Influence of mantle plume on continental rift evolution: A case study of the East African rift system

Abstract

Mantle plume is an essential component of the mantle convection system, and its influence on the geodynamics of continental rifts is of great significance for understanding the crust–mantle interaction. The East African Rift System, as the largest continental rift in the Cenozoic and in the initial stage, provides an excellent option for studying the interaction between the mantle plume and the continental crust. Based on the data such as GPS, seismic tomography, and global crustal model, a viscoelastic-plastic 2D thermodynamic numerical model is established to reconstruct the evolution of the Afar depression, Ethiopian Rift, and Kenyan Rift. By comparing the differences between the models of the Afar depression, Ethiopian Rift, and Kenyan Rift, the relationship between the mantle plume and pre-existing structures and their influence on the evolution of continental rifts are discussed. The results show that the mantle plume can increase the depth of the rift faults, concentrate the distribution of the faults, and strengthen the control of main faults on the rifts, allowing the possibility of narrow rifts. Pre-existing structures control the fault styles and symmetry of the rifts and also the morphology of the mantle plume.