Relative dating geology
Time factors of millions and billions of years is difficult even for adults to comprehend.
However, "relative" dating or time can be an easy concept for students to learn.
However, relative methods are , which is that if there are layers of deposits, those laid down first will be on the bottom and those laid down last will be on the top. However, geological strata are not always found to be in a neat chronological order.
Wind and water erode strata and some areas are uplifted or even tilted.
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.
Shale is initially deposited as clay, from either fresh or salt water.
To determine the relative age of different rocks, geologists start with the assumption that unless something has happened, in a sequence of sedimentary rock layers, the newer rock layers will be on top of older ones. This rule is common sense, but it serves as a powerful reference point.
Geologists draw on it and other basic principles ( to determine the relative ages of rocks or features such as faults.
In the past, relative dating methods often were the only ones available to paleoanthropologists.
As a result, it was difficult to chronologically compare fossils from different parts of the world.