Weathering/Soil

Question 1

What is the difference between mechanical and chemical weathering?

Answer 1

Chemical weathering changes the chemical composition of a rock and mechanical rock alters the size/shape of a rock.

Question 2

Name the mechanical weathering types

Answer 2

Organic activity, ice/frost wedging, joints(sheeting and exfoliation), and abrasion.

Question 3

What is organic activity?

Answer 3

It is when animals burrow into the rock or roots pry trees apart.

Question 4

What is ice wedging?

Answer 4

Water seeks into rock cracks, and when the water freezes the rock is forced apart.

Question 5

What are joints, sheeting, and exfoliation?

Answer 5

Joints happen when pressure is removed from a rock and the rock expands and cracks. When the cracks are parallel to the surface, it is called sheeting. When the sheets fall off, it is called exfoliation

Question 6

What is abrasion?

Answer 6

Water or wind pick up grains of sand that pelt and polish rock.

Question 7

Name the types of chemical weathering

Answer 7

Hydrolysis, carbonation, oxidation, organic acids, acid precipitation, and spheroidal weathering.

Question 8

What is hydrolysis?

Answer 8

Water reacts with minerals to change the minerals composition.

Question 9

What is carbonation?

Answer 9

CO2 dissolves in water to produce carbonic acid. This reacts with calcite.

Question 10

What is oxidation?

Answer 10

Oxygen dissolved in water reacts with a mineral, and it results with colour change.

Question 11

What are organic acids?

Answer 11

Lichen and moss produce acids that eat away at the rock from the surface.

Question 12

What is acid precipitation?

Answer 12

Nitrous oxides and sulfur dioxide dissolve in rainwater and produce acids that dissolve rocks.

Question 13

What is spheroidal weathering?

Answer 13

Water, CO2, and organic acids seep through cracks in rocks and cause chemical weathering.

Question 14

How does climate affect the rate of weathering?

Answer 14

Precipitation increases weathering. Hot temperatures speed up chemical weathering, and cold temperatures have lots of mechanical weathering.

Question 15

How does topography affect the rate of weathering?

Answer 15

Rocks on a slope erode more due to more exposure. Higher altitudes experience more ice wedging.

Question 16

How does rock composition affect the rate of weathering?

Answer 16

Minerals that form at higher temperatures weather first. Sedimentary rocks weather fastest.

Question 17

How does surface area affect weathering?

Answer 17

More surface area means more chemical weathering.

Question 18

What are the four types of soil?

Answer 18

Pedalfer, pedocal, laterite, and regolith.

Question 19

What are the properties of pedalfer?

Answer 19

It is found in temperate, forest areas. It had thick horizons and is acidic. It has aluminum and iron.

Question 20

What are the properties of pedocals?

Answer 20

It is found in semi-arid and steppes. It is calcium rich and it is caliche. It is basic and fertile.

Question 21

What are the properties of laterite?

Answer 21

It is found in high precipitation and warm temperatures areas. It is leached of nutrients and has a lot of chemical weathering. It doesn’t really have an A horizon and is high in iron. It is reddish in colour.

Question 22

What are the properties of regolith?

Answer 22

It is found in polar and desert regions. Mostly mechanical weathering occurs and it is mainly the C horizon.

Question 23

What is the difference between residual and transported soil?

Answer 23

Residual soil is made of the same material as the bedrock below and transported soil is not.

Question 24

What is the difference between a fall, flow, and slide?

Answer 24

In a fall, the material has no contact with the ground. In a flow, individual particles move on one path. And in a slide, a whole “block” of material moves as one cohesive unit.

Question 25

What is slump?

Answer 25

A slump is a slow slide that creates a curved slope called a scarp.

Question 26

What is a rockslide?

Answer 26

A rockslide is a type of slide that moves up to 40mph.

Question 27

What is a mudflow?

Answer 27

It is a mix of water, mud and debris. It is a type of flow and is rapid.

Question 28

What is creep?

Answer 28

Creep is a type of flow that moves extremely slowly and is caused by freezing and thawing.

Question 29

What is solifluction?

Answer 29

Solifluction is a type of flow. Water builds up in thawed layers, allowing water and soil to flow.

Question 30

What is the difference between mature and young soil?

Answer 30

Young soil consists mainly of the C horizon, and mature soil has all horizons.

Question 31

What are the horizons from top to bottom?

Answer 31

O,A,E,B,C, and bedrock.

Question 32

Describe the C horizon.

Answer 32

It is made of regolith and partly altered parent material.

Question 33

Describe the B horizon

Answer 33

Accumulation and deposition of minerals and clay from above happen here.

Question 34

Describe the e horizon

Answer 34

It is lightly colored due to leaching and eluviating.

Question 35

Describe the A horizon

Answer 35

This is topsoil. It is made of mineral matter and humus.

Question 36

Describe the O horizon

Answer 36

It is made of loose, partly decayed plants.

Question 37

What are preventative farming techniques?

Answer 37

Planting windbreaks, contour ploughing, terracing, strip cropping, and no-till.

Question 38

What are some causes of soil erosion?

Answer 38

Wind, water, and human activity.

Question 39

Describe the O horizon

Answer 39

It is made of loose, partly decayed plants.