What evidence might suggest a time interval between two rock layers?

Evidence for a time interval between two rock layers can include the presence of an unconformity, which indicates a gap in the geological record where erosion or non-deposition occurred. Fossil content can also provide clues; if the two layers contain different assemblages of fossils, it suggests that significant time passed between their formation. Additionally, variations in sediment type or characteristics, such as changes in color, grain size, or mineral composition, may indicate different environmental conditions over time.