A sequence of undisturbed sedimentary rocks, the layers get younger going from bottom to top?

Question

IS THE PRINCIPLE OF

Original Horizontality

Superpostion

Cross-cutting

none of the above

Answer 1

Superpostion is the answer to the problem.

It means "positioned over or above"

Each new layer forms on top of the older layer beneath.

Yale Simkin

Answer 2

Superposition is the assumption that the yournger rocks are laid down over the top of older ones. - so this is the answer.

Original Horizontality is the assumption that (unless there are sedimentary structures to indicate otherwise) that sedimentary rocks were laid down in pretty much horizontal layers and and subsequent dip is the result of earth movements.

Cross cutting is where a structure such as a fault or d**e cuts across existing structures ( such as strata ) and therefore the cross cutting feature must be younger than the structures it cuts through.