(Fig. 1).The northern and western rims dip gently northwards and consist of the Upper Cretaceous–Paleogene sequence of Rutba/Msa’d, Hartha, Tayarat, Digma and Akashat Formations, and dip gently northwards. The eastern rim of depression, however, comprises lower Eocene limestone that also dips gently northwards. Deep erosion of the uppermost part of the Rutba Uplift resulted in the formation of various geomorphological features in the Ga’ara Depression (Tamar-Agha and Abdullah, 2013).