Oceanic lithosphere-asthenosphere decoupling is required for the functioning of plate tectonics

大洋岩石圈-软流圈解耦是板块构造能够运行的关键

Evidence of seafloor spreading[1,2]proved the seafloor-spreading hypothesis[3]and led to the discovery of plate tectonics.A further observation-based analysis showed that seafloor-spreading results from downward pulling of the subducting slab[4],which drives plate tectonics and dictates the first order pattern of mantle convection[5](Fig.1a).Continental drift is understood as a passive response to trench retreat under gravity due to seafloor subduction[6].All this,plus the understanding that ocean ridges are passive features[7],has completed the paradigm of the plate tectonics theory.However,a fundamental issue concerning mantle flow subjacent to the spreading oceanic lithosphere remains widely misperceived(Fig.1b,c),which needs correction so as to better appreciate the efficacies of the plate tectonics theory and to correctly understand the origin and evolution of oceanic lithosphere as well as processes of chemical differentiation of the Earth.