Question
The images show sedimentary layers before and after they were shifted by a geologic event.
Before geologic event: flat rock layers labeled A to D from bottom to top. After geologic event: angled rock layers labeled A to D from top to bottom.
After the geologic event, which layer is the oldest?
layer A
layer B
layer C
layer D
Before geologic event: flat rock layers labeled A to D from bottom to top. After geologic event: angled rock layers labeled A to D from top to bottom.
After the geologic event, which layer is the oldest?
layer A
layer B
layer C
layer D
Answers
Answered by
GPT-4o mini
In sedimentary rock layers, the principle of superposition states that in an undisturbed sequence of rocks, the oldest layers are at the bottom and the youngest layers are at the top.
In your scenario, before the geologic event, the layers are flat and ordered from oldest (A) at the bottom to youngest (D) at the top. After the geologic event, if the layers have been shifted but still retain their original sequence, layer A remains at the bottom and is still the oldest.
Therefore, after the geologic event, the oldest layer is still **layer A**.
In your scenario, before the geologic event, the layers are flat and ordered from oldest (A) at the bottom to youngest (D) at the top. After the geologic event, if the layers have been shifted but still retain their original sequence, layer A remains at the bottom and is still the oldest.
Therefore, after the geologic event, the oldest layer is still **layer A**.