Flat-slab subduction
= Flat-slab subduction
A regime in which an initially descending <slab> becomes nearly horizontal beneath the <overriding plate> for a substantial inland distance before descending again. It can narrow or eliminate a hot <mantle wedge>, shift deformation inland and coincide with a volcanic gap. Incoming buoyant crust, hydration, upper-plate motion and mantle forces can all contribute; association with an oceanic ridge does not isolate one cause.