## 2 Study Area  
The central part of the Gulf of Suez area has a long history of tectonic events. The Wadi Araba basin is located in the central part of the Gulf of Suez zone (Figure 1). It has a length of about 80 km and a width of about 30 km, oriented in the NE-SW direction. Along the Wadi Arab basin, there is a major river running through the whole length that is fed by valleys from the Northern and Southern Galala Plateaus. The Northern Galala Plateau is bounded by steep cliffs to the north, east, and south, whereas the Southern Galala Plateau is edged by steep cliffs to the north and east. The highest point of the Northern Galala Plateau is recorded as 1249 m and the altitude decreases westward to reach 400-500 m at the El-Maaza Plateau. The highest point of the Southern Galala Plateau is 1349 m. This plateau is more dissected than the northern plateau.  
The rock units recorded in the study area include marine and non-marine successions varying in age from Paleozoic to Quaternary. The whole succession is underlain by Precambrian basement rocks. Regarding the Oligo-Miocene event of the Suez rifting, the lithology of the study basin is classified into three major tectonoststratigraphic events: the pre-, syn-, and post-rift [22]. Different rock types were recorded in the study basin, including rocks from the Upper Carboniferous Rod El-Hamal Formation. This formation is composed of limestone, shale, and thin layers of sandstone [27]. Rocks from the Permian-Triassic period were recorded in the Qisieb Formation. It has a thickness of about 44 m in the Northern Galala Plateau and consists of interbedded ferruginous, continental, red beds of sandstone and variegated shale [22]. The overlaying Lower Cretaceous Malha Formation consists mainly of white to grey cross-bedded continental sandstone, passing into marine beds [27] (Figure 2). The Upper Cretaceous is represented, from older to younger, by undifferentiated deposits in the Galala Formation and St. Antony Formation, respectively. The Galala Formation is located mainly at the western flank of the study basin and represented by marine limestone with shale (Figure 2). The St. Antony Formation consists of chalky limestone and shallow-water marl [27]. The Lower and Middle Eocene are represented by the Abu Rimth Formation and Mokkattam Group, respectively [28] (Figure 2). The youngest Quaternary units in the study area are represented by the Quaternary and Wadi deposits [28] (Figure 2). The Upper Cretaceous, Quaternary, and Wadi deposits cover the majority of the study area (Figure 2).  
The Wadi Araba deformation basin is a major Late Cretaceous inversion anticline form [29]. It comprises two major ENE anticlines. This plunging anticline has a steep southern limb, where a nearly vertical Upper Cretaceous section is exposed in the northern  
Figure 2: Detailed geological map of the study basin, modified from [28].  
wall of the Southern Galala Plateau [22; 29]. The southern flanks of both folds are found in both ENE deformation zones [22]. The northeastern tip of the Wadi Araba basin reaches to the western side of the Gulf of Suez Rift [29; 30]. The listric faults of the northern and central half grabens of the Suez Rift overlap each other in the zone of Wadi Araba basin, confirming the basin effect on the boundaries of these two faults that caused the propagation of the two mega-half grabens during the rift opening event [29].