The discovery of a low-angle normal fault in the Taurus Mountains: the İvriz detachment and implications concerning the Cenozoic geology of southern Turkey

Abstract

The İvriz detachment fault has been determined on the southern border of the Ulukışla basin separating the metamorphicBolkar Group of the Taurus Mountains and the Paleocene-Lower Eocene Halkapınar formation of basin deposits. The fault dips towardsthe north and has kinematic indicators (asymmetric grain/grain aggregate porphyroclasts, oblique foliation, and S-C fabrics), suggestinga top-to-the-N-NE sense of shearing. The clastic material originating from the Bolkar Group in the sedimentary units of the Ulukışlabasin demonstrates that the detachment fault could have been be active during Latest Cretaceous-Eocene times. The İvriz detachmentmay have initiated as part of a high-angle breakaway fault (the Aydos main breakaway fault) in the south of the Ulukışla basin. Thebreakaway fault then rotated to a low-angle normal fault and its northern continuation played an important role in the exhumation ofthe Central Anatolian Crystalline Complex. This implies that the Upper Cretaceous-Eocene sedimentary basins in central Anatolia weresupradetachment basins rather than collision- or arc-related basins as previously suggested.