Page 150 - Knowledge Organiser Yr8 24-25

Knowledge Base: Science 8.11 Earth and Atmosphere Year 8
3. Types of Rock – Part 2
1.1
Describe how igneous rock is formed.
When molten rock cools and crystallises on or near the surface.
1.2
What is the difference between intrusive and extrusive igneous rock
Intrusive igneous – magma that has cooled slowly, deep underground
Extrusive igneous – magma that has erupted onto the surface as lava and then cooled quickly
1.3
If magma had cooled quickly to form igneous rock, would you expect to see small crystals or large crystals?
Small
1.4
Name two examples of igneous rock.
Granite, pumice, obsidian
1.5
Which properties of igneous rock make it good for kitchen countertops and carvings?
Hard and not porous (does not let water through)
1.6
Describe how metamorphic rock is formed.
From existing rocks which have been changed by heat or pressure
Describe the 3 stages involved in the formation of metamorphic rocks.
1. Earth movements cause rocks to be deeply buried or compressed.
2. This causes the rocks to be heated and puts them under great pressure.
3. They do not melt, but the minerals they contain are changed chemically, and form metamorphic rocks.
Name two examples of metamorphic rock.
Marble and Slate
4. Rock Cycle
4.1
Why is the process of rocks constantly changing called the rock cycle?
The rocks are constantly being changed into different types in a recycling process
4.2
Name the process that changes metamorphic rock into magma
Melting
4.3
Name the processes that change magma into igneous rock
Cooling and freezing
4.4
What is uplift?
When continents collide, forces from inside the earth push rocks upwards and mountains can form
4.5 What is the evidence for the rock cycle? Fossils provide evidence of uplift
4.6
Identify the stages in the rock cycle below
A. Weathering and erosion
B. Transportation and Deposition
C. Sedimentation
D. Compaction and Cementation
E. Burial, high temperature and pressure F. Melting
G. Slow uplift
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