Hand using a green pen to highlight a fault line in a geology worksheet.

- The image displays a geological cross-section with labeled rock layers (A, B) and features like an unconformity.
- The task involves identifying the sequence of events based on stratigraphic principles.
- Principle of Superposition: In undisturbed sedimentary rock layers, the oldest layer is at the bottom (Layer B), and each successive layer above is younger (Layer A).
- Principle of Cross-Cutting Relationships: Features that cut across other rocks are younger than the rocks they cut. The fault cuts through both Layer A and Layer B, so the faulting event occurred after both layers were deposited.
- Unconformity: The wavy line between Layer B and Layer A represents an unconformity, indicating a period of erosion or non-deposition. This means Layer B was deposited, then eroded, and later Layer A was deposited on top.
- Therefore, the correct chronological order of events is: Deposition of Layer B → Erosion/Non-deposition (forming the unconformity) → Deposition of Layer A → Faulting.