Plate tectonics

  1. When did the Earth form?
    4.6 billion years ago
  2. When did the early atmosphere form?
    4-3.8 billion years ago
  3. Early Earth:
    • Earth cooling – continents forming condensing water forms oceans
    • volcanic outgassing
    • Water vapor
    • Ammonia (NH3)
    • Methane (CH4)
    • Hydrogen sulfide (H2S)
    • Hydrogen gas (H2)
    • Carbon dioxide (CO2)
    • formation of Earth’s magnetic field
  4. Photosynthesis:
    • CO2 + H2O + sun ---> C6H12O6 + O2
    • 2.3 billion years ago
    • blue algae could make its own food
  5. aerobic resperation
    • O2 + CHO --> CO2 + H2O
    • (single-celled bacteria)
  6. development of the ozone
    • 1 billion years ago
    • filters harmful UV radiation
    • crucial for the ability to colonize on land
  7. Cambrian
    • 530 million years ago:
    • multi-celled organisms
    • life is widespread in the oceans
  8. Devonian
    • 450 Million years ago
    • terrestrial organisms all over
    • modern atmosphere
  9. Theory of plate tectonics:
    • lithosphere broken into a
    • number of rigid plates (at least 13 major) “floating” in the asthenosphere

    • plates move slowly (~2 cm/year)
    • movement causes plates to collide ® Plate boundary
  10. Seafloor spreading
    age of oceanic crust increases outward from ridges
  11. Cambrian (picture)
Author
kamrunsreno
ID
12321
Card Set
Plate tectonics
Description
NRES 211 midterm
Updated