Answer:
The sediments and the rocks that are found at the surface of the earth are usually different from the underlying bedrocks due to the weathering and erosion process. Weathering and erosion refer to the breaking down of rocks and transporting to other places with the help of agents such as water, wind, and air.
This weathering and erosion is one of the main processes for getting different rock types on the surface at a certain depth. In addition to this, the occurrence of landslides, surface runoff, and some other factors are also responsible for carrying away the rock materials and other particles from one place to another.