An interactive map of the principal geological units of the Shield

An interactive map of the structural features of the Shield

Before the opening of the Red Sea, 30-25 Ma ago, the Arabian Shield (650,000 km²) formed part of a larger geological ensemble, the Arabian-Nubian Shield, which covers several countries, mainly Egypt, Eritrea, Ethiopia, Saudi Arabia, Somalia, Sudan and Yemen. The Arabian-Nubian Shield consists primarily of Neoproterozoic juvenile crust and represents an area of suturing between East and West Gondwana before the Paleozoic. It formed through the accretion of numerous, mainly inter-oceanic, island arcs along ophiolite-lined suture zones and gneissic fault zones between 900 Ma and 550 Ma when the Mozambique ocean closed.