Start Elements used in absolute dating

Elements used in absolute dating

For example, which is older, the bricks in a building or the building itself?

Say for example that a volcanic dike, or a fault, cuts across several sedimentary layers, or maybe through another volcanic rock type.

In a way this field, called geochronology, is some of the purest detective work earth scientists do.

There are two basic approaches: relative age dating, and absolute age dating.

Here is an easy-to understand analogy for your students: relative age dating is like saying that your grandfather is older than you.

Absolute age dating is like saying you are 15 years old and your grandfather is 77 years old.

Sometimes, scientists already know the age of the fossil because fossils of the same species have been found elsewhere and it has been possible to establish accurately from those when the dinosaur lived.

Geologists call this the principle of lateral continuity.

It’s based either on fossils which are recognized to represent a particular interval of time, or on radioactive decay of specific isotopes. Based on the Rule of Superposition, certain organisms clearly lived before others, during certain geologic times.