Great Escarpments are gigantic geomorphic features stretching over thousands of kilometers. Along the margins of the African continent, these escarpments were developed during the last 130 Ma due to rifting processes. However, their genesis and evolution, including the scale of their escarpment retreat over the geological time, generated a long debate.
New field observations from South Africa and Namibia, stretched over 2000 km, and observations taken along the Suez and the Dead Sea rifts, indicate that Great Escarpments evolved as a product of three successive stages:
1. Penetration of mantle plumes below the Gondwana continent, first during the Jurassic—Early Cretaceous and then during the Oligocene, caused crustal heating and slow tectonic uplift, shaping large domes that preceded the continent's breakup. Along the dome flanks, the old geological strata was tilted toward the continental interior.
2. Simultaneously with the slow uplift, a Pre-Rift Truncation Surface (PRTS) was developed, which truncated the tilted geological section by a near-planar, extensively distributed, erosional plain. The truncation surface exposed highly resistant layers, embedded in the tilted geological strata, creating the future location of the Great Escarpments.
3. The gradual localization of the deformation along major fault zones caused the continental break-up and rifting. This was accompanied by rapid uplift and the creation of the Great Escarpments along the high-resistant strata exposed by the PRTS. On the southern African continent facing the Atlantic rift, the Great Escarpments developed in the Early Cretaceous (130 Ma), while along the Red Sea, they were initiated in the Oligocene—Early Miocene (25-20 Ma).
In contrast to previous models highlighting the large-scale backward retreat of the Great Escarpments from their original position since the Early Cretaceous, our results indicate that since their initial creation some 130-25 Ma respectively, these Great Escarpments have undergone only minimal retreat.