Geologic Time Scale, Fossils Unit Test
TRUE OR FALSE - Write T or F in the line (1 Point Each)
1. __________ The Grand Canyon is over 500 million years old.
2. __________ The Grand Canyon was created by a glacier.
3. __________ By looking at the index fossils, a geologist can tell how the age of one layer is related to
another.
4. __________ Relative Dating always gives an exact date for a fossil
5. __________ The Geologic Time Scale has been a work-in-progress for over 200 years.
6. __________ When there is a gap in the layers, or the layers have been rearranged due to uplift,
scientists call this intrusion.
7. __________ With a few exceptions, the layers exposed in the Grand Canyon are all formed of
sedimentary rock.
8. __________ There are no places in the world other than the Grand Canyon with any exposed layers
of rock.
SHORT ANSWER (Complete Sentences) (4 Points Each)
9. What is an index fossil?
10. Scientists use relative dating and the Principle of Superposition to help with determining the age of
some layers of rock. What is another name for this principle (hint: you eat them for breakfast!) and
what does it mean?
11. Sometimes there is a layer of rock that is found world-wide. Give one possible reason for a worldwide layer and one way it might be helpful to geologists.
Using the diagram of the Grand Canyon, answer the questions below:
Write “older” or “younger” in the blank spaces (2 Points Each)
12. The Redwall Limestone layer is __________ than the Supai Group.
13. The Bright Angle Shale is __________ than Hermit Shale.
Fill in the blank (2 Points)
14. The oldest layer in the diagram above is ___________________.
Short Answer (6 Points Each)
15. Based on this diagram, is there any way to tell exactly how old the Tapeats Sandstone layer is? Why
or why not?
16. A geologist in England found a fossil (A) in rock that has index fossils that are also present in the
Supai Group. She also found another fossil (B) under her first fossil that includes index fossils from the
Hermit Shale group. Which fossil is older (A or B), and why?