The two processes that are important in the formation of volcanic arcs at the edge of continental plates are:
- Subduction
- Passing over a hotspot (though this is less common for volcanic arcs specifically associated with subduction zones, it is still relevant in some contexts).
Note: "Uplift" can be related to tectonic processes, but it is not a direct mechanism for forming volcanic arcs. "Plate divergence" refers to processes at mid-ocean ridges, which typically do not produce volcanic arcs along continental edges.