Relationship between Superficial and Deep Tectonics in the African Region Based on Geological-Geophysical Data

The spatial relationships of the lower mantle D" layer elements with Phanerozoic Large Igneous Provinces (LIPs), as well as with the young hotspots and kimberlites in the African region, are discussed. Similar relationships are also shown for the Cape Karoo and Parana extended basins, which had developed as inherited structures along the marginal parts of the region since the Early Paleozoic. The specific locations are marked for all these superficial structures and plumes producing them. These locations indicate the connection between these structures origin and the domains where the Earth's core, Large Low-Velocity Provinces (LLSVPs), and slab graveyards contact with each other. The relationships between plume- and plate-tectonic processes in the Earth's evolution are considered. Constant interaction between the Pacific and Indo-Atlantic segments of the Earth is revealed in the course of these processes. The Pacific segment was characterized by ocean formation during the Phanerozoic time and subsequent subduction under the continental landmasses of Indo-Atlantic segment. The constant character of spreading in the Pacific Ocean was obviously determined by the presence of its direct connection with the Pacific LLSVP. Within the D" layer in the areas of contact between the Pacific subducting slabs and African LLSVP, plume generation occurred periodically, subsequently leading to supercontinental breakup. This determined the specific character of the Indo-Atlantic segment development: the alternation of convergence and continental breakup during the Phanerozoic. In general, despite the significant similarities between the antipodal African and Pacific LLSVPs, their role in formation of the superficial largest structural elements appears to be inequable. Perhaps this is what had become one of the main reasons that caused fundamental differences between these two segments and led to the formation of tectonic asymmetry of the Earth.