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Geol 101: Physical Geology
Summer 2006
EXAM 1
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.
Which of the following is NOT one of the lines of evidence that was
initially used to develop the theory of plate tectonics?
A. the shapes of the continents seem to fit so well together
B. there are similar fossils of plants and animals on different
continents
C. paleomagnetic poles do not match up unless the continents used
to be together
D. the geology matches up from one continent to another
E. old ocean crust was forced up onto the continents as they moved
across the ocean basins
2.
Evidence that North America used to be connected to Eurasia is given by the
fact that the (1) ___________ in North America match up with the (2)
_________ in Europe when the continents are brought back together.
A. (1) Rockies
(2) Alps
B. (1) Rockies
(2) Caledonides
C. (1) Appalachians
(2) Alps
D. (1) Appalachians
(2) Caledonides
E. (1) Cascades
(2) Appalachians
3.
Which of the following continents does NOT show evidence of an ice age
during the Carboniferous because it was part of Laurasia in northern Pangea
and so was near to the equator?
A. North America
B. Africa
C. India
D. Australia
E. Antarctica
4.
One line of evidence that Africa and South America used to be one continent
is that they both show fossil evidence of a type of plant with large seeds.
This plant was called:
A. Cynognathus
B. Glossopteris
C. Tyrannosaurus
D. Mesosaurus
E. Alto Redwood
5.
Which of these statements about paleomagnetism as determined from a study of
spreading ridges is FALSE?
A. there is a clear paleomagnetic signal in rocks to either side of a
spreading ridge
B. rocks along spreading ridges all show normal polarity, no matter what
their age
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C. the paleomagnetic pattern on one side of a ridge is a mirror image of
that on the other side of the ridge
D. there is evidence that Earth’s magnetic poles reverse approximately
every half-million years
E. all the world’s spreading ridges show evidence of paleomagnetic
reversals in the adjacent ocean rocks
6.
The mid-Atlantic ridge is an example of a spreading ridge. As a result of
the process of (1) _________ that occurs at this ridge, the youngest oceanic
crust in the north Atlantic must be located (2) ____________:
A. (1) seafloor spreading
(2) along the ridge itself
B. (1) seafloor spreading
(2) along the coasts of N.
America and Europe
C. (1) seafloor spreading
(2) with a striped pattern of
repeating old and young rocks
D. (1) subduction
(2) along the ridge itself
E. (1) subduction
(2) along the coasts of N.
America and Europe
7.
The fastest plate motion velocity that has been measured anywhere on Earth
is 18 cm/yr, which occurs at the:
A. San Andreas fault
B. mid-Atlantic ridge
C. East Pacific Rise
D. Juan de Fuca spreading ridge
E. Aleutian subduction zone
8.
Which of the following combinations is a correct match between (1) a type of
plate boundary; and (2) a geographic example of that type of plate boundary?
A. (1) divergent
(2) San Andreas fault
B. (1) convergent
(2) Red Sea
C. (1) transform
(2) Japan
D. (1) transform
(2) Himalayas
E. (1) divergent
(2) East African Rift Valley
9.
Which of the following statements about convergent plate boundaries is TRUE?
A. when two continents collide, at least one of the plates will
always subduct
B. the collision of oceanic crust against continental crust will
result in subduction of the continent
C. there are only two types of convergent boundaries: ocean-ocean and
ocean-continent
D. where two ocean plates collide, magma rises through the overriding
plate to form a back-arc basin
E. when two continents collide, a suture zone and a mountain range
form at the collision zone
10.
On average, the geothermal gradient inside the Earth is about:
A. 1000°C per kilometer
B. 100°C per kilometer
C. 50°C per kilometer
D. 25°C per kilometer
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E.
10°C per kilometer
11. As a rock starts to melt, the minerals with the lowest melting temperature
will start to melt first, forming magma. This melted portion can get
squeezed away from the remaining solid rock through a process called:
A. partial melting
B. fractionation
C. differentiation
D. buoyancy
E. crystallization
12.
The type of magma that has the highest silica content is:
A. intermediate
B. ultramafic
C. mafic
D. felsic
E. all magma has the same silica content
13.
Which of the following is unrelated to plutonic processes or features?
A. lava
B. magma
C. plutons
D. batholith
E. intrusive
14.
Which of the following terms has the same meaning as fine-grained texture
in igneous rocks?
A. aphanitic
B. phaneritic
C. porphyritic
D. pyroclastic
E. pegmatitic
15.
When lava erupts and cools, if may form a groundmass of small crystals
occurring together with larger phenocrysts that grew in the magma while it
was still inside the Earth. The resultant type of igneous rock texture is
called:
A. aphanitic
B. phaneritic
C. porphyritic
D. pyroclastic
E. pegmatitic
16.
The gas bubbles that get permanently trapped inside some igneous rocks,
like pumice, are called:
A. pillows
B. phenocrysts
C. pegmatites
D. vesicles
E. ostracods
17.
Which of the following list of minerals is in the correct crystallization
order according to Bowen’s Reaction Series?
A. Na-plagioclase, Ca-plagioclase, K-feldspar, quartz
B. amphibole, Ca-plagioclase, K-feldspar, olivine
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C.
D.
E.
olivine, Ca-plagioclase, quartz, pyroxene
olivine, pyroxene, amphibole, biotite mica
quartz, muscovite mica, K-feldspar, Na-plagioclase
18.
The most common type of volcanic igneous rock is:
A. rhyolite
B. basalt
C. dacite
D. granite
E. andesite
19.
Which type
A.
B.
C.
D.
E.
20.
How many active volcanoes are there in the world?
A. about a million
B. around 10,000
C. around 1,500
D. around 800
E. 42
21.
How many people live on or near to an active volcano?
A. about a billion
B. around 500 million
C. approximately one million
D. around 500,000
E. about 10,000
22.
The type of volcanic hazard that involves a huge cloud of tephra rushing
down the slopes of a volcano is a:
A. lahar
B. lava bomb
C. pyroclastic flow
D. gas cloud
E. ash fall
23.
Which of the following is characteristic of explosive eruptions?
A. shield volcanoes
B. low-viscosity lava
C. mafic lava
D. Plinian columns
E. all volcanoes in Hawaii, Iceland and the Galapagos Islands
24.
Which of the following is the major component of a lahar?
A. lava bombs
B. lapilli
C. volcanic ash
D. lava
E. cinders
of pluton is accurately described as dome-shaped?
batholiths
dikes
sills
laccoliths
volcanic pipes
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25.
The most active volcano in the Cascades is (1) __________ but the largest
known eruption that occurred about 6800 years ago 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
BONUS QUESTIONS
51.
What type of plate boundary is the San Andreas fault in California?
A. divergent
B. convergent: ocean-ocean type
C. convergent: ocean-continent type
D. convergent: continent-continent type
E. transform
52. When considering lava that cools to form basalt, which of the following
terms does not belong with the others?
A. low viscosity
B. mafic
C. a’a
D. pahoehoe
E. stratovolcanoes
53.
The world’s largest lava dome is:
A. Mount St. Helens
B. Mauna Loa
C. Mount Hood
D. Lassen Peak
E. Crater Lake
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