Geology Exam

29 Questions | Total Attempts: 1419

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Geology Exam Quizzes & Trivia

Geology exam #2


Questions and Answers
  • 1. 
    Once a mass of magma is created, the magma's composition cannot be changed
    • A. 

      True

    • B. 

      False

  • 2. 
    Extrusive igneous rocks are also called ___, while intrusive rocks are also called ___.
    • A. 

      Plutonic, volcanic

    • B. 

      Volcanic, plutonic

    • C. 

      Plutonic, granite

    • D. 

      Volcanic, basalt

  • 3. 
    What is a fundamental difference in chemical compostion between the igneous rocks granite and basalt?
    • A. 

      There is no difference

    • B. 

      One rock contains abundant silicon and one rock contains none

    • C. 

      One contains abundadant ferromagnesian minerals and the other has almost none

  • 4. 
    Which of these is a common felsic igneous rock?
    • A. 

      Quartz

    • B. 

      Travertine

    • C. 

      Basalt

    • D. 

      Granite

  • 5. 
    __________ is the dominant rock type being erupted as lava flows at the crests of Earth's oceanic ridge systems, such as in the Atlantic Ocean east of North Carolina.
    • A. 

      Granite

    • B. 

      Pegmatite

    • C. 

      Basalt

    • D. 

      Quartz

  • 6. 
    Most magma generated on earth
    • A. 

      Stays below the surface and forms intrusions

    • B. 

      Sings to the core-mantle boundary because of it's magnetism

    • C. 

      Erupts at the surface and forms volcanic rocks

  • 7. 
    Gasses (volatiles) escaping from magma will produce vesicles (voids or bubbles) in the solified rock.  Which of these is not an example of vesicular texture?
    • A. 

      Scoria basalt

    • B. 

      Rhyolite

    • C. 

      Granite pegmatite

  • 8. 
    What does the term "pyroclastic" mean?
    • A. 

      Any volcanic eruption of a non-silicate magma

    • B. 

      Unusually fluid lava flows

    • C. 

      High-quality obsidian used to make arrowheads and spear points

    • D. 

      "fire broken" materials erupted by a volcano

  • 9. 
    _____ is the primary "driving force" behind volcanic eruptions.
    • A. 

      Magnetism

    • B. 

      Temperature

    • C. 

      Escaping volatiles (gasses)

    • D. 

      Pluto, the Greek god of the underworld

  • 10. 
    A sample of Hawaiian basalt is shown on the left side of the front projection screen.  Which of the following igneous textures is not displayed by this rock?
    • A. 

      Vesicular (or scoria)

    • B. 

      Phaneritic

    • C. 

      Aphanitic

    • D. 

      Porphyritic

  • 11. 
    The primary control on the style of volcanic eruption (quiet versus violent) is
    • A. 

      Depth to the subduction zone

    • B. 

      Height of the volcano

    • C. 

      Magma viscosity

    • D. 

      Magnetism

  • 12. 
    Cinder cones are
    • A. 

      Relatively small steep sided volcanoes

    • B. 

      Typically composed of basalt

    • C. 

      Built from ash, cinders, and other pyroclastic materials

    • D. 

      All of the above

    • E. 

      Only A and B

  • 13. 
    What kind of volcanic material is erupted at the crest of a mid-ocean ridge?
    • A. 

      Pillow lavas

    • B. 

      Welded tuff

    • C. 

      Andesite lava domes

    • D. 

      Carbonatite hornitos

  • 14. 
    ____ is the most dangerous type of volcanic activity.
    • A. 

      Rhyolite pyroclastic flows

    • B. 

      Basalt lava fountains

    • C. 

      Basalt pahoehoe flows

    • D. 

      Carbonatite hornitos

  • 15. 
    Which type of basalt lava flow is shown on the right side of the front projection screen?
    • A. 

      Aa

    • B. 

      Pahoehoe

    • C. 

      Welded tuff

    • D. 

      Quartz

  • 16. 
    A shield volcano
    • A. 

      Sunset Crater, Arizona

    • B. 

      Yellowstone, Wyoming

    • C. 

      Shiprock, New Mexico

    • D. 

      Mauna Loa, Hawaii

    • E. 

      Mt. St. Helens, Washington

  • 17. 
    The igneous plumbing of an extinct volcano
    • A. 

      Sunset Crater, Arizona

    • B. 

      Yellowstone, Wyoming

    • C. 

      Shiprock, New Mexico

    • D. 

      Mauna Loa, Hawaii

    • E. 

      Mt. St. Helens, Washington

  • 18. 
    A very large caldera
    • A. 

      Sunset Crater, Arizona

    • B. 

      Yellowstone, Wyoming

    • C. 

      Shiprock, New Mexico

    • D. 

      Mauna Loa, Hawaii

    • E. 

      Mt. St. Helens, Washington

  • 19. 
    A cinder cone
    • A. 

      Sunset Crater, Arizona

    • B. 

      Yellowstone, Wyoming

    • C. 

      Shiprock, New Mexico

    • D. 

      Mauna Loa, Hawaii

    • E. 

      Mt. St. Helens, Washington

  • 20. 
    A stratovolcano
    • A. 

      Sunset Crater, Arizona

    • B. 

      Yellowstone, Wyoming

    • C. 

      Shiprock, New Mexico

    • D. 

      Mauna Loa, Hawaii

    • E. 

      Mt. St. Helens, Washington

  • 21. 
    Mt. St. Helens is a dormant volcano, which means that it
    • A. 

      Will not erupt again

    • B. 

      Is now classified as a sedimentary rock deposit

    • C. 

      Can only erupt pyroclastic flows approximately once per million years

    • D. 

      Will erupt again in the future

  • 22. 
    A ______ typically results from a major eruption of hundreds of cubic miles of hot ash.
    • A. 

      Shield volcano

    • B. 

      Cinder cone

    • C. 

      Caldera

  • 23. 
    A ______ is a volcanic mudflow that can be a very serious volcanic hazard.
    • A. 

      Lahar

    • B. 

      Fumarole

    • C. 

      Caldera

    • D. 

      Pahoehoe

  • 24. 
    The 1883 eruption of Krakatoa in Indonesia caused several large tsunami that killed thousands of people.
    • A. 

      True

    • B. 

      False

  • 25. 
    Earth's climate is simply too stable to be influenced by large volcanic eruptions
    • A. 

      True

    • B. 

      False

  • 26. 
    The largest masses of igneous intrusive rocks (plutons) exposed at Earth's surface are _________ composed of granite
    • A. 

      Sills

    • B. 

      Dikes

    • C. 

      Laccoliths

    • D. 

      Batholiths

  • 27. 
    A dike is a type of igneous pluton that is _______ relative to the structure or layering of the older rocks that were intruded by the dike.
    • A. 

      Convergent

    • B. 

      Divergent

    • C. 

      Concordant

    • D. 

      Discordant

  • 28. 
    How can hot rocks of Earth's mantle be caused to melt and create basaltic magma?
    • A. 

      They can't- it is impossible to melt mantle rocks

    • B. 

      Reduce the concentration of water and other volatiles

    • C. 

      Reduce the confining pressure on the hot rocks

    • D. 

      Reduce the temperature of the rocks

  • 29. 
    Much of the ______ Ocean basin is rimmed by active subduction zones, therefore it has most of Earth's ______ located around it's margins.
    • A. 

      Pacific, shield volcanoes

    • B. 

      Atlantic, shield volcanoes

    • C. 

      Pacific, composite cones

    • D. 

      Atlantic, composite cones