Earth Science Test Notes

Structure of the Earth 

What are the Layers of the Earth? 

1. Crust 

2. Mantle 

3. Outer Core 

4. Inner Core 

What is the Lithosphere? 

The lithosphere is made up of the crust and the top part of the mantle. 

What is the Asthenosphere? 

The asthenosphere is the mantle below the lithosphere. 

What  is the Earth’s State? e.g. Liquid Outer Core/Solid Inner Core 

The Earth has a liquid outer core and a solid inner core. 

Minerals 

What are Minerals? 

Minerals are the naturally occurring building blocks of rocks. 

Identification Properties of Minerals: 

Crystal Shape – The shape and size of the crystals inside the rock. 

Colour – The main colour of the rock and how intense it is. 

Hardness – How hard it is to scratch the mineral. 

Lustre – How light interacts and reflects from the surface of a mineral. 

Streak – The colour of the mineral when it is turned into fine powder. 

Cleavage – The way the mineral splits to produce a flat surface. 

What is Moh’s Scale? 

Moh’s scale is used to find how easy/hard it is to scratch a minerals surface. A harder material can scratch a softer one. 

 
What are the 10 Minerals on Moh’s Scale? 

1. Talc                                                       6. Orthoclase 

2. Gypsum                                             7. Quartz                                                                       

3. Calcite                                                8. Topaz 

4. Fluorite                                               9. Corundum 

5. Apatite                                               10. Diamond 

What are the 5 Criteria that need to be met for a substance to be considered a mineral? 

1. Solid under room temperature 

2. Naturally occurring (not man-made) 

3. Must be inorganic (not living or made from living things) 

4. Have a fixed chemical formula 

5. Regular crystal structure 

Igneous Rocks 

What is Magma? 

Magma is molten rock beneath the Earth's surface. 

What is Lava?  

Lava is molten rock that has erupted onto the Earth's surface 

How are Igneous Rocks Formed? 

Igneous rocks are formed by the cooling and solidification of molten rock (magma or lava) 

What is an Intrusive Igneous Rock? 

Intrusive rocks are rocks that have formed from magma cooling slowly whilst deep under the surface of the Earth. This process make the crystals bigger. 

What is an Extrusive Igneous Rock? 

Extrusive rocks are rocks that have formed from lava cooling quickly while at or near the surface of the Earth. This process makes the crystals smaller. 

Uses of Intrusive and Extrusive Igneous Rocks: 

What is a Vesicular Igneous Rock? 

The rock has lots of small holes or air bubbles in it. 

What is a Mafic Igneous Rock? 

The rock is high in magnesium and iron and is usually darker in colour. 

What is a Felsic Igneous Rock? 

The rock is high in silicon and aluminium and is usually lighter in colour. 

Weathering & Erosion 

What is Weathering? 

Weathering is the process where rocks and minerals on Earth’s surface are broken down into smaller pieces. 

What is Physical Weathering? 

Physical weathering changes rocks by breaking them into smaller pieces without changing their composition. 

What is Chemical Weathering? 

The chemical reactions that change the mineral composition of rocks. 

What is Erosion? 

The process where soil, rock, and other surface materials are worn away and transported from one location to another. 

What is Sedimentation/Deposition? 

Sediments that have been transported by agents of erosion are dropped or settle in a new location. 

Sedimentary Rocks 

What are Sedimentary Rocks? 

Sedimentary rocks are sediments that have undergone a process where they get compacted.  

What are Clastic Sedimentary Rocks? 

Sediments that have been compacted together by the weight of water or other sediments and cemented together. 

What are Bioclastic Sedimentary Rocks? 

Form as a result of processes that involve living organisms. 

What are Crystalline Sedimentary Rocks? 

Forms when minerals dissolved in water are left behind as crystals when the water evaporites. 

List 3 Common Uses of Sedimentary Rocks: 

- Building Materials 

- Energy Resources 

- Glass Manufacturing 

Metamorphic Rocks 

What are Metamorphic Rocks? 

Rocks that are exposed to extreme heat and pressure causing them to change form. 

What are Contact Metamorphic Rocks? 

When rocks are heated to high temperature as they are near lava or magma. 

What are Regional Metamorphic Rocks? 

When rocks are put under intense pressure or stress underground, causing them to deform. 

What is Recrystallization?  

Where mineral grains grow and rearrange under heat and pressure. 

List 3 Examples of Metamorphic Rocks: 

- Marble (countertops) 

- Slate (roofing tiles) 

- Quartzite (flooring and stair steps) 

Rock Cycle 

What is the Rock Cycle Used for? 

It is used for showing the transformations of different types of rocks. 

Mining 

List 3 Common Minerals Mined in Western Australia: 

- Gold 

- Iron 

- Coal 

What is Open Cut Mining? 

 Used when mineral deposit is near the surface and where large quantities are spread over a large area.  

What is Underground Mining? 

Used when the mineral deposit is deeper and/or concentrated into pockets or narrow veins  

What is Dredging? 

Used when the minerals are found in sand and a large lake can be dug and filled with water 

What is Leach Mining? 

A fluid that will dissolve the mineral is injected through drill holes into the deposit and then pumped out through recovery pipes.