Weathering and Erosion

​Weathering, Erosion, Deposition

What shapes the Earth

Weathering, Erosion, and Deposition are processes that act together to wear down and build up the Earth's surface. These processes have occurred over billions of years.​

What is weathering?

• Weathering is a process that BREAKS DOWN rocks and creates sediments.

• Sediments refer to small pieces of rocks​.

• Two types of weathering: Chemical and Mechanical (physical)​.

Multiple Choice

The breaking down of rocks into smaller pieces

• weathering

• vegetation

• erosion

• deposition

Multiple Choice

What are the 2 types of weathering called?

• Astronomical & Gallactical

• Sedimentary & Metamorphic

• Chemical & Mechanical(physical)

• Weathering & Erosion

Multiple Choice

Small pebbles, pieces of other rock, and sand are called?

• weathering

• sediment

• erosion

• deposition

Chemical Weathering

• Chemical weathering is the decomposition of rock caused by chemical reactions. This creates new compounds.

• Agents of chemical weathering: water, oxygen, acid, and organisms

Multiple Choice

What do we call the process in which rock is broken down by changes in its chemical makeup.

• Chemical weathering

• Mechanical weathering

• Erosion

• Deposition

Mechanical Weathering

• Mechanical weathering is the process of breaking BIG rocks into little ones without changing the chemical composition of a rock.

• ​The most common type of mechanical weathering is the constant freezing, and thawing of water.

• As water freezes, it expands, becoming about 10% larger than it was in liquid form.

• Temperature changes also affect mechanical weathering. As temperatures heat up, the rocks expand.

• As the temperatures cool down, rocks contract.

Multiple Choice

Which of the following is NOT a type of physical weathering?

• burrowing plants

• ice wedging

• plant roots

• acid rain

Erosion

Erosion: natural forces MOVE rock and soil to another place.

Natural forces such as gravity, running water, glaciers, waves and wind cause erosion.​

Weathering is the breaking down of rocks while erosion is the process of moving those pieces.

Multiple Choice

The process by which rock and soil are moved from one place to another is called-

• Chemical weatherin

• Erosion

• Mechanical weathering

• Deosition

Deposition

Deposition: occurs when sediment is LAID DOWN.

So Erosion moves and deposition lays it down somewhere else.

Multiple Choice

_____________ is the dropping off/ depositing of rocks.

• Metamorphosis

• Deposition

• Weathering

• Erosion

Multiple Choice

Some examples of slow changes are

• earthquakes, volcanoes, and landslides

• weathering, erosion and deposition

• sloths in the rain forest

• turtle vs snail racing

Multiple Choice

Some examples of fast changes are

• earthquakes, volcanoes, and landslides

• weathering, erosion and deposition

• sloths in the rain forest

• turtle vs snail racing

Multiple Choice

Select the answer that shows the order of events a rock goes through.

• erosion, weathering, deposition

• weathering, erosion, deposition

• deposition, weathering erosion

• erosion, deposition, weathering

Examples of Physical Weathering

​Ice Wedging:  when liquid water goes into cracks and then freezes causing the cracks to get wider
Wind: blowing sand grinds pieces of rock off larger rocks like sandpaper. This is called Abrasion
Flowing Water:  
Moves rocks and soil as it goes

The strongest weathering force

Examples of Physical Weathering Continued

​Plant Roots:  growing into cracks in the rock, slowly breaking them apart.

Animals: burrow in the ground, break up soil, and loosen rocks to be exposed to further weathering.

Multiple Choice

what kind of weathering is this?

• animal activity

• plant roots

• ice wedging

• glaciers

Multiple Choice

what force makes these stones look like this?

• wind abrasion

• flowing water

• animals

• ice wedging

Examples of Chemical weathering

Air
Oxidation: a chemical reaction in which oxygen combines with an element such as iron to form an oxide (rust)

Acid Rain
Rain, Sleet, or Snow that contain high concentrations of Acids

Multiple Choice

What type of weathering is this? (rock having oxidation reaction with air).

• Mechanical (physical)

• Chemical

Multiple Choice

What type of weathering is this?

• Mechanical (physical)

• Chemical

Multiple Choice

These gravestones have slowly broken down and turned a blackish color due to the action of:

• ice wedging

• abrasion

• acid rain

• mechanical weathering

Multiple Choice

How is mechanical weathering different from chemical weathering?

• Chemical weathering happens over much shorter time frame than mechanical weathering.

• Chemical weathering changes the chemical composition of rocks; mechanical weathering does not.

• Chemical weathering occurs only in tropical climates; mechanical weathering occurs only in cool climates.

• Chemical weathering occurs only in the mountains; mechanical weathering occurs only on flat land.

Multiple Choice

Which has more surface area?

• a large boulder

• a rock broken into many pieces

Factors that effect Weathering

Surface Area: the more rock is exposed to weathering the faster the rock will be worn down.

Temperature: areas with drastic temperature changes have rapid mechanical weathering (ex. seasonal)
Climate: warm and humid areas have faster chemical weathering (ex. tropical)
Type of Rock: minerals in rock determine how quickly weathering will take place

​Deposition

​Ms. Pineda

​How is deposition different from weathering and erosion?

https://www.youtube.com/watch?v=A47ythEcz74​

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What processes do you think rivers contribute to, weathering, erosion, or deposition? 

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​Please write down the question and answer in your notebook.

​Discussion Question

​

Deposition is the laying down of sediments after erosion has occurred.

​

It is a constructive process because it is how layers of sediment are built up and land masses are formed.

​

​Deposition

​

​

• Riverbanks

• Beaches​

• Lakes

• Deltas

• Valleys

​

​What places can you think of where deposition happens?

​

Multiple Choice

Deposition is the ________ down of sediments after erosion has occurred.

• Weathering

• Laying

• Sinking

• Eroding

Multiple Choice

Deposition is a destructive process.

• True

• False

​How did all this sediment get here?​

​

​Deposition is the ​adding of sediment in an area and creates new landforms.

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​1. Sand dunes are formed by sediments carried by the wind.

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​Places formed by deposition​

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​2. River deltas are formed where rivers meet oceans by sediments carried by rivers. The sediments come from erosion upriver.

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​Places formed by deposition​

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​3. Beaches are formed where oceans meet land. The sediments carried by the ocean. The sediments come from the erosion of coral reefs and rocks.

​

​Places formed by deposition​

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​4. Moraines are formed when glaciers made of collected sediments are carried by ice.

​

The sediments come from the erosion of hills and mountains.

​

​Places formed by deposition​

​

Multiple Choice

__________ are formed when glaciers made of collected sediments are carried by ice.

• Moraines

• Beaches

• Sand dunes

• Snow

Multiple Choice

Sand dunes are formed by sediments carried by the _______.

• Water

• Ice

• Wind

• Gravity

Multiple Choice

Beaches are formed where ocean meets _______.

• Land

• Water

• the River

• the Delta

Multiple Choice

Which of the following does NOT affect the rate at which a rock weathers?

• What the rock is made of

• The climate where the rock is found

• The amount of exposed surface area on the rock

• The length of time since the rock was formed

Multiple Select

Abrasion is the grinding and wearing away of rock surfaces through which actions (select all that apply)?

• Waves

• Wind

• Chemical Reaction

• Running Water

• Animal Activity

Multiple Choice

What is weathering?

• The process by which
  water, ice, wind or gravity
  moves fragments of rock
  and soil.

• The process by which
  water, ice, wind or gravity
  deposit rock sediments
  and soil in a new place.

• The breaking down of
  Earth’s crust into smaller
  and smaller pieces.

Multiple Choice

What is erosion?

• The process by which
  water, ice, wind or gravity
  moves fragments of rock
  and soil.

• The process by which
  water, ice, wind or gravity
  deposit rock sediments
  and soil in a new place.

• The breaking down of
  Earth’s crust into smaller
  and smaller pieces.

Multiple Choice

What is deposition?

• The process by which
  water, ice, wind or gravity
  moves fragments of rock
  and soil.

• The process by which
  water, ice, wind or gravity
  deposit rock sediments
  and soil in a new place.

• The breaking down of
  Earth’s crust into smaller
  and smaller pieces.