weathering 08

8/14/2019 Weathering 08

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Weathering, Erosion and Deposition

Weathering ______________________________________________________

__________________________________________________________

ypes of Weathering

A. ________________ weathering

_________________________________________________________

_________________________________________________________

1._______________________

as rocks are heated by the Sun the

outside layers heat up and

____________.

When the temperature falls the outside

layers cool and ____________.

The cycle of heating and cooling cause

the surface of the rock to break off in

slabs or layers. This process is called

___________________________.

Any process that causes rocks to break into smaller

pieces without changing chemically

the physical and chemical breakdown of rocks into

smaller particles called sediment

PHYSICAL

Temperature Change

expand

contract

exfoliation


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______________________________

also called _____________________.

This occurs when water seeps into the

cracks ib a rock. When water freezes

it ____________. The cycle of freezing

and melting causes rocks to break apart.

This same process happens to our roads

and creates ____________ in the road.

_____________________________ This process

occurs when trees and shrubs can grow through

cracks in rocks. Their roots wedge into crevices.

Even moss and lichen wedge their hair-like roots

between the grains that make-up rocks.

_____________________________ sediments carried by streams and wind

blown sand causes particles to collide into each other and the surrounding rock.

expands

Abrasion

Organic Activity

potholes

Frost Wedging

Frost Action
http://www3.interscience.wiley.com:8100/legacy/college/strahler/0471238007/animations/ch15_animations/animation2.htmlhttp://www.classzone.com/books/earth_science/terc/content/visualizations/es1201/es1201page01.cfm?chapter_no=visualization


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____________________________weathering

_______________________________________________________________

_______________________________________________________________

__

1. ________________________ occurs when carbon dioxide in the atmospher

dissolves in the droplets of water that make up clouds. This forms a weak

carbonic acid. Carbonic acid reacts with certain rocks and minerals that

include;

_______________________________________________________________

_

________________ bedrock

Carbonic Acid seeps into the

limestone bedrock through cracks.

This water dissolves the limestone

rock.

A cavern forms that includes the

following features.

___________________________

______________________________________________________

Any process that causes rocks to breakdown by chemical action

and results in a change in the mineral composition

Calcite, limestone, marble and chalk

Carbonation

Chemical

columns

stalagmites

stalactites

sinkholes

Limestone
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1405/es1405page01.cfm?chapter_no=visualizationhttp://www.classzone.com/books/earth_science/terc/content/visualizations/es1405/es1405page01.cfm?chapter_no=visualization


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_______________ occurs when water

dissolves certain minerals in a rock.

For example, granite is very stable in

cool, dry climates but in moist climates

rainfall dissolves much of the mineral

feldspar. The feldspar becomes clay

which is too weak to keep the rock from breaking apart. The mineral quartz

remains behind as sand.

________________ occurs when oxygen in the atmosphere combines with

certain minerals in the rock. For example when oxygen combines with iron

minerals, iron oxide (rust) forms. The chemical change of the mineral

weakens the rock and the rock crumbles.

0. ________________ produce weak acids that can dissolve certain minerals

in a rock, weakening the rock.

. __________________________ Gases produced by humans can dissolve

in the water droplets of a cloud to produce ________________.

These acids include: H2SO4__________________

HNO3 ___________________

Hydration

Oxidation

Plants acids

sulfuric acid

Man-created acids

nitric acid

acid rain


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Weathering Rates

____________________ is the major factor that affects the rate of weathering.

1. Temperature:

a. In warm climates

__________________ is the

dominant type of weathering.

b. In cold climates

__________________ is the

dominant type of weathering.

2. Precipitation:

a. As precipitation increases, the amount (or rate) of weathering by frost action

will _______________________.

b. As precipitation increases, the amount (or rate) of chemical weathering will

__________________________.

3. Chemical weathering is most rapid in ________________________,

_______________________ climates.

4. Due to climate and different weathering processes, landscapes develop

differently.

Climate

chemical action

frost action

increases

increases

moist

warm


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____________________________________ causes differential weathering.

Differential weathering is the process by which softer, less weather-resistan

rocks wear away, leaving harder, more weather-resistant rocks behind.

sandstone shale

limestone dolostone

hich rock type is most resistant to weathering? __________________________

hich rock type is least resistant to weathering? __________________________

_________________________ Weathering takes place on the outside

surface of rocks. So the more __________________ that is exposed to

weathering, the faster the rock will be broken down.

As a rock breaks into smaller pieces, the ________________ area

increases, so the rate of weathering ____________________.

roducts of Weathering

Different types of rocks

dolostone

shale

0.0004- and smaller

0.006-0.0004

0.2-0.006

6.4-2.0

25.6-6.4

25.6 and larger

Size (cm)Name of Sediment

Particle Size

surface area

surface

increases

boulders

cobbles

pebbles

sand

silt

clay
http://courses.soil.ncsu.edu/resources/physics/texture/soilgeo.swf


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_______________________ dissolved minerals cause the hardness in

ground water (and surface water).

Soil

1. Soil is a combination of ________________ and ___________________

2. ________________ is decayed plant and animal material found in soil.

Soil that contains 20 to 30% humus is considered a rich soil for plant growth

3. Soil development

4. Soil layers the SOIL PROFILE

1. ______________ or _______________

is the top layer of soil that contains mor

humus than the layers below.

2. ______________ or _______________

consist of clays and dissolved mineralsthat have been washed down from

above. Contains less humus.

3. __________ consists of weathered roc

fragments, usually from the parent rock

4. ________________ is the layered rock

beneath the soil. Frequently it is theparent rock of the soil above.

5. Residual Vs Transported Soil

If the bedrock matches the rock fragments of thwe C horizon, the soil is

most likely _____________________________. If it does not the soil is

most likely _____________________________.

Dissolved minerals

weathered rock organic material

Humus

B horizonSubsoil

C horizon

Bedrock

A horizonTopsoil

residual

transported


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rosion and Deposition

A. Erosion is

_____________________________________________________

_______________________________________________________________

_

1. Am agent of erosion is a material or force that moves sediments from

one place to another place.

2. Agents of erosion include: __________________,

__________________, __________________ and

____________________.B. Deposition is

__________________________________________________

__________________________________________________________

1. Deposition occurs when the velocity (speed) of running water or the

wind ____________________ and/or when the discharge (volume of water)

____________________.

2. Factors that affect the deposition of sediment:

a. Size

____________________________________________________

__________________________________________________________

b. Density ________________________________________________

_________________________________________________________

the process by which weathered sediments are

carried or transported.

running water wind

glaciers waves

The process by which sediment is dropped or

settles

The size of sediment increases, the rate of

deposition increases.

decreases

decreases

As the density of sediment increases, the rate

(speed) of deposition increases

Time for

Deposition

Time for

Deposition

Rate of

Deposition

Rate of

Deposition

Size of Sediment Size of Sediment

Density of Sediment Density of Sediment
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1205/es1205page01.cfm?chapter_no=visualization


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Shape -

____________________________________________________________

____________________________________________________________

Gravity erosion and deposition

1. Gravity pulls sediments down slopes.

2. The downhill movement of sediments by gravity is called

___________________.

3, Types of mass wasting include: ________________________________

4. Deposition resulting from gravity

As the shape becomes more spherical, the rate of

deposition of the sediment increases.

Talus Pile/ Slope

_________unsorted

Time for

Deposition

Flat------------SphericalShape of Sediments

Rate of

Deposition

Flat------------SphericalShape of Sediments

mass wasting

landslides and mudslides


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5. Gravity is the underlying force behind all erosion; it may act alone or with a

transporting agent.

a. _____________ causes water to flow downhill.

b. _____________ causes glaciers to flow down a valley or spread outward

c. _____________ causes winds by pulling heavier (more dense) cold air

down beneath lighter (less dense) warm air.

Wind erosion and deposition

1. The amount of erosion caused by the wind depends on:

a. The __________________ of sediments being carried.

b. The __________________ of which the wind is blowing.

c. The __________________ that the wind continues to blow.

2.

3. Deposition by wind

__________________

WIND

Gravity

Gravity

Gravity

Size

Speed

Time

Well sorted


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Running Water erosion

1. Running water is the

______________________________________________.

2.

3. When rain falls onto the surface of Earth several things can happen to the

water:

a. __________________________________________________________

b. __________________________________________________________

c. __________________________________________________________

d. __________________________________________________________

4. The volume (amount) of water in a stream is called the streams

______________________.

Factors affecting a streams volume are:

a. Season spring vs. fall; usually greater in the _____________________

b. Climate arid vs. humid; usually greater in

________________________.

c. Weather daily changes in precipitation affect the volume of a stream.

-

dominant form of erosion

runoff

infiltrate / sink into ground

evaporate

accumulate in snow and stored in ponds

discharge

spring

humid climates

saturated


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(watershed) the area of land

drained by a river system-the main river and all

of its tributaries(watershed) the area of land drained

by a river system-the main river and all of its

tributaries

Ontario-St Lawrence

Susquehanna-Chesapeake

Mohawk-Hudson

St Lawrence

Champlain-St Lawrence

Long Island Sound

Delaware

Allegheny-Ohio

Erie- St Lawrence


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Stream factors that cause erosion:

a. _____________ -

________________________________________________

b. ______________ - ______________________________________________

c.

Factors that affect stream velocity:

a. _____________ - _______________________________________________

b. _____________ - _______________________________________________

c. Channel - the path the stream follows. When a stream flows through its

channel its speed will change due to the curvature of the channel.

as velocity increases; erosion increasesVelocity

Volume as volume increases; erosion increases

Stream

Erosion

Stream

Erosion

Velocity

Volume

Gradient as gradient increases; velocity increases

Volume

meanders

as volume increases; velocity increases


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At the outside of the curve, the stream velocity ______________ therefore,

________________ occurs.

At the inside of the curve the stream velocity ____________ therefore,

________________ occurs.

Key:

=

eposited stream

ediment

X = locationmaximum

elocity

X

X

X

X

X

X

X

X

increaseserosion

decreasesdeposition


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Stream Load

a. ___________________ - minerals dissolved in the water

b. ___________________ - small particles carried within the waterc ___________________ - larger particles rolling and bouncing along the

bottom

6. Particle Size vs. Stream Velocity

What is the largest size sediment that can be transported by a stream in which th

water velocity is:

a. 50cm/sec _________________________

b. 150 cm/sec _______________________

c. 250 cm/sec ________________________

Solution

SuspensionSaltation

Sand

PebblesCobbles


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Running Water deposition

1. When a stream enters a body of water. Its speed will ______________, and

therefore the ______________ of sediments occurs. A deposit at the mout

of a stream where it enters a large body of water is called a _____________

2. A delta is an example of the ____________ deposition of sediments in wate

___________________ sediment

3. Deposition can also occur _____________. This results in _________

sorting.

___________________ sediment

Decrease

Deposition

Delta


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decrease

deposition

delta

horizontal

sorted

verticallyvertical

sorted


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. Stream deposition on land can also occur. This deposit is called an

________________.

5. Equilibrium: Erosion = Deposition

Map View

Profile View

erosion

deposition

equilibrium


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6. Formation of an Oxbow Lake the work of erosion and deposition

Deposition

Erosion

Levee

Flood Plain

Oxbow Lake


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Glaciers erosion and deposition

1. A glacier is _____________________________________________

2. Types of Glaciers

a. ___________________ glaciers form in mountain valleys at high

elevations.

examples:_________________

_________________

_________________

b. ____________________ glaciers form over vast areas of land.

examples:

______________________

___________________________

a large mass of moving ice and snow.

Alpine

Alps

Andes

Himalayas

Continental

Greenland

Antarctica


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ground

medial

lateral

faster

Unsorted rock material carried

and deposited by a glacier

Ground

Medial

Lateral


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Terminal/ end

Stream Glacier

U


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4

Interglacial period

11,000


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Wisconsin

Illinoian

Kansan

Nebraskan


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kame

esker

Ground moraine

Terminal moraine

Outwash plain

Braided stream

kettle lake

drumlinErratic


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xt

ge


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weathering 08

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