Download McKnight`s Physical Geography, 10e (McKnight/Hess)

Salt Lake Community College
Geography 1000 – Physical Geography
AJ Allred, Fall 2014
Student Name _____________________
Quiz 12
Chapters 12-13
Soils and Landforms
Notes and Explanations
Notes to Question 1. Everything in this question is true. In Utah and surrounding states, soils are not
only newly developed from recent volcanic events (Entisols and Andisols), but they are also dormant
(Aridosols) for lack water and might stay dormant forever.
If water and careful technology are applied to either dry soils or new soils, then good farm soil can
develop quickly
1. About one third of Earth’s land surface is dominated by “B” climate types. ‘Aridosols’ and
“Entisols” are common in dry regions. They are considered dormant or undeveloped even though
they may be very old or very young in geological history.
True _X___
False ____
Notes to Question 2. Aridosols tend to be somewhat alkaline, as compared to wet soils that tend to be
acidic. Adding water tends to increase CEC in the form of acidity as well as providing enough moisture
for plant growth.
2. When Spanish colonizers and Brigham Young’s pioneers arrived in dry western North America they
would have started irrigation farming that tended to change soil pH from ____ toward ____.
a. 7.0, 8.0
b. 8.0, something more acidic
c. 6.0, conditions with a higher CEC
d. 6.5, 5.5
e. 6.0 to 5.0 or lower
Notes to Question 3. The bedrock portion of Earth’s crust is mostly too deep to become soil. Near the
surface, bedrock can be weathered and eroded into “blanket rock” or regolith that is in transition from
bedrock to development as surface soils.
3.
What part of the Earth’s lithospheric crust is being converted to soil by forces from the hydrosphere,
atmosphere and biosphere?
a. Bedrock
b. Regolith
c. Clay, silt and sad
d. All of the above
e. None of the above
Notes to Question 4. Notes to Questions 5 through 10 below will provide all the information needed for
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answering Question 4 as well.
4. Which soil orders dominate in the “goldilocks” or “breadbasket” regions of the world where food
crops are grown most successfully?
a. Mollisols and Alfisols
b. Mollisols, Histosols and Oxisols
c. Entisols and Andisols
d. Gelisols and Aridosols
e. Mollisols and Spodosols
Notes to Question 5. The jelly-like nature of Arctic and Sub-Arctic soils results from water that is halffrozen much of the time. Gelisols just don’t develop for lack of heat and dryness. The opposite is true for
soils that are in dry climates that are often hot as well. Arizona is a good example. These soils lack the
moisture needed for soil development. In the western USA, aridosols and andisols dominate. These two
soild types are geologically young and not exposed to enough water for development into good farm soil.
They are dormant for reasons that are very different from gelisols that are also dormant or inactive.
5. What soils are under-developed or dormant for lack of environmental activity? These soils are not
necessarily new, young or old. They just don't develop due to being either too cold or too dry.
a.
b.
c.
d.
e.
Aridosols and Alfisols
Vertisols and Oxisols
Gelisols and Aridosols
Andisols and Entisols
Histosols and Mollisols
Notes to Question 6. Oxisols and ultisols are considered worn out from excessive heat and moisture.
In comparison, soils in mid-latitude prairies and steppe country can last forever as grasses and small
animals continually add humus and passageways for soil development. Being just right in temperature
and humidity makes mid-latitudes ideal for producing plants and animals that humans consume. Severe
weather is a consequence of mid-latitude climates that does nothing to diminish the value of soils found
there. See Question 7 also.
6. What regions of the Earth are not likely to host Oxisols and Ultisols?
a. The south end of Hadley cells in the northern hemisphere.
b. The humid tropics and sub-tropics.
c. The middle of continents where severe weather prevails.
d. Places that are humid and either warm or hot most of the year.
e. Places where leaching is widespread.
Notes to Question 7. The central United States is like “Goldilocks Porridge” - - it is not too hot, not too
cold, not too wet and not too dry. Because humans eat grasses (or animals that eat grass) the tall-grass
prairie of Iowa and surrounding states provides conditions that are perfect for Molisols and Alfisols that
are ideal for farming. Coincidentally, mid-latitude cyclones are common in mid-western United States
weather patterns. Tornadoes, blizzards and other severe weather events are also common in places
where soils are idea for farming. See Question 6 also.
7. Places where severe weather is common and where vigorous, four-season climates prevail tend to host
the world’s most productive farm soil.
True ____ False ___
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Notes to Question 8. Clay particles are smaller than silt and sand. Their size and chemical nature make
them “nutritious” for most farming needs. However, the very small size of clay particles makes them
almost as hard as rocks when they are dry, and impossibly sticky and sour when wet. So, vertisols and
clay soils are often useless in spite of their potential.
8. Which of the these soil types is fertile and nutritious, but almost impossible to plow when wet and
almost impossible to plow when very dry?
a. Vertisols
b. Clay soils
c. Both of the above
d. None of the above
e. Histosols
Notes to Question 9. Some leached or eluviation occurs in nearly all soils, including excellent farm soils.
Earthworms and natural grasses are evidence of soils that are ready for farming. Rodents also help
develop soils, providing passageways for water and nutrients.
9. Soils that are well-developed, mature and likely to support good farming __________.
a. are not leached at all and are not contaminated by earthworms, grasses or rodents
b. are not exposed to severe storms or wide variations in seasonal weather
c. have never developed soil horizons, the result of old age and severe weathering
d. are soft and contain relatively large amounts of humus and clay
e. All of the conditions above are required for the world’s best farm soils.
Notes to Question 10. All of the statements in Question 10 are true.
10. The practice of “dry farming” in the arid western United States is possible because ______________.
a. capillary action helps bring water to the root zone
b. Aridosols can support crops in between fallow or ‘resting’ years
c. of high-tech soil management practices that can include satellites using GIS with GPS
d. farmers us large amounts of chemicals and non-renewable fossil fuels and minerals
e. All of the above
Notes to Question 11. About half a billion people live in the ‘danger zone’ of volatile stratovolcanoes that
could erupt at any time. Most of these people are there because they need the farm soil that can develop
from volcanic ejecta, or they just don’t have any place else to go. Even in the United States, millions of
people along the west coast live in the shadow of dangerous, steep-sided stratovolcanoes. Seattle is the
best example.
11. Which of the following is not true?
a. About 50,000,000 people live on the slopes of dangerous strato-volcanoes.
b. Volcanoes of all types deliver much-needed new minerals to the surface for soil development.
c. In the United States, the best soils are often covered with asphalt and concrete.
d. In the United States, millions of people live on the slopes of dangerous, explosive volcanoes.
e. Volcanoes are caused by molten rock (magma) rising convectively under the Earth’s crust.
Notes to Question 12. Nearly all natural Earth elements are found near the surface. That is how we
know about them. Newly ejected pyroclastics are not ready for farming, but can be added to existing
soils as nutrients. In warm, wet climates, volcanic ash and rocks can break down relatively quickly into
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usable farm soil, but not “overnight”.
In the deep Earth mantle, all rocks are melted, but are under so much pressure that they are considered
solid. Near the surface mantle pressure is less, so flow can accelerate, leading to the asthenosphere where
magma can flow quickly to the surface at places where the dry crust is thin enough to allow fracture lines
or puncture zones.
On the surface, newly formed igneous crystals can wear down quickly when sunshine uses water for
weathering by hydrolysis, biologic or mechanical means. Igneous crystals are literally “turned to dust”
that we call soils and sediments.
12. Which statement is true?
a. Of about 100 natural elements, about 40 are found in Earth's crust.
b. Newly formed rocks are crystals that the Sun turns into sedimentary 'dust'.
c. Compression increases so much in the deep asthenosphere that solid mantle turns into liquid magma.
d. Newly ejected igneous soils are more nutritious than old sediments.
e. Newly ejected lava beds and volcanic pyroclastics can support farming in almost any climate.
Notes to Question 13. All of the statements in this question are true. Be careful though: it is also true
that rocks in eastern Utah are dominated by old sedimentary types. See Question 16 below. Of course,
even in old sedimentary regions like eastern Utah, our dry climate tends to promote weathering which
exposes bedrock to erosion that produces new batches of rocks and soils. So, in spite of having some old
rocks, everything below is still true.
13. Which of the following best describes Utah and surrounding states?
a. Land forms and surface rocks are relatively new.
b. Soils are not well-developed.
c. Farming depends on relatively "high tech" and "high finance" resources.
d. Volcanoes erupted recently, and there is vast geo-thermal energy potential.
e. All of the above.
Notes to Question 14. All of the statements below are true.
14. Which of the following statements is true?
a. Oxygen is a major component of some of the world’s hardest rocks.
b. Rocks are recycled over and over, passing through igneous, sedimentary and metamorphic states.
c. Magnesium and poisonous chlorine are two of the most important Earth elements that wash into the
Great Salt Lake from eroding mountains.
d. Tuition at SLCC is lower because of plutonic intrusions into old sediments that brings precious
metals and strategic metals close to the Earth’s surface.
e. All of the above are true.
Notes to Question 15. Oxides of carbon are a major result of combustion and humans are definitely into
burning things. In our modern era, we are creating vast quantities of oxides in to the air: oxides of
carbon from burning hydrocarbon fuels and the unfortunate, unplanned oxides of nitrogen and sulfur.
Carbon dioxide and carbon monoxide are, respectively, the most important “greenhouse” gas (except for
water vapor) and a genuine poison.
15. Which elements found in rocks are most associated with global climate change?
a. oxygen and sulfur
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b.
c.
d.
e.
oxygen and nitrogen
oxygen and carbon
carbon and nitrogen
carbon and sulfur
Notes to Question 16. The eastern half of Utah consists mostly of ancient sediments that have cemented
naturally into sedimentary rocks. These layers of “dust” also hosted climatic periods that were wet and
warm, allowing deposits of organic “muck” to develop. Over millions of years, this organic mass
“morphed” into fossil fuels.
16. The eastern half of Utah consists of ancient sandy sediments that provide fuel our cars, heat for our
homes and light in almost all of our buildings.
True ___ False ___
Notes to Question 17. Utah is dry country that also happens to be located over recently developed
volcanic landscapes that are still warm. We can’t take hot magma home with us, but we can use a heattransfer fluid like ethylene glycol or even ordinary water to absorb magmatic heat and bring it to the
surface for us. Doing so successfully requires more than just tapping geysers, hot pots or hot springs.
We must carefully manage our water resource in dry country. Unfortunately, most of Utah’s geothermal
resources are located far from big cities along the Wasatch Front. Geothermal facilities are still
considered somewhat “high tech” and require careful study, exploration and financing in order to be
successful.
17. Much of Utah contains recently deposited volcanic rocks that are still warm enough to provide vast
amounts of geothermal energy. All we need to add is _______.
a. Water
b. Water and high technology
c. Water, high technology and high finance
d. Water, high technology, high finance and people willing to live in remote areas.
e. Water, high technology, high finance and people willing to live in remote areas with determination
to carefully monitor how well water is recycled back into the Earth for more geothermal heating.
Notes to Question 18. New technology in the United States is now able to extract crude oil and
natural gas that were previously too expensive to reach. The result is a world-wide drop in overall
fuel prices, regardless of what politicians do and turmoil in other oil-producing countries.
18. In the Fall of 2014, gasoline prices have dropped considerably because _______________.
a. politicians raise and lower gas prices to get votes in elections
b. there is less strife and terrorism in the oil-rich Middle East
c. cars are suddenly getting much better mileage
d. large numbers of Utah residents are choosing to ride buses and light rail
e. “fracking” technology fractures sedimentary rocks to release oil and gas in great abundance and new
worries about environmental safety
Notes to Question 19. As explained in the textbook, metamorphism usually takes millions of years;
however, “contact metamorphism” can occur quickly when rocks are suddenly subjected to a
combination of high heat and high pressure that are not quite great enough to fully melt the rock
back into a new igneous crystal.
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For the examples in Question 19, slow, gradual metamorphism can convert organic materials into
fossil fuels as well as produce diamonds. Calcium-based materials can gradually convert to chalk or
gypsum and then into shale, limestone or even hard, beautiful marble with enough time, heat and
pressure. These processes take a long time.
19. What process would convert:
- a pile of silica sand into clear, hard, glass-like crystal called quartz?
- soggy dead animals and plants into feed stock for gasoline?
- slippery black carbon dust into diamond, the hardest stone known?
- crumbly sea shells and chalk into marble for priceless carved statuary?
a.
b.
c.
d.
e.
Contact metamorphism
Subduction and re-melting in the asthenosphere.
Abrasion and compression during rock falls and mass-wasting.
Temperature below melting point, extreme pressure and millions of years.
All of the above
Notes to Question 20. Drilling for oil and gas can reach more than five miles into Earth’s crust, but not
much further, due to the pressure exerted by the weight of rocks above and the heat of magma from
below. As described in the textbook, Earth’s crust is as thin as five miles and as thick as 100 miles, but
penetrating into the crust is possible for only the coolest portion close to the surface.
20. The hardest, toughest known alloy tungsten steel or titanium drill bit would melt into useless liquid if
it were driven into the Earth about _____________ deep.
a. 2 miles
b. 5 miles
c. less than 10 miles
d. about 50 miles
e. about 100 miles
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