Geology 141(B): Fall, 2008First Hour Examination... Page 1 ...
Geology 141(B)Name
Autumn, 20086 October, 2008
GE141: Earth and Environment
First Hour Examination
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. This examination is worth 150 points, or 15% 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.
"They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety."
-- Benjamin Franklin
Section I: Multiple-choice. Please circle the letter of the correct or best response to each question. Each question is worth 4 points; the section as a whole is worth 100 points of the 150 for the exam.
1. The energy that drives the Sun and other stars is derived from
a. nuclear fusionc. nuclear fashion
b. nuclear fissiond. cosmic radiation
2. Of all the matter in the Universe, approximately 90% is
a. oxygen and siliconc. iron and oxygen
b. hydrogen and heliumd. nitrogen and oxygen
3. The most abundant two elements, by weight, in the Earth's crust are
a. oxygen and siliconc. iron and oxygen
b. hydrogen and heliumd. nitrogen and oxygen
4. The Earth's magnetic field is believed to be created by
a. flow of the liquid outer core around the solid inner core.
b. flow within the aesthenosphere.
c. cosmic rays left over from the Big Bang.
d. alignment of the rocks on the mid-oceanic rise and ridge system (MORRS)
5. Evidence for the combined theories of continental drift and plate tectonics includes all of the following except
a. parallel coastlines in various parts of the world, such as western Africa and
eastern South America.
b. matching rocks and geologic structures (folds and faults) across the areas that
"look" like they could be put together again.
c. glacial deposits and erosional marks indicating the ice apparently came out of
the modern ocean, such as in southern South America and southwestern Africa.
d. matching fossils from different parts of the world, though modern biotas in
those regions are totally different.
e. "Polar wandering curves" that differ for different continents, and only make sense
if you allow the continents to move.
f. the existence of major ice caps at both the North and South Poles today.
6. Benioff Zones are
a. inclined planes of earthquakes, marking subduction zones.
b. lines of earthquakes marking spreading centers on the MORRS.
c. parallel sections of coastlines that look like they would match up, according to
plate tectonic theory.
d. areas where GE141 students are exiled after they spell tectonics with an "h".
7. Typical island arc systems include ALL of the following except
a. the Aleutian Islandsd. the Kuril Islands
b. the Hawaiian Islandse. the Java-Sumatra arc
c. the Japanese Islandsf. the lesser Antilles (eastern Caribbean)
8. The San Andreas Fault of California is an example of a(n)
a. transform boundary, where one tectonic plate is sliding past another.
b. subduction zone, where the Pacific Plate is being pushed beneath California.
c. spreading center, where new crust is being created, ultimately to split
California off from the rest of the U.S.
d. active rift zone, like the East African Rift valley.
9. What is an extremely common and critically important ionic substitution pair in the composition of silicate mineral structures?
a. Si and Alc. Al and Fe
b. Si and Od. Si and Fe
10. The major non-silicate mineral group that is most important for its bulk in the Earth's crust is the
a. oxides and hydroxidesc. feldspars
b. sulfidesd. carbonates
11. The non-silicate minerals are chiefly important (and are covered in this class) because
a. they are of major economic significance.
b. they make up the bulk of the Earth's core and mantle.
c. they are the major minerals in almost all soils.
d. they are prettier than silicates and easier to learn in lab.
12. Over 50% of the Earth's crust is made up of
a. oxides and hydroxidesc. feldspars
b. sulfidesd. carbonates
13. Typical sheet silicate minerals include all of the following except
a. claysc. muscovitee. biotite
b. quartzd. talc
14. Mafic magmas
a. are 45-55% SiO2 by weight, and originate by partial melting of the mantle.
b. are >65% SiO2 by weight, and originate by partial melting of continental crust.
c. are created by mixing of partially melted crust and upper mantle.
d. are the rarest type of magma known, and yield diamonds and zircons among
other valuable minerals.
15. The minerals at the top of Bowen's Reaction Series, compared to others in the Series, are those that
a. have the lowest silica content.
b. have the highest melting and crystallization temperatures.
c. are least resistant to chemical weathering processes.
d. all of the above.
e. none of the above
16. A shield volcano, such as Mauna Loa or Kilauea in Hawaii, is almost invariably going to be composed of what volcanic rock type?
a. rhyolitec. basalt
b. andesited. granite
17. Most magmas come from
a. vast reservoirs of molten rock left over from formation of the Earth.
b. the molten material in the Earth's outer core.
c. melting of pre-existing rocks, in the upper mantle or crust.
d. unknown sources geologists are still investigating.
18. The volcanic rock below shows a particular characteristic that is quite common,
though this is perhaps an extreme example. What is shown here?
a. This is a pyroclastic texture common in dikes and sills.
b. This is a porphyritic texture created by a two-stage cooling process.
c. This is an example of an aphanitic texture.
d. This rock can't have any of the minerals from Bowen's Reaction Series in it.
19. The diagram below is a two-component phase diagram that shows graphically what happens in the crystallization of a melt formed from any combination of minerals M and Z.
What would be the composition of the groundmass created in a porphyritic volcanic rock derived from a melt represented by the "x" on the diagram?
a. About 80% mineral M, and 20% Mineral Z.
b. About 50% mineral M, and 50% Mineral Z.
c. About 20% mineral M, and 80% mineral Z.
d. You can't say from this diagram.
20. What is represented on the vertical scale of the diagram in question 18?
a. temperaturec. silica content
b. compositiond. magma depth
21. Mechanical weathering processes include all of the following except
a. oxidationc. root wedginge. exfoliation
b. ice wedgingd. thermal expansion
22. Clay minerals originate
a. from chemical weathering of other silicate minerals.
b. from mechanical weathering of quartz and carbonates.
c. oxidation of iron-bearing rocks like BIF (Banded Iron Formation).
d. in low-temperature felsic magmas that erupt volcanically.
23. The driving processes that provide virtually all the nutrients that sustain the global ecosystem are derived from
a. application of artificial fertilizers.
b. explosive volcanism of intermediate and felsic magmas.
c. chemical weathering of rocks and minerals.
d. erosion of loose sediments on the Earth's surface.
24. The only plant nutrient that is needed in large amounts that is NOT derived from minerals is
a. potassium b. phosphorus c. sulfur d. nitrogen e. iron
25. If you see a bag of fertilizer in a local store that has four numbers on the front (e.g., 12-4-4-2), these refer to the percent composition of the four major plant nutrients contained in that fertilizer. Which of the following elements is NOT included in this analysis?
a. potassium b. phosphorus c. sulfur d. nitrogen e. iron
Section II: 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; materials outside the space allotted will not be read. PLEASE ALSO try to write legibly; 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; there are 50 points possible for this entire section. (And PLEASE remember as well that, as promised on the syllabus, I WILL deduct a point each time I see "volcanoe" or "techtonic!")
26. Copper, silver, gold, cobalt, mercury and lead are all well-known transferric elements. What is their significance to the history of our planet and solar system? (10 points)
27. What are the nine silicate minerals that make up Bowen's Reaction Series? Enter the name of each in its proper position in the following chart.
(10 points: 2-1-1-1-1-1-1-1-1)
/
/
/
/
|
|
|
28. Compare and contrast the formation of the Andes Mountains with the creation of the Aleutian Islands, with particular emphasis on the tectonic settings that result in their readily apparent differences. How are they similar? How are they different? (10 points)
29. Why are volcanic eruptions from volcanoes such as Mount St. Helens or Soufriere Hills so much more dangerous than those from Kilauea or Mauna Loa? [Don't just tell me how they're different, but tell me why they're different!] (5 points)
30. What is the critical difference between weathering and erosion ? (5 points)
BONUS QUESTION (+5 for a correct answer; no penalty if you don't know) :
What is the relevance of Einstein's famous equation, E= mc2 to the Big Bang?
Section III: Geography. On the maps on the following page (the maps are printed back-to-back), please 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 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! (10 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:On the map of the world:
Lake OntarioFrance
Chesapeake BaySwaziland
LouisianaAndes Mountains
OregonTaiwan
AlbertaAleutian Islands
Grade on exam: ______out of 150 possible*.
* If this is below 105, please see me within the next week !!!
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.