It's a meaningless trivial distraction that has nothing to do with the mechanism. The difference between "A plate is being subducted" and "a plate is subducting" lies in the tense and/or the voice. It's no different to "The door is being opened" versus "The door is opening". Neither statement implies whether the door is being pushed open or pulled open. As a reminder: sub·duc·tion (sb-dkshn) n. A geologic process in which one edge of one crustal plate is forced below the edge of another. And yes, I know subduction originates from French, however, a reminder of the fact that the definition makes no allusion to the driving force, whether it be a push or a pull, seemed appropriate at this juncture. And seeing as how this is supposedly a science forum, even if we are in the pseudo science section, here is some peer reviewed literature that proves my point: Intra-oceanic subduction systems: tectonic and magmatic processes By Robert D. Larter I quote from page 215: (emphasis mine) Clearly, the paragraph is phrased in the context of slab pull, and equally clearly the only difference between subducted and subducting is the voice being used by the author. To put this in perspective, I could change it to this: (or something similar) So clearly, your trivial nitpick is tantamount to trolling, and wholly irrelevant, because the use of subducting versus subducted depends on the voice being used, not the mechanism. Addendum: I am of the personal opinion that you now owe Ophiolite an apology for your... Whatever you want to call this... And given that timely apologies seem so important to you - given your earnest pursuit of Ophiolite for such, there is no doubt in my mind that you will take the earliest possible opportunity to apologize to him.