Solid Tectonic and Other Processes

• existing rock is bent, tilted, folded, and fractures by pressure (not igneous processes)
  

Tilting

• sedimentary rocks - once laid horizontally now tilted or folded
  • "dip" or angle from horizontal
  • "strike" perpendicular direction
    • California Coast Range and Transverse Range

• major uplift and deformation of large landmasses
  • not caused by plate tectonics
    
    
• Isotatic rebound - stays in equilibrium with "root" of mountains
  • lifted primarily by removal of weight & mass
    • (ice caps, oceans, or sediment)
      • Rocky Mountains (float on asthenosphere)
      • Florida, Yucatan Peninsula
      • Black Hills in Dakotas (crustal warping)

Folding

• wrinkling of Earth's crust and
  compressional forces over time deform rock
  • Appalacian Mountains
  • Tablecloth example
    

• simple folds - wavy like, with symmetrical folds
  • syncline or synclinal trough
  • anticline or anticlinal ridge (like an ant hill)
    • often exposed by erosion
    • Waterpocket fold, Utah
    • Death Valley fold

• rigid rocks rupture instead of fold
• tensional or lateral forces often associated with faulting
  • vertical displacement usually occurs
    • earthquakes associated with slips

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

• Fault Block Mountain Ranges (also called Fault-Scarp Mtn. Ranges)
  • characteristic of the American West - Grand Tetons, Sierra Nevada
  • gentle fronts slope, steep back-side escarpment
  • massive displacement of rock, exposing deeply-formed rocks; creates rainshadow
    
    
• Horst & Graben landforms - tensional forces
  • Great Basin, African Rift Valley, Jordan
    • Parallel faults drop block known as graben
      • classic graben example: Death Valley