Geotectonic Questions

Multiple Choice:
1. What is the name of the Mesozoic supercontinent that consisted of all of the present
continents?
a) Eurasia
b) Laurasia
c) Pangaea
d) Gondwanaland
2. When did the supercontinent Pangaea begin to break apart?
a) about 10,000 years ago
b) about 10 million years ago
c) about 200 million years ago
d) about 570 million years ago
3. What age are the fossils of the reptile Mesosaurus found in Africa and South
America that suggested that the two continents were once together?
a) early Cenozoic
b) late Mesozoic
c) early Mesozoic
d) late Paleozoic
4. Which plate is being subducted beneath western South America?
a) the Pacific plate
b) the South American plate
c) the Nazca plate
d) the South Atlantic plate
5. New oceanic lithosphere forms at __________ .
a) divergent plate boundaries
b) convergent plate boundaries
c) transform plate boundaries
d) all of these are possible
6. Which of the following is not a divergent plate boundary?
a) the Great Rift Valley of East Africa
b) the East Pacific Rise
c) the San Andreas fault
d) the Mid-Atlantic Ridge
7. Partial melting and the production of magma takes place at ________ .
a) divergent plate boundaries
b) ocean-ocean convergent plate boundaries
c) ocean-continent plate boundaries
d) all of these
8. At what type of plate boundary do shallow-focus earthquakes occur?
a) Convergent
b) Divergent
 c) Transform
d) all of these
9. The Hawaiian Islands formed at a _________ .
a) convergent boundary
b) divergent boundary
c) transform boundary
d) none of these
10.Which of the following are not associated with convergent plate margins?
a) deep-focus earthquakes
b) rift valleys
c) island arcs
d) deep-sea trenches
11.What are ophiolite suites?
a) fragments of oceanic lithosphere emplaced on a continent
b) groups of seafloor magnetic anomalies
c) wedge-shaped packages of sediments that form at passive margins
d) micro-continents that have traveled a long distance
12.Transform faults ___________ .
a) often offset spreading centers
b) can cut across continents
c) involve horizontal movement
d) all of these
13.Stretching stresses, basaltic lavas, and shallow earthquakes are associated with
______ .
a) subduction zones
b) continent/continent convergence
c) spreading centers
d) transform boundaries
14.Compressive stresses, granitic magmas, and intermediate depth earthquakes are
associated with __________ .
a) subduction zones
b) continent/continent convergence
c) spreading centers
d) transform boundaries
15.Shearing stresses and shallow earthquakes are associated with:
a) subduction zones
b) continent/continent convergence
c) spreading centers
d) transform boundaries
16.If the Atlantic Ocean is widening at a rate of 3 cm per year how far (in kilometers)
will it spread in a million years?
a) 300 kilometers
b) 30 kilometers
c) 30 miles
 d) 3 kilometers
17.In 50 million years?
a) 150 kilometers
b) 1000 kilometers
c) 1500 kilometers
d) 30 kilometers
18.At convergent plate boundaries where oceanic and continental crust meet _________
.
a) no associated volcanism occurs
b) oceanic crust is subducted
c) continental crust is subducted
d) oceanic crust is created
19.One remarkable realization associated with the discovery of seafloor spreading was
that _____________ .
a) the crust of the continents is more dense than the crust of the ocean
b) the crust of the oceans is very young relative to the age of the crust of the continents
c) mountains are more dense than then mantle
d) the rotational poles of the Earth have migrated.
20.Which segment of the Atlantic Ocean opened first?
a) Northern
b) Southern
c) Central
d) it all opened at the same time
21.Which of the following is not a chain of volcanic islands associated with ocean-ocean
convergence?
a) the Aleutian Islands
b) the Hawaiian Islands
c) the Mariana Islands
d) the Philippine Islands
22.Volcanic island arcs are associated with __________ .
a) transform plate boundaries
b) divergent plate boundaries
c) ocean-ocean convergent plate boundaries
d) ocean-continent convergent plate boundaries
23.Melange deposits are associated with ______ .
a) divergent boundaries
b) subduction margins
c) transform boundaries
d) all of these
24.Which of the following mountains did not form as a result of collision between two
continents?
a) Appalachians
b) Urals
c) Andes
 d) Himalayas
25.Which of the following increases with distance from a mid-ocean ridge?
a) the age of oceanic lithosphere
b) the depth to the sea floor
c) the thickness of the lithosphere
d) all of the above
26.Sea-floor spreading is driven by volcanic activity ____________.
a) in the middle of abyssal plains
b) along mid-ocean ridges
c) at the edges of continental shelves
d) along fracture zones
27.Within the sea floor, the rate of heat flow is greatest ____________.
a) along mid-ocean ridges
b) along fracture zones
c) at the edges of ocean basins
d) in the center of abyssal plains
28.Beneath a blanket of sediments, oceanic crust is primarily composed of two rocks,
____________.
a) granite and diorite
b) gabbro and basalt
c) sandstone and shale
d) slate and gneiss
29.Continental lithosphere ____________.
a) is thicker than oceanic lithosphere
b) contains more mafic rocks than oceanic lithosphere
c) is denser than oceanic lithosphere
d) contains no crustal material, consisting solely of lithified upper mantle
30.Continental coastlines that occur within the interior of a tectonic plate are called
____________.
a) internal margins
b) passive margins
c) active margins
d) inert margins
31.Tectonic plates might consist of ____________.
a) continental lithosphere only
b) oceanic lithosphere only
c) oceanic or continental lithosphere or a combination of both
d) either oceanic or continental lithosphere, but not both
32.At a divergent plate boundary, two opposed plates ____________.
a) move toward one another
b) move away from one another
c) slide past one another
33.At a convergent plate boundary, two opposed plates ____________.
a) move toward one another
 b) move away from one another
c) slide past one another
34.At a transform plate boundary, two opposed plates ____________.
a) move toward one another
b) move away from one another
c) slide past one another
35.Mid-ocean ridges are ____________.
a) convergent plate boundaries
b) divergent plate boundaries
c) transform plate boundaries
36.The youngest sea floor occurs ____________.
a) along passive margins
b) along active margins
c) along mid-ocean ridges
d) randomly over the entire ocean basin
37.Subduction zones are ____________.
a) convergent plate boundaries
b) divergent plate boundaries
c) transform plate boundaries
38.At a subduction zone, the overriding plate ____________.
a) is always composed of continental lithosphere
b) is always composed of oceanic lithosphere
c) may be composed of either oceanic or continental lithosphere
39.At a subduction zone, the downgoing (subducting) plate ____________.
a) is always composed of continental lithosphere
b) is always composed of oceanic lithosphere
c) may be composed or either oceanic or continental lithosphere
40.At transform plate boundaries ____________.
a) earthquakes are common, but volcanoes are absent
b) volcanoes are common, but earthquakes do not occur
c) both earthquakes and volcanoes are common
41.Segments of the mid-ocean ridge system are offset. Between the offset segments
weobserve ____________.
a) a second series of ridges, perpendicular to the main set
b) deep-ocean trenches
c) transform faults
d) None of the above is correct.
42.When two bodies of continental lithosphere are pushed together at a convergent
boundary, the result is ____________.
a) Subduction
b) collision and mountain formation
43.Melange deposits are associated with a _______ plate margin
a) passive
b) shear
 c) tensional margin
d) compressional margin
44.Thrust faults are associated with a _______ plate margin.
a) Passive
b) spreading center
c) continental/ocean convergent
d) transform
45.The presence of "magnetic stripes" recorded in the oceanic crust reflects
__________ .
a) reversals in polarity of the Earth's magnetic field
b) the rate of sea floor spreading
c) variation in composition of the oceanic crust
d) all of these
46.Transform faults _____________ .
a) can offset of spreading centers
b) can cut across continental crust
c) exhibit horizontal offset
d) all of these
47.Ophiolites _________________ .
a) are an ancient piece of sea floor
b) are emplaced in a compressional setting
c) are primarily igneous rocks with a thin sedimentary covering
d) all of these
48.The southern supercontinent was called:
a) Laurentia.
b) Glossopteris.
c) Gondwanaland.
d) Pangea.
49.The sliding of seafloor beneath a continent or island arc is known as:
a) obfuscation.
b) obduction.
c) subduction.
d) obliteration.
50.The tectonic plates of Earth are part of Earth's:
a) crust.
b) mantle.
c) lithosphere.
d) asthenosphere.
51.The San Andreas Fault in California is a:
a) convergent plate boundary.
b) divergent plate boundary.
c) transform plate boundary.
d) none of these.
52.Which of the following features would you expect to find at an ocean-ocean
convergent boundary?
a) volcanic island arc.
b) ocean trench.
c) earthquakes.
d) all of these.
53.Which of the following features would you expect to find at an ocean-continent
convergent boundary?
a) deep ocean trench.
b) volcanic mountain chain.
c) earthquakes.
d) all of these.
54.Which of the following would you expect to find at a continent-continent convergent
boundary?
a) deep ocean trench.
b) suture zone.
c) volcanic mountain chain.
d) all of these.
55.Passive continental margins are created at:
a) divergent plate boundaries.
b) convergent plate boundaries
c) transform plate boundaries
d) all of these.
56.The Hawaiian Islands are the result of:
a) subduction.
b) seafloor spreading.
c) a mantle plume.
d) none of these.
57.A large supercontinent that existed 225 million years ago was:
a) Gondwanaland.
b) Laurasia.
c) Glossopteris
d) Pangea.
58.The age of the seafloor is relatively young because:
a) it is continuously generated at mid-ocean ridges.
b) it is continuously destroyed at subduction zones.
c) both of the above.
d) none of the above.
59.If a plate moves 20 mm per year, how far will it move in 1 million years?
a) 20 meters.
b) 20 kilometers.
c) 20 centimeters.
d) 2,000 kilometers.
60.The East African Rift is an example of:
 a) a continent-continent convergent boundary.
b) an ocean-continent convergent boundary.
c) an ocean-ocean convergent boundary.
d) a divergent plate boundary.
61.Which of the following provides evidence of plate motion?
a) chains of seamounts in the ocean basins.
b) the age distribution of the Hawaiian Islands.
c) the age distribution of basalt at mid-ocean ridges.
d) all of these.
62.In what layer of the Earth does plate tectonics occur?
a) Asthenosphere
b) Lithosphere
c) Mesosphere
d) Tectosphere
63.Which is the largest lithospheric plate?
a) African
b) Antarctic
c) Eurasian
d) Pacific
64.Where are the most transform faults found?
a) Hotspot tracks
b) Spreading ridges
c) Subduction zones
d) Transform margins
65.What cycle is the result of plate tectonics?
a) The Bowen cycle
b) The Carnot cycle
c) The Davis cycle
d) The Wilson cycle
66.Which one of the following islands was formed as a result of volcanic activity along a
mid-ocean ridge?
a) Iceland
b) Japan
c) Hawaii
d) The Aleutians
67.The San Andreas fault between the Pacific and North American plates is an example
of a:
a) Continent-continent convergent plate boundary
b) Transform fault boundary
c) Ocean-continent convergent plate boundary
d) Divergent plate boundary
68.At a divergent plate boundary, lithospheric plates:
a) Slide past each other
b) Collide with each other
 c) Rift apart
d) Move under each other
69.What happens when oceanic crust collides with continental crust?
a) Compression causes both crusts to fold into mountains
b) The two lithospheric plates grind past each other
c) The lighter oceanic crust overrides the continental crust
d) The heavier oceanic crust is subducted into the earth's mantle
70.Oceanic trenches are formed by:
a) Sea-floor spreading
b) The collision of continents
c) The subduction of oceanic crusts into the earth's mantle
d) The subduction of continental crust into the earth's mantle
71.The sea floor of the Pacific Ocean is:
a) Getting larger
b) Getting smaller
c) Staying the same size
d) Being torn in half
72.Mountains located in the interior of lithospheric plates, such as the Urals and the
Appalachians, are thought to have formed as a result of:
a) Continental rifting
b) Ancient continent-continent plate convergence
c) Transform faulting
d) Ancient ocean-continent plate convergence
73.The Himalaya Mountains are believed to be the current location of a(an):
a) Continent-continent convergent plate boundary
b) Ocean-continent convergent plate boundary
c) Divergent continental plate boundary
d) A hot spot
74.The rigid layer of the earth's crust and the upper mantle together form the:
a) Lithosphere
b) Asthenosphere
c) Continents
d) Core
75.The asthenosphere is best described as:
a) A rigid rock layer
b) Semi-molten
c) Composed of basaltic rock
d) Liquid like the earth's outer core
76.Compared to ocean crust near deep-sea trenches, crust near ocean ridges is...
a) Younger
b) Older
c) the same ages
d) magnetically reversed
77.The magnetic pattern of ocean floor rocks on one side of an ocean ridge is...
 a) a mirror image of that of the other side
b) younger than that on the other side
c) much different from the magnetic pattern found in rocks on land
d) at right angles to the ocean ridge
78.Features found at divergent boundaries include...
a) ocean ridges
b) deep sea trenches
c) crumpled mountains
d) island arc volcanoes
79.Subduction results in the formation of...
a) a deep sea trench
b) a magnetic reversal
c) a rift valley
d) new continental crust
80.Continental-continental plate collisions produce...
a) island arcs
b) rift valleys
c) deep sea trenches
d) mountain ranges
81.Crust is neither destroyed nor formed along which of the following boundaries?
a) Convergent
b) Divergent
c) Transform
d) magnetic
82.The driving forces of tectonic plates are related to convection currents in Earth's...
a) Crust
b) Mantle
c) inner core
d) outer core
83.Which one of the following is associated with a mid ocean ridge?
a) Subduction zone
b) Basaltic pillow lavas
c) Ocean trench
84.The flat part of ocean basins between the mid ocean ridges and oceanic trenches is
known as:
a) Continental Shelf
b) Abysmal Plain
c) Abyssal plain
d) Continental slope
85.Which of the following forces is prevalent at divergent (constructive) plate margins?
a) Tensional
b) Compressional
c) Shear
d) None
 e) Tensional and compressional
86.At which type of plate margin would you expect to find a volcanic island arc?
a) Divergent (constructive)
b) Convergent (oceanic-oceanic)
c) Convergent (oceanic-continental)
d) Convergent (continental-continental)
e) Transform
87.The main topographic feature that is found along the centre of mid-ocean ridges
a) Ocean trench
b) Island arc
c) Mountain belt
d) Rift valley
e) Thrust faults
88.At which type of plate margin would you expect to find fold mountains such as the
Himalayas?
a) Divergent (constructive)
b) Convergent (oceanic-oceanic)
c) Convergent (oceanic-continental)
d) Convergent (continental-continental)
e) Transform
89.The largest early Paleozoic continent was called:
a) Siberia.
b) Laurentia.
c) Gondwana.
d) Baltica.
90.Laurentia and Baltica were separated by the:
a) Atlantic Ocean.
b) Iapetus Ocean.
c) Pacific Ocean.
d) Panthalassa Ocean.
91.Laurentia and Baltica were soon joined to form:
a) Asia.
b) Gondwana.
c) Pangaea.
d) Lauraisa.
92.The Late Paleozoic collision between Baltica and Gondwana occurred in the:
a) Hercynian orogeny.
b) Uralian orogeny.
c) Altai orogeny.
d) None of the above.
93.At the end of the Permian Period, the single ocean surrounding Pangaea was called
the:
a) Iapetus Ocean.
b) Pacific Ocean.
 c) Panthalassa Ocean.
d) Atlantic Ocean.
94.The Appalachian and Ouachita mountains were formed during the Paleozoic as a
result of:
a) continental rifting.
b) continental collisions.
c) continental drifting.
d) passive margin deposition.
95.In the Taconic orogeny, Laurentia collided with:
a) Baltica.
b) Siberia.
c) Avalonia.
d) Gondwana.
96.The collision of Baltica and Laurentia occurred during this orogeny:
a) Taconic orogeny.
b) Caledinian orogeny.
c) Acadian orogeny.
d) Hercynian orogeny.
97.The Ouachita orogeny of Late Paleozoic age resulted from collision of the southern
margin of North America with the northern margin of:
a) Africa.
b) South America.
c) Siberia.
d) Asia.
98.At the beginning of the Paleozoic Era, Rodinia had fragmented into:
a) two continents.
b) four continents.
c) three continents.
d) six continents.
99.At the end of the Paleozoic Era, tectonic activity had assembled:
a) two continents.
b) four continents.
c) one continent.
d) six continents.
100. The Ural Mountains of Russia formed in the:
a) Ordovician Period.
b) Permian Period.
c) Silurian Period.
d) Devonian Period.
101. The Taconic orogeny were formed during the Early Paleozoic as a result of:
a) continental rifting.
b) continental collisions.
c) continental drifting.
d) microcontinent accretion.
102. In the Acadian orogeny, Laurasia collided with:
a) Baltica.
b) Siberia.
c) the remnants of Avalonia.
d) Gondwana.
103. The Taconic orogeny that began in the _______ can be related to _______ .
a) Carboniferous, closing of Iapetus
b) Ordovician, opening of Iapetus
c) Ordovician, closing of Iapetus
d) Ordovician, collision of North America and Gondwana
104. Pull-apart basins and rifts are generally associated with a _________ plate
boundary.
a) transform
b) divergent
c) convergent
d) all plate boundaries
105. New oceanic crust and lithosphere are formed at ____________.
a) divergent boundaries
b) convergent boundaries
c) transform boundaries
106. The oldest oceanic crust occurs ________ and the youngest occurs __________.
a) at mid-ocean ridges, along subduction zones
b) at mid-ocean ridges, along the continental margins
c) along the continental margins, at mid-ocean ridges
d) along the continental margins, along subduction zones
e) somewhere beneath the continental slope, at mid-ocean ridges
107. Tectonic plates are made up of ______ that floats on the underlying _________.
a) basalt, gabbro
b) lithosphere, asthenosphere
c) continental crust, mantle
d) continental and oceanic crust, lithosphere
e) lithosphere, outer core
Complete:
1. The age of oceanic lithosphere increases with increasing distance from a mid-oceanic
ridge.
2. Deep-sea trenches are associated with convergent plate boundaries.
3. The Hawaiian Islands are caused by a hot spot.
4. The supercontinent Pangaea began to break up during the Mesozoic Era.
5. The Moho lies within the lithosphere.
6. Typically, the youngest unit is an ophiolite sequence is submarine sediments.
7. Melange deposits are associated with convergent plate boundaries.
8. In which ocean are most of the world's convergent plate boundaries located? Pacific
Ocean.
9. What is an example of a transform plate boundary? The San Andreas Fault.
10.What type of boundary is parallel to the direction of plate boundary? Transform Plate
boundary.
11.When was the supercontinent of Pangea assembled? Approximately 250 million years
ago.
12.What ocean used to lie between Africa and Eurasia and was the ancestor to today's
Mediterranean Sea? Tethys.
13.Mid-ocean ridges are also referred to as spreading centers.
14.An island arc forms when there is what convergence? Ocean-ocean convergence.
15."Oblique" boundaries combine convergent and divergent motion with what motion?
Transform.
16.The Paleozoic Era began with a continuation of the breakup of the supercontinent
Rodinia.
17.A series of continental collisions during the Paleozoic formed the supercontinent called
Pangea.
18.The time of “ancient life” has been named the Paleozoic Era, which is the first era of the
Phanerozoic Eon.
19.During the Ordovician Period, Gondwana drifted over the South Pole, resulting in the
formation of large glaciers and a worldwide drop in sea level.
20.Gondwanan glaciation is indicated by deposits of Late Ordovician tillites.
21.During the early Cambrian, landmasses containing present-day South America, Africa,
India Australia, and Antarctica collided together to form the massive continent of
Gondwana.
22.North America, Greenland, and northern Great Britain formed the continent of Laurentia.
23.The Lapetus ocean separated Laurentia from Baltica.
24.The collision of Laurentia and Baltica formed the larger continent of Laurasia.
25.The northern Gondwana collided with the southern Laurentia to form the Hercynian
orogeny.
26.The continents of Siberia and Kazakhstania collided during the Pennsylvanian to form the
Altai mountains of central Asia.
27.The collision of Baltica with Kazakhstania during the Permian caused the Ural mountains
and the suturing of these two continents.
28.Pangaea was formed by the collision of Laurasia with Gondwana. The single ocean
surrounding this continent from pole to pole was called Panthalassa ocean.
29.At the beginning of the Paleozoic, most major continents were located near the equator,
which promoted warm climates.
30.The collision of North America with the Avalonia terrane occurred during the Tectonic
orogeny of Ordovician age.
31.The collision of Laurentia and Baltica occurred during the Caledonian orogeny of
Silurian age.
32.The collision of Laurentia with Baltica formed the continent of Laurasia.
33.In the Early to Middle Devonian, the remainder of Avalonia collided with Laurasia
during the Acadian orogeny.
34.Late Paleozoic suturing of Gondwana and Laurasia along the southern North America
and the northern South America occurred in the Ouachita orogeny.
35.The Paleozoic Era began with the break-up of Rodinia, and ended with the assembly of
Pangaea.
36.East Gondwana contained the modern continents of Africa and South America.
37.The Lapetus Ocean separated Baltica from Laurentia.
38.Laurasia and Gondwana were joined together in the Late Paleozoic by collision between
eastern North America and the northwestern Africa.
39.During the Hercynian orogeny, the northern portion of Gondwana converged with
Southern Baltica.
40.The Uralian orogeny brought together Baltica and Kazakhstania as the final event in the
assembly of Pangaea.
TRUE or FALSE:
1. The oldest rocks on Earth are found in ocean crust: FALSE
2. Glossopteris is a type of plant fossil found on a number of continents: TRUE
3. Benioff Zones are associated with continent-continent convergent margins: FALSE
4. Ocean-ocean convergent boundaries are also sites of subduction: TRUE
5. All plates are presently moving in the same direction: FALSE
6. The direction of motion of a plate cannot change over time: FALSE
7. Most active geologic processes (earthquakes, volcanoes) are associated with plate
boundaries: TRUE
8. Divergent plate boundaries form where there is upwelling from the asthenosphere: TRUE
9. Active continental margins form near mid-ocean ridges: FALSE
Active continental margins form near subduction zones.
10.Plate tectonic processes cause sea-level to move up and down: TRUE
11.Plate tectonic processes are responsible for development of large mountain belts: TRUE
12.The last Paleozoic age is the Pennsylvanian age: FALSE
The last Paleozoic age is the Permian age
13.The most important step in the assembly of Pangaea was the collision of Laurasia with
Gondwana: TRUE
14.Siberia and Kazakhstania were the first continents to be joined together to eventually
form Pangaea: FALSE
Siberia and Kazakhstania were the last continents to be joined together to eventually form
Pangaea.
15.The collisions that built Pangaea were responsible for building the Appalachian and
Ouachita mountains of North America: TRUE
16.Pangaea was surrounded by a single ocean called Tethys: FALSE
Pangaea was surrounded by a single ocean called Panthalassa.
17.Gondwana covered the South Pole during the Ordovician Period: TRUE
18.The Ouachita Mountains formed along the southern margin of North America: TRUE
19.The Taconic orogeny involved the collision between Laurasia and Baltica: FALSE
The Taconic orogeny involved the collision between Laurentia and Avalonia.
20.Erosion of the Caledonian orogeny formed the Old Red Sandstone: TRUE