Weathering Chapter 6

Front 1

name 4 types of mechanical weathering

Back 1

frost wedging, salt crystal growth, sheeting, biological activity

Front 2

what are the two basic categories of weathering

Back 2

Mechanical weathering and Chemical weathering

Front 3

iron weathers through a process called

Back 3

oxidation

Front 4

potassium feldspar weathers in the presence of water containing

Back 4

carbonic acid

Front 5

weathering that alters the internal structure of rock materials

Back 5

chemical

Front 6

High humidity (moist) climates ________chemical weathering (speed up or slow down)

Back 6

speed up

Front 7

Low humidity (dry) climates (such as the interior of continents) _______ chemical weathering (speed up or slow down)

Back 7

slow down

Front 8

Higher temperatures ____________ chemical weathering (speed up or slow down)

Back 8

speed up

Front 9

Lower temperatures ___________ chemical weathering (speed up or slow down)

Back 9

slow down

Front 10

Which soil horizon will contain the greatest amount of organic material

Back 10

O horizon

Front 11

Where does the clay that accumulates in the B horizon come from

Back 11

The A and E horizons are above the B, so percolating groundwater will pick up the clay from those layers.

Front 12

what makes up healthy soil

Back 12

water, air, mineral matter, and organic matter

Front 13

the disintegration of rock into smaller and smaller fragments

Back 13

mechanical weathering

Front 14

the erosion or disintegration of rocks, building materials, etc

Back 14

chemical weathering

Front 15

the down slope movement of rock, regolith, and soil under direct influence of gravity

Back 15

mass movement

Front 16

transformation of rock into one or more new compounds

Back 16

chemical weathering

Front 17

Breaking rock into smaller and smaller pieces without changing the rock's mineral composition is what

Back 17

mechanical weathering

Front 18

frost wedging

Back 18

Water expands when it freezes, and repeated cycles of freezing and thawing slowly weaken the structural integrity of porous and cracked rocks. Over time, frost wedging enlarges tiny cracks into huge fissures. The fissures eventually split the rock completely.

Front 19

salt crystal growth

Back 19

As water evaporates, salt crystals form. As these crystals gradually grow larger, they weaken the rock by pushing apart the surrounding grains or enlarging tiny cracks.

Front 20

when large masses of igneous rock, particularly granite, are exposed by erosion, concentric slabs begin to break loose, this is know as what?

Back 20

Sheeting

Front 21

the removal and or erosion of great weight or pressure of rocks or ice that lie on the surface

Back 21

unloading

Front 22

Continual sheeting or weathering eventually causes the slabs to separate or spall off. Which creates what?

Back 22

exfoliation dome

Front 23

Plant roots growing and burrowing animals are an example of what type of mechanical weathering?

Back 23

Biological activity

Front 24

fractures in a rock, along which there is no movement are what?

Back 24

joints

Front 25

dissolution

Back 25

The process of dissolving minerals or rock in a solution also a form of chemical weathering

Front 26

Name the 4 types of chemical weathering

Back 26

Dissolution, Oxidation, Hydrolysis, and spheroidal weathering

Front 27

How is carbonic acid formed in nature?

Back 27

carbon dioxide in the air dissolves in raindrops making carbonic acid (as acidic rainwater soaks into the ground carbon dioxide in the soil may increase the acidity of the water)

Front 28

oxidation

Back 28

The removal of one or more electron from an atom or ion (gets its name because elements often combined with oxygen)

Front 29

Oxidation can occur only after iron is freed from the silicate structure, by what process

Back 29

Hydrolysis

Front 30

Hydrolysis

Back 30

the reaction of any substance with water

Front 31

What occurs when carbonic acid reacts with calcite rich rock such as limestone

Back 31

They are dissolved into soluble products and later is carried away by under ground water and often reforms later into the formation of limestone caverns

Front 32

What products result when carbonic acid reacts with potassium feldspar?

Back 32

The weathering of potassium feldspar generates a residual clay mineral, a soluble salt (potassium bicarbonate) and some silica

Front 33

Name two common products of oxidation

Back 33

Hematite (reddish-brown rust) and Limonite (yellowish-colored rust)

Front 34

List several minerals that are especially susceptible to oxidation

Back 34

Iron and olivine are the most common. Pyroxene, hornblende, and biotite are common, but not as common.

Front 35

Explain why angular masses of rock often become spherical boulders

Back 35

Because water penetrates extensively jointed rock. Then chemical weathering decomposes mines and enlarges joints. After the rocks are attacked more on the corners and edges and then take on a spherical shape

Front 36

Spheroidal Weathering

Back 36

weathering that attacks the edges and corners faster than the single flat surface. Thus making the angular rock more smooth and rounded

Front 37

differential weathering

Back 37

the difference in degree of discoloration,

disintegration, etc., of rocks of different kinds

exposed to the same environment.

Front 38

How does climate influence weathering

Back 38

Temperature and moisture exert a strong influence on rate of chemical weathering. The frequency of freeze thaw cycles greatly effects the amount of frost wedging. Warm weather and high humidity are ideal for chemical weathering. Polar regions chemical weathering in ineffective because frigid temperatures keep the moisture locked up as ice. When in arid regions the is not enough moisture to foster chemical weathering

Front 39

interface

Back 39

a common boundary where different parts of a system interact

Front 40

regolith

Back 40

the layer of rock and mineral fragments produced by weathering

Front 41

Soil

Back 41

a combination of mineral and organic matter, water, and air

Front 42

humus

Back 42

the decayed remains of animal and plant life (organic matter)

Front 43

How is regolith different from soil

Back 43

Soil is more than accumulation of weathered debris. Soil is a combination of mineral and organic matter, water, and air

Front 44

Parent material

Back 44

The source of the weathered mineral matter from which soil develops

Front 45

When the parent material of soil is bedrock it is known as what

Back 45

residual soil

Front 46

When the parent material of soil is unconslidated sediment it is known as what

Back 46

transported soil

Front 47

List the five basic controls of soil formation

Back 47

Parent material, time, climate, plants and animals, and topography

Front 48

What factor is most influential in soil formation

Back 48

climate

Front 49

Slope orientation

Back 49

the direction a slope is facing

Front 50

How might the direction a slope is facing influence soil formation

Back 50

It might effect how much sunlight it receives and and its moisture content

Front 51

horizons

Back 51

a layer in the soil profile

Front 52

Soil profile

Back 52

vertical section through all of the soil horizons

Front 53

eluviation

Back 53

The washing out of fine soil components by downward flowing percolating water

Front 54

The depletion of soluble materials from the upper soil to the lower soil is called what

Back 54

leaching

Front 55

Consists of the topsoil and the subsoil and is often other plant and animal life are within its confines

Back 55

solum

Front 56

Topsoil consists of what horizons

Back 56

O and A horizons

Front 57

O horizon

Back 57

Loose and partly decayed organic matter

Front 58

A horizon

Back 58

Mineral matter mixed with some humus

Front 59

E horizon

Back 59

zone of eluviation and leaching

Front 60

B horizon or the subsoil

Back 60

Accumulation of clay transported from the E horizon often known as the subsoil (zone of accumulation)

Front 61

Hardpan

Back 61

A very compact and impermeable layer of fine clay particles in the B horizon

Front 62

C horizon

Back 62

Partially altered parent material

Front 63

Soils that lack horizons

Back 63

Immature soil

Front 64

Soil that has been relatively stable over an extended time span and has a well developed soil profile

Back 64

Mature Soil

Front 65

Name all the horizons in order from top to bottem

Back 65

Horizons O, A, E, B, and C (under them is unweathered parent material)

Front 66

What is the difference between eluviation and leaching

Back 66

Leaching sucks the materials from the upper soil when eluviation is washing the materials to the lower soils

Front 67

Zone of accumulation

Back 67

(The b horizon) The accumulation of fine clay particles enhances the water retention in the soil

Front 68

Soil Taxonomy

Back 68

A soil classifying system that consists of six hierarchical categories based on observable soil characteristics (12 soil orders)

Front 69

Which term is used to describe chemical weathering processes?

Back 69

decomposition

Front 70

he formation of caves is associated with this form of chemical weathering.

Back 70

dissolution

Front 71

Why is humus an essential component of soil?

Back 71

It is an important source of plant nutrients and enhances the soil’s ability to retain water.

Front 72

The chemical weathering of silicate minerals frequently produces _________

Back 72

clay minerals

Front 73

The layer of rock and mineral fragments produced by weathering is referred to as __________

Back 73

regolith

Front 74

What is the difference between residual soil and transported soil?

Back 74

Residual soil is produced from rock, whereas transportation soil is produced from unconsolidated sediment.

Front 75

Why would the presence of earthworms aid soil production?

Back 75

Earthworms effectively mix organic and inorganic matter.

Front 76

Soils that contain a large amount of clay, which causes them to shrink and swell according to the amount of water they contain

Back 76

vertisol

Front 77

Which types of soils are rich in iron aluminum oxides, are heavily leached, and are considered poor for agricultural use?

Back 77

Oxisols

Front 78

At what point does soil become sediment?

Back 78

When soil makes it down slope and enters into a stream