Imagine that you're a geologist, studying the amazing rock formations of the Grand Canyon.Your goal is to study the smooth, parallel layers of rock to learn how the land built up over geologic time.Therefore, at any time, the total of parent isotope fraction and daughter isotope fraction add up to 1.Similarly, the percentage of parent isotope percentage and daughter isotope percentage add up to 100 at all times.Relative dating requires an extensive knowledge of stratigraphic succession, a fancy term for the way rock strata are built up and changed by geologic processes.Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence.
Throughout the history of life, different organisms have appeared, flourished and become extinct.
In order to do so we will have to understand the following: To better understand these concepts, let's look at an archeological example: Imagine we are a group of archeologists studying two different trash pits recently discovered on the Tulane University campus and at the Audubon Zoo (where they all aksed for you).
By carefully digging, we have found that each trash pit shows a sequence of layers.
By the definition of a half-life, the amount of parent isotope at each half-life is half of what it was before the half-life elapsed.
As the amount of parent isotope decreases by radioactive decay, the amount of the daughter isotope increases commensurately.
Now imagine that you come upon a formation like this: What do you think of it? How can you make any conclusions about rock layers that make such a crazy arrangement?