WEATHERING AND EROSION
Weathering
Weathering is the __________ down and ___________ away of
rock material.
Climate affects the rates of weathering:
________
__________ conditions tend to rot material quicker.
Cooler dry conditions take _______________________ to rot.
Two Types of Weathering
1. Physical or Mechanical Weathering
The ____________ _______ of rock material into smaller pieces
is ________________or ______________________ weathering.
There is _______ a change in the chemistry (composition) of the
rock.
Types of Mechanical Weathering
a. ________________ - works like sand paper and wears the rock
down by rubbing water, ice, sand or wind across it.
2. Chemical Weathering
The breaking down of the ______________ of a rock into a new
and different substance.
Types of Chemical Weathering
a. __________________ – the combining of elements (like iron)
reacting with oxygen; ‘rusting of rock’- rock turns red.
Examples: Eastern Tennessee and Hematite (from the lab)
b. _______________ – Rock reacts with water, gases and solutions
to form acids which can add or remove elements from minerals
Examples: Carlsbad Caverns, New Mexico - carbonic acid and the
Parthenon in Greece shows effects of pollution and acid rain.
Erosion
The ____________________ of rock material to another location
is erosion.
The 5 agents of erosion
1. _________ water
4. ___________
2. _____________
3. _________
5. Ocean ________ and currents
Examples: Balancing rock of Zimbabwe Africa and Dust Storm in New Mexico
b. ___________________ - a significant difference between hot
and cold temperatures over a period of time.
Examples: Rock spikes in Wyoming
c. _________ action – the continuous freezing and melting of water
Examples: Exfoliation domes at Enchanted Rock, Texas
d. ________________ – pulls rock material down
Examples: Talus slopes in the Sierra Madres & land slide in Peru
e. _______________ activity – burrowing animals and root pry.
Examples: Worm tubes from the Sea of Cortez and Root pry,
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Camp Goddard< Oklahoma
Factors that interact to cause erosion are….
1. __________________ – downward pull
2. __________________– speed or velocity
Gravity and momentum interact to carve out and build up Earth’s
surface by…..
1. ___________________ – carving out process
2. ___________________ – building up process
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I. ______________ erosion and deposition
IV. ___________Water (Rivers)
In _______ (dry) landscapes the primary erosional force is ______
Wind picks up dry particles and hurls them along blasting them
against exposed rock – the process is called_______ __________.
1. Rivers generally start at a ________ elevation level and flow
downward to _____ level. They may begin as _______ melt or
a natural spring.
Erosional feature : __________ in rocks
Example: Land Bridge, Arches National Park
2. The early course of a river (the ____________ part) is
marked by greater _____________ (speed) due to the
greater ________ and _________.
The most common deposits of wind are _______ _______. Particles
of sand are carried along and deposited by the wind.
Depositional feature: _________________________________
Example: White Sands National Monument, NM
II. __________________ erosion is carried out by 3 processes:
a. Water percolates through rock and _____________ it
(weathering)
b. Dissolved rock is moved as it _________ through
(erosion)
c. Dissolved rock is then deposited
Erosional feature: dissolved rock _________
Depositional feature: dissolved limestone is _____________ to
form stalagmites and stalactites in each cave
Example: Natural Bridge Caverns, San Antonio
3. Creates a ____ shape in the terrain. The _________ the
river, the ____________ the “V” shape.
4. As the river ages it stretches across _____________ land.
With the decreased slope the river’s path develops bends and
curves called _______________
5. __________ _________ are meanders that cut off from the
main channel.
6. _______________cuts on the outside of the meander until
the meander is cut off.
7. ______________eventually seals off the meander leaving a
‘lake’ behind.
Number the pictures below to show the correct order in the
formation of oxbow lakes.
III. ______________, rivers of ice creep down from mountains as
a result of the pull of gravity, and have a tremendous influence
of earth’s surface.
Erosional feature: bulldozing the debris down the slope and cutting
the U shaped __________ - (depression on Earth’s surface)
Depositional feature: _____________ – debris left behind
Example: New York’s Manhattan Island
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________
______
_______
_______
The __________of a river is where it flows into a large body of water.
At the mouth of a river, mud is_______________ forming a new land
mass called the________.
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