ENVIRONMENTAL EARTH SCIENCE
WEATHERING VIDEO WORKSHEET
DATE:
___________________________
Read these questions, then answer them while watching
the first part (first 14 min) of the
Annenburg/CPB video
"Weathering and Soils"
from
The Earth Revealed
series. Compare
your answers with other students to verify them.
Weathering is the first step in wearing down the Earth's
surface.
1. What were the conditions that caused Cleopatra's
Needle to weather faster in NYC than in
Egypt?
2. All rocks at the Earth's surface weather, which is
really the way rocks:
3. The breaking of rocks into smaller fragments (pieces)
or into individual crystals is called:
4. What causes rocks that we see at the surface to be already fractured?
5. Release of
pressure as deeply formed rock approaches the surface causes rocks to:
A.
B.
C.
6. How does exfoliation and any other kind of fracturing
lead to other types of mechanical
weathering?
7. Why do rocks fracture in climates in which the
temperature goes below freezing?
8. Where do we see damage from ice expansion in
something artificial?
9. List three terms that refer to the natural breakup
(fragmentation) of rock at the Earth's
surface.
10. When a rock such as granite goes through physical
weathering, is it still the same kind
of rock? Explain why or why not.
11. The other major type of weathering is:
12. How does physical weathering increase the rate of
chemical weathering?
13. The main agents of chemical weathering are:
14. These solutions are usually ___________
_____________ and are able to slowly decompose most rock minerals.
15. How is carbonic acid formed? What rock does it affect the most?
16. Unlike physical (mechanical) weathering, chemical
weathering actually
_________________ the _________________ of the rock.
17. How is rusting of metal similar to chemical
weathering?
18. What minerals form from rusting?
19. What two climate conditions are important for faster
decomposition (chemical weathering)?
Why?
20. Name two of the few minerals that are stable at the
Earth's surface.
21. What kind of minerals are most unstable at the
Earth's surface?
22. Explain how granite can weather even though it
contains quartz, a
mineral that
resists chemical decomposition.
23. What can happen to rock particles after they become
separated from each other?
24. Explain how our society speeds up the chemical
weathering process.
25. In addition to rocks, what else is affected by acid
rain?
26. What is the greatest benefit to people of the
weathering process?
Why?
Not on video --------------
27. In the process called root wedging, roots of trees grow into fractures, and the pressure of the growing
root can crack rocks right in half.
Where would this process be most active?
28. Is root wedging physical or chemical weathering?
29. Chemical weathering occurs most rapidly in minerals
that contain metals such as Fe, Mg, Ag,
Cu, and Al. Use the Appendix in
the back of your textbook to name five
minerals that will decompose through
chemical weathering. Do not include the
minerals mentioned in the video that
form FROM weathering.
ENVIRONMENTAL EARTH SCIENCE
WEATHERING HOMEWORK WORKSHEET
DATE:
Use your notes if you need more room for this assignment
(numbers are continued from the video worksheet).
30. Locate a large rock near your house. Describe or
draw a map of its location.
31. Observe your rock carefully. Describe what you see.
32. Are there any small or large fractures (cracks) in
your rock? How do you think these
formed?
33. Is there any kind of coating or discoloration on
your rock that scratches off easily? How do you think this formed?
34. Does your rock crumble easily or is it strong? Based on this, use the
information from the video to speculate about how long it has been exposed
at the surface, how deep in the Earth it formed, and the type
of minerals it is composed of.
Answers
ANSWERS
1. What were the conditions that caused Cleopatra's
Needle to weather
faster in NYC than in Egypt?
HUMIDITY, REACTION OF WATER WITH SALTS ABSORBED FROM THE
MUD WHEN IT
WAS BURIED.
2. All rocks at the Earth's surface weather, which is
really the way
rocks:
ADAPT THEMSELVES TO THE ENVIRONMENTAL OF EARTHS SURFACE
3. The breaking of rocks into smaller fragments (pieces)
or into
individual crystals is called:
DISINTEGRATIO
OR FRAGMENTATION OR MECHANICAL
WEATHERING
4. What causes rocks that we see at the surface to be
already
fractured?
TECTONIC ACTIVITY
5. Release of pressure as deeply formed rock approaches
surface causes
rocks
to:
A.
EXPAND UPWARD
B.
CRACK INTO SHEETS
C.
PLATES PEEL OFF IN LAYERS: EXFOLIATION
6. How does exfoliation and any other kind of fracturing
lead to other
types
of mechanical weathering?
EXPOSES THE ROCK TO WATER AND ICE WEDGING
7. Why do rocks fracture in climates in which the
temperature goes
below
freezing?
WATER FREEZES IN THE FRACTURES, EXPANDS, WIDENS AND LENGTHENS THE
FRACTURE
8. Where do we see damage from ice expansion in something
artificial?
ROADS AFTER WINTER ARE CRACKED, HEAVED.
9. List three terms that refer to the natural breakup
(fragmentation)
of
rock at the Earth's surface.
DISINTEGRATION OR PHYSICAL WEATHERING OR FRAGMENTATION OR
MECHANICAL
WEATHERING
10. When a rock such as granite goes through physical
weathering, is
it
still the same kind of rock?
Explain why or why not.
YES, COMPOSITION HAS NOT CHANGED, ONLY THE SIZE OF
PIECES.
11. The other major type of weathering is:
CHEMICAL WEATHERING OR DECOMPOSITION
12. How does physical weathering incre se the rate of
chemical
weathering?
EXPOSES MORE SURFACE AREA TO CHEMICAL WEATHERING
13. The main agents of chemical weathering are:
WATER IN THE SOIL AND MOISTURE IN THE AIR
14. These solutions are usually _WEAK _____ __ACIDS______
and are able
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to slowly decompose most rock minerals.
15. How is carbonic acid formed? What rock does it affect the most?
RAIN PICKS UP CO2 FROM THE AIR, MORE CARBON FROM SOIL.
16. Unlike physical (mechanical) weathering, chemical
weathering
actually
_CHANGES________ the __COMPOSITION____ of the rock.
17. How is rusting of metal similar to chemical
weathering?
COMPOSITION OF NAIL IS CHANGED FROM IRON TO IRON OXIDE
18. What minerals from from rusting?
LIMONITE, GUERTITE, HEMATITE
19. What two climate conditions are important for faster
decomposition
(chemical weathering)? Why?
HIGH MOISTURE, HIGH TEMPERATURES. MOISTURE COMBINES WITH
MINERALS,
HIGHER TEMPS SPEED UP CHEMICAL REACTIONS
20. Name two of the few minerals that are stable at the
Earth's
surface.
QUARTZ, HEMATITE,
21. What kind of minerals are most unstable at the
Earth's surface?
MINERALS THAT FORMED AT THE HIGHEST TEMPERATURES.
22. Explain how granite can weather even though it
contains quartz, a
mineral that resists chemical decomposition.
THE OTHER MINERALS SUCH AS PLAGIOCLASE, ORTHOCLASE
DECOMPOSE AND
LOOSEN THE QUARTZ THEY ARE ATTACHED TO
23. What can happen to rock particles after they become
separated from
each other?
WASHED AWAY, DEPOSITED TOGETHER SAND CAN FORM SANDSTONE,
SILT CAN FORM
SILTSTONE.
24. Explain how our society speeds up the chemical
weathering process.
ACID RAIN FROM SULFER DIOXIDE COMBINED WITH MOISTURE IN
THE AIR, ALSO
FROM CO2, NOx, CO, ALL FROM IDUSTRIAL AREAS, POWER PLANTS, CARS.
25. In addition to rocks, what else is affected by acid
rain?
FORESTS, PLANTS, LAKES
26. What is the greatest benefit to people of the
weathering process?
Why?
SOIL, ITS THE FOUNDATION FOR THE ENTIRE TERESTRIAL FOOD
CHAIN.
Not on video --------------
27. In the process called root wedging, roots of trees grow into
fractures, and the pressure of the growing root can crack rocks
right in half. Where would this process be most active?
WHERE THERE IS LOTS OF VEGETATION
28. Is root wedging physical or chemical wethering?
PHYSICAL
29. Chemical weathering occurs most rapidly in minerals
that contain
metals such as Fe, Mg, Ag, Cu, and Al.
Use the Appendix in the
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(file: wthrngvd.qaa 4/27/94)
back of your textbook to name five minerals that will decompose
through chemical weathering. Do not
include the minerals
mentioned in the video that form FROM weathering.
STANDARD TEXT: ALL MINERALS IN APPENDIX M EXCEPT
GRAPHITE, GOLD.
APPENDIX N: TALC, SPHALERITE,
MUSCOVITE, BIOTITE, DOLOMITE,
HORNBLENDE, FELDSPAR, AUGITE, OLIVINE, GARNET, TOPAZ, CORUNDUM.
NOT: BAUXITE, LIMONITE, KAOLINITE, BECAUSE THESE ARE PRODUCTS OF
WEATHERING AND SO ARE STABLE AT THE EARTHS SURFACE.
HONORS TEXT: ALL MINERALS IN APPENDIX M EXCEPT HEMATITE,
GRAPHITE,
GOLD, ALL MINERALS LISTED UNDER NONMETALLIC LUSTER MOSTLY DARK
COLORED, ALSO TALC, FELDSPAR, DOLOMITE. NOT: BAUXITE, LIMONITE,
KAOLINITE, BECAUSE THESE ARE PRODUCTS OF WEATHERING AND SO ARE
STABLE AT THE EARTHS SURFACE.
Use the back of this paper to answer the following
questions:
30. Locate a large rock near your house. Describe or draw
a map of its
location.
31. Observe your rock carefully. Describe what you see.
32. Are there any small or large fractures (cracks) in
your rock? How
do you think these formed?
33. Is there any kind of coating or discoloration on your
rock that
scratches off easily? How do you think this formed?
34. Does your rock crumble easily or is it strong? Based on this, use
the information from this worksheet to speculate about how long it
has been exposed at the surface, how deep in the Earth it formed,
and the type of minerals it is composed of.
TO: Carmen
Andrews
FROM: Tony Mitchell
DATE: 4/27/94
RE: FYI
For future time management reference: to produce the
Weathering video
worksheet, I had to:
1. preview the video,
2. reread the course objectives for this topic,
3. reread last years lecture notes on this topic,
4. reread the textbook information,
5. look up the text definitions for the terms in this
video,
6. electronically copy the learning objectives to this
document from
another,
7. rewrite the objectives into questions in the order
they are
presented on
the video while stopping and starting the video,
8. replay the video over each area where a question was
answered,
9. write the additional assignment at the end of the
worksheet,
10. replay the entire video to test the worksheet and
make minor
changes,
11. rewrite the lesson plans to replace last years
lecture with this
video and
worksheet,
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(file: wthrngvd.qaa 4/27/94)
12. make backup copies of the files,
13. print the worksheet,
14. run off copies for each student.
I started this at 8:00 pm, finished printing at 12:30,
and will run
off copies the next day, for a total of 4.75 hours. That works out to
just about the standard 1 to 1 ratio of planning/prep
time to class
time that one would expect in a new (less than 3 years
old) course.
Of course, next year we may only have to edit the
worksheet slightly,
if at all, before printing and copying, so we will have
4.5 hours to
write reports on library usage and such.
(By the way, this memo took 20 min. not included in the
above.)
cc: J. Casioppo
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(file: wthrngvd.qaa 4/27/94)
other
weathering notes.
DIAGRAM 2. fracturing due to changes in temp throughout
year, day.
example: Kalahari desert. analogy: glass from freezer to
boiling
water. 3. ice wedging (aka frost wedging, aka frost
action):
fracturing of rocks due to expansion as water freezes.
Occurs where
temps go above, below freezing daily. Water seeps into
tiny fractures,
freezes at night, expands and so widens and lengthens
the fracture.
When the temp goes back above freezing more water
enters, then puts on
more pressure when it freezes. DIAGRAM, example: Mt. Washington in
White Mts notes it freezes. DIAGRAM, example: Mt.
Washington in White
Mts of New Hampshire: top of mt looks like pile of
boulders from ice
action- was probably smooth 10,000 years ago after
glaciers wore it
smooth. 5. abrasion as surface is worn down by products
of weathering
such as sand grains as they are caried by agents of
erosion. Examples:
sediment in streams wears down, smooths and rounds
rocks, debris at
base of glacier scratches, wears down surface example:
scratches in
Whigville. 6. Rocks break as they fall down hillsides.
7. People
blast, drill, break, dig rocks to mine, quarry, remove
rock to produce
products for society. Examples: concrete, slate
sidewalks, all metals,
crushed stone, everything that came from a mine.
ASSIGNMENT 1. Find a
large rock, descibe it's location and appearance, and
any sign of
physical weathering. 2. list mineral containing metals,
and so will
oxidize easier than others.
WDAY: Thu DATE: Apr 1, 1993 TOPIC: Chemical weathering:
oxidation,
hydration, OUTLINE NOTES 1. Describe your large rock and
its evidence
of physical weathering. 2. Chemical weathering (aka
decomposition):
the breakdown of rock into materials with a different
composition.
Processes: 4. Solution: some minerals dissolve into
water easier:
especially with Na, Ca 5. Carbonic acid (from CO2 in air
dissolving
into rain and organic material in soil) will dissolve
minerals with Ca
such notes organic material in soil) will dissolve
minerals with Ca,
especially Calcite, the mineral in the rock limestone.
example: old
gravestones. 6. acidity increases chemical weathering.
Acidity comes
from both natural and human sources: diagram acid rain.
ASSIGNMENT 1.
Reread section on products of weathering, identify 5
minerals that
will form 5 products of weathering.
WDAY: Fri DATE: Apr 2, 1993 TOPIC: Chemical weathering,
chem/physical,climate OUTLINE NOTES 1. Interaction of
physical/chem
weathering. 2. Phys speds up chem by increasing surface
area exposed
to amosphere. DIAGRAM. breaking rocks exposes more
surfaces to air. 3.
Chem weathering may loosen particles from surfaces by
dissolving,
oxidizing, hydrating out some crystals, remaining
crystals released.
example: bottle containing rocks in water for three plus
years- lots
of loose particles clouding water. 4. Climate and
weathering: pick
three different climates, describe their temps,
moisture, vegetation,
and the effects of these on phys, chem weathering.
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