Igneous Rocks - 8.4 Metamorphic Rocks

Question 1

What does ‘metamorphic’ mean in relation to rocks?

Answer 1

“Metamorphic” means that the rock has changed form.

Question 2

How are metamorphic rocks formed?

Answer 2

Metamorphic rocks form when high temperature and pressure alter existing igneous or sedimentary rocks.

Question 2

Can metamorphic rocks form from other metamorphic rocks?

Answer 2

Yes, metamorphic rocks can also form from other metamorphic rocks.

Question 3

What causes rock to change into a metamorphic form?

Answer 3

Intense heat and extreme pressure cause rock to change into a metamorphic form.

Question 4

What are examples of minerals found in metamorphic rocks?

Answer 4

Examples include garnets, sapphire, and ruby.

Question 5

Where can metamorphic rocks be formed?

Answer 5

Metamorphic rocks can be formed deep beneath the Earth’s surface where pressure is very high.

Question 6

What effect does pressure have on rock formation deep beneath the Earth’s surface?

Answer 6

The pressure can be thousands of times greater than at the Earth’s surface, causing rock to change.

Question 7

What is recrystallisation in metamorphic rock formation?

Answer 7

Recrystallisation is the process where new crystals grow as molten rock cools down.

Question 7

How do minerals form during recrystallisation?

Answer 7

The particles in molten rock move around, allowing new minerals to form.

Question 7

Why do metamorphic rocks contain more minerals than igneous rocks?

Answer 7

New minerals form during recrystallisation, which increases the variety of minerals in metamorphic rocks.

Question 8

How can diamonds form in metamorphic rocks?

Answer 8

Diamonds form when carbon in rocks crystallises under high pressure and temperature deep in the Earth’s mantle.

Question 9

At what depth and temperature do diamonds form in metamorphic rock?

Answer 9

Diamonds form at depths over 150 kilometers and temperatures around 1,000°C.

Question 10

What is foliation in metamorphic rocks?

Answer 10

Foliation is the process where minerals in metamorphic rock form layers or bands under pressure.

Question 11

What causes the formation of bands or layers in metamorphic rocks?

Answer 11

Heat and pressure cause minerals to be squashed into flat or needle-like shapes, forming bands.

Question 12

What can happen to the bands in a metamorphic rock under pressure?

Answer 12

Pressure can squash and crumple the bands, causing them to become wavy.

Question 13

What is the rock cycle?

Answer 13

The rock cycle is a model that explains the endless cycle of change that rocks undergo.

Question 14

What breaks rocks down during the rock cycle?

Answer 14

Weathering breaks rocks down into smaller pieces.

Question 15

What are the agents of erosion in the rock cycle?

Answer 15

Water, wind, and ice are agents of erosion that carry away rock pieces.

Question 16

How can sedimentary rocks form in the rock cycle?

Answer 16

Sedimentary rocks form when eroded pieces of rock are deposited as sediments and compacted together.

Question 17

How can metamorphic rocks form through the rock cycle?

Answer 17

Any rock can be melted by magma and turned into a metamorphic rock.

Question 18

What are the key changes that rocks undergo in the rock cycle?

Answer 18

Rocks undergo weathering, erosion, deposition, melting, and metamorphism.

Question 19

Can igneous rocks also become metamorphic rocks?

Answer 19

Yes, igneous rocks can be altered by heat and pressure to become metamorphic.

Question 20

How do temperature and pressure affect rock texture during metamorphism?

Answer 20

Temperature and pressure can cause the rock’s minerals to recrystallize or form layers, changing its texture.

Question 21

How do rocks contribute to Earth’s geological processes?

Answer 21

Rocks undergo continuous changes through weathering, erosion, melting, and metamorphic processes, contributing to Earth’s geological activity.