Question
How is radioactive decay used to date sedimentary rocks?
A. The amounts of potassium and argon in sedimentary rocks are measured.
B. The amounts of carbon-14 and nitrogen in sedimentary rocks are measured.
C. The amounts of unstable elements in each layer of the sedimentary rocks are compared.
D. The amounts of unstable elements in the volcanic layers above and below the sedimentary layers are measured.
A. The amounts of potassium and argon in sedimentary rocks are measured.
B. The amounts of carbon-14 and nitrogen in sedimentary rocks are measured.
C. The amounts of unstable elements in each layer of the sedimentary rocks are compared.
D. The amounts of unstable elements in the volcanic layers above and below the sedimentary layers are measured.
Answers
GPT-4o mini
The correct answer is:
**D. The amounts of unstable elements in the volcanic layers above and below the sedimentary layers are measured.**
Radioactive decay is used to date sedimentary rocks indirectly by dating the associated volcanic layers (which are often a few layers above or below the sediment) using methods like potassium-argon (K-Ar) dating or uranium-lead (U-Pb) dating. This allows geologists to establish an age range for the sedimentary layers based on the dates derived from the volcanic layers.
**D. The amounts of unstable elements in the volcanic layers above and below the sedimentary layers are measured.**
Radioactive decay is used to date sedimentary rocks indirectly by dating the associated volcanic layers (which are often a few layers above or below the sediment) using methods like potassium-argon (K-Ar) dating or uranium-lead (U-Pb) dating. This allows geologists to establish an age range for the sedimentary layers based on the dates derived from the volcanic layers.