Precambrian tectonics build mtns, over billions of years of inactivity these mountains are eroded. Sea come in, marine sediments deposited. These are linear regions that were deformed during tectonism. Results in formation of mountains. Includes large component of thrusting- crust breaks up into thrust sheets that are stacked on top of each other due to compression.
Orogenic belts tend to get younger away from the craton.
Terranes - accreted to the continents during orogenies. Classic fold and thrust belt. Created in the Paleozoic during consolidation of Pangaea. Represents past convergent margin, but not just one convergent event. That time interval punctuated by 3 major orogenic episodes.