You might have noticed that many of the oldest age dates come from a mineral called zircon.That’s because zircon is super tough – it resists weathering. Each radioactive isotope works best for particular applications.Yet, you’ve heard the news: Earth is 4.6 billion years old. That corn cob found in an ancient Native American fire pit is 1,000 years old. Geologic age dating—assigning an age to materials—is an entire discipline of its own.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.When subjected to external stimuli, mineral emits light due to these changes.This luminescence is weak and distinct as apply heat (TL), visible light (OSL) or infrared (IRSL).
These changes are cumulative, continuous and time dependent to radiation exposure.
With absolute age dating, you get a real age in actual years.
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.
we often make reference to fossils to explain the past of living beings. Fossils are remnants (complete or partial) of living beings that have lived in the past (thousands, millions of years) or traces of their activity that are preserved generally in sedimentary rocks.
Have you ever wondered how science knows the age of a fossil? If you think of a fossil, surely the first thing that comes to your mind is a dinosaur bone or a petrified shell that you found in the forest, but a fossil is much more.