What does the Law of Superposition state?

The Law of Superposition is a fundamental principle in geology that states that in any sequence of undisturbed sedimentary rocks, the oldest layers are located at the bottom, with progressively younger layers stacked on top. This principle helps geologists determine the relative ages of rock formations and understand the chronological sequence of geological events.

When observing a vertical succession of sedimentary rocks, each layer represents a period of deposition; hence the deeper the layer, the older it generally is. This allows geologists to reconstruct geological histories and even infer conditions of the Earth at different times based on the types of sediments found in each layer. Thus, the correct understanding that the oldest rocks are at the bottom confirms the application of the Law of Superposition within sedimentary sequences.

The other options suggest incorrect relationships about the positioning of sedimentary layers. For example, stating that the oldest rocks are on top is contrary to the fundamental definition of superposition, as is suggesting that layers are deposited in a random order, which would contradict the orderly nature of sedimentary processes.