The Earth's Crust

Practice exam questions written by Timothy H. Heaton,
Professor of Earth Sciences, University of South Dakota

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  1. The term stratification applies to what kinds of rocks?
    All rock types.
    Only Precambrian rocks.
    Primarily to igneous rocks.
    Primarily to metamorphic rocks.
    Primarily to sedimentary rocks.

  2. What is the meaning of 'superposition' in reference to a layered sequence of sedimentary rocks?
    The name of the highest layer.
    The name of a dike or other feature that cuts across the layers.
    The position of layers forced upward along a fault.
    The principle that the layers were originally horizontal.
    The principle that higher layers are younger.

  3. What is an unconformity?
    A sedimentary surface that represents a time gap in the sedimentary record.
    An offset of sedimentary layers along a fault.
    The boundary between two rock types such as sandstone and shale.
    The top of an anticlinal fold.
    Tilted (non-horizontal) strata.

  4. Match rock type under an unconformity with the name of the unconformity.
    Rock type Unconformity
    Igneous rock.
    Metamorphic rock.
    Sedimentary strata parallel to the unconformity.
    Sedimentary strata not parallel to the unconformity.
    Angular unconformity.
    Disconformity.
    Nonconformity.

  5. What is the youngest era in the geologic column?
    Cenozoic.
    Mesozoic.
    Paleozoic.
    Phanerozoic.
    Precambrian.

  6. Where does deposition of sediment most commonly occur?
    On mountaintops.
    On plateaus.
    On shallow slopes.
    On steep slopes.
    Under water.

  7. Match each mineral or material with the sedimentary rock it becomes lithified into.
    Sediment Sedimentary rocks
    Calcite.
    Clay.
    Gravel.
    Peat.
    Silt.
    Quartz.
    Coal.
    Conglomerate.
    Limestone.
    Sandstone.
    Shale.
    Siltstone.

  8. What happens to metamorphic rocks if they are subjected to differential stress during metamorphism?
    They become bedded.
    They become graded.
    They become igneous.
    They become foliated.
    They become plutonic.

  9. Match each igneous or sedimentary with the type of rock it becomes when metamorphosed.
    Protolith Metamorphic derivative
    Basalt.
    Granite.
    Limestone.
    Sandstone.
    Shale.
    Gneiss.
    Greenschist.
    Marble.
    Quartzite.
    Slate.

  10. Match each type of metamorphism with its pressure and temperature conditions.
    Type of metamorphism Conditions (relatively speaking)
    Burial metamorphism.
    Contact metamorphism.
    Regional metamorphism.
    Subduction zone metamorphism.
    High pressure, high temperature.
    High pressure, low temperature.
    Low pressure, high temperature.
    Low pressure, low temperature.

  11. What is the origin of continents on the earth?
    They are a collection of sutured microcontinents eroded flat.
    They are fragments derived from meteorites.
    They are relicts of the earth's original smooth crust.
    They formed directly from mid-ocean ridges.
    They rose gradually from the earth's core.

  12. What is continental crust made of?
    Almost entirely of igneous rocks from top to bottom.
    Almost entirely of metamorphic rocks from top to bottom.
    Almost entirely of sedimentary rocks from top to bottom.
    An igneous/metamorphic 'basement' covered in places by a thin 'veneer' of sedimentary rocks.
    A sedimentary 'basement' covered in places by a thin 'veneer' of igneous/metamorphic rocks.

  13. Match each description with the continental term it applies to.
    Description Name
    Flat areas with exposures of sedimentary rock.
    Flat areas with exposures of igneous and metamorphic rocks.
    Non-mountainous flat areas of any surface type.
    Uplifted mountain belts.
    Cratons.
    Orogens.
    Shields.
    Stable platforms.

  14. Which type of continental margin is not at a tectonic plate boundary?
    Accreted terrane margin.
    Continental collision margin.
    Continental convergent margin.
    Passive margin.
    Transform fault margin.

Please report any problems or errors to Dr. Heaton.