Folding

• existing rocks are bent, tilted, folded, or fractures by pressure
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• sedimentary rocks - once laid horizontally now tilted or folded
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• compressional forces over time deform rock
  • wrinkle Earth's crust
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• simple folds - wavy like, with symmetrical folds
  • syncline or synclinal trough
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• tensional or lateral forces often associated with faulting
  
  
  
  

Normal fault - tensional forces drop block one block rises, the other slips downward Grand Tetons, Sierra Nevada, Great Basn Strike-slip fault - lateral movement one block slides past another block San Andreas fault

• Fault Block Mountain Ranges (also called Fault-Scarp Mtns.)
  • gentle fronts slope, steep back-side escarpment
    • massive displacement of rocks
    • exposing deeply-formed rocks
  • characteristic of the American West
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• Horst & Graben Landforms - tensional forces
  • Parallel faults drop block known as graben
    • characteristic of the Great Basin
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Physical Index