Final answer:
Using the concept of biostratigraphic correlation, we can infer that two sites containing the same species of fossils are of similar age. This allows geologists to use absolute dating from one site, such as potassium-argon dating, to estimate the age of the other site. Assumptions in radiometric dating are accounted for when calculating the accurate age of geological materials.
Step-by-step explanation:
When two sites both contain fossil remains of the same extinct animal species and there is a potassium-argon date for one site, we can infer that the other site has a similar age using the concept of biostratigraphic correlation. This method uses the presence of identical fossils in different geological layers to determine that the layers were deposited at the same time, therefore suggesting a similar age. Geologists can use the known absolute dating of one site, obtained through techniques such as potassium-argon dating, to make inferences about the age of the other site without directly dating it. This is based on the assumption that the same species of fossils found in different locations but in the same layer of rock are of the same age due to simultaneous deposition.
Moreover, geologists rely on certain assumptions with radiometric dating, such as no daughter atoms being present when the rock first formed and the rock or mineral being a closed system. While these assumptions may not always hold true, geologists employ various methods to account for potential discrepancies and still calculate an accurate age for the geological materials. By comparing the ratio between parent and daughter atoms and knowing the decay rate, geologists can quantitatively determine the age of rocks, minerals, and fossils.