Inception and evolution of the Turkana Depression: A review from the perspective of the longest-lived sector of the East African Rift

Abstract

The Turkana Depression comprises a highly anomalous sector of the East African Rift (EAR), distinct in its antiquity, structural complexity, geomorphology and attenuated crustal architecture. Previous studies inferred these distinctions derive from pre-existing lithospheric heterogeneities, especially Cretaceous–early Paleogene Central African Rift (CAR) tectonism. Yet, Paleogene extensional deformation is neither clearly typical CAR, nor EAR. Instead, extension gradually evolved from primarily plate-driven (slab pull), to a hybrid state where mantle plume-related (active) processes became increasingly important (particularly c. 23- 7 Ma) to one after c. 7 Ma where active rifting processes d..