摘要

<正>The ascendent theory that unifies the Earth Sciences is Plate Tectonics, a regime which is unique to Earth. Other convectively active, solid silicate bodies of our Solar System (Venus, Mars, and Io) are encased in a single deforming ‘‘lid"; on these, multiple plates and hence plate motions do not exist [1]. As Earth’s tectonic plates are driven by the sinking of old and cold oceanic lithosphere at subduction zones, understanding how new subduction zones originate is vital for a complete plate tectonic theory. Proposed mechanisms of subduction initiation (SI) are controversial but can be either spontaneous, i.e., caused by forces originating at the SI site, or induced by ongoing plate motions [2].