Rocks and Minerals - 8.4 Metamorphic Rocks [ARCHIVE] Flashcards
What is metamorphic rock?
An existing igneous/sedimentary rocks are changed by heat, pressure, or chemical processes.
How are metamorphic rocks formed?
When high temperature and pressure alter existing igneous/ sedimentary rocks.
Can metamorphic rocks form from other metamorphic rocks?
Yes, metamorphic rocks can also form from other metamorphic rocks.
What causes rock to change into a metamorphic form?
- Intense heat
- Extreme pressure
What are examples of minerals found in metamorphic rocks?
- Garnets
- Sapphire
- Ruby
Where can metamorphic rocks be formed?
Deep beneath the Earth’s surface where pressure is very high.
What effect does pressure have on rock formation deep beneath the Earth’s surface?
The pressure can be thousands of times greater than at the Earth’s surface, causing rock to change.
What is recrystallisation in metamorphic rock formation?
The process where new crystals grow as molten rock cools down.
How do minerals form during recrystallisation?
The particles in molten rock move around, allowing new minerals to form.
Why do metamorphic rocks contain more minerals than igneous rocks?
New minerals form during recrystallisation, which increases the variety of minerals in metamorphic rocks.
How can diamonds form in metamorphic rocks?
When carbon in rocks crystallises under high pressure and temperature deep in the Earth’s mantle.
At what depth and temperature do diamonds form in metamorphic rock?
Diamonds form at depths over 150 kilometers and temperatures around 1,000°C.
What is foliation in metamorphic rocks?
The process where minerals in metamorphic rock form layers or bands under pressure.
What causes the formation of bands or layers in metamorphic rocks?
Heat and pressure cause minerals to be squashed into flat or needle-like shapes, forming bands.
What can happen to the bands in a metamorphic rock under pressure?
Pressure can squash and crumple the bands, causing them to become wavy.
