The Record of Time: Relative Techniques
since, all sedimentary rock is formed through the gradual accumulation of sediment at the surface over time, and since the principle of superposition tells us that newer sediment is deposited on top of older sediment, the same must also be true for fossils contained within the sediment.
the principle of cross-cutting states that any geologic feature that crosses other layers or rock must be younger then the material it cuts across.
Anthropology 120 NM HED Area III: Laboratory Science
then, by applying the principle of cross-cutting we are able to relatively date those processes.
Dating Methods | Answers in Genesis
much like the principle of cross-cutting, the principle of inclusions relatively dates objects based on their placement within other earth materials.
What is Relative Dating? - Law of Superposition, Principles of
The Principle of Superposition
the 19th century, however, geologists could only establish the relative ages of rock units.