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Geol 101: Physical Geology
Summer 2006
EXAM 2
Write your name out in full on the scantron form and fill in the corresponding ovals to spell out your name. Also
fill in your student ID number in the space provided. Do not include the dash and do not leave any spaces. Make
sure you have all 8 pages of the exam. There are 55 questions. For each question, select the correct answer and fill
in your choice on the scantron form. You MUST use pencil on the scantron form!
1. Changes in mineral assemblage and texture that result from subjecting a rock to high pressures and
temperatures is called:
A. diagenesis
B. metamorphism
C. none of the above
2. High temperature-low pressure favors__________ metamorphism.
A. contact
B. blueschist facies
C. amphibolite-granulite facies
D. none of the above
3. Blueschist facies high pressure-low temperature metamorphism occurs:
A. at divergent margins
B. in the crust near faults
C. deep in subduction zones
4. The upper temperature-pressure limit of metamorphism is controlled by:
A. the melting point of the rock
B. the amount of water present in the rock
C. both of the above
D. none of the above
5. As depth increases, the pressure on rock increases and the melting point temperature of rocks generally:
A. decreases.
B. increases
C. stays the same
6. The increasing temperature with depth in the Earth is called the:
A. geothermal gradient
B. thermalcline
C. thermeometric inclination
D. none of the above
7. Slaty cleavage generally forms on planes that:
A. follow the original bedding planes
B. follow planes perpendicular to the maximum stress direction
C. follow planes parallel to the maximum stress direction
8. In schist and gneiss, the lighter colored bands consist of:
A. quartz and feldspars
B. sheet silicates
C. calcite
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9 Marble is a metamorphic rock consisting of large crystals of:
A. calcite
B. quartz
C. feldspar
D. gypsum
10. What is meant by the term chronological sequence?
A. it refers to the absolute ages of rocks
B. it is one of the principles of stratigraphy used to determine relative ages
C. it is the geologic time scale that we use to characterize the ages of all rocks
D. it is the order that things happened in geologic history
E. it is the amount of time that a radioactive substance takes to decay
11. The principle of stratigraphic superposition states that:
A. all sedimentary beds start off being horizontal
B. all sedimentary beds are eventually deformed and tilted by tectonic forces
C. any sedimentary bed is older than the bed above it and younger than the bed below it
D. any sedimentary bed is younger than the bed above it and older than the bed below it
E. any sedimentary bed must be older than any feature that cuts through it or disrupts it
12. When magma of a batholith cools against the surrounding rocks to form an igneous rock, the boundary
between the igneous rock and the surrounding rocks is called a/an:
A. disconformity
B. angular unconformity
C. nonconformity
D. unconformity
E. intrusive contact
13. Which of the following provides the most accurate way of determining the age of a sedimentary rock layer?
A. relative age sequence
B. fossil succession
C. index fossil
D. fossil assemblage
E. fossilized algae
14. Which of the following geologic time divisions is a shorter duration of time than all the others?
A. epochs
B. eras
C. periods
D. eons
E. half-life
15. Which of the following periods is older than all the others?
A. Ordovician
B. Tertiary
C. Jurassic
D. Silurian
E. Quaternary
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16. The ancestors of modern humans first appear in the geologic record about 2.5 million years ago during the:
A. Paleocene
B. Miocene
C. Holocene
D. Pliocene
E. Eocene
17. Which of the following statements is true of electron capture?
A. an atom releases a pair of protons and a pair of neutrons from the nucleus
B. an atom releases a proton and a neutron from the nucleus
C. an atom releases an electron from the nucleus causing a neutron to turn into a proton
D. an atom absorbs an electron into the nucleus causing the atomic number to decrease by
1
E. an atom remains unchanged but gives off gamma rays and generates a lot of heat
18. An isotope that undergoes decay starts off as a/an (1) _____ and always becomes a (2) _____:
A. (1) unstable isotope (2) stable isotope
B. (1) daughter
(2) son
C. (1) daughter
(2) parent
D. (1) parent
(2) daughter
E. (1) parent
(2) mutant
19. If the half-life of a radioactive isotope is 10 million years, and a crystal forms containing 200 of these isotopes,
how old is the crystal at the point when only 25 of the original radioactive isotopes are left in the crystal?
A. 10 million years old
B. 20 million years old
C. 30 million years old
D. 40 million years old
E. 50 million years old
20. Stress is exactly the same as:
A. force
B. pressure
C. strain
D. force divided by area
E. pressure divided by volume
21. Which of the following types of deformation is equivalent to plastic deformation?
A. brittle
B. ductile
C. elastic
D. earthquakes
E. fracturing
22. The part of the Earth that is most prone to brittle deformation is the:
A. crust
B. mantle
C. outer core
D. inner core
E. all parts are prone to brittle deformation
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23. The speed that deformation occurs inside rocks due to plate tectonics is:
A. without exception, extremely slow
B. about 3 cm per year
C. called the strain rate
D. fast enough to observe on a day-to-day basis
E. very rapid for the case of ductile deformation
24. For any fault that has a dip between >0° and <90°, the rocks above the fault form the (1) _________ and the
rocks below the fault form the (2) __________.
A. (1) hanging wall (2) footwall
B. (1) footwall (2) fault scarp
C. (1) fault plane (2) footwall
E. (1) footwall (2) hanging wall
E. (1) hanging wall (2) fault plane
25. The type of fault that forms in a region of the crust undergoing lateral sliding is a/an:
A. reverse fault
B. normal fault
C. oblique-slip fault
D. strike-slip fault
E. thrust fault
26. The type of fault that is sometimes referred to as a thrust fault is a/an:
A. reverse fault
B. normal fault
C. oblique-slip fault
D. left-lateral fault
E. right-lateral fault
27. The San Andreas fault that is an example of a/an:
A. reverse fault
B. normal fault
C. oblique-slip fault
D. left-lateral fault
E. right-lateral fault
28. Rocks that warp downwards in the center of a fold produce a type of fold called a/an (1) _______ whereas rocks
that warp upwards in the center produce a/an (2) ________.
A. (1) anticline
(2) monocline
B. (1) anticline
(2) syncline
C. (1) syncline
(2) anticline
D. (1) syncline
(2) monocline
E. (1) anti-plunging fold (2) plunging fold
29. In December 2004, a M9.0 earthquake generated a tsunami that ultimately killed about 283,000 people around
the rim of the Indian Ocean. The earthquake itself occurred in this country:
A. India
B. Thailand
C. Sri Lanka
D. Indonesia
E. Sumatra
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30. The process of creep along faults is when:
A. faults have low amounts of friction along them so they slide all the time
B. faults produce one long continuous earthquake
C. slow-slipping faults start to slip faster and faster until an earthquake occurs
D. faults slip in response to elastic rebound
E. there is not enough tectonic stress available to produce an earthquake
31. Which of these locations in the continental USA experienced the largest magnitude earthquake in historic times
(a M8.1)?
A. Charleston, South Carolina (in 1886)
B. Borah Peak, Idaho (in 1983)
C. San Francisco, California (in 1906)
D. Northridge, California (in 1994)
E. New Madrid, Missouri (in 1812)
32. What is the picture to the right showing?
A. a seismometer
B. a seismogram
C. a seismograph
D. a surface wave
E. two separate earthquakes
A
33. In the picture on the right, what is represented by the
quantity labeled as “A”?
A. the wave amplitude
B. earthquake magnitude
C. earthquake intensity
D. the seismic wave speed
E. the P-S time interval
34. Which of the following types of seismic waves does NOT emanate from the focus of the earthquake?
A. body waves
B. P-waves
C. secondary waves
D. surface waves
E. primary waves
35. P-waves are able to move through:
A. solids only
B. solids and liquids only
C. solids and gas only
D. solids, liquids and gas
E. consolidated rocks (but not loose sediment)
36. How many seismograph stations are required to determine the location of an earthquake epicenter?
A. 1
B. 2
C. 3
D. 4
E. 5
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37. Which of the following statements is TRUE?
A. an earthquake has only one magnitude but the intensity can vary
B. an earthquake has only one intensity but the magnitude can vary
C. the magnitude of an earthquake decreases with increasing distance from the epicenter
D. the intensity of an earthquake is the least at the epicenter
E. earthquake magnitude is measured using the Modified Mercalli scale
38. The most energy ever released during a single earthquake occurred in 1960 in this location:
A. Alaska
B. Chile
C. New Madrid
D. California
E. Pacific Northwest
39. As seismic waves pass from a rock layer of a certain density to an adjacent rock layer with a different density, the
following is true:
A. the waves vanish at the interface between the two rock layers
B. the waves pass across the boundary unchanged
C. some of the wave rays get reflected
D. some of the wave rays get refracted
E. both C and D above
40. When seismic waves from an earthquake reach the boundary between the mantle and the outer core:
A. all of the body waves get refracted
B. all of the body waves get reflected, but none are refracted
C. all P-waves vanish
D. all S-waves vanish
E. all P-waves speed up
41. As a result of the properties of the outer core (as alluded to in the previous question):
A. we know that the outer core must be a liquid
B. an S-wave shadow zone is created beyond 105° of arc away from an earthquake focus
C. a P-wave shadow zone is created from 105-140° of arc away from an earthquake focus
D. seismographs in the P-wave shadow zone do not record the earthquake
E. all of the above
42. The Earth has a magnetic field because:
A. magnetic minerals are common at temperatures above the Curie point
B. it has a magnetic iron-nickel core
C. the liquid outer core creates an electric current which induces a magnetic field
D. all planets have magnetic fields when they form
E. the giant domino effect causes it
43. The boundary between continental and oceanic crust at continental margins occurs:
A. right along the coastline
B. below the continental shelf
C. below the continental slope
D. below the continental rise
E. below the ocean trench
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44. The deepest part of all the world’s oceans is:
A. the mid-Atlantic ridge
B. the East Pacific Rise
C. off the west coast of North America
D. the abyssal plains
E. the Marianas trench
45. Mid-ocean ridge mountain ranges are commonly associated with this type of faulting:
A. normal faults
B. transform faults
C. thrust faults
D. both A and B above
E. both B and C above
46. The oceanic tectonic plate that used to exist off the entire west coast of North America but which has long since
been almost completely subducted, was the:
A. Juan da Fuca plate
B. Farallon plate
C. Cocos plate
D. Pacific plate
E. Nazca plate
47. The collective term used to describe any and all processes responsible for mountain building is:
A. orogenesis
B. collision
C. subduction
D. isostacy
E. erogeny
48. Which of the following shows the components of a subduction zone in the correct order of occurrence?
A. trench - forearc - volcanic arc - backarc
B. trench - backarc - volcanic arc - forearc
C. trench - forearc - island arc - accretionary wedge
D. accretionary wedge - forearc - trench - backarc
E. accretionary wedge - trench - volcanic arc - backarc
49. Which of the following does NOT have an association with the Himalayas Mountains?
A. suture zone
B. 90 km thick continental crust
C. continent-continent collision
D. fault-block mountains
E. escape tectonics
50. When microcontinents are (1) __________ onto the edge of an existing continent, the continent gets wider as
result of the addition of this new (2) ____________.
A. (1) orogenied
(2) island arc
B. (1) accreted
(2) terrane
C. (1) sutured
(2) mountain belt
D. (1) attached
(2) oceanic plateau
E. (1) subducted
(2) crustal fragment
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BONUS QUESTIONS
51. On January 26th, 1700, this region was hit by a massive M9.0 earthquake that caused a tsunami:
A. Alaska
B. Japan
C. Sumatra
D. Pacific Northwest
E. New Madrid, Missouri
52. In 1970, a M7.9 earthquake in Peru resulted in 25,000 deaths in response to this seismic hazard:
A. ground shaking
B. a landslide
C. liquefaction
D. fire
E. a tsunami
53. The boundary between the crust and the mantle is called the:
A. Mojo
B. Jomo
C. Ohno
D. Moho
E. SloMo
54. Before being a part of Pangea, North America and Africa were both a part of:
A. Romania
B. Rodinia
C. Ridona
D. Ramada
E. Rwanda
55. On the map below, the location of the Caledonides Mountains is given by:
A. “A”
B. “B”
C. “C”
D. “D”
E. “E”
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