How important is fossil correlation in geology?

Very. It is one of the keys to stratigraphic correlation. When I started studying geology, plate tectonics was still a neat "theory". That was only 42 years ago. Now it is accepted as fact. read more

In oil and gas exploration fossil correlation is used to map marker beds that help define various oil and gas plays. Of course as mentioned above, fossil correlation makes relative dating of formations possible. The existence of a known fossil bed allows the geologist to know that beds below are older, and those above are younger. read more

The principle of fossil correlation states that the strata containing a group of fossils that are all the same age must be of similar age to the fossils. Strata are layers of rock, and each single layer is known as a stratum. read more

Since geology is primarily a study of history, it was and is important to have all the mapped rock units fit into a coherent sequence of origin and the only way to do this is on the basis of age. Thus, different formations in different areas could be correlated on the basis of common age. read more