These geochemical traits point to the adakite-like affinity for Pertek andesite-dacite porphyries, however, they present some geochemical characteristics of both oceanic slab-derived and continental crust-derived adakites and show a dual character. Enrichment in K2 O, Th, Rb, and Hf in these adakitic porphyries is mostly associated with the crust-derived terrigenous sediments during active subduction, before the Early Miocene. It is concluded that the continent-continent collision between the Arabian Plate and Eurasian Plate, break-off of Bitlis slab, and the onset of volcanism in the region was developed at Early to Middle Miocene, and the Pertek adakitic volcanism was triggered by collision- and slab break-off-induced asthenospheric mantle flows. | Turkish Journal of Earth Sciences Turkish J Earth Sci 2021 30 948-972 http earth TÜBİTAK Research Article doi yer-2104-16 Generation of collision-induced Early to Middle Miocene adakitic magmas in Pertek Tunceli area from Eastern Anatolia postsubductional setting Turkey 1 2 3 Sevcan KÜRÜM Hakan ÇOBAN Pınar AYDIN 1 Department of Geology Faculty of Engineering University of Fırat Elazığ Turkey 2 Faculty of Engineering and Architecture University of Bitlis Eren Bitlis Turkey 3 Institute of Science and Technology University of Fırat Elazığ Turkey Received Accepted Published Online Final Version Abstract Early to Middle Miocene andesite-dacite porphyries are well exposed to the Pertek area of Tunceli Eastern Anatolia and represent an example of adakite-like magma generation in Eastern Anatolia postsubductional collisional setting. Mineral associations in these porphyries are composed of plagioclase oligoclase-andesine-labradorite amphibole pargasite-ferropargasite biotite rare quartz K-feldspar and minor Fe-Ti oxides. Geochemically they are high-K calc-alkaline in nature and characterized by high SiO2 gt 62 wt. Al2O3 mostly gt 16 wt. Na2O K2O ratio and Sr generally gt 400 ppm contents. Volcanic rocks display depletion in HFSEs Nb Ta and Ti and slight negative Eu anomaly have low HREEs Y KÜRÜM et al. Turkish J Earth Sci In this regard adakite-like signature of Cenozoic Tethyan oceanic crust in the Oligocene and collision of intermediate-acidic porphyries from the Anatolian Arabian and Anatolian Plates Şengör and Yılmaz 1981 postsubductional tectonic settings have been reported by Koshnaw et al. 2017 . Because the compression resulted several workers . Varol et al. 2007 Karslı et al. 2009 from the collision of two plates the Eastern Anatolia 2010 2011 2013 Topuz et al. 2011 Eyüboğlu et al. 2011c region had been shortened and thickened Şengör et al. 2012 Şen and Şen 2013 Lechmann et al. 2018 Yücel
