Rocks of different origins and ages occur in three fundamentally different geological provinces
Mountain belts
- Long, linear, and smoothly arcuate provinces characterized by generally high elevation
- Have thick accumulations of sedimentary rocks of marine origin
- Have extensive suites of intrusive igneous rocks and volcanic activity; volcanoes are often explosive
- Sedimentary rocks are deformed by faults and folds which accomplish crustal shortening
- Sedimentary and igneous rocks are often metamorphosed as well as deformed