into siltstone, kaolinite-dominated claystone that in many cases ends with a layer of ironstone in the uppermost part of the formation,especially in the northwestern and southern rims of the Ga’ara Depression. These fining upward cycles are fluvial sediments deposited by meandering rivers. The sandstones of Ga’ara Formation represent the channels of these rivers, while the claystones represent the river overbank deposits, lakes and abandoned channel sediments (Tamar Agha, 1986). The presence of rippled surfaces in some of the massive ironstone indicates deposition by sand-loaded currents and flowing into lake margin and/or represents overbank deposits of fluvial depositional environment (Talbot and Allen, 1996; Nichols et al., 2007).