Humus – decayed material in soil

Erosion – the wearing away of the earth’s topsoil

Clay – holds water in soil

Red soil – has large amounts of iron

Mineral

1. never man made
2. never made of things that were once alive
3. arranged in a pattern that forms a crystal

Geologists divide rocks into 3 main groups

1. Igneous – formed from hot magma
2. Sedimentary – formed from the soil deposits made by moving water and pressed together
3. Metamorphic – seems to be formed by a change in heat or pressure

Gems – rare and costly minerals such as rubies, diamonds, or emeralds

One revolution of the earth around the sun takes 365 ¼ days.

Delta – a deposit of sand of soil at the mouth of some rivers, usually in a triangle shape

Changing seasons are caused because the earth is tilted.

1. causes night and day

2. takes one day

3. rotates west to east

1. rotates on its axis

Gravity causes water to move and therefore causes the water’s energy.

1. the third largest continent

2. includes Canada, the U.S., Mexico, and Central America

Asia

1. the largest continent
2. contains the highest mountain, Mt. Everest

Africa

1. the second largest continent
2. contains many countries including Egypt, Ethiopia, and Nigeria

1. the fourth largest continent

2. contains many countries including Chile, Brazil, and Peru

1. the fifth largest continent
2. the only continent where no people (except researchers) live

1. the second smallest continent
2. responsible for most of the settlement of North and South America
3. contains many countries including Italy, Germany, France, and Spain

1. the smallest continent
2. called the "Island Continent"
3. only one country

1. Igneous – (formed from hot magma)

• granite – forms most of the earth’s crust under the continents
• pumice – full of air holes which make it light enough to float
• obsidian – shiny, black, smooth, glassy, used to make arrowheads

1. Sedimentary – (formed from soil deposits made by moving water and pressed together)

• sandstone – made of sand that is pressed down under the ocean
• conglomerate – contains pebbles that are cemented together
• limestone – can be made from shells of sea creatures
• chalk – will leave a white mark on a dark surface
• shale – formed from mud or clay

1. Metamorphic – (formed by a change in heat of pressure)

• marble – can be highly polished, is used for statues such as the Lincoln Memorial
• slate – is very hard and smooth, may be used to write on