The ductile shear zone in granitoid of the Central Anatolian Crystalline Complex, Turkey: Implications for the origins of the Tuzgölü basin during the Late Cretaceous extensional deformation

Abstract

The Emizözü shear zone is the west–northwest-trending ductile shear zone within the Ağaçören granitoid in central Turkey. Deformation that affected the granitoid along the Emizözü shear zone resulted in mylonites with mylonitic foliation and stretching lineation. The textural features of the deformed minerals suggest that mylonitization occurred under conditions of upper greenschist facies. The shear indicators, including asymmetric porphyroclasts, oblique foliation, and shear bands, suggest a down-dip (top-to-the-southwest) displacement. The orientation of stretching lineation, as well as kinematic indicators, indicates the extensional character of the Emizözü shear zone. Although it is not precisely dated, the available age constraints suggest that the zone formed at 78–71 Ma. According to field and micro-structural data, the Ağaçören granitoid was most likely emplaced during a regional deformation in central Turkey, and synchronously or shortly after was overprinted by the extensional Emizözü shear zone. The zone can also be correlated with the earlier stage development of the Tuzgölü basin in central Turkey.