Fossils and Geological Time
Fossils are the preserved remains of ancient life, and they help scientists date rocks and understand how Earth has changed.
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Fossils are the preserved remains of ancient life, and they help scientists date rocks and understand how Earth has changed.
- Fossils form in sedimentary rock
- The geological time scale spans 4.6 billion years
- Dinosaurs lived in the Mesozoic
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Fossils and Geological Time?
Within Earth & Environmental Science, which covers our planet, its resources and ecosystems, and how people can protect the environment, this topic explains Fossils and Geological Time. Earth and environment topics show how the planet’s systems shape landscapes, climate and life, with models that make these processes visible.
Check that you can explain Fossils and Geological Time in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Fossils and Geological Time helps you explain the environment around you and weigh up how people can protect it.
Fossils and Geological Time in detail
Fossils are the preserved remains or traces of ancient organisms, usually found in sedimentary rock. They form when organisms are quickly buried and hard parts, such as shells and bones, are replaced by minerals, or leave imprints, and they can also be preserved in amber, ice or tar.
Fossils show how life has changed and help date rocks: the oldest layers are usually at the bottom. The geological time scale divides Earth's 4.6-billion-year history into eons, eras and periods, such as the Cambrian, Jurassic and Quaternary. Radiometric dating of rocks measures the decay of radioactive isotopes to find actual ages. Mass extinctions mark boundaries.
How the interactive helps you understand Fossils and Geological Time
Watch the timeline in the interactive. Use any sliders or buttons it offers to change the values and see how the timeline responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Fossils and Geological Time.
Real-life uses and examples
- Use a diagram of Fossils and Geological Time to describe the steps of a process in order.
- Discuss how human activity changes Fossils and Geological Time, using a named example.
- Explain how Fossils and Geological Time affects the landscape or climate near you.
Common mistakes to avoid
- Describing a process without the timescale it works over.
- Presenting one cause as the only cause of an environmental change.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Fossils and Geological Time
What is Fossils and Geological Time?
Fossils are the preserved remains of ancient life, and they help scientists date rocks and understand how Earth has changed.
What are the most important points about Fossils and Geological Time?
The main points are: Fossils form in sedimentary rock; The geological time scale spans 4.6 billion years; Dinosaurs lived in the Mesozoic.
Why is Fossils and Geological Time useful?
Understanding Fossils and Geological Time helps you explain the environment around you and weigh up how people can protect it.
How can I practise Fossils and Geological Time?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Fossils and Geological Time?
Related topics in Earth & Environmental Science include Plate Tectonics, Mountains and Landforms, Clouds and Precipitation.