Earth Tectonics & Science

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  1. What is the ø of the earth?
    8,000 miles
  2. What is the ø of the sun?
    800,000 miles
  3. What is the earth circumference?
    24,000 miles
  4. Describe Earth's 3 distinct, concentric layers:
    • Iron Core
    • Mantle
    • Crust
  5. Describe 2 types of the Earth's Crust:
    • Oceanic → Mafic → Basalt
    • Continental → Felsic → Granitic
  6. Describe 3 sources of Earth's residual Heat:
    • Gravitational energy
    • Kinetic energy → planetesimal collisions
    • Meteor impacts
  7. Heat from within the Earth is continually generated by:
    Radioactive decay
  8. What is a Lithosphere and where is located?
    Rigid outer layer containing "crust" & frozen part of the upper mantle
  9. What is the Asthenosphere and where is located?
    • Partially melted upper mantle
    • has plastic-like
  10. What is the Lower Mantle and where is located?
    • Mesosphere
    • Solid layer of rocks
    • between the asthenosphere iron core
  11. What are the components of Earth's core and where are they located?
    • Liquid Core
    • Solid Iron Core
  12. What happened to most of the hydrogen and helium that accumulated with Earth's mass?
    • Escaped
    • Earth did not have enough gravity
  13. How much free oxygen was available very early in Earth's history?
    Almost none
  14. What does the presence of pyrite grains in early sedimentary rocks imply?
    Back then was no free oxygen because pyrite was not oxidized like in today's atmosphere.
  15. Describe the occurrence of "Banded Iron Formations" during early Earth times?
    (2.5 - 2 billion yrs)
    • BIF require abundant oxygen
    • Therefore, during that time there must have been more free oxygen
    • Became thick + cover vast areas
  16. Which ancient life forms were present at least 3.5 billion years ago that began creating Earth's fee oxygen?
    Bacteria + Algae
Card Set
Earth Tectonics & Science
Unit 4
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