Mantle plume- induced subduction initiation: Mechanisms and implications for plate tectonics

Abstract

Subduction initiation, a cornerstone of plate tectonics, remains shrouded in complexity and mystery. This study reviews numerical models and natural occurrences of subduction initiation induced by mantle plumes on Earth and other terrestrial planets. We argue that mantle plumes, as non-plate tectonic agents, can initiate subduction in both ancient and contemporary settings without pre-existing lithospheric weaknesses. Our analysis of numerical simulations indicates that far-field stresses and the plume’s tail play pivotal roles in initiating subduction, while lithospheric weak zones and plate dynamics modulate the symmetry of subduction zones. The positioning of oceanic plateaus relative to the mantle plume significantly impacts subduction initiation. This paper also explores additional properties of mantle plumes crucial for subduction zone formation, fostering a more comprehensive understanding of plume-induced subduction initiation and its implications for global tectonics.