Unit 4 Chapter 10 Weathering and Soil Formation

Question 1

the process by which rock materials are broken down by the action of physical or chemical processes

Answer 1

weathering

Question 2

a breakdown of rock into smaller pieces by physical means

Answer 2

mechanical weathering

Question 3

the grinding and wearing away of rock surfaces through the mechanical action of other rock or sand particles

Answer 3

abrasion

Question 4

the process by which rocks break down as a result of chemical reactions

Answer 4

chemical weathering

Question 5

rain, sleet, or snow that contains a high concentration of acids

Answer 5

acid precipitation

Question 6

Name three things that can cause abrasion.

Answer 6

wind, water, and gravity can cause abrasion

Question 7

frost action

Answer 7

one type of mechanical weathering caused by alternating freezing and thawing of soil and rock.

Question 8

ice wedging

Answer 8

one type of frost action. Starts when water seeps into cracks during warm weather. When the temperature drops, the water freezes and expands, causing the ice to push against the sides of the crack and the crack to widen.

Question 9

How do plants cause weathering?

Answer 9

Plants often send their roots into existing cracks. As the plant grows, the force of the expanding root causes the crack to widen.

Question 10

List 3 animals that can cause weathering.

Answer 10

ants, mice, worms, rabbits, coyotes, gophers, moles, etc

Question 11

acid precipitation

Answer 11

precipitation is normally acidic, however acid precipitation contains more acid than normal. This high level of acidity can cause very rapid weathering of rock.

Question 12

acids in groundwater

Answer 12

In certain places the groundwater contains weak acids such as carbonic or sulfuric acid. These acids react with rocks in the ground such as limestone. A chemical reaction occurs dissolving the limestone. Caverns are formed from the eating away of the limestone.

Question 13

lichens

Answer 13

consist of fungi and algae. Contribute to chemical weathering.

Question 14

What can cause oxidation?

Answer 14

Oxidation occurs when oxygen combines with an elements to form an oxide. Rust is an example of chemical weathering caused by oxidation.

Question 15

List 3 things that cause chemical weathering of rocks.

Answer 15

Water, acid, and air

Question 16

Describe 5 sources of chemical weathering.

Answer 16

water - water dissolves rock over a long period of time
acid precipitation - the higher level of acidity can cause very rapid weathering of rock
acid in groundwater - acid in groundwater dissolves limestone and may form caverns
acids in living things - lichens produce acids that can slowly break down rock
air - oxygen in the air causes certain elements such as iron to oxidize.

Question 17

the process by which softer, less weather resistant rocks wear away and leave harder, more weather resistant rocks behind

Answer 17

differential weathering

Question 18

How does an increase in surface area affect the rate of weathering?

Answer 18

As the surface area increases, the rate of weathering also increases

Question 19

Why would a mailbox in a warm, humid climate experience a higher rate of weathering than a mailbox in a cold, dry climate?

Answer 19

Warm, humid climates have higher rates of weathering because oxidation happens faster when temperatures are higher and when water is present.

Question 20

Why do mountaintops weather faster than rocks at sea level?

Answer 20

Mountains weather faster because they are exposed to more wind, rain, and ice, which are agents of weathering.

Question 21

a loose mixture of rock fragments, organic material, water, and air that can support the growth of vegetation

Answer 21

soil

Question 22

a rock formation that is the source of soil

Answer 22

parent rock

Question 23

the layer of rock beneath soil

Answer 23

bedrock

Question 24

the soil quality that is based on the proportions of soil particles

Answer 24

soil texture

Question 25

the arrangement of soil particles

Answer 25

soil structure

Question 26

dark, organic material formed in soil from the decayed remains of plants and animals

Answer 26

humus

Question 27

the removal of substances that can be dissolved from rock, ore, or layers of soil due to the passing of water

Answer 27

leaching

Question 28

What is soil formed from?

Answer 28

Soil is formed from parent rock, organic material, water, and air.

Question 29

Why is the topsoil in tropical rain forests thin?

Answer 29

Heavy rains leach precious nutrients into deeper layers of soil, resulting in a very thin layer of topsoil.

Question 30

What climate has the most productive soil?

Answer 30

Temperate climates have the most productive soil.

Question 31

What property of soil influences soil moisture?

Answer 31

Soil structure

Question 32

What property of soil influences how nutrients can be dissolved in soil?

Answer 32

soil fertility

Question 33

What is the difference between residual and transported soils?

Answer 33

Residual soil remains above its parent rock. Transported soil is blown or washed away from its parent rock.

Question 34

Which climate has the most thick, fertile soil?

Answer 34

temperate climate

Question 35

How does soil temperature influence arctic soil?

Answer 35

In arctic climates, weathering occurs very slowly. At low temperatures, decomposition of plants and animals happens more slowly. Slow decomposition limits the amount of humus and nutrients in the soil.

Question 36

a method to maintain the fertility of the soil by protecting the soil from erosion and nutrient loss

Answer 36

soil conservation

Question 37

the process by which wind, water, ice, or gravity transports soil and sediment from one location to another

Answer 37

erosion

Question 38

Why is soil important?

Answer 38

Soil provides nutrients to plants, houses for animals, and stores water.

Question 39

What can soybeans and peanuts do for nutrient-poor soil?

Answer 39

They restore important nutrients to the soil and provide cover to prevent erosion.

Question 40

How does crop rotation benefit soil?

Answer 40

If the same crop is grown year after year in the same field, certain nutrients become depleted. To slow this process, a farmer can plant different crops which will use up less nutrients or different nutrients from the soil.

Question 41

List different methods of soil conservation and describe how each prevents the loss of soil.

Answer 41

contour plowing - helps prevent erosion from heavy rains
terracing - prevents erosion from heavy rains on steep hills
no-till farming - prevents erosion by providing cover that reduces water runoff
cover crop - crops that are planted between harvests to replace certain nutrients and prevent erosion (soybeans)
crop rotation - changing what crop is planted in which field to reduce nutrient depletion.