Question

According to the Law of Superposition, in undisturbed, horizontal, sedimentary rock layers, the oldest layer is at the bottom. Each higher layer is younger than the rocks below it. Why is it important that the rock layers be undisturbed?

A. If the rock layers are disturbed, sedimentary rock will turn into an intrusion
B. If the rock layers are disturbed, the absolute age of the rocks will change
C. If the rock layers are disturbed, certain layers may be missing or relocated
D. If the rock layers are disturbed, the Law of Superposition is proven wrong
Please explain why you chose this answer

Answer 1

The correct answer is C. If the rock layers are disturbed, certain layers may be missing or relocated.

The Law of Superposition is a fundamental principle used in geology to determine the relative ages of rock layers. It states that in an undisturbed sequence of sedimentary rocks, the oldest rocks are at the bottom and the youngest rocks are at the top. This is because sedimentary rocks are formed by the accumulation of sediment over time, with each layer representing a snapshot of the environment at a particular point in time.

If the rock layers are disturbed, such as by folding, faulting, or erosion, the original order of the layers can be disrupted. In extreme cases, layers can be overturned or completely removed, leading to missing or relocated layers. This can make it difficult or impossible to use the Law of Superposition to determine the relative ages of the remaining layers.