques and 30 glaciated valleys were identified. Paleoglaciers did not override the entire mountains, however, valley glaciers converged where topographic conditions were suitable.The maximum extent of glaciation covered an area of ca. 600 km2. The largest glacier was ca. 19 km in length. Moreover, 15 of the valley glaciers were over 10 km in length. Their average thickness was 75 m, and the maximum glacial thickness, in the Eastern Munzurs, was found to be ca. 300 m. The total volume of ice reached ca. 45 km3. The paleoglaciers reached as low as 1350 m above sea level. The average ELA was calculated approximately 2600 m above sea level, indicating an equilibrium line altitude depression of 1000–1100 m. The paleotemperatures, estimated based on different scenarios at the time of the maximum extent of Munzur glaciers, were 8–10 °C lower than today. The mountains experienced an increase in precipitation through this period with respect to the current precipitation scheme.

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  AtıfScopus9·WoS10·OpenAlex16·TR Dizin8

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• MakaleAçık Erişim2020Scopus SJRQ3/r/munzur/3108
  Geochemical, stable (O, c, and b) and radiogenic (sr, nd, pb) isotopic data from the eskişehir-kızılcaören (nw-anatolia) and the malatya-kuluncak (e-central anatolia) f-ree-th deposits, Turkey: Implications for nature of carbonate-hosted mineralization

  Çimen, Okay; Corcoran, Loretta; Kuebler, Corinne; Simonetti, Stefanie S.; Simonetti, Antonio

  In Turkey, the largest fluorine (F)-rare earth element (REE)-thorium (Th) deposits are located within the Eskişehir-Kızılcaören (north-western Anatolia) and the Malatya-Kuluncak (east-central Anatolia) regions, and these are associated with Oligocene extensional alkaline volcanic and Late Cretecaous-Early Paleocene postcollisional intrusive rocks, respectively. In the Kızılcaören region, the basement units include the Triassic Karakaya Complex and the Late Cretaceous oceanic units (Neotethyan suture) that are cut and overlain by phonolite and carbonatite intrusions and lava flows. In the Kuluncak region, the plutonic rocks are mainly composed of syenite, quartz syenite, and rare monzonite, and these cut the late-Cretaceous Karapınar limestone, which hosts the F-REE-Th mineralization in contact zones. A carbonatite sample from the Kızılcaören region displays both a total rare earth element (TREE) concentration (4795 ppm) and δ11B (–6.83‰) isotope composition consistent with mantle-derived carbonatite; whereas it is characterized by heavier δ13C (+1.43‰) and δ18O (+20.23‰) isotope signatures compared to those for carbonatites worldwide. In contrast, the carbonates which host the F-REE-Th mineralization in the Kuluncak region are characterized by lower TREE concentrations (5.13 to 55.88 ppm), and heavier δ13C (–0.14 to –0.75‰), δ18O (+27.36 to +30.61‰), and δ11B (+5.38 to +6.89‰) isotope ratios compared to mantle-derived carbonatites. Moreover, the combined initial87Sr/86Sr (0.70584 to 0.70759) and143Nd/144Nd (0.512238 to 0.512571) isotope ratios for samples investigated here are distinct and much more radiogenic compared to those for carbonatites worldwide, and therefore indicate significant crustal input and/or hydrothermal metasomatic-related alteration. Overall, stable and radiogenic isotope data suggest that the host carbonate rocks for the F-REE-Th mineralization in both the Kızılcaören and the Kuluncak regions consist of hydrothermally metasomatized carbonatite and limestone, respectively. The mineralization in the Kızılcaören region may potentially be related to carbonatite magmatism, whereas the mineralization in the Kuluncak region, which most likely formed through interactions between the plutonic rocks and surrounding limestone at contact metamorphism zone, involved hydrothermal/magmatic fluids associated with extensive postcollisional magmatism.

  AtıfScopus15·WoS14·OpenAlex18

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• MakaleAçık Erişim2019Scopus SJRQ2/r/munzur/3795
  Microborings as indication of cryptic life modes in the foraminifer Orbitoides: Maastrichtian sediments of the Haymana and Nallihan districts (Ankara, Turkey)

  Görmüş, Muhittin; Demırcan, Huriye; Kadioğlu, Yusuf Kağan; Yağmurlu, Fuzuli; Us, Muhammed Sami

  Widespread Maastrichtian siliciclastics and carbonates cropping out in the Haymana (S Ankara) and Nallihan (NW Ankara) districts in the northwest and central Anatolia basins include rich Orbitoides occurrences. Microborings in the Orbitoides tests are interesting to notify. In this study, the details of their morphologic structures were investigated. Microborings were analyzed in more than 650 equatorial thin sections of the Orbitoides tests and 100 hard rock thin sections. The abundance of microborings increases in the siliciclastics towards the Cretaceous/Palaeogene boundary (K/Pg). They were identified as Maeandropolydora osmaneliensis Nielsen and Görmüs, Maeandropolydora isp. Curvichnus semorbis Nielsen, Oichnus simplex Bromley, Oichnus isp. Maeandropolydora osmaneliensis Nielsen and Görmüs. Maeandropolydora isp., semicircular to circular microborings of Curvichnus semorbis Nielsen and Oichnus simplex Bromley are related to parasitic life modes. Irregular wider unidentified microborings are hermit type life mode tunnels. Abundance of the microborings might be related to shallower siliciclastic environmental conditions such as feeding and suitable Eh-pH, test shape, and easy entrance to the test for parasites. Smaller benthic foraminifera are seen in both microspheric and megalospheric Orbitoides tests as parasites. In conclusion, occurrences of microborings and encrustations are associated with parasitism by appearances of Maeandropolydora osmaneliensis Nielsen and Görmüs, Curvichnus semorbis Nielsen and Oichnus simplex Bromley and commensally attachment by microalgae.

  AtıfScopus10·OpenAlex8

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• MakaleAçık Erişim2016Scopus SJRQ1/r/munzur/3293
  Geochemistry of the metavolcanic rocks from the Çangaldağ complex in the central pontides: Implications for the middle jurassic arc-back-arc system in the neotethyan intra-pontide ocean

  Çimen, Okay; Göncüoğlu, M. Cemal; Sayit, Kaan

  The Cangaldağ Complex in northern central Turkey is one of the main tectonic units of the Central Pontide Structural Complex that represents the remains of the poorly known Intra-Pontide branch of the Neotethys. It comprises low-grade metamorphic rocks of intrusive, extrusive, and volcaniclastic origin displaying a wide range of felsic to mafic compositions. Petrographically the complex consists of basalts-andesites-rhyodacites and tuffs with minor amount of gabbros and diabases. On the basis of geochemistry, the Cangaldağ samples are of subalkaline character and represented by both primitive and evolved members. All rock types are variably depleted in Nb compared to LREEs, similar to the lavas from subduction-related tectonic settings. In N-MORB normalized plots, the primitive members are separated into 3 groups on the basis of levels of enrichment. The first group is highly depleted and displays characteristics of boninitic lavas. The second group is relatively enriched compared to the first group but still more depleted than N-MORB. The third group, however, is the most enriched one among the three, whose level of enrichment is around that of N-MORB. The overall geochemical features suggest that the Cangaldağ Complex has been generated with the involvement of a subductionmodified mantle source. The chemistry of the primitive members further indicates that the melts generated for the formation of the Cangaldağ Complex probably occurred in both arc and back-arc regions above an intraoceanic subduction within the Intra-Pontide branch of the Neotethys.

  AtıfScopus39·WoS39·OpenAlex31

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• MakaleAçık Erişim2011Scopus SJRQ2/r/munzur/4484
  Palaeoearthquakes on the Kelkit Valley Segment of the North Anatolian Fault, Turkey: Implications for the Surface Rupture of the Historical 17 August 1668 Anatolian Earthquake

  Zabci, Cengiz; Akyüz, Husnu Serdar; Karabacak, Volkan; Sançar, Taylan; Altunel, Erhan; Gürsoy, Halil; Tatar, Orhan

  AtıfOpenAlex31

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• MakaleYalnız künye2009Scopus SJRQ1/r/munzur/5661
  ²⁰⁷Pb- ²⁰⁶Pb, ⁴⁰Ar- ³⁹Ar and fission-track geothermochronology quantifying cooling and exhumation history of the Kaman- Kırşehir region intrusions, Central Anatolia, Turkey

  Otlu, Nazmi; Güney, Özlem; Heizler, Matt; Jonckheere, Raymond C.; Tichomirowa, Marion; Boztuğ, Durmuş

  Kaman-Kırşehir yöresi granitik intrüzyonları, Torid-Anatolid platformu (TAP) ve yitim zonu üzerinde gelişen Orta Anadolu Ofiyolitini (OAO) içeren okyanusal ada yayı arasında Senomaniyen–Türoniyen’de gerçekleşen kıta-okyanusal ada yayı çarpışması sonrası gerilme rejiminde oluşmuşlardır. Bu granitoyidler, kuzeyden güneye doğru, Çamsarı kuvars siyeniti, Hamit kuvars siyeniti, Bayındır nefelin-kankrinit siyeniti, Durmuşlu nefelin-nozeyan-melanit siyenit porfiri ve Baranadağ kuvars monzoniti birimlerinden oluşur. Bu intrüzif kayaçlar, Orta Anadolu Kristalin Karmaşığına (OAKK) ait metamorfik kayaçlarla OAO’ne ait birimleri sıcak dokanakla keser ve Geç Paleosen–Erken/Orta Eosen yaşlı sedimanter birimler tarafından uyumsuz olarak örtülürler. Çamsarı kuvars siyenitinin tek zirkon ²⁰⁷Pb- ²⁰⁶Pb buharlaşma yaşı 95.7±5.1 My olarak bulunmuştur; Hamit ve Baranadağ birimlerinin yaşları ise birbirlerinden ayırt edilemeyecek derecede yakın olup, ağırlıklı ortalama yaşları 74.3±4.5 My olarak belirlenmiştir. Benzer şekilde, Hamit ve Baranadağ birimlerinin amfibol ⁴⁰Ar- ³⁹Ar yaşları da birbirlerinden ayırt edilemeyecek derecede yakındır ve ağırlıklı ortalama yaş 72.7±0.1 My olarak belirlenmiştir. Çamsarı, Hamit, Baranadağ ve Durmuşlu birimlerinin apatit fizyon izi yaş verilerinin (deniz düzeyinden) yüksekliğe göre değişimleri incelendiğinde, ~57 ve ~61 My aralığında oldukça hızlı bir yükselme hızıyla (> 1 km/My) yüzeylendikleri belirlenmiştir. Böyle bir yüzeylenme tarihçesi, aynı zamanda, fizyon izi uzunluk ölçümlerine dayalı zaman-sıcaklık modelleme çalışmalarıyla da desteklenmiştir. Apatit fizyon izi jeotermokronolojisi verileriyle belirlenen Erken–Orta Paleosen yaşlı bu hızlı yüzeylenmenin, İzmir-Ankara-Erzincan (İAE) okyanusunun kapanmasını takiben TAP ve Avrasya Levhası (AL) arasında gelişen kıta-kıta çarpışmasına bağlı sıkışma rejimiyle meydana geldiği ve hatta bu sırada Orta Anadolu önülke basenlerinin de (OAÖB) açıldığı ileri sürülmektedir.

  AtıfTR Dizin11

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