The key difference between relative dating and radiometric dating is that the dating cannot provide actual numerical dates whereas the radiometric dating can provide actual numerical dates.
Relative dating and radiometric dating are two types of parameters that we use to describe the age of geological features and to determine the relative order of past events. Here, we are talking about millions and billions of years. Let us discuss more details about these terms.
CONTENTS
1. Overview and Key Difference
2. What is Relative Dating
3. What is Radiometric Dating
4. Side by Side Comparison – Relative Dating vs Radiometric Dating in Tabular Form
5. Summary
What is Relative Dating?
Relative dating is determining the relative order of past events via determining the approximate age of geological features. The method of reading this order is called stratigraphy. This does not give the actual numerical dates. Therefore, this can only explain the sequence of events without giving details on “when” these events took place. Fossils are the key to determine the relative dating in sedimentary rocks. A sedimentary rock contains different layers being the oldest at the bottom and youngest at the top. This is what we call “superposition”. With time, different organisms appear and flourish leaving their fossils in sedimentary rocks. Therefore, we can identify the sequence of different lives on earth via relative dating.
What is Radiometric Dating?
Radiometric dating is determining the exact order of past events via determining the absolute age of geological features. We can use this method to determine how long a rock was formed and the ages of fossils that are trapped in these rocks. There we use trace radioactive impurities incorporated in these rocks when they were formed.
Figure 01: Radiometric Dating of Fossils
In this method we compare the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. It provides us with actual numerical dates.
What is the Difference Between Relative Dating and Radiometric Dating?
Relative dating is the method of providing the relative order of past events via determining the approximate age of geological features. Therefore, it cannot provide actual numerical dates. Radiometric dating is determining the exact order of past events via determining the absolute age of geological features. Therefore, it can provide actual numerical dates. This is the key difference between relative dating and radiometric dating.
Summary – Relative Dating vs Radiometric Dating
Relative and radiometric dating are important parameters in determining the sequences and ages of past events. The difference between relative dating and radioactive dating is that the relative dating cannot provide actual numerical dates whereas the radioactive dating can provide actual numerical dates.
Reference:
1. “Relative Dating.” Science Learning Hub. Available here
2. “Radiometric Dating.” Wikipedia, Wikimedia Foundation, 10 July 2018. Available here
Image Courtesy:
1.’Relative dating of fossils’By Jillcurie – Own work, (CC BY-SA 3.0) via Commons Wikimedia