Types of rocks

Science · Earth's Systems · ages 9-11

Name ______________________ Date ____________

Which word describes rock breaking apart right where it sits, without being moved?
- Erosion
- Weathering
- Deposition
Which type of rock forms when melted rock cools and hardens?
- Igneous rock
- Sedimentary rock
- Metamorphic rock
Fossils usually form when a dead plant or animal gets buried in sediment.
Circle one: True False
Sand grains break off a cliff (step A). Wind carries the sand across the desert (step B). The sand piles up in a new spot (step C). Which word matches step B?
- Erosion
- Weathering
- Deposition
A rock used to be shale, but heat and pressure inside the Earth changed it into slate without melting it. What type of rock is slate?
- Igneous
- Sedimentary
- Metamorphic
The layers of sediment that trap and preserve a fossil are called strata.
Circle one: True False
A river carries broken rock pieces downstream and drops them on a flat plain when it slows down. Which step is missing from this description?
- Erosion, because nothing moved the pieces
- Deposition, because nothing was dropped anywhere
- Weathering, because nothing broke the rock apart at the start
Priya says, 'All rocks with big crystals must be metamorphic rocks.' What is wrong with her thinking?
- Metamorphic rocks never have crystals
- Igneous rock can also have big crystals if magma cools slowly underground
- Big crystals only form in sedimentary rock

Answer key

For grown-ups. Fold this page away before handing over the rest.

Weathering · Weathering breaks rock into smaller pieces in the same spot. Nothing has moved yet.
Igneous rock · Igneous rock comes from magma or lava that cools and hardens into solid rock.
True · Sediment piles up around the remains, and over a long time it turns to sedimentary rock, preserving the shape inside.
Erosion · Erosion is the step where broken pieces get carried away, like sand moving in the wind.
Metamorphic · Metamorphic rock forms when heat and pressure change an existing rock into a new kind, without melting it.
True · Strata are the layers of sediment, and later sedimentary rock, that build up over time with fossils trapped inside them.
Weathering, because nothing broke the rock apart at the start · The story starts with pieces already broken and moving, so it skips weathering, the step where the rock first breaks apart.
Igneous rock can also have big crystals if magma cools slowly underground · Slow-cooling magma underground grows big crystals too, so crystal size alone can't tell you a rock is metamorphic.