Chapter 3 - Rocks

Think about this…

Why do we study rocks???

What can be learned by studying rocks???

Well… we can learn mo better bout Mr Erf.

So what is a rock and where does it come from???

Well…atoms, like oxygen and carbon and magnesium…and all the others combine to make up molecules…

Then these molecules combine to make up minerals…

And then these minerals combine to make up rocks…

So a rock is a combination of 1 or more minerals.

The Rock Cycle

• Shows how any rock may be transformed from one type into another.

• It’s a continuous process that causes rocks to change.

Vocab terms

• Magma – underground molten rock

• Lava – above ground molten rock

• Crystallization – formation of minerals from cooling magma/lava

• Weathering – any process that breaks down rocks into smaller pieces (sediment)

• Erosion - transportation of sediment

Vocab terms

• Deposition – accumulation of sediment.

• Compaction - joining all the sediment.

• Cementation - “gluing up” all the sediment.

• Lithification (alternate term) – compaction and cementation of sediment.

• Metamorphism – changing one type of rock into another by heat/pressure/chemicals.

3 Types of Rocks

1. Igneous - from cooled magma or lava.

Granite is the usual igneous rock.

2. Sedimentary Rocks = made from sediment (small pieces) packed/glued together.

Sandstone is a common sedimentary rock.

3. Metamorphic = is made by heat and pressure and hot water…it is metamorphosed (changed).

Marble is a common metamorphic rock.