In sedimentary rocks, where are the oldest layers typically found?

In sedimentary rocks, the principle of superposition applies, which states that in an undisturbed sequence of sedimentary layers, the oldest layers will be found at the bottom and the younger layers will accumulate on top of them. This is due to the way sediment is deposited over time; as new layers of sediment are added, they create pressure that compacts the older layers beneath. This systematic layering reflects the chronological order of deposition, allowing geologists to interpret the geological history of the area. Therefore, the oldest layers being at the bottom of the formation aligns with this fundamental principle of sedimentology.