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. 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. Time factors of millions and billions of years is difficult even for adults to comprehend.
High School Earth Science/Relative Ages of Rocks
1. Relative age dating | Digital Atlas of Ancient Life
In , a young doctor named Nicholas Steno was invited to dissect the head of an enormous great white shark that had been caught by local fisherman near Florence, Italy. Steno was struck by the resemblance of the shark's teeth to fossils, known as "tongue stones", recovered from inland mountains and hills Figure While it may seem obvious today, most people at the time did not believe that fossils were once part of living creatures. The reason was that the fossils of clams, snails, and other marine animals were found in tall mountains, miles from any ocean. Two schools of thought explained these fossils.
Dating Rocks and Fossils Using Geologic Methods
Absolute age dating — 3. Geological time scale — 4. Geological maps.
This page has been archived and is no longer updated. Despite seeming like a relatively stable place, the Earth's surface has changed dramatically over the past 4. Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free. These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth's surface is moving and changing.