Shaka Ridge (South Atlantic)—a Remnant of Continental Crust?

Abstract As a result of a study of igneous rocks of the basalt - andesite series, dredged on the Shaka Ridge in the South Atlantic, it was found that they differ from the basalts of mid-ocean ridges and ocean islands, and have an age of 183.8 ± 2.2 Ma, comparable to the time of manifestation of the Karoo-Maud mantle plume in central Gondwana. Geochemical and Sr–Nd–Pb isotopic features of the studied igneous rocks show their similarity with the Jurassic mafic complexes of the Ferrar province in Antarctica and the Falkland Islands, formed during the intrusion of the Karoo-Maud plume and under the influence of paleo-Pacific subduction. However the supply of ice rafted debris into the study area due to ice transportation is considered unlikely. Based on the all data obtained, it was concluded that the Shaka Ridge is a continental block that was moved during the opening of the South Atlantic in the Early Cretaceous-Early Miocene from the continental margin of Africa along an extended transform fault into the present Bouvet triple junction area.