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GEOLOGY 101 – The Earth – David Boutt Final Encounter with Planet Earth – December 15, 2006

This is a pyramid exam, in which you take the same exam twice. The first time, you will be

given 30 minutes to answer the questions by yourself, without using books or notes. Please hold your answer sheet quietly until asked to hand it in.

After the first answer sheet is handed in, you may change seating and answer the same questions on the second sheet, this time consulting in small groups (less than 8 students each) with your colleagues, and your books and notes. Please turn the second sheet in at the front of the class when you're done, and SHOW YOUR ID as you do.

Your final grade is weighted with the first (solo) exam worth 75% and the second, 25%. INSTRUCTIONS - Read carefully - Best of Luck 1) Complete Student ID Sections (LAST NAME, then First Name + ID NUMBER) FOR

BOTH EXAM ANSWER SHEETS! 2) Mark in the sensing circles carefully with soft #2 "lead" pencil, and avoid erasure. 3) Each question constitutes 4 points each, 100 points total each exam, weighted as above. 4) Only one correct answer to each question. 5) Suggestions: Look for KEY words in any question. Answer all the ones you're sure of,

then go back and work on the rest.

1) The unifying geological theory which explains the nature and behavior of Earth's lithosphere is:

(a) radioactivity (b) plate tectonics (c) the hydrologic cycle (d) uniformitarianism (e) geologic time

2) The distinction between the crust and mantle is based on a difference in _____; the

distinction between the lithosphere and asthenosphere is primarily on the basis of a difference in _____.

(a) chemistry (mineral content); degree of physical rigidity (b) color; chemistry (mineral content) (c) degree of physical rigidity; chemistry (mineral content) (d) chemistry (mineral content); chemistry as well. (e) carbon

3) If body of igneous (source) rock is subjected to partial melting, the magma that is

produced is expected to be _____. (a) identical in chemical composition to the source rock (b) more mafic than the source rock (c) more silicic than the source rock (d) denser than the source rock (e) contain green minerals favored by phrogs of the asthensphere

4) The classification of metamorphic rocks is based on

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(a) a demented geologist's imagination. (b) texture and grain size. (c) composition (mineralogy) and texture. (d) rock type prior to metamorphism. (e) texture and color.

5) Viscosity of magmas depends mainly on what two factors?

(a) Thickness and speed of the flow (b) Temperature and silica composition (c) Amount of magma and direction of flow (d) Duration and height of eruption (e) Water and alumina content of magma

6) The distribution of earthquakes on Earth

(a) is at random throughout the interior of plates. (b) occurs parallel to all folded mountain belts. (c) is restricted to areas of fault zones in the shield. (d) outlines plate boundaries. (e) outlines continental margins.

7) A key factor that helps us locate distant earthquake epicenters is that

(a) P-waves and S-waves travel at about the same speed. (b) S-waves move about twice as fast as P-waves. (c) S-waves travel about as fast as surface waves. (d) surface waves travel about as fast as S-waves. (e) P-waves travel about twice as fast as S-waves.

8) Which of the following statements is NOT true?

(a) Normal faults generally result from tension. (b) Strike-slip faults are often associated with transform faults. (c) Normal faults develop on a large scale in rift systems. (d) Reverse faults are generally associated with compression. (e) Thrust faults are generally associated with tension.

9) The separation of clastic materials according to grain size is called (a) collimating. (b) graduating. (c) dessication. (d) sorting. (e) none of the above.

10) The dominant structural features that affected the Appalachian Mountains of New

England are (a) normal faults that uplifted the rocks of New England. (b) normal faults that depressed the New England craton.

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(c) strike-slip faults that moved the future site of Boston east and then west. (d) thrust faults that moved rocks from east to west. (e) thrust faults that moved rocks from west to east.

11) Normal, reverse, and thrust are all examples of _____ faults.

(a) strike-slip (b) dip-slip (c) oblique-slip (d) left-lateral (e) oblique-slip

12) The Earth is approximately how old?

(a) 15 billion years (b) 4.6 billion years (c) 40 million years (d) 6,000 years

13) The hydrologic cycle is driven by:

(a) solar heat (b) wind (c) evaporation (d) internal heat (e) gravity

14) The principal erosional agent which shapes Earth's surface above sea level is: (a) running water (b) wind (c) organic life (d) mass wasting (e) ice

15) Examine the sequence of geologic events in block diagram below. The numbers

correspond to units or events From oldest (first) to youngest, which is most nearly correct? (a) Deposition of units 1-7, folding, Intrusion of 14, erosion, deposition of 8-9,

emplacement of 15, erosion, deposition of 10-12, cutting of 13 (b) Deposition of units 1-7, folding, erosion, deposition of 8-12, Intrusion of 14,

emplacement of 15, cutting of 13 (c) Folding, Deposition of units 1-7, Intrusion of 14, erosion, deposition of 8-9,

emplacement of 15, erosion, deposition of 10-12, cutting of 13 (d) Deposition of units 1-7, emplacement of 15, erosion, deposition of 8-9,

Intrusion of 14,erosion, deposition of 10-12, cutting of 13 (e) Deposition of units 1-7, folding, Intrusion of 14, deposition of 8-12,

emplacement of 15, cutting of 13

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16) Using the figure above the radiometric ages for the igneous rocks are: Unit 14 =

200 m.y., Unit 15 110 m.y., unit 10 = 75 m.y. How much time is missing between the deposition of unit 9 and unit 10?

(a) 200 m.y. (b) 90 m.y. (c) 45 m.y. (d) 35 m.y. (e) 125 m.y.

17) Using the figure above what geologic principle is applied to determine that unit 15

is younger than unit 14? (a) principle of inclusions (b) principle of baked contacts (c) principle of original horizontality (d) principle of cross-cutting relations (e) principle of geologic origins

1 2 3

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5

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7 8 9

10

11

12

13

14

15

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Use the figure above for the next four questions. 18) The Nazca plate is moving 10.9 cm/yr to the east whereas the South American

plate is also moving to the east at 6.4 cm/yr. What is the rate of convergence of the plates?

(a) 4.5 cm/yr (b) 6.4 cm/yr (c) 0 cm/yr (d) 3 cm/yr (e) 17.3 cm/yr

19) What type of geologic activity would you expect at this type of plate boundary?

(a) large oceanic trench (b) earthquake activity (c) mountain building (d) volcanoes (e) all of the above

20) The Pacific plate and the North American plate form what type of boundary along

the west coast of the US? (a) convergent (b) divergent (c) transform (d) subduction (e) passive

A

B C D

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21) Which letter (A-D) on the map on the previous page indicates an oceanic hot-spot locality?

(a) A (b) B (c) C (d) D

22) Which letter (A-D) on the map (on the previous page) indicates a spreading center

locality? (a) A (b) B (c) C (d) D

23) Igneous rocks are ___________.

(a) are formed through the freezing of melt (b) can be produced at the surface of the Earth as well as deep below the surface (c) are the most common type of rocks within the Earth (d) All of the above are correct

24) The majority of the rocks that occur at the surface of the Earth are _____.

(a) intrusive igneous rocks (b) extrusive igneous rocks (c) sedimentary rocks (d) metamorphic rocks

25) Approximately what percentage of the Earth's surface is covered with water?

(a) 30% (b) 50% (c) 70% (d) 85% (e) 100%