The forearc region includes any forearc basin, outer-arc high, accretionary prism and the trench itself.[1] The accretionary prism is located at the slope of the trench break where there is significantly decreased slope angle. Between the break and the magmatic arc, a sedimentary basin filled with erosive material from the volcanic arc and substrate can accumulate into a forearc basin which overlays the oldest thrust slices in the wedge of the forearc region.[2]