Levin, Chapter 3

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  1. What was the primary dating method used to construct the Geologic Time Scale?
    Heat loss from the earth
    Radioactivity
    Rate of Sedimentation
    Relative dating techniques
    Saltiness of the ocean

  2. What was the Cretaceous Period named after?
    Ancient tribe of the British Isles
    Chalk deposits
    Coal deposits
    Ice Age sediments
    The Island of Crete

  3. What is the correct order of the periods of the Mesozoic Era?
    Cretaceous, Jurassic, Triassic
    Jurassic, Cretaceous, Triassic
    Jurassic, Triassic, Cretaceous
    Triassic, Cretaceous, Jurassic
    Triassic, Jurassic, Cretaceous

  4. Which geologic period in America corresponds to the lower Carboniferous Period in the rest of the world?
    Devonian
    Mississippian
    Pennsylvanian
    Permian
    Silurian

  5. Which time period name is a remnant of the oldest attempt at a geologic time scale?
    Cambrian
    Paleocene
    Paleogene
    Paleozoic
    Quaternary

  6. Why did rate of sedimentation turn out to be a poor geologic clock?
    Sedimentary rock differs in thickness from zero to several miles.
    The final condition of the system is impossible to estimate accurately.
    The initial condition of the system is impossible to estimate accurately.
    The rate of deposition is too variable and there are periods of no deposition.
    There are too many sedimentary rock types included in most sedimentary sections.

  7. Why did the saltiness of the ocean turn out to be a poor geologic clock?
    All salt was added to the oceans during a single cataclysm.
    Salt cycles through the oceans rather than building up over time.
    Salt is not added to the oceans at a very uniform rate.
    The final condition of the system is impossible to estimate accurately.
    The initial condition of the system is impossible to estimate accurately.

  8. Match each radioactive parent isotope with its final daughter isotope.
    Carbon-14
    Potassium-40
    Rubidium-87
    Uranium-235
    Uranium-238
    Argon-40
    Lead-206
    Lead-207
    Nitrogen-14
    Strontium-87

  9. Match each radioactive parent isotope with the type of decay it undergoes.
    Carbon-14
    Potassium-40
    Rubidium-87
    Uranium-235
    Uranium-238
    Alpha decay
    Beta decay
    Electron capture
    Gamma decay

  10. Match each radioactive isotope with the type of material that can can be used to date.
    Carbon-14
    Potassium-40
    Rubidium-87
    Uranium-235
    Uranium-238
    Igneous rocks
    Organic remains
    Sedimentary rocks
    Water
    All of the above

  11. Match each radioactive parent isotope with its half life.
    Carbon-14
    Potassium-40
    Rubidium-87
    Uranium-235
    Uranium-238
    1,250,000,000 years
    4,470,000,000 years
    48,800,000,000 years
    5,730 years
    705,000,000 years

  12. The half life of Radon-222 is about 4 days. If a sample of Radon-222 undergoes decay for 8 days, how much of the original parent isotope will be left?
    100%
    75%
    50%
    25%
    12.5%

  13. Which element decays through a long series of intermediate steps before reaching a stable daughter isotope?
    Carbon
    Polonium
    Potassium
    Rubidium
    Uranium

  14. If two radiometric dates on the same rock don't match because they are dating different events in the rock's history, what are the dates called?
    Concordant dates
    Discordant dates
    Erroneous dates
    Relative dates
    Time-parallel dates

  15. When an igneous rock crystal is dated, what event does the date generally refer to?
    The age of the liquid magma that the rock was formed from
    The date on which a geologist removed the rock from the outcrop
    The date that the crystal was first exposed to air
    The last time the crystal fell below the blocking temperature
    The time at which the crystals in the rock first started to solidify

  16. Match the components of an isochron diagram to their definitions or indications.
    Component Definition/Indication
    Scatter of points
    Slope of best-fit line
    X-axis
    Y-axis
    Y-intercept
    Age of rock
    Confidence in date
    Initial isotope ratio
    Ratio of daughter & 3rd isotope
    Ratio of parent & 3rd isotope

  17. To calculate a radiocarbon date, what is the amount of Carbon-14 in the sample compared with?
    The amount of Carbon-12 in the sample
    The amount of Carbon-12 in the surrounding air or sediment
    The amount of Nitrogen-12 in the sample
    The amount of Nitrogen-14 in the sample
    The amount of Nitrogen-14 in the surrounding air or sediment

  18. What is the most problematic assumption in Carbon-14 dating?
    That atmospheric Carbon-14 generation has been constant over time
    That Carbon-14 has been passed down the full length of the food chain
    That Carbon-14 has not leaked out of the materials being dated
    That the daughter product of Carbon-14 decay has not leaked
    That the decay rate of Carbon-14 has been constant over time

  19. What does the "Paleocene Series" refer to?
    A scheme for dating rocks
    A scheme for identifying rocks
    Igneous and metamorphic rocks deep in the earth's crust
    The rocks formed during Paleocene time
    The time interval called the Paleocene

  20. What is the age of the Solar System and Earth based on the results of radiometric dating?
    1.8 billion years
    2.5 billion years
    4.5 billion years
    5.4 billion years
    6,000 years

  21. What is the age of the Cambrian/Precambrian boundary?
    125 million years
    251 million years
    321 million years
    542 million years
    731 million years

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