Argon argon radioactive dating method
However, the age of each fossil primate needs to be determined so that fossils of the same age found in different parts of the world and fossils of different ages can be compared.There are three general approaches that allow scientists to date geological materials and answer the question: "How old is this fossil?Most sediment is either laid down horizontally in bodies of water like the oceans, or on land on the margins of streams and rivers.Each time a new layer of sediment is deposited it is laid down horizontally on top of an older layer.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).In the Grand Canyon, the layers of strata are nearly horizontal.
The principle of superposition builds on the principle of original horizontality.
This is the principle of original horizontality: layers of strata are deposited horizontally or nearly horizontally (Figure 2).
Thus, any deformations of strata (Figures 2 and 3) must have occurred after the rock was deposited.
" First, the relative age of a fossil can be determined.
Relative dating puts geologic events in chronological order without requiring that a specific numerical age be assigned to each event.