New
New
Year 8

Metamorphic rock

I can describe how rock can be changed deep underground.

New
New
Year 8

Metamorphic rock

I can describe how rock can be changed deep underground.

Lesson details

Key learning points

  1. In a crystal, the atoms are all arranged in a very regular pattern.
  2. In some substances, very high pressure, at a high temperature, can push particles together to form crystals.
  3. Between tectonic plates, the pressure and temperature are high enough for large crystals to grow inside solid rock.
  4. Metamorphic rocks form under extreme pressure and temperature, altering original structures.
  5. Aligned crystals in metamorphic rocks give them useful properties (e.g. decoration or easily separated into sheets).

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.

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.

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).

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which of the following statements about minerals is correct?
All minerals are human-made.
Correct answer: Minerals are pure substances with a crystal structure.
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.
1 - melting
2 - cooling
3 - solidification
Q3.
Rocks have a melting point because they are composed of minerals with strong chemical bonds.
Correct Answer: high
Q4.
Match the following terms to their description.
Correct Answer:mantle,the thick, solid layer beneath the crust

the thick, solid layer beneath the crust

Correct Answer:core,the central part of Earth

the central part of Earth

Correct Answer:crust,the outermost layer of Earth

the outermost layer of Earth

Q5.
A is a solid with a regular, repeating arrangement of atoms, typically forming when melted rock cools and solidifies.
Correct Answer: crystal
Q6.
Scientists use to simulate and study Earth's structure, processes, and phenomena that cannot be directly observed.
Correct Answer: models

6 Questions

Q1.
Which of the following is a definition of pressure?
Correct answer: The effect of a force acting over an area.
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?
sedimentary
igneous
Correct answer: metamorphic
Q3.
Starting with the conditions experienced by the rock, sort the following steps into the correct order to describe the formation of metamorphic rock.
1 - Rock experiences extreme pressure and temperature.
2 - Particles are pushed together to form crystals.
3 - Crystals grow inside solid rock.
Q4.
Which property of metamorphic rocks allows them to be easily separated into sheets?
high density
Correct answer: aligned crystals
hardness
colour
Q5.
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.
Correct answer: Large crystals form over millions of years.
Large crystals form at Earth's surface.
Q6.
At plate boundaries, rocks are subjected to extreme pressure and temperature.
Correct Answer: tectonic