1. What is the principle of cross-cutting relationships?

a. Geologic features that cut through rocks must form before the rocks that they cut through.
b. Geologic features that cut through rocks must form after the rocks that they cut through.
c. Geologic features that cut through rocks must form at roughly the same time as the rocks that they cut through.

2. What happens during radioactive decay?

a. Parent isotopes turn into energy.
b. Energy turns into daughter isotopes.
c. Daughter isotopes turn into parent isotopes.
d. Parent isotopes turn into daughter isotopes.
e. Daughter isotopes turn into energy.

3. What is the scientific definition of half-life?

a. the amount of time over which the number of daughter isotopes increases by half
b. the number of daughter isotopes that will be gained during a single radioactive decay event
c. the number of parent isotopes that will be lost during a single radioactive decay event
d. the amount of time over which the number of parent isotopes decreases by half

4. What does the term unconformity mean?

a. a missing rock layer in a sequence that represents a period of erosion or nondeposition
b. an extra rock layer that represents a period of erosion
c. an extra rock layer that represents a period of deposition
d. a missing rock layer in a sequence that represents a period of deposition

5. In the following rock sequence, how much erosion might have occurred between rock layer A and rock layer B?

Block Layer B
Block Layer A

a. more time than it took to deposit rock layer A
b. none or only a very small amount (Time does not equate to erosion.)
at least 1 million years
c. more time than it took to deposit rock layer B
d. at least 10,000 years

6. Which of the geologic principles listed here is incorrectly defined?

a. The principle of cross-cutting relationships states that the fault or intrusion that cuts across several rock layers is older than these layers.
b. The principle of superposition states that in an undisturbed sequence of rock layers, the older layers are at the bottom of the sequence and the younger layers are at the top.
c. The principle of lateral continuity states that sedimentary beds originate as layers that extend in all directions until they thin out at the edge.
d. The principle of inclusions states that an inclusion within a rock layer is older than that layer.
e. The principle of original horizontality states that sediment is initially deposited in a horizontal position.

7. What is the significance of an unconformity?

a. An unconformity can sometimes negate one or more geologic principles.
b. An unconformity represents an interval of time that is missing from the rock record.
c. The creation of an unconformity favors the deposition and lithification of rock layers.
d. An unconformity shows a more detailed history for a particular interval of time in the rock record.
e. An unconformity is a series of rock layers that is completely uninterrupted.

8. When a beta particle is emitted during radioactive decay, the atomic number of the isotope _____.

a. increases by 1
b. remains the same
c. decreases by 1
d. decreases by 2
e. increases by 2

9. What remains after a sample undergoes two half-lives?

a. 50 percent of the sample is composed of parent atoms, and 50 percent of the sample is composed of daughter atoms.
b. 100 percent of the sample is composed of daughter atoms.
c. 75 percent of the sample is composed of parent atoms, and 25 percent of the sample is composed of daughter atoms.
d. 25 percent of the sample is composed of parent atoms, and 75 percent of the sample is composed of daughter atoms.
e. 100 percent of the sample is composed of parent atoms.

10. How might a numerical date for a layer of sedimentary rock be determined?

a. One or more igneous bodies near the sedimentary rock layer are radiometrically dated; the sedimentary rock layer is always younger than the igneous rock, regardless of its placement.
b. One or more igneous bodies near the sedimentary rock layer are radiometrically dated; the sedimentary rock layer is always older than the igneous rock, regardless of its placement.
c. All of the different grain types in the sedimentary layer are radiometrically dated, and the average of these results determines the age of the layer.
d. The order of occurrence of the sedimentary layer is related to a local igneous body that has been radiometrically dated, thus yielding an age range for the sedimentary layer.
e. The order of occurrence of the sedimentary layer is related to a local metamorphic rock that has been radiometrically dated, thus yielding an age range for the sedimentary layer.

11. What is the difference between strain and stress?

a. Stress is the change in rock mass that results from strain, which is the force that deforms the rock.
b. Remember that stress causes the movement of plates at tectonic plate boundaries.
c. Stress is the change in rock shape that results from strain, which is the force that deforms the rock.
d. Strain is the change in rock mass that results from stress, which is the force that deforms the rock.
e. Strain is the change in rock composition that results from stress, which is the force that deforms the rock.