Teaching relative age dating
PALEONTOLOGY, AND in particular the study of dinosaurs, is an exciting topic to people of all ages.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.Sequencing the rock layers will show students how paleontologists use fossils to give relative dates to rock strata.Once students begin to grasp "relative" dating, they can extend their knowledge of geologic time by exploring radiometric dating and developing a timeline of Earth's history.
They then see some new vocabulary and get to practice applying it before closing out for the day.
The Law of Superposition, which states that in an undisturbed horizontal sequence of rocks, the oldest rock layers will be on the bottom, with successively younger rocks on top of these, helps geologists correlate rock layers around the world.
This also means that fossils found in the lowest levels in a sequence of layered rocks represent the oldest record of life there.
INTRODUCTION Scientists have good evidence that the earth is very old, approximately four and one-half billion years old.
Scientific measurements such as radiometric dating use the natural radioactivity of certain elements found in rocks to help determine their age.