Fold Mountains are commonly associated with continental crust. They are formed due to convergence between two continental plates or between an oceanic and a continental plate. This convergence happens at the convergent plate boundaries, also called as continental collision zones or compression zones.
The convergence of two continental plates causes sediments between them to get squeezed and thrusted upward leading to the formation of fold mountains along the plate boundary. Similarly, when oceanic-continental convergence takes place, the denser oceanic plate submerges and continental plate is thrusted upward to form fold mountains along the continental plate margin. For this reason, most of the fold mountains are found on the edge or former edge of the continental plate boundaries.