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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?
- Weathering
- Erosion
- Deposition
Which type of rock forms when melted rock cools and hardens?
- Sedimentary rock
- Igneous rock
- Metamorphic rock
Burial in sediment can help a dead plant or animal become a fossil.
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
A rock formed when buried sand grains are compacted and cemented together is sedimentary rock.
Circle one: True False
A fossil shell is found in rock made of cemented sediment. Which explanation connects burial to the shell's preservation?
- Sediment buried the shell, then melted into lava that cooled around the shell to preserve its shape.
- The shell grew inside solid sedimentary rock after the sediment had already hardened around it.
- Sediment buried the shell, then became sedimentary rock while evidence of the shell remained inside.
Priya says, 'Big crystals prove this rock is metamorphic.' Which fact should she consider?
- Metamorphic rocks always lack crystals, whatever heat and pressure they experience
- Slowly cooled igneous rock can have big crystals too
- Large crystals grow only in sedimentary layers and never in cooled magma

Answer key

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

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Weathering · Weathering breaks rock down where it is. The description does not include transport.
Igneous rock · Igneous rock comes from magma or lava that cools and hardens into solid rock.
True · Burial can protect remains or an imprint. Some become fossils, but burial does not guarantee preservation.
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 · Compaction packs sediment grains together, and cement joins them. This is a sedimentary-rock formation process.
Sediment buried the shell, then became sedimentary rock while evidence of the shell remained inside. · Burial covered the shell. The sediment became sedimentary rock, with evidence of the shell preserved inside as a fossil.
Slowly cooled igneous rock can have big crystals too · Slow cooling can produce large crystals in igneous rock. Crystal size alone does not prove that a rock is metamorphic.