Difference between relative and chronometric absolute dating techniques
But instead of saying that one layer is x number of years old, you can simply describe it as older than the layer above it yet younger than the layer below it.
Relative age starts from the bottom and works upward.
Here, we are looking at events relative to other events.
When we put both absolute and relative time together, we create a geologic time scale.
They are both important in terms of Earth's history and its geological timeline, and they work together in concert to build the planet's geological record.
In this lesson, we're going to discuss what each type of time is and why it is important so that you too can understand how they work to describe past events on Earth. Let's start with absolute time, also called chronometric time ('chrono' means 'time' and 'metric' means 'measure').
Relative time, also called chronostratic time tells us when events occurred relative to each other.
For example, a rock layer that is below another one is older, and we know this even without knowing how old the rocks are simply by their position relative to each other.