If the last of a plate is subducted, the result is a boundary between the overriding plate and whatever was on the other side of the subducted plate. For instance, the west coast of North America was once a subduction zone between the North American Plate and the Farallon Plate. Eventually, the Farallon Plate was almost completely subducted and North America met the spreading center between the Farallon and Pacific Plates, forming the current boundary, which includes the San Andreas Fault.

If, instead of a spreading center reaching the trench, the plate includes continental crust, then a continental collision results, as in the case of India colliding with Eurasia.