The shield is divided into crustal blocks or tectonostratigraphic terranes delineated by ophiolite shear zones or sutures. These terranes are paired across the Red Sea, starting from the south, these include Nakfa (870-840 Ma) with Asir (785-720 Ma, 850-790 Ma), Haya (870-790 Ma) with Jiddah (870-760 Ma), Gabgaba (735-700 Ma) and Gebeit (832-810 Ma) with Hijaz (870-807 Ma), and Eastern Desert (810-720 Ma) with Midyan (780-710 Ma). In addition the Halfa (2.6-1.2 Ga, 750-718 Ma) and Bayuda (806 Ma) terranes are in the western portion of the shield, and the Hulayfah (720 Ma), Ha'il (740 Ma), Afif (750-695 Ma, 840-820 Ma, 1.86-1.66 Ga), Ad Dawadimi (695-680 Ma), and Ar Rayn (667 Ma) terranes in the eastern portion.