Tectonic Conditions of Origin and Geodynamic Setting of Opening of the Rifts of the Red Sea and the Gulf of Adena

The article presents results of the study that identifies tectonic conditions responsible for the origin of the Late Cenozoic rifts of the final stage of the development of the Red Sea and the Gulf of Aden. The rifts, connected at the right angle, had different stages of oceanic opening. We propose a geodynamic model of the Red Sea rift formation, based on data on the continental-lower crustal nature of the high-density basement of this rift. Our Paleotectonic reconstructions support the previous model of the pre-rift location of Arabia near the “shores” of Africa and the deep entry of the Yemen “Corner” of Arabia into the “Triangle” of the Afar Depression. The separation and syn-rift removal of Arabia from Africa occurred in different and unique tectonic settings, is shown. The Red Sea Rift originated in the largest area of the Late Proterozoic juvenile crust protruding in the central part of the Arabian‒Nubian Shield. In contrast, the Gulf of Aden Rift formed within a large pericontinental sedimentary basin, which is unusual for rifts of all ages and types. The directions of the rift separation Arabia from Africa were predetermined historically and coincided with the boundaries of ancient lithospheric blocks that experienced different tectonic development. These geological boundaries, related to the deep geo-divisions, outlined in the crustal structure as pan-African folding belts of various ages and types.