New
New
Metamorphic rock
I can describe how rock can be changed deep underground.
Lesson 7 of 7
New
New
- Year 8
Metamorphic rock
I can describe how rock can be changed deep underground.
Lesson details
Key learning points
- In a crystal, the atoms are all arranged in a very regular pattern.
- In some substances, very high pressure, at a high temperature, can push particles together to form crystals.
- Between tectonic plates, the pressure and temperature are high enough for large crystals to grow inside solid rock.
- Metamorphic rocks form under extreme pressure and temperature, altering original structures.
- Aligned crystals in metamorphic rocks give them useful properties (e.g. decoration or easily separated into sheets).
Keywords
Pressure - The effect of a force acting over an area.
Metamorphic rock - Rocks that have changed due to heat and/or pressure (e.g. marble, slate).
Aligned - Grains that line up in the same direction are described as aligned.
Common misconception
Pressure and heating caused by burying alone is enough to cause metamorphism or rock to melt.
Highlight that the temperatures / pressures needed for metamorphism or rocks to melt are typically found at plate boundaries / hot spots.
Repeat Task B, part 2b (the modelling activity) using a shell imprint, rather than stirring rod imprints, to illustrate how fossils become deformed / destroyed during metamorphosis.
Teacher tip
Equipment
Toothpicks (could use matchsticks), rulers ×2; plasticine, stirring rods (optional: shells).
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of the following statements about minerals is correct?
Which of the following statements about minerals is correct?
All minerals are human-made.
Minerals are only found in sedimentary rocks.
Minerals do not have any crystal structure.
Q2.Sort the following steps into the correct order in which they occur during the formation of igneous rocks from melted rock.
Sort the following steps into the correct order in which they occur during the formation of igneous rocks from melted rock.
Q3.Rocks have a melting point because they are composed of minerals with strong chemical bonds.
Rocks have a melting point because they are composed of minerals with strong chemical bonds.
Q4.Match the following terms to their description.
Match the following terms to their description.
Q5.A is a solid with a regular, repeating arrangement of atoms, typically forming when melted rock cools and solidifies.
A is a solid with a regular, repeating arrangement of atoms, typically forming when melted rock cools and solidifies.
Q6.Scientists use to simulate and study Earth's structure, processes, and phenomena that cannot be directly observed.
Scientists use to simulate and study Earth's structure, processes, and phenomena that cannot be directly observed.
Assessment exit quiz
6 Questions
Q1.Which of the following is a definition of pressure?
Which of the following is a definition of pressure?
The amount of energy in an object.
The speed at which an object moves.
The weight of an object.
Q2.Which of the following types of rock change due to extreme temperature and/or pressure?
Which of the following types of rock change due to extreme temperature and/or pressure?
sedimentary
igneous
Q3.Starting with the conditions experienced by the rock, sort the following steps into the correct order to describe the formation of metamorphic rock.
Starting with the conditions experienced by the rock, sort the following steps into the correct order to describe the formation of metamorphic rock.
Q4.Which property of metamorphic rocks allows them to be easily separated into sheets?
Which property of metamorphic rocks allows them to be easily separated into sheets?
high density
hardness
colour
Q5.Which of the following statements about the formation of large crystals in metamorphic rocks is correct?
Which of the following statements about the formation of large crystals in metamorphic rocks is correct?
Large crystals form quickly.
Large crystals form under low pressure.
Large crystals form at Earth's surface.
Q6.At plate boundaries, rocks are subjected to extreme pressure and temperature.
At plate boundaries, rocks are subjected to extreme pressure and temperature.
