Fossils & the Story of Rocks
Fossils & the Story of Rocks
Learning Objective
At the end of the lesson you will know what fossils are and be able to describe the three main types of rock: sedimentary, igneous, and metamorphic.
What Are Fossils?
Fossils are the remains or traces of plants and animals that lived long ago, preserved in rock.
How Fossils Form
Fossils usually form when a plant or animal is quickly buried by mud or sand. Over time, the remains can turn into stone.
Where Can We Find Fossils?
Most fossils are found in sedimentary rocks because these rocks form in layers where plants and animals can be trapped.
Types of Rock
There are three main types of rock: sedimentary, igneous, and metamorphic. Each forms in a different way.
Sedimentary Rock
Sedimentary rocks are made from tiny pieces of other rocks or once-living things, pressed and cemented together in layers.
Igneous Rock
Igneous rocks form when hot, melted rock (magma or lava) cools and hardens.
Metamorphic Rock
Metamorphic rocks start as another type of rock but have changed because of extreme heat and pressure.
How Are Rocks Different?
Sedimentary
Igneous & Metamorphic
Igneous is hard, often shiny or grainy. Metamorphic has bands or layers, is often hard and shiny.
Formed in layers, may have fossils, grainy or crumbly texture.
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Rocks Cycle Explained
Rocks change from one type to another over time through the rock cycle. Heat, pressure, weathering and melting help rocks transform.
Why Study Fossils & Rocks?
Fossils teach us about ancient life and the history of Earth. Rocks help us understand our planets structure.
Fun Fact!
Some dinosaurs are only known because scientists found fossilised bones in sedimentary rocks.
Quick Quiz
Which type of rock are fossils usually found in? A) Igneous B) Sedimentary C) Metamorphic
Lesson Summary
Today you learned about fossils and the three main rock types. Can you explain to a friend how each type forms?