Geology 141 (B)
Name
Spring, 2004
.
15 May, 2004
GE141: Physical Processes of Planet Earth
Final Examination
This examination is worth 300 points, or 30% of your overall
semester grade. Exams will be graded as quickly as possible; your
individual point total will be entered on the last page to ensure that
only you know how well you did on the exam, unless you choose to
divulge that information to others.
PLEASE NOTE: After exams are graded, I will return your exam ONLY to you.
It will not be released to friends, roommates, your lab partner, or anyone else.
This is to ensure YOUR security and confidentiality. So that I can mail your
exam back to you if you're gone before they're graded, please enter
your mailing address here:
"It is with places rough and smooth,
The road of life is laid,
And it is the rough spots mostly
Of which character is made."
-- Virginia K. Oliver
Geology 141: Spring, 2004
Lecture Final Examination
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INSTRUCTIONS: PLEASE read the instructions and questions CAREFULLY
and completely. If you do not understand a question as it appears on the
exam, PLEASE ASK FOR CLARIFICATION!! It is to YOUR benefit to do so.
Please respond to each question in the most appropriate fashion. Please
make your responses concise and to the point, but thorough; use sketch
diagrams any place you believe that they may help explain your response.
There should be ample space provided for an adequate response to each
question; PLEASE RESTRICT YOUR RESPONSES TO THE SPACE PROVIDED
and try to write as legibly as you can; I CANNOT give any credit for responses I
can't read! The number of points for each question is indicated in parentheses
after the question.
(And PLEASE remember as well that, as promised on the syllabus, I WILL
deduct a point each time I see "volcanoe" or "techtonic!")
1. In the cross-sectional sketch of the Earth shown below, please identify and label each of
the four major layers that make up the Earth. (10 points total)
Below or next to each label, please identify at least one major distinguishing
characteristic of each layer (e.g., thickness, composition, etc.)
The lithosphere consists of
the
and the
Geology 141: Spring, 2004
Lecture Final Examination
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2. What is the "Pacific Ring of Fire"? Describe completely the geologic/tectonic setting(s)
that has led to its creation, in as much detail as you can on this one page. (20 points)
Geology 141: Spring, 2004
Lecture Final Examination
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3. What are two basic criteria that substances must meet to be considered minerals, which
do not apply to rocks? (5 points: 3-2)
(1)
(2)
4. The most abundant two elements in the Earth's crust, by weight, are (5 pts: 3-2)
(47%) and
(27%)
5. Though most plutonic rocks, by volume, are felsic in character, most dikes and sills are
actually mafic. Why is this? (5 points)
6. While working for the Peace Corps in southern Mexico, you have encountered a high,
isolated mountain that looks like the following sketch from a distance. Local people in a
village 10 km away only know it as a mountain. What specific kind of rock would you
expect to find there, and what would you want to warn the local people to be on the
lookout for as far as a possible danger from this mountain, and why? (10 points)
Geology 141: Spring, 2004
Lecture Final Examination
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7. (a) Sketch an example of an igneous rock with a porphyritic texture, and (b) label each of
the two major components that define this texture. (c) What produces this kind of
texture in an igneous rock? (10 points: 4-2-4)
8. In the chart below, I've indicated the size ranges for various clastic sediments. Name
the sediments that are characterized by those size clasts (I've given you the first), and
identify the sedimentary rocks that are created by the cementation and compaction of
those sediments (10 points - 1 point each).
Size
|
Sediment Name
|
Sedimentary Rock
|
|
> 256 mm
|
Boulders
|
|
|
|
|
2 - 256 mm |
|
|
|
|
|
0.06 - 2.0 mm
|
|
|
|
|
|
0.004-0.06 mm
|
|
|
|
|
|
|
|
(massive)
<0.004 mm |
|-------------------------------|
|
(fissile)
|
|
Geology 141: Spring, 2004
Lecture Final Examination
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9. What is one specific parent material for each of the following non-clastic sedimentary
rocks? (i.e., What materials - not the specific minerals involved - recrystallize to become
each of these rock types?) (5 points: 3-2)
Limestone
Chert
10. What is the ultimate source for almost all of the cements in sedimentary rocks? Give an
example of one of these cements. (5 points: 3-2)
Source:
Example:
11. What are the two major specific geologic processes that are responsible for both the
shortening and thickening of the continental crust? (5 points: 3-2)
12. (a) What is a seismic gap, and (b) why are they at all significant? (10 pts.: 6-4)
Geology 141: Spring, 2004
Lecture Final Examination
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13. Why do all the mountain ranges from Utah west across Nevada and into eastern
California, ending with the Sierra Nevada, run north-south? What kind of process(es)
and forces have produced these mountains and intervening valleys, to give this region
the name of the Basin and Range of the United States? (10 points)
14. What are three of the four independent variables that ultimately will determine the
character of a metamorphic rock? (5 points: 2-2-1)
1.
2.
3.
15. You have been working in an archeological excavation on the northern shore of the
Caspian Sea, in Azerbaijan. In one of your fine-sieved fractions of materials from an
Geology 141: Spring, 2004
Lecture Final Examination
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ancient house floor, you've found a seed of marijuana (Cannabis sativa L.). The project
director is furious - suspecting you have been smoking the weed, and screaming that if
anyone is caught with drugs in the project, you could all be sent to jail and the
excavation canceled. What is one sure-fire test that you could apply to this seed - which
is about the size of the letter "o" in this word - that would prove that it is indeed part of
the 3-5,000-year-old geologic record you're excavating at this site, and not something
modern? (5 points)
16. Global warming has melted glacial ice in Antarctica to expose a mountain peak never
before seen. You have been part of the first geological team on this site, and have
returned with a bunch of samples of granite and coarse-grained schists, that you can
relate to a complicated geologic picture. All you need to complete your study and write a
major scientific paper are age determinations on the rocks. What technique would you
use, and why? (5 points)
17. The Principle of Uniformitarianism ("the present is the key to the past") and Occam's
Razor ("the simplest explanation is usually the right one") are basic to the interpretation
of geologic history and science in general. What are three other fundamental principles
that we apply in the study of sedimentary rocks in particular? (5 points: 2-2-1)
1.
2.
3.
18. The Urals, Appalachians, Alps, Himalaya, and most other major mountain ranges share
a common type of history. How did these mountains come into being? (10 points)
Geology 141: Spring, 2004
Lecture Final Examination
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19. What is the S-wave shadow zone, and how is it significant to our understanding of the
internal structure of the Earth? (10 points)
Geology 141: Spring, 2004
Lecture Final Examination
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20. Identify three ways that water contributes to mass wasting in the geologic environment
(5 points: 2-2-1)
1.
2.
3.
21. Approximately 50% of the U.S. population relies at least in part on water from wells
drilled through the water table. What is the water table beneath the Earth's surface?
Where does all that water come from? (10 points: 5-5)
Geology 141: Spring, 2004
Lecture Final Examination
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22. The sketch-map below shows an area surrounding the Whatchatooya River in
Alabama. Identify each of the geomorphic features indicated by the respective letters
(i.e., what is the feature located at A, B, etc.) (10 points - 1 point each):
A. is a(n)
B. is a(n)
C. is a(n)
D. is a(n)
E. is a(n)
Where would erosion be the dominant process?
Where would deposition of bedload materials be the dominant process?
In what two areas would you expect fine-grained sediments (i.e., silts, clays, and
organics) to be the main thing deposited?
&
Would you want to have a house in the precise center of this area (at "X")? Why
or why not?
.
Geology 141: Spring, 2004
Lecture Final Examination
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23. Capacity and competence are critical factors in stream sediment consideration. What
are each of these? (10 points: 5-5)
Competence is
Capacity is
24. Karst landscapes such as those of Kentucky, Florida, Puerto Rico and the Yucatán
Peninsula, are almost invariably underlain by what specific kind of rock? (5 points)
25. Why are caves almost always formed right at or slightly below the water table? (5
points)
26. What are the two principal means by which glaciers move? (5 points: 3-2)
a)
b)
Geology 141: Spring, 2004
Lecture Final Examination
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27. Glacial ice is very soft. How, then, do glaciers effectively erode underlying rock surfaces
to provide the sculpted landscapes we see throughout New England and in high
mountain ranges throughout the world? (5 points)
28. Describe how a kettle pond, such as Colby Bog, Stuart Pond, or Hamilton Pond, is
formed in a glacial environment. (5 points)
29. Identify one major INdirect effect of major glaciation. That is to say, identify a
significant change in the world environment that was caused by Pleistocene glaciation
(and/or the conditions that led to the glaciation) that was outside the area covered by
glacial ice itself. (5 points)
Geology 141: Spring, 2004
Lecture Final Examination
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30. Describe how a rain-shadow desert is formed, such as that in eastern Washington,
eastern Oregon and Nevada. (10 points)
31. The dominant agent of erosion in the world's deserts, in terms of the total mass of
material moved over time, is
(5 points)
.
32. Why is loess, whether derived from deserts or glaciated environments, such an
excellent parent material for the world's richest agricultural soils? (10 points)
Geology 141: Spring, 2004
Lecture Final Examination
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33. Why are the coasts of tropical environments (like Florida, the Bahamas, and Hawaii)
dominated by carbonate sediments, although there is actually more carbonate produced
by organisms in cold marine waters like those of Maine?
(5 points)
34. What is the dominant geologic process active along cliffed coasts like those of Maine
and much of the Pacific Coast of the U.S. ? (5 points)
35. What causes the tides? Where, specifically, do the highest tides in the world occur?
(10 points: 5-5)
Tides are caused by
The highest tide range in the world occurs in
36. What is the difference between resources and reserves? Include in your response clear
indication that you know what each IS. (10 points)
Geology 141: Spring, 2004
Lecture Final Examination
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37. Identify and describe at least three major ways in which economic ores can form. (10
points: 4-3-3)
(1)
(2)
(3)
Geology 141: Spring, 2004
Lecture Final Examination
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38. On the maps on the following page (the maps are printed back-to-back), locate precisely
each of the following localities or features. FOR SMALL FEATURES OR LOCALITIES,
use a sharp arrow drawn from your label to the feature, so your label can be easily read
and there can be no doubt about what you are labeling. PLEASE remember that it is to
your benefit that your label is clear enough that there is NO question as to your meaning
or intent (OR spelling)! (20 points, 1 point each)
And YES, all labels must be correctly spelled for credit!
[ Since all you have to do is copy the name from the list below! ]
On the map of the U.S. & Canada:
Bay of Fundy
Washington, D.C.
Georgia
Oklahoma
Arizona
Long Island
San Francisco Bay
Alberta
Montana
Minnesota
On the map of the world:
Galápagos Islands
Baja California
New Guinea
Ganges River
Cuba
Nile River
Ural Mountains
Amazon River
Kamchatka
Java
Grade on exam:
out of 300 possible.
Total points for Course:
out of 960 possible. (
%)
Course Grade:
Have a great and relaxing summer break!
And just in case you've never seen the largest-denomination bill that ever used to circulate
among the general public - a little something to help you through the summer months: