Rocks are constantly changing and being transformed through various geological processes. Weathering breaks down rocks into sediments which are then eroded and transported by water, wind or ice. The sediments may settle and become compacted into sedimentary rocks through cementation. Heat and pressure metamorphose sedimentary and igneous rocks into different types of metamorphic rocks. Extreme heat melts rocks into magma and their subsequent cooling forms new igneous rocks, completing the continuous rock cycle.

1. Rock Cycle
• Weathering breaks down the rocks
• Erosion wears them into smaller pieces as they are
transported towards the sea

2. Igneous rocks
Common igneous rocks
GRANITE PEGAMATITE SYENITE GABBRO
Plutonic or intrusive
igneous rocks
VOLCANIC SCORIA PUMICE OBSIDIAN BASALT
Volcanic or extrusive
igneous rocks

3. Metamorphic rocks
Common metamorphic rocks
Clay Clay minerals Clay minerals, Sandstone
Limestone
minerals or slate slate, or schist with quartz
Original rock and
metamorphism
intense
increase in intense increase very intense intense increase in
temperature in temperature increase in increase in temperature
and pressure and pressure temperature temperature and pressure
and pressure and pressure
Metamorphic rock
SLATE SCHIST GNEISS QUARTZITE MARBLE

4. The rock cycle
SEDIMENTARY ROCK
MAGMA
compaction and
cementation
and erosion
weathering
melting
cooling
SEDIMENTS METAMORPHIC ROCK
IGNEOUS ROCK