Question

an outcrop of rock shows three horizontal layers. a fault cuts through the bottom two layers but not the top layer. which statement accurately describes the sequence of events?
the fault is the oldest feature described.
the bottom layer is younger than the fault.
the top layer is the youngest feature.
the fault is the same age as the top layer.

Explanation:

This uses the principle of superposition (oldest rock layers form first, at the bottom) and cross-cutting relationships (a fault that cuts layers is younger than the layers it cuts). The bottom two layers formed first, then the fault cut them, then the top layer formed (since the fault doesn't affect it). Thus the top layer is the youngest feature.

Answer:

The top layer is the youngest feature.