Thrust faults can cause repetition of stratigraphic beds in a vertical cross-section. What term describes the resulting pattern?

• A. A repeated sequence of beds
• B. An unconformity
• C. A syncline
• D. A dip-slip anomaly

Answer: (A)

Thrust faults in compressional settings push slices of rock on top of other slices, so in a vertical cross-section the same stratigraphic package can appear more than once as it’s stacked along the fault. This duplication creates a pattern described as a repeated sequence of beds—the same units show up again higher in the section. An unconformity would show a gap where rocks are missing, a syncline is a downfold that bends beds without duplicating them, and a dip-slip anomaly refers to fault offset rather than repeating the same beds.