Question

the diagram shows horizontal rock layers. according to the law of superposition, which statement is supported by the diagram?
layer c is the oldest layer.
layer b is younger than layer d.
layer c is older than layer a.
layer d is the youngest layer.

Explanation:

The law of superposition states that in undisturbed horizontal rock layers, the oldest layers are at the bottom and the youngest are at the top. From the diagram, the layers from bottom to top (oldest to youngest) are A, B, C, D.

• "Layer C is the oldest layer" is wrong as A is older than C.
• "Layer B is younger than layer D" is wrong as B is older than D.
• "Layer C is older than layer A" is wrong as A is older than C.
• "Layer D is the youngest layer" is correct as D is at the top, so it's the youngest.

Answer:

Layer D is the youngest layer.