Question

Why does the superposition principle work?

Answer 1

In geology, superposition means that when sediments are laid down, from bottom to top, they are laid down in a certain order with the oldest at the bottom and the youngest at the top and so for horizontal layered sediments it is correct to say that the lowest layers are the oldest and the highest are the youngest. But care must be taken for where there are large scale folds, overturned, then the oldest layer can be on top of the younger but usually folding will be obvious but more difficult to detect on a large scale.