Nubian-Arabian Shield

a large outcrop of the Precambrian basement in the northeastern part of the African Platform. The rift of the Red Sea bisects the shield along its axis; as a result the western half of the shield is in Africa (the Nubian Desert), and the eastern half occupies the western part of the Arabian Peninsula. The shield is composed of a thick and strongly dislocated stratum of gneisses and schists with pockets of quartzite and marble dating from the Upper Proterozoic. This stratum has been breached by granite intrusions (several generations). There are recent outflows of basalt.