On the geodynamics of the Alpine collisional granitoids from Central Anatolia: petrology, age and isotopic characteristics of the granitoids of the Ekecikdag Igneous Association (Aksaray/Turkey)


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Toksoy-Köksal F.

GEODINAMICA ACTA, cilt.31, ss.1-26, 2019 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 31 Konu: 1
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1080/09853111.2019.1597677
  • Dergi Adı: GEODINAMICA ACTA
  • Sayfa Sayıları: ss.1-26

Özet

Granitoids of the Ekecikdag Igneous Association (Central Anatolia/Turkey) are products of collisional-post-collisional magmatism in the Ekecikdag area. These granitoids are granodiorite, microgranite and leucogranite. Field relations of granodiorites with microgranites is obscured, but leucogranites intrude both rock types. Mean zircon laser ablation (LA)-ICP-MS Pb-206-U-238 ages of granodiorites and microgranites are 84.52 +/- 0.93 Ma and 80.7 +/- 1.6 Ma, respectively, and age of leucogranites is suggested as 80 Ma, based on field relations combined with Pb-206/U-238 and Rb-Sr ages. Crystallisation temperatures of granodiorites, microgranites and leucogranites are 728 degrees C-848 degrees C, 797 degrees C-880 degrees C, 704 degrees C-809 degrees C, respectively. Geochemical characteristics including Sr-Nd isotopic evidences infer a non-cogenetic character, as there is a high crustal contribution in I-type granodiorite sources, a crustal source with insignificant and significant mantle inputs in S-type microgranites and leucogranites, respectively. LA-ICP-MS Lu-Hf isotope data from zircons reveal their crustal nature (epsilon Hf-(t): -1.3 +/- 0.5 to -8.8 +/- 0.5). Crustal melting linked to the Alpine thickening during the Late Cretaceous led to formation of heterogeneous sourced granitoids with crustal dominated sources in the Ekecikdag area. Understanding of the nature and evolution of collisional Ekecikdag granitoids is not only important to put contribution in the geodynamic evolution of Central Anatolia and surrounding Alpine area, but also to better understand systematics of collisional magmatic systems.