What island is there a demand for independece from france?

The answer is - Corsica.

The island that is in demand for greater autonomy and independence is the Mediterranean island of Corsica. This is an on going dispute with decades. The Corsican people do not consider themselves as French, and they do not have the same political attitude and interest as France, so they are trying to move away from France, and even without full independence to still have their own special government that will decide about the island and not France. 

Answer accretion;

None of them. they are likely to occur on any plate boundary