Which principle states that younger layers of rock are deposited on top of older layers?

• A. Law of Superposition
• B. Relative dating
• C. Geologic time scale
• D. Absolute dating

Answer: (A)

In an undisturbed sequence of sedimentary rocks, the oldest material settles first and is buried beneath newer layers, so each successive layer is younger than the one beneath it. This ordering is known as the Law of Superposition. It’s the fundamental idea behind relative dating, letting us determine which rocks are older or younger without assigning exact ages. The other terms describe broader dating methods or timelines rather than the specific principle that younger layers sit on top of older ones: relative dating is the overall approach using such principles, the geologic time scale is the organized record of Earth's history, and absolute dating provides numerical ages.