GEOL 101 Chapter 9: Chapter 9
Document Summary
Mountains do not occur in isolation but rather as a part of elongate ranges called mountain belts or orogens. A map of present-day earth reveals about a dozen major orogens, and numerous smaller ones. Mountain building: the process of forming a mountain belt. Mountain building has happened many times and in many places over. Mountain building not only leads to uplift, the vertical rise of the land surface and the rock beneath, but also causes rocks to undergo deformation, when they bend, break, or flow. These include joints (cracks), faults (fractures on which one body of rock slides past another), folds (bends, curves, or wrinkles of rock layers), and tectonic foliation (a fabric or layering in rock) A mountain-building event, or orogeny, may last for tens of millions of years. Study of the types of geologic structures that we see in the alpine cliff emphasizes that during deformation, rocks can undergo one or more of the following change.
