The temporal evolution of the active margin along the Southeast Anatolian Orogenic Belt (SE Turkey): Evidence from U-Pb, Ar-Ar and fission track chronology

The Southeast Anatolian Orogenic Belt (SAOB) resulted from the north-dipping subduction of the southern Neotethyan oceanic lithosphere in late Mesozoic and early Cenozoic. However, the timing and the rate of the continental collision are still under debate. Here, we present new U-Pb, Ar-Ar and Fission Track ages from the I-type calc-alkaline granitoids (Esence, Doğanşehir and Baskil) cutting the Göksun, Ispendere and Kömürhan ophiolites and also the Malatya-Keban metamorphics representing the Tauride active continental margin along the SAOB. In this study, high- to low-temperature thermochronological methods, applied to the granitoids, are used to understand the temporal and geodynamic evolution of the Tauride active continental margin and continental collision between Tauride and Arabian platforms in the frame of the Neotethyan convergence during Cretaceous and Miocene. The U-Pb zircon ages range from 83 to 88 Ma for the Baskil and from 81 to 83 Ma for the Esence granitoids. The 39Ar-40Ar ages indicate that these late Cretaceous granitoids cooled below 300 °C in 6-10 Ma. The formation ages and the timing of the gradual cooling of the late Cretaceous granitoids are similar to metamorphism age and the timing of the exhumation of the HP/LT Bitlis metamorphics during this stage. The combined field, geochemistry and geo-thermochronological data suggest that the first continental collision event occurred between Bitlis-Pütürge micro-continents to the south and Tauride platform to the north in an oblique subduction zone between 84 and 74 Ma. The granitoids continued uplifting during early-middle Eocene together with the exhumation of HP/UHT Berit metaophiolite in an extensional regime related to the opening of the Maden back-arc basin. This period also let the intrusion of the Doğanşehir arc magmatism, intruding the Pütürge and Malatya-Keban metamorphics, Berit metaophiolite, and Maden Complex. The Eocene Doğanşehir granitoid has similar U-Pb and 39Ar-40Ar ages, suggesting a fast cooling. The apatite fission track (AFT) ages for all granitoid bodies suggest that they were mainly cooled or uplifted in two episodes, where the first one is in the Eocene in an extensional setting. The AFT data marked the final continental collision between the Taurides and the Arabian platform first in Oligocene and the break-off of the subducted slab and the delamination process caused fast uplift of the Eastern Anatolia during middle to late Miocene. © 2016 International Association for Gondwana Research.106Y231This study is a part of the PhD thesis of the first author and was financially supported by TUBİTAK (project no: 106Y231 ). We are grateful to two anonymous reviewers for their invaluable suggestions that improved the quality of the paper. The editorial handling by Dr. Yener Eyüboğlu is greatly acknowledged. Appendix

Rapid cooling history of a Neotethyan ophiolite: Evidence for contemporaneous subduction initiation and metamorphic sole formation

The Beyşehir-Hoyran Nappes, including Mesozoic carbonate platform rocks, deep-sea sediments, and ophiolite-related units, crop out extensively on the western limb of the Isparta Angle in the Central Taurides, Turkey. The ophiolite-related rocks are represented by variably serpentinized harzburgitic mantle tectonites, tectonically underlain by a subophiolitic metamorphic sole and mélange. The harzburgitic mantle tectonites and metamorphic sole are intruded by undeformed isolated dikes. Protoliths of the metamorphic sole are similar to within-plate alkali basalts and associated sediments. The isolated dikes were geochemically derived mainly from tholeiitic magma and, to a lesser extent, from alkaline magma. Five isolated dike samples yielded U-Pb ages ranging from 90.8 ± 1.6 Ma to 87.6 ± 2.1 Ma (zircon) and from 102.3 ± 7.4 Ma to 87.5 ± 7.9 Ma (titanite). Seven amphibolite samples yielded U-Pb age ranges of 91.1 ± 2.1-88.85 ± 1.0 Ma (zircon) and 94.0 ± 4.8-90.0 ± 9.4 Ma (titanite) and a 40Ar-39Ar age range of 93.7 ± 0.3-91.4 ± 0.4 Ma (hornblende). U-Pb and 40Ar-39Ar ages of mineral phases with different closure temperatures (~900-500 °C) from the isolated dikes and metamorphic sole rocks are almost identical and overlapping within 1?, suggesting that both the magmatic growth of oceanic crust and formation of metamorphic sole were contemporaneous and cooled very rapidly. Hence, all the data should be interpreted as the crystallization ages of the ophiolite and metamorphic sole pair. Genesis of suprasubduction zone-type oceanic crust, genesis and exhumation of the metamorphic sole, and postmetamorphic dike emplacement within the Inner Tauride Ocean can be best explained by subduction initiation and rollback processes during the Late Cretaceous based on petrological and geochronological data obtained from the ophiolitic rocks of the Beyşehir-Hoyran Nappes. © 2019 Geological Society of America.China University of Geosciences, Wuhan 113Y412 Mersin Üniversitesi GPMR201702 National Natural Science Foundation of China: 91755213Alastair Robertson, Benxun Su, and Associate Editor Erdin Bozkurt are thanked for their constructive and very valuable comments that improved the quality of the paper. We would like to thank Seher Kuru and Aynur G?rb?z for their help during cathodoluminescence imaging of zircons at Mersin University. G?zide ?nal is thanked for drawing the figures. This work was funded by T?BITAK (Project no. 113Y412) awarded to O. Parlak, and Chinese National Natural Science Foundation grant 91755213, awarded to T. Kusky. O. Parlak acknowledges the Open Fund (GPMR201702) of State Key Lab of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan for additional support

Comparison of sedation requirements for cataract surgery under topical anesthesia or retrobulbar block

PURPOSE. Topical anesthesia is increasingly being used for cataract surgery. However, it is believed that topical anesthesia causes an increased risk of intraoperative complications from unrestricted eye movement and insufficient pain control and more need for sedation. It is difficult to compare pain and anxiety experienced by individual patients; therefore, the authors used the method of patient-controlled sedation to determine whether there is a difference in sedation requirements under topical or retrobulbar anesthesia

Integrase Strand Transfer Inhibitors (INSTIs) Resistance Mutations in HIV-1 Infected Turkish Patients.

OBJECTIVES: Integrase strand transfer inhibitor (INSTI) is a new class of antiretroviral (ARV) drugs designed to block the action of the integrase viral enzyme, which is responsible for insertation of the HIV-1 genome into the host DNA. The aim of this study was to evaluate for the first time INSTI resistance mutations in Turkish patients. METHODS: This study was conducted in Turkey, between April 2013 and April 2015 using 169 HIV-1-infected patients (78 ARV naive patients and 91 ARV-experienced patients). Laboratory and clinical characteristics of ARV naive and ARV-experienced patients were as follows: gender (M/F): 71/7 and 80/11, median age: 38 and 38.4; median CD4(+) T-cell: 236 and 216 cells/mm(3), median HIV-1 RNA: 4.95+E5 and 1.08E+6 copies/ml. Population-based seqeunces of the reverse transcriptase, protease, and integrase domains of the HIV-1 pol gene were used to detect HIV-1 drug resistance mutations. RESULT: INSTI resistance mutations were not found in recently diagnosed HIV-1-infected patients. However, ARV-experienced patients had major resistance mutations associated with raltegravir and elvitegravir; the following results were generated:F121Y, Y143R, Q148R and E157Q (6/91 - 6.6%). CONCLUSIONS: The prevalence of INSTI resistant mutations in ART-experienced patients suggested that resistance testing must be incorporated as an integral part of HIV management with INSTI therapies