Geologic Dating

Card Set Information

Author:
Canvas47
ID:
249915
Filename:
Geologic Dating
Updated:
2013-12-01 03:54:19
Tags:
Geology Geologic Dating
Folders:

Description:
Study Guide for Geology: Geologic Dating
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user Canvas47 on FreezingBlue Flashcards. What would you like to do?


  1. Explain the difference between relative and absolute dating of earth materials.
    RELATIVE DATING is the age of the earth material in relation to another while ABSOLUTE DATING is the actual age of earth material.
  2. List and briefly explain the tools used in relative dating.

    Superposition
    Oldest rocks are on the bottom.
  3. List and briefly explain, the tools used in relative dating.

    Original Horizontality
    Rock layers that are flat are not disturbed. Sediments are deposited in a horizontal position.
  4. List and briefly explain, the tools used in relative dating.

    Cross Cutting
    A younger feature cuts through an older feature.
  5. List and briefly explain, the tools used in relative dating.

    Inclusions
    One rock unit is enclosed within another. Inclusion is younger.
  6. List and briefly explain, the tools used in relative dating.

    Unconformity
    Break (gap) in the geologic rock record due to erosion.
  7. List and briefly explain, the tools used in relative dating.

    Faunal Succession
    Fossil organisms succeed one another in a definite and determinable order.
  8. List, briefly explain, and identify the three types of unconformities.

    Disconformity
    Flatline sedimentary layers on either side are parallel.
  9. List, briefly explain, and identify the three types of unconformities.

    Angular Unconformity
    Tilted rocks are overlain by flat-layering rocks. Stress causes the tilting.
  10. List, briefly explain, and identify the three types of unconformities.

    Nonconformity
    Older metamorphic or intrusive igneous rocks in contact with younger sedimentary layers. Contact metamorphism occurs.
  11. What is a fossil?
    Remains or traces of prehistoric life.
  12. List several types of fossils.
  13. What is an index fossil?
    Fossils used to date geologic time periods.
  14. Discuss the correlation of rock layers using physical criteria and fossils.
  15. What is radioactivity?
    Spontaneous decay of unstable atomic nuclei.
  16. How is radioactivity used to give numerical dates to Earth materials?
    Radiometric Dating is used measures the ratio of parent radioactive atoms to stable daughter product atoms.
  17. List several isotopes commonly used in the radiometric dating.
    • Rubidium-87
    • Carbon-14
    • Uranium-238
    • Uranium-235
    • Potassium-40
  18. List and briefly discuss the major subdivisions of the geologic time scale.
    Eras

    Periods

    Epochs
  19. What are the dates that divide each era in the Phanerozoic Eon.
    • Paleozoic: 542mil-250mil
    • Mesozoic: 250mil-65mil
    • Cenozoic: 65-present day
  20. What occurred during each era of the Phanerozoic Eon?

    Paleozoic
    Largest mass extinction in Earth's history, the Permian–Triassic extinction event
  21. What occurred during each era of the Phanerozoic Eon?

    Mesozoic
    The first mammals appeared
  22. What occurred during each era of the Phanerozoic Eon?

    Cenozoic
    The first humans appeared
  23. Briefly explain the significance of the Precambrian division of the geologic time scale
    88% of Geologic Time

What would you like to do?

Home > Flashcards > Print Preview