Question

read the passage and answer the following question(s).
dating rock strata
scientists can determine the age of rock layers by measuring radioactive elements within the rock. radioactive elements found in sedimentary rocks decay quickly, so this method can only date sedimentary rocks that are less than 50,000 years old. volcanic rock contains radioactive elements that decay very slowly, so scientists can date volcanic rocks that are much older than 50,000 years.
a team of scientists is investigating a rock formation found in a region. the diagram shows the rock formation that the scientists are investigating.
how can volcanic rock layers be used to learn more about a location?
a. they can be used to determine the exact ages of the fossilized organisms.
b. they can be used to determine the periods between future eruption events.
c. they can be used to determine the exact dates of the sedimentary rock layers.
d. they can be used to determine the time periods before and after eruption events.

Explanation:

Volcanic rock contains radioactive elements that decay very slowly. Scientists can date volcanic rocks that are much older than 50,000 years. This means volcanic rock layers can be used to determine the time periods before and after eruption events.

Answer:

D. They can be used to determine the time periods before and after eruption events.