Answer Key for Relative Dating Worksheet
1. Sand
2. It is the top layer.
3. Superposition
4. After layer 3 but before 5.
5. Layer 4 cuts through 1-3, but not 5, so 5 must be newer.
6. Law of Cross-cutting relationships
7. Oil and water appear to have disturbed/moved the rock layers.
8. Law of Original Horizontality
9. The igneous pluton D – it is on both sides of the fault.
10. D
11. Downward
12. The coal layer.
13. The rocks folded.
14. Compression forces or stress could have caused this.
15. Possible disturbance in the plate being pushed upward. Layers on top not tilted because
they were deposited after the disturbance.
16. Law of Original Horizontality.
17/18. Law of Cross-cutting relationships.
Page 2 – Rock Layers RMFB etc
1. Youngest to oldest: H, R, M, F, B, I
2. Rock layer H cuts through layer M, so it is newer.
3. The layers on the left do not line up with the layers on the right because they were disturbed
by a fault line and shifted.
4. It occurred between F & M based on the shape of M layer’s deposit. It is uniform at the top.
5. The fossil found in layer F would be older since that layer was there first; prior to the fault.
6. You would not expect to find fossils in R since that layer is closest to the crust signifying it is a
newer layer. H could have some included from its travel through the others.
Page 3: Radiometric dating and Relative dating
1. RA
2. RE
3. RA
4. RE
5. RA
6. RE
Layer Order: Oldest to Youngest
1st pic - E, F, G, H, I, J, L, K, D, C, A, B
2nd pic - P, M, L, K, A, R, J, W, T, B, F, E, H
Page 4 Sequencing after a Thunderstorm- correct order is:
1st A thunderstorm began.
2nd A child ran through the mud puddle.
3rd Hailstones fell during the thunderstorm.
4th The mud puddle dried.
5th The baking heat of the sun caused cracks to form in the mud puddle.
Matching principles to explanation/graphic
C - Original Horizontality
E – Lateral Continuity
A - Superposition
F – Inclusions
B – Unconformities
D - Cross-cutting relationships