Weathering And Mass Wasting Flashcards

1
Q

What are the two types of weathering?

A

Mechanical and chemical.

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2
Q

What does colluvial mean?

A

Deposited by gravity

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3
Q

What different types or forces of mechanical weathering exist?

A

Frost
Pressure release
Temperature
Biota

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4
Q

What occurs due to frost?

A

Mechanical weathering; frost expansion breaks rocks
Creates colluvial deposits called talus

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5
Q

What is talus?

A

Colluvial deposits; it’s angle of repose is 35-37 degrees

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6
Q

What is pressure release?

A

Removal of large material causes rock below to expand
Called exfoliation

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7
Q

How does temperature cause weathering

A

Heat from fires or extreme events can cause rock expansion
(IE Exploding or cracking rock in campfire)

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8
Q

How can biota be a cause of rock weathering?

A

Tree roots exploiting a crack in a rock for example, putting more pressure on it

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9
Q

What are the three types of chemical weathering

A

Solution/carbonation
Oxidation
Hydrolysis

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10
Q

How does solution/carbonation weathering occur?

A

Rain water is acidic and can react with the calcium carbonate in rocks like limestone and marble
Creates sinkholes and karst topography

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11
Q

What is oxidation in terms of chemical weathering?

A

The rusting of iron content in rocks causing their degradation

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12
Q

What are the two main factors in mass movement

A

Gravity first
Waters a close second

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13
Q

What fundamentally defines how mass movement occurs?

A

When the forces of gravity exceed the material/slopes resistance occurs

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14
Q

How does capillary action relate to mass wasting?

A

Particles of small sizes (clay/silt) can be held together with a small amount of moisture and form steep slopes
Too much water saturation can cause them to fail

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15
Q

What are types of slow mass movement are there?

A

Soil creep
Soliluction
Rock glaciers

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16
Q

What is soil creep?

A

Slow movement of soil on slopes >5 degrees
Causes terracettes

17
Q

What is solifluction?

A

Top layer dethawing atop a frozen layer.
Occurs on very gentle slopes
Usually at high elevations or up north

18
Q

What is a rock glacier?

A

A mix of rock and ice that is moving like a glacier but slower than a ice glacier

19
Q

What are types of rapid mass movement?

A

Rotational slumps
Rockfall
Debris flows
Snow avalanches

20
Q

What is a rotational slump?

A

Unstable blocks rotate as they slide, ends up stepped
Caused by undercuts and saturation

21
Q

What is rockfall

A

Unstable blocks break loose, often due to water
Sometimes occurs on sloped bedding planes
Creates talus

22
Q

What is debris flow?

A

Saturated layers of soil and rocks
Usually caused by water running on soils where it usually isn’t
Ie creek diverting course or water run off in fire altered landscapes