What concept explains that rocks are generally younger than the layers beneath them in sedimentary sequences?

The concept that explains that rocks are generally younger than the layers beneath them in sedimentary sequences is known as superposition. This principle is a fundamental concept in geology and stratigraphy which states that in any undisturbed sequence of sedimentary rocks, the oldest layers are at the bottom, and the younger layers are deposited on top. This layering occurs due to the accumulation of sediments over time, where new layers are created as sediment is deposited by various processes, such as water or wind.

Superposition is crucial for understanding geological history and the relative ages of rock formations, enabling geologists to reconstruct past environments and the sequence of events that have led to the present-day landscape. It serves as a foundational principle for stratigraphy, allowing scientists to derive insights from the arrangement and types of rocks present in a given location.