Rocks

Aims

Pupils should gain an understanding of:

• How rocks are weathered by expansion and contraction and by freezing of water;
• The rock cycle which involves sedimentary, metamorphic and igneous processes that take place over different time scales;
• The classification of rocks as sedimentary, metamorphic or igneous on the basis of their processes of formation, and that these processes affect their texture and the minerals they contain;
• Igneous rocks being formed from liquid rock called magma;
• The size of crystals in different types of igneous rock depending on where and how fast the liquid rock cools;
• The fact that there are places of very high temperature and pressure under the Earth’s crust and that the Earth’s crust is not always the same thickness;
• The weathering of rocks by physical and chemical processes;
• Fossils being the remains of living creatures found in sedimentary rocks;
• The fact that sedimentary and igneous rocks can be changed into metamorphic rocks by high temperatures and pressures.