The Calanchio-Uweinat uplift exists in Eastern Libya between longitudes : 24°00´E and 25°00´E and separating the Kufra Basin (Libya) from the Dakhla Basin (Egypt) [Klitzsch 1971 and El Ramly 1980].
This uplift has a NW-SE trend and occurred since the Paleozoic and Mesozoic time. Along the edge of this uplift occurs series of block faulting during the Jurassic – Cretaceous transition. Regional compression from the SE direction towards the NW direction was the cause of these movements. Most of the faults are of the strike- - slip type with horizontal throw reaching up to 15 km with average of 5km.
Recent detailed geological field work by the Egyptian Geological Survey and the Libyan Industrial Research Centre (M. Said et al, 2000) and edited by K. Oweiss (2000) on Jabal Arkenu Sheet, in addition to the work done by M. Said et al., 2001 on Jabal Asbah sheet confirmed the existence of the Calanchio - Uweinat uplift. Both Jabal Asbah and Jabal Arkenu are within the framework of the Calanchio – Uweinat uplift.
The Jabal Arkenu area is composed of undifferentiated Precambrian rocks overlain by Paleozoic and Mesozoic sediments which are intruded by granites and gabbro ring complexes and volcanic rocks of Tertiary age.
On the otherhand, the Jabal Asbah area include exposed undifferentiated Precambrian rocks overlain by Paleozoic and Mesozoic sediments, covered partially by Quaternary deposits.
Hydrogeologically, the Calanchio – Uweinat – major anticline acts as a groundwater divide between the Kufra Basin to the west and the Dakhla Basin to the east. This is one of the scientific evidences reached by the present author (1977-1982) during his work on the groundwater potentialities of Eastern Libya with the United Nations Food and Agriculture Organization (FAO). The results of his studies showed that the two major groundwater basins are not hydraulically connected and there is no groundwater movement from the Kufra Basin in Libya to the Dakhla Basin in Egypt. Accordingly, the previous hydrogeologic views by various hydrogologists that they are connected, are clearly cancelled.