h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The problem seems to be that when continental plates move apart, they are extended by the addition of oceanic plate material to the continental plate. So although it may be the North American plate at the Antilles boundary, it is at this point an oceanic plate.

How can I change the Entry to remove this grey area?

dystopia, I've reworded the section on Island arcs. Is that more to your liking?

Yes. I will get off your case now! It was really the reference to age which concerned me as this is a bit of a red herring. I think the inclusion of the detail about the Antilles provides a good example. Its hard trying to write a general account of complex matters to strike a balance between a broad overview and getting bogged down in endless detail; and then smart know-it-all comes along and has to have their say!!!

You are right, for example the north eastern Atlantic lies above the western edge of the European plate but the material is oceanic rather than continental. I think, given that your focus is islands and not plate tectonics, it might be best to gloss over this aspect, especially as the Pacific is very complicated.