Question
The diagram shows a cross section of layers of sedimentary rocks. The types of fossils in each layer are shown.
Ground surface
Layer A
Layer B
Layer c
Layer D
Layer E
Key
Types of Fossils
Gastropod
Coral
Ammonite
Crinold
Based on the information in the cross section, select the three statements that are most likely correct.
Layer A is at the top, so it is the youngest layer.
The gastropod fossils are above the crinoid fossil, so gastropods evolved from crinoids.
Layer C is below Layer B, so Layer C is older.
There is no coral fossil in Layer D, so corals must have become extinct.
The ammonite fossil is above the crinoid fossil, so the crinoid is older.
Ground surface
Layer A
Layer B
Layer c
Layer D
Layer E
Key
Types of Fossils
Gastropod
Coral
Ammonite
Crinold
Based on the information in the cross section, select the three statements that are most likely correct.
Layer A is at the top, so it is the youngest layer.
The gastropod fossils are above the crinoid fossil, so gastropods evolved from crinoids.
Layer C is below Layer B, so Layer C is older.
There is no coral fossil in Layer D, so corals must have become extinct.
The ammonite fossil is above the crinoid fossil, so the crinoid is older.
Answers
Answered by
GPT-4o mini
Based on the information provided in the cross-section of layers of sedimentary rocks and the principles of relative dating in geology, the three most likely correct statements are:
1. **Layer A is at the top, so it is the youngest layer.**
This statement is correct because, in sedimentary rock layers, the top layer is typically the youngest due to the process of deposition.
2. **Layer C is below Layer B, so Layer C is older.**
This statement is also correct, as the Law of Superposition states that in undisturbed sedimentary rock layers, the lower layers are older than the layers above them.
3. **The ammonite fossil is above the crinoid fossil, so the crinoid is older.**
This statement is correct as well, as it follows the same principle of superposition: if the ammonite fossil is in a layer above the crinoid fossil, then the crinoid must be older.
The other statements are not correct:
- The statement about gastropods evolving from crinoids is not confirmed by the fossil record or the positioning of the layers.
- The absence of coral fossils in Layer D does not necessarily mean corals became extinct; it may simply indicate that conditions were not suitable for their presence or they were not preserved.
1. **Layer A is at the top, so it is the youngest layer.**
This statement is correct because, in sedimentary rock layers, the top layer is typically the youngest due to the process of deposition.
2. **Layer C is below Layer B, so Layer C is older.**
This statement is also correct, as the Law of Superposition states that in undisturbed sedimentary rock layers, the lower layers are older than the layers above them.
3. **The ammonite fossil is above the crinoid fossil, so the crinoid is older.**
This statement is correct as well, as it follows the same principle of superposition: if the ammonite fossil is in a layer above the crinoid fossil, then the crinoid must be older.
The other statements are not correct:
- The statement about gastropods evolving from crinoids is not confirmed by the fossil record or the positioning of the layers.
- The absence of coral fossils in Layer D does not necessarily mean corals became extinct; it may simply indicate that conditions were not suitable for their presence or they were not preserved.