How do fosils help in determining the relative age of strata? Are the three different localities around the same relative age?

Fossils play a crucial role in determining the relative age of strata, which refers to the order and sequence of rock layers. The principle of fossil succession states that fossils succeed each other in a definite and determinable order, allowing scientists to establish a relative timeline of when different organisms existed. This principle relies on the fact that certain organisms lived and became extinct during specific time periods.

To determine the relative age of strata using fossils, scientists utilize the concept of index fossils. Index fossils are widespread and abundant organisms that only lived for a short period of time but were geographically widespread. By identifying and dating the index fossils within a specific layer of rock, scientists can infer the approximate age of that layer and compare it to the ages of other strata. If the same index fossils are found in different layers or localities, it suggests that those layers were formed during the same relative age.

However, it is important to note that while fossils can provide evidence for relative age, they do not provide precise numerical ages. For that, scientists utilize absolute dating techniques such as radiometric dating, which involves analyzing the ratios of radioactive isotopes and their decay products in rocks.

Regarding the three different localities, if they contain the same index fossils or exhibit similar fossil assemblages, it suggests that they are indeed of the same relative age. However, it is essential to conduct a more comprehensive study, considering other factors like the geological context and the presence of unconformities, to make a definitive conclusion about their relative ages.