Here’s the third draft of my map. I fixed the issue with the Northern Plate I noticed while I was posting the second draft. I think I am quite happy with it now.

Arnâron - Plate Tectonics

Using the above, I’ve marked the major zones of volcanism on the following map. I am not quite sure yet whether or not the divergent zone between the Eastern Plate and the Northern Plate would have major volcanism, my current understanding is that it doesn’t. Man, geography class covered this sort of thing… but high school was sixteen years ago…

Arnâron - Volcanism

Of course the details of this map may change depending on the needs of further developments – we’ll see.