2.3: Questions

Figure \(\PageIndex{1}\): Tectonic plates. (Image from Wikimedia Commons.)

Question 1 In Figure \(\PageIndex{1}\), the orange color represents
Felsic lithosphere rock
Mafic lithosphere rock
Asthenosphere rock
Magma

Question 2 In Figure \(\PageIndex{1}\), the light grey color represents
Felsic lithosphere rock
Mafic lithosphere rock
Asthenosphere rock
Magma

Question 3 In Figure \(\PageIndex{1}\), the dark grey color represents
Felsic lithosphere rock
Mafic lithosphere rock
Asthenosphere rock
Magma

Question 4 In Figure \(\PageIndex{1}\), C is a/an
Oceanic-oceanic divergent boundary
Oceanic-oceanic convergent boundary
Continental-continental convergent boundary
Oceanic-continental convergent boundary

Question 5 In Figure \(\PageIndex{1}\), H is a/an
Oceanic-oceanic convergent boundary
Continental-continental convergent boundary
Oceanic-oceanic divergent boundary
Continental-continental divergent boundary

Question 6 In Figure \(\PageIndex{1}\), K is a/an
Oceanic-oceanic convergent boundary
Transform boundary
Continental-continental convergent boundary
Continental-continental divergent boundary

Question 7 In Figure \(\PageIndex{1}\), J is a/an
Oceanic-oceanic divergent boundary.
Continental-continental convergent boundary.
Oceanic-oceanic convergent boundary.
Transform boundary.

Question 9 In Figure \(\PageIndex{1}\), E is a/an
Continental-continental convergent boundary
Passive continental margin
Continental-continental divergent boundary
Active continental margin

Question 10 In Figure \(\PageIndex{1}\), L is a/an
Passive continental margin
Active continental margin
Continental-continental divergent boundary
Continental-continental convergent boundary

Question 11 In Figure \(\PageIndex{1}\), the deep valley at E is a
Transform boundary
Divergence
Rift valley
Trench

Question 12 In Figure \(\PageIndex{1}\), the deep valley at H is a
Rift valley
Divergence
Transform boundary
Trench

Question 13 In Figure \(\PageIndex{1}\), the volcanoes at A are a/an
Island arc
Batholith
Laccolith
Hotspot volcanoes

Question 14 In Figure \(\PageIndex{1}\), the volcanoes at N are a/an
Batholith
Laccolith
Island arc
Hotspot volcanoes

Question 15 In Figure \(\PageIndex{1}\), the mountains at E are
Andean-type mountains
Hotspot volcanoes
An island arc
Collisional mountains

Question 16 In Figure \(\PageIndex{1}\), the mountains at K are
Andean-type mountains.
Hotspot volcanoes.
An island arc
Collisional mountains.

Question 17 In Figure \(\PageIndex{1}\), where does new lithosphere rock form?
D, M
B, D, G, K, M, N
B, E
K

Question 18 In Figure \(\PageIndex{1}\), where does ridge push occur?
H, K
B, F
D, M
G

Question 19 In Figure \(\PageIndex{1}\), where does slab pull occur?
E, L
D, M
B, F
D, G, M

Question 20 In Figure \(\PageIndex{1}\), where are the subduction zones?
D, G, M
F
B, F
G, N

Question 21 In Figure \(\PageIndex{1}\), the Hawaii islands resemble the volcanoes at
K
F
A
N

Question 22 In Figure \(\PageIndex{1}\), the Aleutian islands resemble the volcanoes at
K
F
A
N

Question 23 In Figure \(\PageIndex{1}\), the Mid-Atlantic Ridge resembles plate boundary
C
H
E
A

Question 24 In Figure \(\PageIndex{1}\), the plate boundary between Nazca plate and South American plate resemble plate boundary
A
C
E
H

Question 25 In Figure \(\PageIndex{1}\), the Eastern African rift valleys resemble plate boundary
E
A
H
C

Question 26 In Figure \(\PageIndex{1}\), the East coast of North America resembles the coastline
E
L
A
H

Question 27 In Figure \(\PageIndex{1}\), where does decompression melting occur under divergence?
K
B, F
D, M
N

Question 28 In Figure \(\PageIndex{1}\), where does volatile-driven melting occur?
N
B, F
K
D, M

Question 29 In Figure \(\PageIndex{1}\), below which location is there a mantle plume?
B, F
D, M
K
N

Question 30 In Figure \(\PageIndex{1}\), the Alps are an example of the mountain at
E
N
K
A

Question 31 Why are the Mesosaurus fossils important in continental drift?
Because the species were known to live on several continents
Because the species had been long extinct
Because the species were very large in size
Because the species could not travel across the sea

Question 32 Why did the distribution of Mesosaurus fossils support the idea of continental drift?
Because the fossils were found in areas with similar climates
Because the fossils were found in rocks of different ages
Because the fossils were only found in South America and Africa
Because the fossils were found in many different locations around the world

Question 33 What type of plant did Wegener cite as evidence for Pangaea's existence?
Ferns
Conifers
Mesosaurus
Glossopteris

Question 34 How did opponents of continental drift explain the existence of identical fossil organisms in different parts of the world?
Rafting, transoceanic land bridges
Continental drift and sea floor spreading
Weather patterns and ocean currents
Human migration and trade

Question 35 What was unusual about the seeds of the Glossopteris plant?
They were too large to be carried by the wind
They were very small and could be carried by the wind
They were only found in certain locations
They were only found in rocks of a certain age

Question 36 Why did Wegener believe that the landmasses that made up Pangaea were located near the South Pole?
Because the continents were moving towards the equator
Because the Glossopteris plants and associated flora grew in cool climates
Because the oceans were smaller during the Permian age
Because the Mesosaurus fossils were found in rocks of a certain age

Question 37 Why did Wegener reject the proposal of extreme global cooling as the cause of the late Paleozoic glaciation?
Because of the presence of tropical swamps in the Northern Hemisphere
Because of the absence of glaciers in the Northern Hemisphere
Because of the presence of coal deposits in the Southern Hemisphere
Because of the lack of evidence for glaciation in the Southern Hemisphere

Question 38 Why did the scientific community reject or view continental drift?
The hypothesis did not withstand critical testing from all areas of science
The evidence for continental drift was based on a single discipline
The concept of continental drift was already widely accepted
The idea of continental drift was too simple to be considered

Question 39 What was necessary for a comprehensive scientific hypothesis like continental drift to gain wide acceptance?
It must withstand critical testing from all areas of science
It must lack a clear mechanism for the proposed process
It must be based on untestable assumptions
It must be supported by evidence from a single area of science

Question 40 What is the term used to describe the large segments of the Earth's lithosphere that are in constant motion with respect to one another?
Lithospheric plates
Tectonic blocks
Oceanic crusts
Continental drifts

Question 41 Where do most major interactions between plates occur?
Along the plate boundaries
In the Earth's core
In the mantle
At their centers

Question 42 What type of plate boundary is characterized by two plates moving apart?
Plateau boundary
Convergent plate boundary
Divergent plate boundary
Transform plate boundary

Question 43 Under which type of plate boundary does lithosphere subduction occur?
Plateau boundary
Convergent plate boundary
Divergent plate boundary
Transform plate boundary

Question 44 What is an important difference between the plate tectonics theory and Wegener's continental drift hypothesis?
The continents move through the ocean floor, not with it
The plates are static and do not move relative to each other
The continents move with the ocean floor, not through it
The plates are defined entirely by the margins of a single continent

Question 45 What was a significant consequence of the breakup of the supercontinent Pangaea?
The formation of the Himalayan mountain range
The creation of the Pacific Ocean
The destruction of the African continent
The creation of a new ocean basin: the Atlantic

Question 46 What type of rocks are found along the eastern seaboard of the United States as a result of the breakup of Pangaea?
Sedimentary rocks
Metamorphic rocks
Fossilized rocks
Weathered igneous rocks

Question 47 Pangaea's breakup is a demonstration of
How mountains form on Earth
How plates and plate boundaries change over geologic time scale
How the surface of Earth is a fixed piece of rock that does not change
How continents float on the oceans

Question 48 What was the result of the highly fractured continental crust during the breakup of Pangaea?
The formation of a volcanic island arc
Pathways for huge quantities of fluid lavas to reach the surface
The formation of a large mountain range
The creation of a deep ocean trench

Question 49 What was one of the early goals of the ocean drilling project of the late 1960s?
To discover new species of marine life
To map the ocean floor terrain
To explore the deepest parts of the ocean
To gather samples of the ocean floor in order to establish its age

Question 50 What pattern of sediment distribution was found by the drill cores?
Sediments are thickest on the ridge crest and decrease with distance from the ridge
Sediments are only found near the continents
Sediments are evenly distributed across the ocean floor
Sediments are almost entirely absent on the ridge crest and increase with distance from the ridge

Question 51 What was the expected pattern of oceanic crust age according to the seafloor-spreading hypothesis?
The youngest crust would be found at the ridge crest and the oldest near the continents
The crust would be the same age everywhere
The crust would be older near the ridge crest and younger near the continents
The oldest crust would be found at the ridge crest and the youngest near the continents

Question 52 What can be inferred about the age of the ocean basins compared to the continental crust based on the data collected by ocean drilling?
Ocean basins are significantly older than the continental crust
Ocean basins and continental crust are roughly the same age
The age of ocean basins and continental crust cannot be compared
Ocean basins are geologically younger than the continental crust

Question 53 What is the maximum age of the seafloor found by ocean drilling?
More than 4 billion years
Approximately 500 million years
No seafloor older than 180 million years
Around 1 billion years

Question 54 Why does the age of the seafloor support the idea that ocean basins are geologically young?
Because the oldest seafloor is younger than most continental crust
Because the seafloor is not affected by geological processes
Because the age of the seafloor is similar to the age of the continental crust
Because the seafloor is constantly being destroyed and recreated

Question 55 How do rocks that contain paleomagnetism respond to change in Earth's magnetic field?
They reverse the direction of the magnetic field
They point toward the current position of the magnetic poles
They are unaffected by the Earth's magnetic field
They point toward the position of the magnetic poles at the time of their formation

Question 56 What is the purpose of the Curie point in the context of paleomagnetism?
It is the temperature below which the Earth's magnetic field reverses
It is the temperature below which minerals lose their magnetism
It is the temperature below which minerals become magnetic
It is the temperature below which lava solidifies

Question 57 What happens to the magnetite grains in basaltic lava as the lava cools?
They remain nonmagnetic and do not change orientation
They become nonmagnetic and align themselves randomly
They become magnetized and align themselves with the magnetic lines of force
They become magnetized but do not align themselves with the magnetic lines of force

Question 58 What technique is used to establish the age of each lava flow in the magnetic time scale?
Seismographic monitoring
Radiometric dating
Paleomagnetic analysis
Geologic mapping

Question 59 What is the expected pattern of magnetic stripes on one side of an oceanic ridge compared to the other side?
Completely random and unrelated
Identical but shifted by a certain distance
Opposite in polarity but similar in width
A mirror image of each other

Question 60 What is the result of subsequent reversals in the polarity of Earth’s magnetic field on the pattern of magnetic stripes?
A random mixture of normal and reverse polarities
A pattern of normal and reverse magnetic stripes
A complete erasure of the existing magnetic stripes
A single, uniform stripe of magnetized crust

Question 61 What is the primary reason for the sinking of cold, dense slabs of oceanic lithosphere into the mantle?
They are denser than the surrounding warm asthenosphere
They are being forced down by the movement of the Earth's core
They are being pulled down by the force of convection currents
They are being pushed down by the surrounding asthenosphere

Question 62 What happens to a subduction slab as it descends into the mantle?
It is continually replaced by cooler, denser lithosphere from above
It continually warms up and becomes less dense
It melts and becomes part of the asthenosphere
It remains the same temperature and density