Author: Arif DELİ, Hükmü ORHAN
Publishing Date: 2007
Volume 22 Issue 4
The Jurassic-Cretaceous sequence comprising five formations and resting with angular unconformity on the low grade metamorphic rocks of Karakaya Complex (Upper Triassic) crops out in the study area located about 14 km SW of Ankara (Turkey). The Sinemurian–Bathonian? Bayirkoy Formation comprises five members having lateral and vertical transition among each other. It is found at the base of the sequence and was deposited in a shallow marine environment. The Middle-Upper Jurassic ÇakÍrlardere Formation is represented by marly Ammonitico-rosso at the bottom, by oolitic nodular limestone with abundant ammonite and pelagic oolitic limestone at the middle and by pelagic micritic limestones at the top, and overlies conformably the Bayirkoy Formation. The Upper Jurassic-Lower Cretaceous Sogukcam Formation contains the cherty limestones, rests conformably on the Çakirlardere Formation. The Lower Cretaceous Alacaatli Formation is characterized by pelagic limestone and sandstones and is underlain by the Sogukcam Formation with paraconformity. The Upper Cretaceous Akkayatepe sedimentary mélange includes blocks derived from the Çakirlardere and the Sogukcam Formations and, lies conformably on the Alacaatli formation.
Key Words: Ankara; AlacaatlÍ-Beytepe village; Jurassic; sedimentary mélange; ammonitico-rosso; nodular limestone