Though relative dating can only determine the sequential order in which a series of events occurred, not when they occurred, it remains a useful technique.
Relative dating by biostratigraphy is the preferred method in paleontology and is, in some respects, more accurate.
however, this process is not enough to allow the layers to change their positions.
This principle allows sedimentary layers to be viewed as a form of vertical time line, a partial or complete record of the time elapsed from deposition of the lowest layer to deposition of the highest bed.
The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah is a great example of Original Horizontality and the Law of Superposition, two important ideas used in relative dating.