Dating fossils ppt
Scientists also use direct evidence from observations of the rock layers themselves to help determine the relative age of rock layers.
Specific rock formations are indicative of a particular type of environment existing when the rock was being formed.
Although most attention in today's world focuses on dinosaurs and why they became extinct, the world of paleontology includes many other interesting organisms which tell us about Earth's past history.
If certain fossils are typically found only in a particular rock unit and are found in many places worldwide, they may be useful as index or guide fossils in determining the age of undated strata.
By using this information from rock formations in various parts of the world and correlating the studies, scientists have been able to establish the geologic time scale.
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.