ESCI Exam 2 Part 3

Card Set Information

ESCI Exam 2 Part 3
2011-04-07 22:58:02
earth history UNH ESCI

Earth History, orogeny
Show Answers:

  1. Craton
    the stable interior part of a continent thick crust and deep lithospheric roots - composed of Pre-Cambrian rocks, shield + platform
  2. Shield
    core crystalline material, nucleus of a continent
  3. Platform
    flat lying sediment carapace around the shield
  4. Wilson cycle
    the break up and subsequent accretion to again form a supercontinent - cycle takes 300 to 500 mil. years
  5. Rodinia
    Neoprotezoic supercontinent (Late Pre-Cambrian, earlier than Pangaea)- breaks apart 750 mil years ago
  6. Laurentia
    North American craton - surrounded by passive margins- no plate boundaries, no trench and subduction zone
  7. Taconic
    Mountain building period that created the Appalachian Belt - Ordovician 480 yo. collision of an island arc with the margin of Laurentia
  8. Evidence for mountain building
    • Stratigraphic - unconformity
    • Structural - faulting and folding
    • Volcanic/radiometric - can be dated
    • Sedimentary - weight of thick crust pushes the lithosphere down, creates basins on each side of the mountain, sed. erodes and collects in basins
  9. Flysch
    marine deposits that first fill into foreland basin (clastics+volcanic ash)
  10. Molasse
    Continental deposits (delatic and fluvial - siltstones and conglomerates) that fill in on top of flysch