@article{ElmasKoralayDuruetal.2017,
  author    = {Elmas, Ali and Koralay, Ersin and Duru, Olgun and Schmidt, Alexander},
  title     = {Geochronology, geochemistry, and tectonic setting of the Oligocene magmatic rocks (Marmaros Magmatic Assemblage) in Gokceada Island, northwest Turkey},
  series = {International Geology Review},
  volume    = {59},
  journal   = {International Geology Review},
  number    = {4},
  publisher = {Taylor \& Francis Group},
  address   = {Philadelphia},
  issn      = {0020-6814},
  doi       = {10.1080/00206814.2016.1227941},
  pages     = {420 -- 447},
  year      = {2017},
  abstract  = {Through the zmir-Ankara-Erzincan and the Vardar oceans suture zones, convergence between the Eurasian and African plates played a key role in controlling Palaeogene magmatism in north-western Anatolia, northern Aegean, and eastern Balkans. LA-ICP-MS dating of U and Pb isotopes on zircon separates from the tuffs of the Harmankaya Volcanic Rocks, which are inter-fingered with the lower-middle Eocene deposits of the Gazikoy Formation to the north of the Ganos Fault and the Karaaac Formation in the Gelibolu Peninsula, yielded a late Ypresian (51Ma) age. The chemical characteristics suggest that the lavas and tuffs of the Harmankaya Volcanic Rocks are products of syn- or post-collision magmas. These volcanic rocks show also close affinities to the subduction-related magmas. In addition to the already known andesitic volcanic rocks, our field observations in Gokceada Island indicate also the existence of granitic and rhyolitic rocks (Marmaros Magmatic Assemblage). Our U-Pb zircon age data has shown that the newly discovered Marmaros granitic plutons intruded during late Oligocene (26Ma) into the deposits of the Karaaac Formation in Gokceada Island. LA-ICP-MS dating of U and Pb isotopes on zircon separates from the Marmaros rhyolitic rocks yielded a late Oligocene (26Ma) crystallization age. Geochemical characteristics indicate that the more-evolved Oligocene granitic and rhyolitic rock of the Marmaros Magmatic Assemblage possibly assimilated a greater amount of crustal material than the lower Eocene Harmankaya Volcanic Rocks. Geochemical features and age relationships suggest increasing amounts of crustal contamination and a decreasing subduction signature during the evolution of magmas in NW Turkey from the early Eocene to the Oligocene. The magmatic activity developed following the northward subduction of the zmir-Ankara-Erzincan oceanic lithosphere and the earliest Palaeocene final continental collision between the Sakarya and Anatolide-Tauride zones.},
  language  = {en}
}
@article{HajialioghliMoazzenJahangirietal.2011,
  author    = {Hajialioghli, Robab and Moazzen, Mohssen and Jahangiri, Ahmad and Oberh{\"a}nsli, Roland and Mocek, Beate and Altenberger, Uwe},
  title     = {Petrogenesis and tectonic evolution of metaluminous sub-alkaline granitoids from the Takab Complex, NW Iran},
  series = {Geological magazine},
  volume    = {148},
  journal   = {Geological magazine},
  number    = {2},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {0016-7568},
  doi       = {10.1017/S0016756810000683},
  pages     = {250 -- 268},
  year      = {2011},
  abstract  = {The Takab complex is composed of a variety of metamorphic rocks including amphibolites, metapelites, mafic granulites, migmatites and meta-ultramafics, which are intruded by the granitoid. The granitoid magmatic activity occurred in relation to the subduction of the Neo-Tethys oceanic crust beneath the Iranian crust during Tertiary times. The granitoids are mainly granodiorite, quartz monzodiorite, monzonite and quartz diorite. Chemically, the magmatic rocks are characterized by ASI < 1.04, AI < 0.87 and high contents of CaO (up to similar to 14.5 wt \%), which are consistent with the I-type magmatic series. Low FeO(t)/(FeO(t)+MgO) values (< 0.75) as well as low Nb, Y and K(2)O contents of the investigated rocks resemble the calc-alkaline series. Low SiO(2), K(2)O/Na(2)O and Al(2)O(3) accompanied by high CaO and FeO contents indicate melting of metabasites as an appropriate source for the intrusions. Negative Ti and Nb anomalies verify a metaluminous crustal origin for the protoliths of the investigated igneous rocks. These are comparable with compositions of the associated mafic migmatites, in the Takab metamorphic complex, which originated from the partial melting of amphibolites. Therefore, crustal melting and a collision-related origin for the Takab calc-alkaline intrusions are proposed here on the basis of mineralogy and geochemical characteristics. The P-T evolution during magmatic crystallization and subsolidus cooling stages is determined by the study of mineral chemistry of the granodiorite and the quartz diorite. Magmatic crystallization pressure and temperature for the quartz-diorite and the granodiorite are estimated to be P similar to 7.8 +/- 2.5 kbar, T similar to 760 +/- 75 degrees C and P similar to 5 +/- 1 kbar, T similar to 700 degrees C, respectively. Subsolidus conditions are consistent with temperatures of similar to 620 degrees C and similar to 600 degrees C, and pressures of similar to 5 kbar and similar to 3.5 kbar for the quartz-diorite and the granodiorite, respectively.},
  language  = {en}
}