Question
The diagram shows layers of rock, A, B, C, D, and igneous intrusion E.
A, B, C, D, and E MOST likely formed in which sequence?
A.
First → → → Last
D C B E A
B.
First → → → Last
A B C D E
C.
First → → → Last
E D C B A
D.
First → → → Last
A E B C D
A, B, C, D, and E MOST likely formed in which sequence?
A.
First → → → Last
D C B E A
B.
First → → → Last
A B C D E
C.
First → → → Last
E D C B A
D.
First → → → Last
A E B C D
Answers
GPT-4o mini
To determine the most likely sequence in which the layers of rock (A, B, C, D) and the igneous intrusion (E) formed, we need to understand the principles of geological formation, particularly the Law of Superposition and the concept of intrusive relationships.
1. **Law of Superposition**: In an undeformed sequence of sedimentary rocks, the oldest layers are at the bottom, and the younger layers are above them.
2. **Igneous Intrusions**: When an igneous intrusion (E) occurs, it typically cuts through the existing rock layers (A, B, C, D), indicating that the intrusion is younger than the layers it intersects.
Based on these principles, let's analyze the options:
- **Option A (D, C, B, E, A)**: This sequence would imply that D is the oldest, followed by C, B, then E (the intrusion), and finally A. This does not follow the principle, as A should be younger than at least some layers.
- **Option B (A, B, C, D, E)**: Here, A is the oldest, followed by B, then C, D, and E. This contradicts the concept of intrusive relationships, as E (the intrusion) should not be the youngest if it cuts through A, B, C, and D.
- **Option C (E, D, C, B, A)**: In this sequence, E is the oldest, which contradicts the intrusive principle since the intrusion is always younger than the layers it cuts through.
- **Option D (A, E, B, C, D)**: This implies A is the oldest and then E cuts through, which makes E younger than A. However, if E is the intrusion, it should be younger than B and C.
Given these analyses:
The correct sequence of formation should be that A, B, C, and D form from oldest to youngest, with E as an intrusion that cuts through some or all of the layers, making it younger than those it cuts through. Therefore, none of the provided options perfectly adheres to geological principles.
If I must select the sequence closest to conventional geological understanding, it should highlight that E is an intrusion that typically forms last after the layers below it. This points to an answer closest to:
**C (E, D, C, B, A)** - but as outlined this option breaks the principles, I would clarify that E would properly need to follow the last laid layers.
In proper geological terms, assuming D is above C, and so, ideally: **A, B, C, D, and finally E** (not represented in the options provided).
1. **Law of Superposition**: In an undeformed sequence of sedimentary rocks, the oldest layers are at the bottom, and the younger layers are above them.
2. **Igneous Intrusions**: When an igneous intrusion (E) occurs, it typically cuts through the existing rock layers (A, B, C, D), indicating that the intrusion is younger than the layers it intersects.
Based on these principles, let's analyze the options:
- **Option A (D, C, B, E, A)**: This sequence would imply that D is the oldest, followed by C, B, then E (the intrusion), and finally A. This does not follow the principle, as A should be younger than at least some layers.
- **Option B (A, B, C, D, E)**: Here, A is the oldest, followed by B, then C, D, and E. This contradicts the concept of intrusive relationships, as E (the intrusion) should not be the youngest if it cuts through A, B, C, and D.
- **Option C (E, D, C, B, A)**: In this sequence, E is the oldest, which contradicts the intrusive principle since the intrusion is always younger than the layers it cuts through.
- **Option D (A, E, B, C, D)**: This implies A is the oldest and then E cuts through, which makes E younger than A. However, if E is the intrusion, it should be younger than B and C.
Given these analyses:
The correct sequence of formation should be that A, B, C, and D form from oldest to youngest, with E as an intrusion that cuts through some or all of the layers, making it younger than those it cuts through. Therefore, none of the provided options perfectly adheres to geological principles.
If I must select the sequence closest to conventional geological understanding, it should highlight that E is an intrusion that typically forms last after the layers below it. This points to an answer closest to:
**C (E, D, C, B, A)** - but as outlined this option breaks the principles, I would clarify that E would properly need to follow the last laid layers.
In proper geological terms, assuming D is above C, and so, ideally: **A, B, C, D, and finally E** (not represented in the options provided).