C4.3 (Metamorphic rocks)

Question 1

What are metamorphic rocks?

Answer 1

Metamorphic rock is formed by the action of heating and/ or pressure on the sedimentary or igneous rock.

Question 2

How is metamorphic rock formed?

Answer 2

Metamorphic rocks are formed from other rocks that are changed because of heat and/ or pressure. Earth’s movements can cause rocks to be deeply buried or squeezed. As a result, the rocks are heated and put under great pressure. They do not melt, but the minerals they contain are changed chemically, forming metamorphic rocks.

Question 3

Give some properties of metamorphic rocks.

Answer 3

• Metamorphic rocks sometimes contain layers
• Metamorphic rocks are non-porous
• Metamorphic rocks contains crystals
• Metamorphic rocks very very rarely contain fossils

Question 4

Give some examples of metamorphic rocks (and the rock they were formed from).

Answer 4

E.g Marble (started out as limestone) and

Slate (started out as mudstone)

Question 5

Why do metamorphic rocks rarely contain fossils?

Answer 5

Any that were present in the original sedimentary rock will not normally survive the heat and pressure.

Question 6

Why might metamorphic rocks be useful?

Answer 6

Metamorphic rocks are useful because, for example,

Marble is non-porous and many people like how it looks. This is why it is used for kitchen worktops.

Slate is non-porous. It is made up of layers, so it can be split into thin sheets. This is why it makes good roofing tiles.