Generally causing deep earthquakes, their namesake "zones" form island arcs and trenches.
The A-type, also called "delamination," may only proceed for a few hundred kilometers, as it involves only continental material. This is contrasted with the B-type, where oceanic crust may be recycled for a thousand kilometers. Generally causing deep earthquakes, their namesake "zones" form island arcs and trenches. For 10 points – name this process of a tectonic plate sliding under another.
The A-type, also called "delamination," may only proceed for a few hundred kilometers, as it involves only continental material.
{subduction}