How do scientist determine rock age using fossils?
In geology there are two main uses to which fossils are put. These are biostratigraphic correlation and environmental interpretation. Before discussing these two points, I should say that these two utilities of fossils are not necessarily those that are most interesting to a paleontologist who studies fossils. Evolutionary studies are important because of the light they shed on the mechanism of evolution and the interaction between evolution and extinction, not necessarily because evolution indirectly provides a powerful tool for matching up rocks of the same age but of different composition in widely separated areas. Deciphering ancient environments is important, but the paleontologist is concerned with the ancient communities of life that once inhabited those environments, about the interactions, competition, and predation among members of the community, and how food supplies are gathered, partitioned, and utilized by community members. Biostratigraphic Correlation The matching up of
