Talus is best described as which feature?

• A. Rock fragments lying at the base of steep slopes
• B. Loose material on a rocky slope
• C. Sheet of concentric plates spall off due to release of overburden pressures
• D. Quartz sand

Answer: (A)

Talus is an apron of broken rock that accumulates at the base of a cliff or steep slope after pieces break off from mechanical weathering and rockfall. The fragments are typically angular and poorly sorted, forming a scree-covered pile at the slope’s foot. This places talus at the bottom of the exposure rather than on the slope itself, which is why it’s the best description for the feature.

The other ideas don’t fit: material lying on a rocky slope would be distributed on the slope surface rather than at the base; sheet spalling from unloading overburden describes exfoliation of rock layers, not an accumulation at the cliff foot; and quartz sand is a fine sediment, not a rock-fragment talus deposit.