For 10 points, name this process by which large areas of very high and rugged terrain is formed.
The namesake regions in which this process occurs are sometimes characterized by "nappe," or a large displaced sheet of rock, and were co-theorized by Zwart and Pitcher. Hercynotype versions of this process take place in back-arc basins, and the Cordilleran type occurs with low geothermal gradient.  The alpinotype ones have the most rapid characteristic change, and specific "belts" where this activity occurs includes the Hudsonian and Nevadan ones in North America. For 10 points, name this process by which large areas of very high and rugged terrain is formed.
The namesake regions in which this process occurs are sometimes characterized by "nappe," or a large displaced sheet of rock, and were co-theorized by Zwart and Pitcher.
{orogeny} [accept word forms; accept equivalents like {mountain} formation]