chapter 4

  1. reflects differences
    in mineral crystal size.
    Texture
  2. Large crystals easily
    seen, course –grained.
    Phaneritic
  3. Very tiny crystals,
    individual crystals cannot be seen without magnification, fine-grained.
    Aphanitic
  4. igneous rock with
    mixed texture with both large and small grained crystals.
    Porphyry
  5. large crystals in a
    porphyry
    Phenocrysts
  6. existing
    rock in the countryside prior to intrusion by magma

    Intrusive
    igneous rock – has forced its way into the surrounding country rock.
    Country rock
  7. magma which has come
    to the surface and cooled more rapidly, come from volcanoes
    • Extrusive igneous
    • rocks
  8. magma which flows out
    on the surface of the earth.
    Pyroclastic rocks
  9. very tiny droplets of
    magma thrown into the air, often glass.
    volcanic ash
  10. larger pieces of
    volcanic rocks thrown into the air, cooled and formed as they fall.
    Bombs
  11. name for all pyroclastic
    rocks (those thrown into the air)
    Tuff
  12. volcanic glass filled
    with air pockets called vesicles.
    Pumice
  13. from lava flows, very
    tiny vesicles, very solid and dense. Comprised entirely of glass.
    Obsidian
  14. a liquid’s resistance
    to flow. Resistance increases with an increase of silica. Mafic rocks have low
    viscosity, felsic rocks have a high viscocity.
    Viscosity
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Anonymous
ID
6477
Card Set
chapter 4
Description
geo
Updated