Like all terrestrial planets, the Earth’s interior is differentiated.This means that its internal structure consists of layers, arranged like the skin of an onion.There is more to the Earth than what we can see on the surface.
The law was first proposed in the 17th century by the Danish scientist Nicolas Steno.
Other examples of non vertical superposition would be modifications to standing structures such as the creation of new doors and windows in a wall.
Superposition in archaeology requires a degree of interpretation to correctly identify chronological sequences and in this sense superposition in archaeology is more dynamic and multi-dimensional.
For purposes of relative dating this principle is used to identify faults and erosional features within the rock record.
Then, by applying the Principle of Cross-Cutting we are able to relatively date those processes.