EG55: Structure and stratigraphy of Al Jaww Plain, southeastern Al Ain, United Arab Emirates: implications for aquifer systems and mantle thrust sheets

This study presents the findings of an integrated geophysical and borehole study conducted in the Al Jaww Plain, Al Ain, United Arab Emirates, focused on the properties of groundwater aquifers, the Semail ophiolite contact, and the subsurface structure and stratigraphy. By analyzing groundwater borehole data, three interconnected groundwater aquifer types were identified and their hydrogeological properties were characterized. The near-surface Quaternary unconfined aquifer is a fresh groundwater aquifer with an average thickness of 25 m. The second aquifer, with an average thickness of 110 m, is connected to the upper Quaternary freshwater aquifer and is interpreted as part of the surficial aquifer system, while the underlying third aquifer has an average thickness of 200 m. Using electrical resistivity tomography, the depth of the water table and groundwater potential in the shallow unconfined Quaternary aquifer near Jabal Mundassa were estimated, consistent with the observations of the unconfined Quaternary aquifer from across the entire Al Jaww Plain as identified by the groundwater borehole cross-section. In addition, this study provides insights into the area's subsurface structural and stratigraphic features, revealing the westward extension of the Hawasina thrust sheet within the plain. Gravity and magnetic data analyses in the southeastern Al Jaww Plain delineate the Semail ophiolite's extent. Notably, the magnetic data reveal the presence of an NW-SE-oriented magnetic anomaly detached from the main ophiolite thrust, which corresponds to the interpreted contact between the Semail ophiolite and the carbonate rocks on the Bouguer gravity map.