Download Relative Ages of Rocks

Relative Ages of Rocks Worksheet
Name _________________________ Period _____
In the blank at the left, write the term that completes each statement.
___________________ 1. The processes that are changing the earth today are the same as they were in the past.
This is called_____.
___________________ 2. The law of _____ states that an older rock layer and things buried in it are
underneath young layers unless the layers have been disturbed.
___________________ 3. Forces generated by an _____ may change rock layers placement.
___________________ 4. Some rock layer may have a break in the record they are called_____.
___________________ 5. What could cause a rock layer to be missing?
Look at the cross-sectional view of the rock layers shown in the diagram below. For each question, decide
which of the two named materials is older. Assume the layers have not been overturned. Write the name of the
older material on the line provided.
___________________ 6. tan sandstone and brown sandstone
___________________ 7. brown sandstone and gray limestone
___________________ 8. gabbro dike and brown sandstone
___________________ 9. gabbro dike and gray shale
___________________ 10. snail fossil and trilobite fossil
___________________ 11. snail fossil and dinosaur bone
___________________ 12. snail fossil and green shale
___________________ 13. dinosaur bone and red sandstone
___________________ 14. red sandstone and gray limestone
___________________ 15. tan limestone and tan sandstone
___________________ 16. tan limestone and gray limestone
Complete the following statement.
17. The type of unconformity shown in the diagram is a(n) ________________________.
In the blank at the left, write the letter of the term or phrase that best completes each statement.
_____ 18. In layers of undisturbed sedimentary rock, the oldest rocks are on the _____.
a. top b. bottom c. middle
_____ 19. Sediments deposited in layers form _____ rocks.
a. sedimentary
b. igneous c. metamorphic
_____ 20. The statement that old rocks are on the bottom in layers of undisturbed rock is
called the _____.
a. law of superposition
b. tectonic theory c. uniformitarianism
_____ 21. Sometimes layers of rock are shifted or folded by forces generated by _____.
a. superposition
b. earthquakes c. volcanoes
_____ 22. Determining the age of rocks by examining their position in a layer is
called _____.
a. relative age dating
b. absolute age dating c. earthquake dating
_____ 23. Gaps in rock layers are called _____.
a. faults
b. unconformities
c. holes
_____ 24. The type of unconformity in which part of the rock layer is missing could be caused by _________.
a. weathering and erosion
b. extrusions
_____ 25. The layers of rock are called______.
a. Eras b. strata c. minerals
_____ 26. One way to match rock ages is to see if both rocks have the same type of _____
a. index fossils
b. volcanoes
_____ 27. Sometimes rock layers are visible because they have been exposed by _____
cutting through them.
a. volcanoes
b. streams
_____ 28. Some unconformities are the result of _____.
a. erosion
b. aliens
29. Number the rock layers according to their relative ages.
Label the oldest rock type #1.
A.
B.
C.
D.
E.
F.
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(adapted from Helgeson)