|
|
|
Science at key stage 3 (Year 8)
Unit 8H: The rock cycle
Section 3: What is different about metamorphic rocks?
|
|
Objectives |
| Children should learn: |
- that increasing temperature and pressure can cause some rocks to change in the solid state
- that metamorphic rocks are formed from pre-existing rocks during metamorphism, as a result of high pressure and/or high temperature
|
Activities |
|
Outcomes |
|
Children: |
- Explain, with illustrations, theories about the formation of metamorphic rocks, and ask pupils to examine samples of metamorphic rock and compare them with the sedimentary rocks from which they were formed,
eg limestone and chalk with marble, sandstone with quartzite, shale with slate. Using slides or photographs, show pupils illustrations of the alignment of grains,
eg in slate. Ask pupils to choose one pair of sedimentary and metamorphic rocks, describe the differences between them and explain how the metamorphic rock was formed.
|
|
- name some metamorphic rocks
- describe how metamorphic rocks differ from sedimentary rocks,
eg the crystals may be aligned, they may be less porous, fossils may or may not be distorted, no grains may be visible, the rock may be harder
- describe the processes by which a particular metamorphic rock is formed
|
|
Points to note |
- Pupils may not be aware that metamorphism means 'changing form'.
- It may be helpful for some pupils if the processes and types of rock are presented on a series of cards or using ICT and pupils are asked to arrange them.
- Metamorphic rocks can be formed from igneous, sedimentary or metamorphic rock, but the changes from sedimentary to metamorphic are most easily seen. Sedimentary rocks that contain 'platey' minerals,
eg shale, may change to show alignment of crystals, as in slate. Other metamorphic rocks,
eg marble and quartzite, leave a 'sugary' texture because the minerals from which they were formed resist pressure equally in all directions.
|
|
|
This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
|
|
|
|
