How do fossils help us determine the age of rock layers?

Fossils help us determine the age of rock layers by identifying the age of the fossils. To do this, we compare the fossils to a known timeline of when certain species existed. By looking at rock layers, we can determine which layer is older or younger than the others. This is due to the Law of Supposition. For example, let's say we have a few rock layers where we can't determine the exact age. By identifying fossils in these rock layers and knowing roughly when these living organisms existed in the past, we can date the rock layers. We can do this by comparing the known timeline of the species to the rock layers. If we examine the image below, we can see layers A, B, C, and D. We know layer A is younger than layer B and that B is younger than layer C. However, if we did not have any fossils, we would not know the exact age of the rock layers. To determine the age of a rock layer, we need to identify the fossils in the rock layer and compare them to the known timeline of the species. We can then determine the age of the rock layer based on when the species existed. It's important to note that the accuracy of this method relies on our knowledge of the fossils. If we don't have a lot of information about the fossils, our methods will be less accurate. Additionally, fossils can be rare or our knowledge of them can change. So, the more we know about the fossil, the more accurate our methods will be.