Geomechanical properties of Upper Cretaceous-Eocene carbonates forming the foundations of El Galala City, El Galala El Bahariya, Egypt

Abstract

This study aims to evaluate the physical and engineering properties of the Upper Cretaceous- Eocene carbonate rocks, and assess the hazards related to these rocks. Also, the integration between geologic data, field measurements with the engineering properties of the carbonate rocks are the targets to achieve a better result about the nature and strength of the foundation carbonate rocks under El Galala city. The carbonate rocks of the present study are exposed at the upper part of El Galala El Bahariya plateau. The Upper Cretaceous- Eocene carbonate rocks that forming the cap unit of the eastern part of El Galala El Bahariya plateau (Northern Galala) are selected to be the target of the present study, where there exist many investment projects, such as El Galala city that is currently constructed on the top surface of this plateau. El Galala El Bahariya is a high flat topped plateau and is one of the most impressive topographical features in the northern part of the Eastern Desert. The study area is located in the northwestern part of Gulf of Suez, which includes the eastern edge of El Galala El Bahariya plateau. The study area is defined by Latitudes 2915 and 29°35N and Longitudes 32°15and 32°35E. New Galala road constructed ascending El Galala El Bahariya from north to south that facilitated the present study and sampling process. Coastal and new Galala road are connected in the middle latitude of El Galala El Bahariya plateau by a NE oriented pumping stations road. From the field study and measurements of many sections, a composite stratigraphic section was measured in the eastern scarp of El Galala El Bahariya plateau. The total thickness of these units is about 900 m. The section begins at the base with the Paleozoic units (Rod El Hamal, Abu Darag and Ahemir Formations) that followed upward by Permo-Triassic (Qiseib Formation), Jurassic (sandstone and marl), Lower Cretaceous (Malha Formation) and Upper Cretaceous (Galala Formation and carbonates) and finally all these rocks are capped by more than 200 m of hard, massive dolomitic limestone and dolostone rocks that are belonging to Eocene rocks that are charged by kartisified caves.