From Rock To Soil

Question 1

What are rocks?

Answer 1

Hard materials made of natural compounds that make up most of the earth’s surface and earth below the surface.

Question 2

Natural compounds

Answer 2

Mixture of minerals

Question 3

Minerals’ existence in rock

Answer 3

Crystal form

Question 4

What is quartz?

Answer 4

Silicon dioxide

Question 5

What are feldspars?

Answer 5

A group of aluminosilicate minerals that contain Calcium, Potassium and Sodium.

Question 6

Uses of rocks

Answer 6

Construction purposes, obtaining metals from ores or gemstones from minerals.

Question 7

Types of rock

Answer 7

Igneous, metamorphic and sedimentary

Question 8

Weathering

Answer 8

Rock broken down by the action of things in its environment.

Question 9

How does the rock cycle help us?

Answer 9

Building materials (limestone, marble, granite), gemstones, uplift gives access to materials, creates soil.

Question 10

Freeze thaw weathering

Answer 10

Freezing and thawing expands cracks in rocks and breaks them up.

Question 11

Reduction in pressure

Answer 11

Causes rock to expand and layers to peel off like an onion, exfoliation.

Question 12

Heating and cooling

Answer 12

Causes expansion and contraction of rock, causes cracks and breaks.

Question 13

What is Biological weathering?

Answer 13

Plants and animals cause rocks to break up by growing in them/ hitting them.

Question 14

What is chemical weathering?

Answer 14

Rain is slightly acidic, as it reacts with the carbon dioxide in the air, this then dissolves the calcium carbonate in limestone and dissolves it.

Question 15

How is clay formed?

Answer 15

Water + Feldspars = Clay

Question 16

How is quartz created?

Answer 16

Quartz is impermeable, so when a rock containing quartz breaks down, the quartz crystals are set free as sand.

Question 17

How is soil created?

Answer 17

Sand + Clay + Rotting Vegetation = Soil

Question 18

What are intrusive igneous rocks and how are they formed?

Answer 18

• Intrusive igneous rocks are igneous rocks that are formed inside the earth’s crust.
• They are formed when magma underground moves higher up due to the pressure and its minerals begins to crystallise at different temperatures, the crystals then lock together, forming rocks such as granite.
• These rocks tend to have bigger crystals.

Question 19

What are extrusive igneous rocks and how are they formed?

Answer 19

• An extrusive igneous rock is any rock derived from magma that was shot out from Earth’s crust.
• They are formed when magma shoots out of a volcano as lava and cools immediately, causing rocks such as basalt to form.
• These tend to have smaller crystals.

Question 20

What dives the rock cycle?

Answer 20

Tectonic plates.

Question 21

What are the different layers of the solid profile?

Answer 21

Humus, topsoil, subsoil, rock that is being weathered, bedrock.

Question 22

What does the humus do?

Answer 22

It is a thin layer of rotting vegetation, the nutrients in it return back to the soil.

Question 23

What does the topsoil do?

Answer 23

The topsoil is rich in humus and minerals from rock, so it’s good for growing crops.
It contains sand that makes it crumbly and helps the roots to spread better.

Question 24

What does the subsoil do?

Answer 24

The subsoil has only a little humus, but a lot of minerals, tree roots reach here.

Question 25

How do earthworms improve soil?

Answer 25

• They digest leaves and clay, making their waste rich in nutrients.
• The bore tunnels, allowing air and water to circulate.