How does absolute age differ from relative age?

1 Answer
Dec 5, 2015

One has an explicit date and the other is relative

Explanation:

Click here to see my response to this question regarding the dating of fossils

In short, absolute dating is a technique by which isotopes of a certain element are measured and then using a particular decay system (for example, #U-Pb#) an age can be constructed. This will give you a number and then you would calculate an associated uncertainty. For example, I may date a zircon mineral by measuring U and Pb and get an age of 2013 #+-# 15 Ma ( Ma = million years ago).

If I were to date something relatively I would have an idea of the sequence of geological events but no idea how long ago they look place. I could say what came first and second and third and so on but I would have no idea whether this all happen 10 minutes ago or 4 billion years ago!