Age Estimation of Qash Qooly Valley in Dokan Vicinity, North Iraq Using Exposure Age Determination Method

Qash Qooly valley runs parallel to Pera Magroon, Sara and Surdash anticlines, almost in SE-NW trend, and merges with the Lesser Zab River 9 km southeast to Dokan town. Before its development, it was a large basin with width ranges between 2~3 km, which was filled during Pleistocene or may be Late Pliocene by different types of sediments. The presence of the calcrete on the top indicates a wet period that has lasted for a long time as indicated from the thickness of the calcrete and alluvial fan sediments. The age of Qash Qooly valley was estimated using the exposure age determination method. The type of the sediments, their thicknesses, and erosion intensity and sediments' dens dissection by rills were the main features used. This study concluded that the age of the basin is Pliocene—Late Pleistocene, whereas the valley started to be developed during uppermost Late Pleistocene and is still active in shifting its course.