Adakite-like intrusive rocks from the Bozüyük area (NW Turkey)

We have discovered a felsic intrusive unit (the Karaköy granite; 125±4.2 M.A.), which was emplaced into the Triassic metamorphic rocks of the Sakarya Zone as small stocks and dikes in the north of the Bozüyük Town of NW Turkey. This area is close to the İzmir-Ankara Suture which is the remnant of northern branch of Neo-Tethys Ocean. The Karaköy granitic rocks are composed of equigranular leuco granites, granodiorites, tonalites and their hypabyssal equivalents. They are represented by peraluminous and low-K rocks, displaying high SiO2, Al2O3, Na2O, Sr, and low K2O, MgO, Yb and Y. They exhibit negative Nb-Ta anomalies similar to the subduction related magmas. By contrast, lack of negative Eu anomaly and presence of high Sr/Y and low K2O/Na2O ratios are likely to the adakite-like magmas and/or Archaean TTG's. In the light of the findings obtained from this study, we conclude that there was an active north-dipping subduction zone within the northern Neo-Tethys Ocean during the Early Cretaceous, and adakite-like intrusive rocks derived possibly from the melting of basaltic topmost layer of the subducted slab.