Here's why:
* Sedimentary rock formation: Sedimentary rocks are formed by the accumulation of sediment (like sand, mud, or organic matter) over time. These layers build up, with the oldest layers at the bottom and the youngest layers at the top.
* Erosion and exposure: Over millions of years, these layers can be exposed by erosion, which wears away the rock. The oldest layers, being at the bottom, are the first to be exposed.
* Geological time scale: Think of it like a time capsule. The bottom of the cliff represents the furthest back in time, while the top represents the more recent past.
Therefore, the oldest sedimentary rocks would be found at the base of the cliff, while the youngest rocks would be closer to the top (assuming the cliff has been eroded to expose these layers).
