Two types of absolute dating
It is possible to tell the number of years ago a particular rock or archeological site had been formed.Two broad categories of classification methods are relative dating and absolute dating.In the case of carbon dating, it is not the initial quantity that is important, but the initial ratio of C, but the same principle otherwise applies.Recognizing this problem, scientists try to focus on rocks that do not contain the decay product originally.When it comes to determining the age of stuff scientists dig out of the ground, whether fossil or artifact, “there are good dates and bad dates and ugly dates,” says paleoanthropologist John Shea of Stony Brook University.The good dates are confirmed using at least two different methods, ideally involving multiple independent labs for each method to cross-check results.
Methods fall into one of two categories: relative or absolute.
This is a method that does not find the age in years but is an effective technique to compare the ages of two or more artifacts, rocks or even sites.
It implies that relative dating cannot say conclusively about the true age of an artifact.
Before more precise absolute dating tools were possible, researchers used a variety of comparative approaches called relative dating.
These methods — some of which are still used today — provide only an approximate spot within a previously established sequence: Think of it as ordering rather than dating.With uranium-lead dating, for example, the process assumes the original proportion of uranium in the sample.