Geol 101: Physical Geology
Fall 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.
The largest
A.
B.
C.
D.
E.
type of pluton is a:
batholith
dike
sill
laccolith
volcanic pipe
2.
The type of
A.
B.
C.
D.
E.
volcanic hazard that involves a mudflow made of ash is called a:
lahar
tsunami
pyroclastic flow
debris avalanche
lava bomb
3.
The type of
of Pompeii
A.
B.
C.
D.
E.
volcanic hazard that resulted in the deaths of the inhabitants
in 79 AD was a:
lahar
gas cloud
pyroclastic flow
debris avalanche
lava flow
4.
A 16 million-year-old analog to the 251-million-year-old Siberian Traps is
the:
A. eruption of Mount St. Helens
B. Columbia River Flood Basalts
C. Idaho batholith
D. Sierra Nevada batholith (Yosemite)
E. eruption of Mount Mazama
5.
The largest volcano on Earth is also the tallest mountain on Earth (measured
from base to top). The volcano is called (1) ___________ and it is a type of
(2) ___________.
A. (1) Mauna Loa
(2) stratovolcano
B. (1) Mauna Loa (2) shield volcano
C. (1) Kilauea
(2) stratovolcano
D. (1) Kilauea
(2) shield volcano
E. (1) Mauna Loa
(2) composite volcano
6.
When Mount St. Helens (1980) and Mt. Pinatubo (1991) erupted, they both
produced a high, vertical plume of ejected pyroclastic material called a:
A. lateral blast
B. pyroclastic flow
C. tephra cloud
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D.
E.
lapilli eruption
Plinian column
7.
Volcanoes with steep slopes that form from the accumulation of viscous lava
and pyroclastic flows are:
A. shield volcanoes
B. stratovolcanoes
C. composite volcanoes
D. either A or B above
E. either B or C above
8.
If a volcano erupts explosively and then collapses into the void left by
the emptying of the magma chamber below the mountain, it produces a wide and
deep circular hole called a:
A. crater
B. cinder cone
C. lava dome
D. caldera
E. maar crater
9.
The most active volcano in the Cascades is (1) __________ but the largest
known eruption that occurred here in pre-historic times was the eruption of
(2) __________.
A. (1) Crater Lake
(2) Mt. St. Helens
B. (1) Mt. St. Helens (2) Lassen Peak
C. (1) Mt. St. Helens
(2) Mt. Mazama
D. (1) Mt. Mazama
(2) Mt. Tehama
E. (1) Mt. Shasta
(2) Mt. St. Helens
10.
The cities of Seattle and Tacoma are at risk from lahars that could be
produced during an eruption of:
A. Mount St. Helens
B. Mount Rainier
C. Mount Hood
D. Mount Shasta
E. Lassen Peak
11.
Which Cascades volcano is actually the world’s largest lava dome that sits
inside the caldera of the ancient volcano called Mount Tehama?
A. Crater Lake
B. Mount Shasta
C. Lassen Peak
D. Mount Hood
E. Mount St. Helens
12.
Which of the following definitions most accurately pertains to weathering?
A. the physical or chemical breakdown of rock exposed to air,
water, and organic matter
B. the downslope movement of loose material under the influence of
gravity
C. the sole process by which regolith becomes soil
D. the movement of sediment by surface processes involving wind,
water, and ice
E. none of these statements defines weathering
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13.
Which of the following forms of weathering does NOT involve a mechanical
weathering process?
A. oxidation
B. frost wedging
C. thermal effects
D. unloading
E. biological activity
14.
Which of the following combinations of weathering process and resultant
effect is the correct combination?
A. frost wedging and spalling
B. oxidation and exfoliation
C. thermal effects and acid mine drainage
D. crystal growth and spalling
E. unloading and exfoliation
15.
Minerals like halite and calcite are particularly prone to chemical
weathering through the process of dissolution. As a result, the following
type of rock is prone to this type of weathering:
A. limestone
B. rock salt
C. marble
D. all of the above
E. none of the above
16. What mineral commonly breaks down into clay when it is chemically
weathered?
A. quartz
B. muscovite
C. feldspar
D. olivine
E. calcite
17.
18.
19.
The correct order of soil horizons from the top down is:
A.
O E A C B
B.
O A E B C
C.
O C B A E
D.
A O E C B
E.
A B C D E
Sedimentary rocks are the most common type of rock at the Earth’s surface,
but they actually only comprise about _______ of the Earth’s crust
altogether.
A. 5%
B. 10%
C. 25%
D. 50%
E. 75%
In sedimentary rock types, the term clastic means the same thing as:
A. chemical
B. biochemical
C. biogenic
D. detrital
E. lithic
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20.
Match the sedimentary rock type shale with the corresponding grain size
below:
A. clay
B. silt
C. sand
D. pebble
E. boulder
21. Match the sedimentary rock type arkose with the corresponding grain size
below:
A. clay
B. silt
C. sand
D. pebble
E. boulder
22. Match the sedimentary rock type conglomerate with the corresponding grain
size below:
A. clay
B. silt
C. sand
D. pebble
E. none of the above
23. Sediment particles in quartz sandstone that formed in a desert are
typically:
A. poorly sorted and angular
B. poorly sorted and well rounded
C. well sorted and angular
D. well sorted and well rounded
E. made of feldspar
24.
The two possible forms of sediment production that allow limestone to form
are:
A. biochemical and biogenic
B. biogenic and detrital
C. bioclastic and detrital
D. detrital and chemical
E. biogenic and clastic
25.
Which of the following correctly describes the process that occurs during
lithification?
A. partial melting
B. diagenesis
C. metamorphism
D. migmatite development
E. metasomatism
26.
The type of sedimentary structure that describes a layer of sediment in
which the grain size steadily decreases from the bottom to the top of the
layer is called:
A. bedding
B. cross-bedding
4
C.
D.
E.
27.
28.
graded bedding
stratification
a bedding plane
The correct combination of ripple shape and potential environment in which
the ripple developed is:
A. symmetric / single direction wind flow
B. symmetric / river channels
C. asymmetric / ocean waves
D. asymmetric / tidal flats
E. asymmetric / river channels
An example
A.
B.
C.
D.
E.
of a trace fossil:
leaf imprint
fossilized shells
fossilized bones
dinosaur footprint
fossilized seeds
29.
The zone of metamorphism is above the zone of (1)________ but below the
zone of (2)_________.
A. (1) diagenesis
(2) partial melting
B. (1) magma
(2) migmatites
C. (1) 150°C
(2) 800°C
D. (1) partial melting
(2) diagenesis
E. (1) molten magma
(2) partial melting
30.
Which of the following statements regarding lithostatic pressure is
correct?
A. it is caused by the weight of the overlying rocks
B. it is equal in magnitude from all directions
C. it causes rocks to decrease in volume but it does not change the
rock shape
D. all of the above
E. none of the above
31.
Which of the following statements about metamorphism is FALSE?
A. metamorphic rocks form from existing sedimentary, igneous, or
metamorphic rocks
B. metamorphism involves melting of existing rocks to form new
minerals
C. during metamorphism, existing minerals are transformed into new
minerals
D. metamorphism is controlled by pressure, temperature, fluids, and
time
E. metamorphic means “change of form”
32.
Which of the following metamorphic terms does not belong with the others?
A. foliation
B. schistosity
C. gneissic texture
D. hornfels
E. slaty cleavage
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33.
In the lists of metamorphic rocks below, which one shows rocks in the
correct order from lowest to highest metamorphic grade for an initially clayrich rock?
A. slate - phyllite - schist - gneiss
B. slate - schist - phyllite - gneiss
C. schist - phyllite - slate - gneiss
D. gneiss - slate - phyllite - schist
E. gneiss - schist - phyllite - slate
34.
Metamorphism of limestone produces:
A. granulite
B.
hornfels
C. quartzite
D. slate
E. marble
35.
What type of metamorphism results in the development of an aureole?
A. dynamic
B. shock
C. regional
D. contact
E. burial
36.
Which type
A.
B.
C.
D.
E.
of metamorphism is associated with the process of metasomatism?
thermal
hydrothermal
regional
burial
dynamic
37.
Which type of metamorphism would NOT be expected to produce predominantly
mechanical deformation?
A. regional
B. impact
C. burial
D. dynamic
E. all of the above are dominated by mechanical deformation
38.
What is meant by the term chronological sequence?
A. it is one of the principles of stratigraphy used to determine
relative ages
B. it refers to the absolute ages of rocks
C. it is the geologic time scale that we use to characterize the
ages of all rocks
D. it is the amount of time that a radioactive substance takes to
decay
E. it is the order that things happened in geologic history
39.
In stratigraphy, the principle of stratigraphic superposition states that:
A. all sedimentary beds start off being horizontal
B. all sedimentary beds are separated by bedding planes
C. a sedimentary bed is younger than the bed above it and older
than the bed below it
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D. a sedimentary bed is older than the bed above it and younger
than the bed below it
E. a sedimentary bed must be older than any feature that cuts
through it or disrupts it
40. The type of unconformity across which the beds have different inclinations
is called a/an:
A. disconformity
B. angular unconformity
C. nonconformity
D. conformity
E. intrusive contact
41.
42.
If magma intrudes into existing rocks in the crust, the boundary between
these so-called country rocks and the igneous rock that forms from the magma
is called a/an:
A. disconformity
B. angular unconformity
C. nonconformity
D. unconformity
E. intrusive contact
Some rocks contain fossils of species that only lived for a relatively
short time in Earth history. These are called:
A. index fossils
B. fossil assemblages
C. fossil successions
D. trace fossils
E. Vanilla Ice fossils
43. The time divisions in the Geologic Column that represent the longest
lengths of time are called:
A. eras
B. epochs
C. eons
D. periods
E. years
44.
The Holocene is an example of a/an:
A. era
B. epoch
C. eon
D. period
E. absolute age
45. Which of the following statements is true of alpha decay when referring to
radioactivity?
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
7
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
46.
The correct definition of half-life when referring to an unstable isotope
is as follows:
A. the amount of time needed to completely decay all parent
isotopes into daughter isotopes
B. half the amount of time needed to completely decay all parent
isotopes into daughter isotopes
C. the amount of time needed to completely decay all daughter
isotopes into parent isotopes
D. the amount of time needed to decay half of the daughter isotopes
into parent isotopes
E. the amount of time needed to decay half of the parent isotopes
into daughter isotopes
47.
Stress is the same as:
A. force
B. pressure
C. strain
D. force divided by area
E. pressure divided by volume
48.
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
49.
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
50.
For rocks that
increases:
A. the
B. the
C. the
D. the
E. the
are being deformed inside the crust, as the temperature
rocks get more brittle
rocks get less brittle
rocks get less ductile
strain rate increases
pressure must start to decrease
BONUS QUESTIONS
51.
What volcanic hazard was responsible for the deaths of 1700 people at Lake
Nyos, Cameroon, in 1986?
8
A.
B.
C.
D.
E.
pyroclastic flow
lava flow
lava bombs
gas cloud
ash fall
52.
Which of the following sedimentary structures is common in sand dunes?
A. cross-bedding
B. trace fossils
C. graded bedding
D. mudcracks
E. all of the above
53.
Which of the following is NOT a marine depositional environment?
A. alluvial fan
B. delta
C. continental shelf
D. continental slope
E. beach
54. Cambrian, Ordovician, Silurian, Devonian, Carboniferous (Camels Only Sit
Down Carefully). What comes next?
A. Triassic then Permian
B. Tertiary then Quaternary
C. Cretaceous then Tertiary
D. Permian then Triassic
E. Jurassic then Cretaceous
55.
A sedimentary bed contains three fossils: A, B, and C. Fossil A formed from
an animal that only existed in the Cambrian and Ordovician Periods. Fossil B
only existed in the Ordovician Period. Fossil C existed for a very long time
on Earth- from the Cambrian to the Triassic Period. Based on this fossil
assemblage, the age of the rock is:
A. Cambrian
B. Ordovician
C. Silurian
D. sometime between the Cambrian and the Triassic is all that we
can tell
E. impossible to determine
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