Advance and perspective of study on the interaction between slow-spreading South Mid-Atlantic ridge and mantle plume

Revealing the possible connection between mid-ocean ridge (MOR) and mantle plume would provide an important way with us to know the material components and dynamics of the Earth mantle, which has been the frontier and focus of solid earthscience research for more than forty years. The global MOR system is as long as more than eighty thousand kilometers, and a significant fraction of MOR segments has been influenced by their adjacent mantle plumes. Previous studies have shown that the formation and evolution of the Atlantic Ocean are closely associated with mantle plume. Especially, during the opening of the South Atlantic Ocean (SAO), the South Mid-Atlantic ridge (SMAR) system has been interacted with its nearby mantle plumes (e.g., Saint Helena, Ascension, Tristan da Cunha, Gough, Discovery mantle plume) with different extents, which lead the mid-ocean ridge basalts (MORBs) along the SMAR system keep a significant compositional heterogeneity. In this paper, we systemically reviewed the characteristics of global ridge and plume (ridge-plume) interaction, and the tectonic evolution and mantle source nature of the SAO. Further, we summarized the geochemistry features of MORBs sampled from SMAR 13.2°S to 24.2°S segments, which have indicated that ① the magma evolution and the nature of mantle source of the SMAR system; ② the main direction of the Saint Helena plume materials propagating to the SMAR system; ③ the influence scope of Saint Helena plume on the SMAR system (14.2°S~20.4°S segments); ④ the spatial distribution of plume-affected asthenosphere mantle between the SMAR system and the Saint Helena plume. Finally, we raised several important scientific questions and proposed some future perspectives in this study field to scholars. © 2022 Geological Society of China. All rights reserved.