What principle could be used to describe the layering of sedimentary rocks in terms of age?

The correct principle that describes the layering of sedimentary rocks in terms of age is superposition. This principle asserts that in any undisturbed sequence of sedimentary rock layers, the oldest layers are at the bottom, and younger layers are deposited on top. This concept is fundamental in geology for understanding the relative ages of rock layers and the fossils contained within them, allowing geologists to construct a chronological history of the Earth's surface.

When sediment accumulates over time, it typically forms horizontal layers, and as additional sediment is deposited, it compresses the underlying layers, preserving their order. Therefore, by examining the sequence of rock strata, one can infer the relative ages of these layers, with the understanding that later deposits must cover earlier ones. This principle helps in the interpretation of geological history and the development of the geologic time scale.

Other principles, such as catastrophism and uniformitarianism, deal more with the processes that shape the Earth and events that can change rock layers but do not specifically emphasize the chronological order of sedimentary layers as directly as superposition does. Radiometric dating is a technique for determining absolute ages of rocks and fossils, rather than establishing their relative age based on layer positioning.