Mountain formation refers to the geological processes that underlie the formation of mountains. These processes are associated with large-scale movements of the earth's crust (plate tectonics). Mountain formation is related to plate tectonics. Folding, faulting, volcanic activity, igneous intrusion and metamorphism are all parts of the orogenic process of mountain building. The understanding of specific landscape features in terms of the underlying tectonic processes is called tectonic geomorphology, and the study of geologically young or ongoing processes is called neotectonics.