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Geol 101: Physical Geology
Fall 2007
EXAM 3
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.
2.
3.
Stress is the same as:
A. force
B. pressure
C. strain
D. force divided by area
E. pressure divided by volume
If a rock deforms under the influence of a stress, but then returns to its
original shape when the stress is removed, then the deformation behavior is
described as:
A. brittle
B. plastic
C. elastic
D. ductile
E. magical
If a rock deforms by flowing or bending, the deformation is said to be:
A. elastic
B. plastic
C. ductile
D. either A or B above
E. either B or C above
4. For rocks that are being deformed inside the crust, as the temperature
increases:
A. the rocks get more brittle
B. the rocks get less brittle
C. the rocks get less ductile
D. the strain rate increases
E. the pressure must start to decrease
5.
The tensional stress that formed a joint:
A. was oriented parallel to the orientation of the joint
B. was oriented perpendicular to the orientation of the joint
C. was oriented obliquely to the orientation of the joint
D. cannot be determined from the joint orientation
E. was produced by the cooling of basalt lava
6. If a fault is dipping at any angle, the block of rock above the fault is the
(1) _________ and the block of rock below the fault is the (2) __________.
A. (1) footwall
(2) hanging wall
B. (1) footwall
(2) fault scarp
C. (1) fault plane
(2) footwall
D. (1) hanging wall
(2) fault plane
E. (1) hanging wall
(2) footwall
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7. When a fault slips, the (1) ________ moves up and the (2) ________ moves
down:
A. (1) hanging wall
(2) footwall
B. (1) footwall
(2) hanging wall
C. (1) fault block
(2) fault plane
D. (1) fault scarp
(2) fault plane
E. the answer depends on the type of fault
8. The type of fault that forms in a region where the crust is undergoing
compression is a:
A. thrust fault
B. reverse fault
C. normal fault
D. both A and B above
E. all of the above
9.
Along the San Andreas fault, the west side is moving towards the north and
the east side is moving relatively towards the south. This makes the San
Andreas fault:
A. a normal fault
B. a right-lateral fault
C. a left-lateral fault
D. a reverse fault
E. either a left or right-lateral fault (depending on what side of
the fault you are standing on)
10. Rocks that warp upwards in the center of a fold produce a type of fold
called a/an (1) _______ whereas rocks that warp downwards 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
11.
Geologic evidence suggests that a magnitude 9.0 earthquake hit the
continental United States in the year 1700, producing a tsunami that
ultimately hit Japan. Where did this earthquake occur?
A. along the San Andreas fault of California
B. southern Alaska
C. in the New Madrid region of Missouri
D. offshore from Charleston, South Carolina
E. in the Pacific Northwest
12.
The Great San Francisco earthquake in 1906 was the most devastating
earthquake in the history of the United States, killing about 3,000 people.
This magnitude 7.8 earthquake happened because of motion along the:
A. Cascadia subduction zone
B. Aleutians subduction zone
C. San Andreas fault
D. Borah Peak fault
E. Basin and Range faults
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13.
Seismic waves are recorded by an instrument called a (1) _________ and the
record of the earthquake that the instrument generates is called a (2)
_________.
A. (1) seismograph
(2) seismometer
B. (1) seismograph
(2) seismogram
C. (1) seismometer
(2) seismograph
D. (1) seismogram
(2) seismograph
E. (1) seismogram
(2) seismometer
14.
The epicenter of an earthquake is:
A. the location along a fault where the earthquake rupture starts
B. the point from which body waves radiate into the surrounding
rocks
C. the point on the Earth's surface directly above the earthquake
focus
D. exactly the same as the focus of an earthquake
E. sometimes at the Earth's surface, but not always
15.
The first two seismic waves to arrive after an earthquake are:
A. the S-wave then the P-wave
B. the P-wave then the S-wave
C. the Love wave then the Rayleigh wave
D. the Rayleigh wave then the Love wave
E. dependent on the distance to the earthquake
16. Three seismograph stations are needed to find the epicenter of an
earthquake because:
A. the more, the better
B. at least one of the stations could have made a mistake
C. some instruments cannot measure the P-S time interval
D. more than three stations takes too long to process the
seismogram data
E. three distance measurements are needed to define a point on a
map
17.
Which of the following is NOT a type of measurement scale for earthquakes?
A. moment magnitude scale
B. Modified Mercalli intensity scale
C. Richter scale
D. Saffir-Simpson scale
E. all of the above are used for measuring earthquakes
18.
The intensity of an earthquake:
A. is variable depending on the distance to the epicenter
B. doesn’t change for an earthquake, no matter how far away it was
C. is measured using the moment magnitude scale
D. will be the same for all earthquakes having an identical
magnitude
E. none of the above
19. Which of the following is an accurate description of liquefaction due to an
earthquake?
A. when ground shaking causes water-saturated sediment to act like
quicksand
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B. when a shift of the ocean bottom produces a giant wave at the
surface
C. when earthquakes cause waterlogged mountain slopes to produce
landslides
D. when seismic waves get amplified in loose sediments, causing
more shaking
E. when an earthquake causes bodies of water to slosh back and forth
20.
Which of the following is an accurate definition of the term tsunami?
A. it is a type of earthquake that occurs under the ocean
B. it is a type of seismic wave that causes a lot of damage to tall
buildings
C. it is a water wave generated in the ocean as a result of an
earthquake
D. it is a type of landslide triggered in a mountainous region
during an earthquake
E. it is an ancient Japanese method of studying earthquakes
21. The average density of the Earth is 5.5 g/cm3 whereas the average
density of surface rocks is 2.5-3.0 g/cm3. This information alone can
only tell us that:
A. the Earth is comprised of many layers with different densities
B. the deep interior of the Earth must have a density greater than
5.5 g/cm3
C. the deep interior of the Earth must have a density less than 5.5
g/cm3
D. the deep interior of the Earth must have a density less than 2.5
g/cm3
E. measurements of surface rock densities must be inaccurate
22.
23.
The process whereby seismic wave motion directions change as they pass
across a boundary from one rock layer into a rock layer with a different
density is:
A. wave reflection
B. wave refraction
C. wave rays
D. wave interference
E. wave shadowing
Considering that (1) _________ are unable to pass through liquids, we know
that the (2) __________ must be a liquid because seismic wave shadow zones
are observed after a major earthquake occurs.
A. (1) P-waves
(2) outer core
B. (1) P-waves
(2) inner core
C. (1) S-waves
(2) outer core
D. (1) S-waves
(2) inner core
E. (1) S-waves
(2) asthenosphere
24. The boundary between the crust and the mantle is called the:
A. Mojo
B. Jomo
C. Ohno
D. Moho
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E.
SloMo
25.
The Earth has a magnetic field because:
A. the liquid part of the core creates an electric current which
induces a magnetic field
B. magnetic minerals are common at temperatures above the Curie
point
C. it has a magnetic iron-nickel core
D. all planets have magnetic fields when they form
E. the Earth is a giant domino
26.
The edge of the continental shelf:
A. is somewhere beneath the continental slope
B. is the true edge of the continents
C. is always about the same distance away from the coastline
D. is marked by an almost vertical drop-off into the deep ocean basin
E. is consistently at a water depth of about 135 meters
27. The east coast of North America is a/an (1) __________ continental margin
because (2) ___________.
A. (1) active
(2) it is right along a tectonic plate boundary
B. (1) active
(2) it is far from a tectonic plate boundary
C. (1) passive
(2) it is right along a tectonic plate
boundary
D. (1) passive
(2) it is far from a tectonic plate boundary
E. (1) passive
(2) it is characterized by earthquakes and
volcanoes
28. Which of the following portion of the ocean floor is the flattest?
A. ocean trenches
B. ocean ridges
C. continental slope
D. abyssal plains
E. continental rise
29.
30.
31.
Which of the following is a portion of the world’s longest mountain range?
A. Marianas trench
B. Himalayas
C. Caledonides
D. Cascades
E. mid-Atlantic ridge
The tectonic plate that used to exist off the west coast of North America
but which has long since been subducted, was the:
A. Juan da Fuca plate
B. Farallon plate
C. California plate
D. Pacific plate
E. Exotic plate
What is meant by the term orogenesis?
A. it is a type of metamorphism
B.
it is the process by which subducting plates melt
C. it is the development of a new rift valley
D. it is the creation of mountain ranges
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E.
32.
Island arc
A.
B.
C.
D.
E.
it is a type of folding
volcanoes form:
whenever subduction occurs
when a continent subducts underneath another continent
at ocean-ocean plate boundaries
along the Cascadia subduction zone
somewhere beneath the continental slope
33. Backarc. Volcanic arc. Forearc. What’s missing from this list for an oceancontinent subduction zone?
A. island arc
B. deep arc
C. subduction arc
D. Noah’s arc
E. trench
34.
The pile of crumpled sea floor sediments that build up where an ocean plate
starts to subduct is called a/an:
A. forearc basin
B. island arc
C. batholith
D. turbidity flow
E. accretionary wedge
35. When a microcontinent collides with a larger continent, it gets added to the
edge of the continent and is then referred to as a/an:
A. accreted continent
B. terrane
C. island arc
D. accretionary wedge
E. mountain range
36.
What is meant by saltation?
A. where evaporation of water causes salt crystals to grow
B. it is a type of erosion caused by rivers
C. when particles of sediment are suspended in flowing water
D. where sediment particles bounce along the ground due to wind or water
currents
E. it is a type of erosion caused by wind-blown sediment
37. Which of these controls on mass wasting reduces the cohesion of slope
material?
A. a decrease in the steepness of the slope
B. an increase in the amount of water in the regolith
C. an increase in the amount of vegetation cover
D. an increase in the shear strength of the regolith particles
E. all of the above
38. The steepest slope that can be produced by a pile of unconsolidated
sediment is called the:
A. angle of criticality
B. angle of concern
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C.
D.
E.
angle of repose
angle of mass wasting
angle of cohesion
39. The type of landslide that involves slow sliding of sediment above a
concave slip surface is called:
A. a slump
B. a rock slide
C. a mudflow
D. a debris avalanche
E. creep
40.
41.
All air-saturated sediment flows are called (1)________ whereas all watersaturated sediment flows are called (2)_________:
A. (1) granular flows
(2) slurry flows
B. (1) granular flows
(2) mudflows
C. (1) debris flows
(2) slurry flows
D. (1) slurry flows
(2) viscous flows
E. (1) slurry flows
(2) granular flows
About 99% of all liquid fresh water on Earth is stored:
A. in the oceans
B. in swamps
C. in the ice caps
D. underground
E. in rivers
42. The amount of water that flows down a river channel over some length of
time is called the:
A. discharge
B. stream load
C. channel gradient
D. flow velocity
E. capacity
43.
All sediment deposited by rivers is called:
A. regolith
B. a point bar deposit
C. bed load
D. alluvium
E. a floodplain deposit
44. Point bars grow in size through (1)___________ whereas floodplains build up
by (2)____________.
A. (1) cut bank development
(2) floods
B. (1) meandering
(2) lateral accretion
C. (1) lateral accretion
(2) vertical accretion
D. (1) erosion on the inside of a meander
(2) natural levee
growth
E. (1) vertical accretion
(2) alluvium deposition
45.
Deltas get their name from the Greek letter, . What is the only type of
delta that really has this triangular shape when viewed from above?
A. stream-dominated delta
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B. wave-dominated delta
C. bird’s foot delta
D. tide-dominated delta
E. all deltas have a triangular shape – that’s why they’re called
deltas
46.
A continental divide is:
A. a mountain chain separating rivers that flow into different
oceans
B. a mountain chain separating drainage basins emptying into the
same ocean
C. a high standing area inside a drainage basin
D. a boundary between two different patterns of river drainage
E. a mountain range at a divergent plate boundary
47. The type of river drainage that resembles the shape of veins in a leaf is
called:
A. trellis
B. dendritic
C. rectangular
D. radial
E. deranged
48.
Which of the following statements about ultimate base level is FALSE?
A. rivers cannot erode deeper than ultimate base level
B. ultimate base level is always sea level
C. ultimate base level can change through time
D. a lake is a type of ultimate base level
E. all of the above statements are false
49. Rivers try
call a/an:
A.
B.
C.
D.
E.
50.
to maintain a smooth, concave, longitudinal profile, which we
local base level
ultimate base level
evolved stream
graded stream
half-pipe
Stream piracy is a direct result of:
A. incised meandering
B. downcutting
C. lateral erosion
D. headward erosion
E. drunken bandits on river barges
BONUS QUESTIONS
51.
The average amount of motion along the San Andreas fault is:
A. 1 cm per year
B. 3 cm per year
C. 10 cm per year
D. 1 m per year
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E.
52.
3 m per year
The largest earthquake in historic times had a magnitude of 9.5 and
occurred off the coast of this country:
A. Peru
B. Chile
C. Mexico
D. United States of America
E. Indonesia
53.
Why are a few errant P-waves sometimes recorded in the P-wave shadow zone?
A. as a result of P-wave reflections off the inner core
B. they move along the surface into the P-wave shadow zone
C. because S-waves get refracted through the outer core
D. because the location of the P-wave shadow zone moves around
E. they aren’t (the statement is false)
54.
Which of the following is not considered to be a component of oceanic crust?
A. pillow basalt
B. sheeted dike complex
C. peridotite
D. gabbro
E. deep sea sediments
55.
Where would you expect to find a distributary?
A. on an alluvial fan
B. in a meandering channel
C. along a braided river system
D. in a slurry flow
E. on a delta
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