Radioactive dating is also called
According to the principle of original horizontality, these strata must have been deposited horizontally and then titled vertically after they were deposited.
In addition to being tilted horizontally, the layers have been faulted (dashed lines on figure).
Just as when they were deposited, the strata are mostly horizontal (principle of original horizontality).
The layers of rock at the base of the canyon were deposited first, and are thus older than the layers of rock exposed at the top (principle of superposition).
For example, in the rocks exposed in the walls of the Grand Canyon (Figure 1) there are many horizontal layers, which are called strata.
Layers that cut across other layers are younger than the layers they cut through (principle of cross-cutting relationships).Relative dating puts geologic events in chronological order without requiring that a specific numerical age be assigned to each event.Second, it is possible to determine the numerical age for fossils or earth materials.The principle of superposition builds on the principle of original horizontality.The principle of superposition states that in an undeformed sequence of sedimentary rocks, each layer of rock is older than the one above it and younger than the one below it (Figures 1 and 2).