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.The study of fossils and the exploration of what they tell scientists about past climates and environments on Earth can be an interesting study for students of all ages.Teaching about Earth's history is a challenge for all teachers.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.
Extinction of species is common; most of the species that have lived on the earth no longer exist.
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.
This would also mean that fossils found in the deepest layer of rocks in an area would represent the oldest forms of life in that particular rock formation.
In reading earth history, these layers would be "read" from bottom to top or oldest to most recent.
INTRODUCTION Scientists have good evidence that the earth is very old, approximately four and one-half billion years old.