[1] The Red Sea Hills are composed of the exposed Neoproterozoic volcano-sedimentary rock of the Arabian-Nubian Shield.
The Oligocene uplift caused the rejuvenation of their streams and the increased erosion removed most of the limestone and sandstone to expose the basement layer.
[6] The Red Sea Hills are a source of porphyry, which was being mined as early as the fourth millennium BC.
[7] The Red Sea Hills are inhabited by the Beja people who speak a Cushitic language and practice pastoralism.
They mainly live near the dry riverbeds, wādīs, that flow seasonally into the sea and the Nile, where there is limited vegetation.