Question 1

The mid-ocean ridges are elevated above the surrounding sea floor because ____________.

Accepted Answer

A)  ridge rocks are hot and therefore of relatively low density 
B)  the lithospheric plates are thickest at the ridges so they stand up taller 
C)  rising ocean currents leave a vacuum above the ridge 
D)  ridge rocks are mafic, whereas the ocean basin crust consists of ultramafic rock 
A)  ridge rocks are hot and therefore of relatively low density 
B)  the lithospheric plates are thickest at the ridges so they stand up taller 
C)  rising ocean currents leave a vacuum above the ridge 
D)  ridge rocks are mafic, whereas the ocean basin crust consists of ultramafic rock

Question 2

Unlike the lithosphere,the asthenosphere ____________.

Accepted Answer

A)  is relatively weak and flows readily 
B)  has a density similar to the core 
C)  varies in thickness from place to place 
D)  is relatively cool 
A)  is relatively weak and flows readily 
B)  has a density similar to the core 
C)  varies in thickness from place to place 
D)  is relatively cool

Question 3

All lithospheric plates are approximately the same size and contain a combination of oceanic and continental crust.

Accepted Answer

A) True 
 B)False

Question 4

Regions of the sea floor with positive magnetic anomalies were formed during times when Earth's magnetic field ____________.

Accepted Answer

A)  was exceptionally strong 
B)  was exceptionally weak 
C)  had normal polarity 
D)  had reversed polarity 
A)  was exceptionally strong 
B)  was exceptionally weak 
C)  had normal polarity 
D)  had reversed polarity

Question 5

The theory of plate tectonics ____________.

Accepted Answer

A)  incorporates continental drift but not sea-floor spreading 
B)  incorporates sea-floor spreading but not continental drift 
C)  incorporates and explains both sea-floor spreading and continental drift 
D)  does not incorporate sea-floor spreading or continental drift 
A)  incorporates continental drift but not sea-floor spreading 
B)  incorporates sea-floor spreading but not continental drift 
C)  incorporates and explains both sea-floor spreading and continental drift 
D)  does not incorporate sea-floor spreading or continental drift

Question 6

Deformed (bent,stretched,or cracked)lithosphere occurs ____________.

Accepted Answer

A)  randomly over the surface of Earth 
B)  primarily within the interiors of tectonic plates 
C)  primarily on the margins of tectonic plates 
A)  randomly over the surface of Earth 
B)  primarily within the interiors of tectonic plates 
C)  primarily on the margins of tectonic plates

Question 7

At transform plate boundaries ____________.

Accepted Answer

A)  earthquakes are common, but volcanoes are absent 
B)  volcanoes are common, but earthquakes do not occur 
C)  both earthquakes and volcanoes are common 
A)  earthquakes are common, but volcanoes are absent 
B)  volcanoes are common, but earthquakes do not occur 
C)  both earthquakes and volcanoes are common

Question 8

Within the sea floor,the rate of heat flow is greatest ____________.

Accepted Answer

A)  along mid-ocean ridges 
B)  along fracture zones 
C)  at the edges of ocean basins 
D)  in the center of abyssal plains 
A)  along mid-ocean ridges 
B)  along fracture zones 
C)  at the edges of ocean basins 
D)  in the center of abyssal plains

Question 9

The thickness of oceanic lithosphere is ____________.

Accepted Answer

A)  uniformly 100 km 
B)  greatest at the geographic poles and least near the equator 
C)  greatest near the mid-ocean ridges and thins out away from the ridges 
D)  least near the mid-ocean ridges and thickens away from the ridges 
A)  uniformly 100 km 
B)  greatest at the geographic poles and least near the equator 
C)  greatest near the mid-ocean ridges and thins out away from the ridges 
D)  least near the mid-ocean ridges and thickens away from the ridges

Question 10

The apparent polar-wander path obtained from magnetite crystals in basalts on the North American continent is now interpreted to be the result of ____________.

Accepted Answer

A)  wandering of the geomagnetic north pole 
B)  drifting of the North American continent 
A)  wandering of the geomagnetic north pole 
B)  drifting of the North American continent

Question 11

Wegener's evidence for a united Pangaea was so compelling that virtually all geologists agreed with the idea of continental drift during his lifetime.

Accepted Answer

A) True 
 B)False

Question 12

The Wadati-Benioff zone is a belt of earthquakes found ____________.

Accepted Answer

A)  within an otherwise stable continental interior 
B)  within an overriding plate at a subduction zone 
C)  within a downgoing plate at a subduction zone 
D)  along mid-ocean ridges 
A)  within an otherwise stable continental interior 
B)  within an overriding plate at a subduction zone 
C)  within a downgoing plate at a subduction zone 
D)  along mid-ocean ridges

Question 13

Tectonic plates move at rates that are approximately ____________.

Accepted Answer

A)  1 to 5 cm every 1,000 years 
B)  1 to 15 cm/year 
C)  1 to 15 m/year 
D)  10 to 100 m/year 
A)  1 to 5 cm every 1,000 years 
B)  1 to 15 cm/year 
C)  1 to 15 m/year 
D)  10 to 100 m/year

Question 14

Wegener proposed continental drift after he observed evidence from fossils,glacial deposits,and the fit of the continents that suggested all of the continents were once ____________.

Accepted Answer

A)  aligned north to south along the prime meridian during the late Cenozoic 
B)  aligned east to west along the equator during the late Mesozoic through the Cenozoic 
C)  combined to form a supercontinent (he termed Rodinia) in the Proterozoic 
D)  combined to form a supercontinent (he termed Pangaea) in the late Paleozoic through the Mesozoic 
A)  aligned north to south along the prime meridian during the late Cenozoic 
B)  aligned east to west along the equator during the late Mesozoic through the Cenozoic 
C)  combined to form a supercontinent (he termed Rodinia) in the Proterozoic 
D)  combined to form a supercontinent (he termed Pangaea) in the late Paleozoic through the Mesozoic

Question 15

Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ____________.

Accepted Answer

A)  the addition of new crust due to hot-spot volcanism 
B)  the addition of new crust due to sedimentation 
C)  the addition of new lithospheric mantle as a result of cooling 
D)  reasons that geologists cannot determine at present 
A)  the addition of new crust due to hot-spot volcanism 
B)  the addition of new crust due to sedimentation 
C)  the addition of new lithospheric mantle as a result of cooling 
D)  reasons that geologists cannot determine at present

Question 16

If we mentally align the continents to fit Wegener's concept of Pangaea,evidence of late Paleozoic glacial deposits ____________.

Accepted Answer

A)  is more difficult to explain than in the modern continental configuration 
B)  is much more readily explained than in the modern continental configuration 
C)  makes very little sense in either the Pangaea configuration or the modern configuration 
A)  is more difficult to explain than in the modern continental configuration 
B)  is much more readily explained than in the modern continental configuration 
C)  makes very little sense in either the Pangaea configuration or the modern configuration

Question 17

The oldest sediments on the ocean floor are about ____________ years old.

Accepted Answer

A)  50 thousand 
B)  4 billion 
C)  200 million 
D)  2.5 million 
A)  50 thousand 
B)  4 billion 
C)  200 million 
D)  2.5 million

Question 18

Most of the pushing force that drives plate motion is produced ____________.

Accepted Answer

A)  at mid-ocean ridges 
B)  at subduction zones 
C)  at collision zones 
D)  in the interiors of continental plates 
A)  at mid-ocean ridges 
B)  at subduction zones 
C)  at collision zones 
D)  in the interiors of continental plates

Question 19

The deep ocean floor is flat and nearly featureless.

Accepted Answer

A) True 
 B)False

Question 20

The apparent polar-wander paths for continents that were not connected over some span of geologic history will likely ____________ concerning the positions of the ancient magnetic pole.

Accepted Answer

A)  agree 
B)  disagree 
A)  agree 
B)  disagree

The mid-ocean ridges are elevated above the surrounding sea floor because ____________.

Unlike the lithosphere,the asthenosphere ____________.

All lithospheric plates are approximately the same size and contain a combination of oceanic and continental crust.

Regions of the sea floor with positive magnetic anomalies were formed during times when Earth's magnetic field ____________.

The theory of plate tectonics ____________.

Deformed (bent,stretched,or cracked)lithosphere occurs ____________.

At transform plate boundaries ____________.

Within the sea floor,the rate of heat flow is greatest ____________.

The thickness of oceanic lithosphere is ____________.

The apparent polar-wander path obtained from magnetite crystals in basalts on the North American continent is now interpreted to be the result of ____________.

Wegener's evidence for a united Pangaea was so compelling that virtually all geologists agreed with the idea of continental drift during his lifetime.

The Wadati-Benioff zone is a belt of earthquakes found ____________.

Tectonic plates move at rates that are approximately ____________.

Wegener proposed continental drift after he observed evidence from fossils,glacial deposits,and the fit of the continents that suggested all of the continents were once ____________.

Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ____________.

If we mentally align the continents to fit Wegener's concept of Pangaea,evidence of late Paleozoic glacial deposits ____________.

The oldest sediments on the ocean floor are about ____________ years old.

Most of the pushing force that drives plate motion is produced ____________.

The deep ocean floor is flat and nearly featureless.

The apparent polar-wander paths for continents that were not connected over some span of geologic history will likely ____________ concerning the positions of the ancient magnetic pole.

The Earth in Context

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

The Wrath of Vulcan: Volcanic Eruptions

Pages of Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

A Violent Pulse: Earthquakes

Crags, cracks, and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of Earth

Riches in Rock: Energy and Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Running Water: the Geology of Streams and Floods

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

Dry Regions: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Filters

Exam 2: The Way the Earth Works: Plate Tectonics

The mid-ocean ridges are elevated above the surrounding sea floor because ____________.

Unlike the lithosphere,the asthenosphere ____________.

All lithospheric plates are approximately the same size and contain a combination of oceanic and continental crust.

Regions of the sea floor with positive magnetic anomalies were formed during times when Earth's magnetic field ____________.

The theory of plate tectonics ____________.

Deformed (bent,stretched,or cracked)lithosphere occurs ____________.

At transform plate boundaries ____________.

Within the sea floor,the rate of heat flow is greatest ____________.

The thickness of oceanic lithosphere is ____________.

The apparent polar-wander path obtained from magnetite crystals in basalts on the North American continent is now interpreted to be the result of ____________.

Wegener's evidence for a united Pangaea was so compelling that virtually all geologists agreed with the idea of continental drift during his lifetime.

The Wadati-Benioff zone is a belt of earthquakes found ____________.

Tectonic plates move at rates that are approximately ____________.

Wegener proposed continental drift after he observed evidence from fossils,glacial deposits,and the fit of the continents that suggested all of the continents were once ____________.

Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ____________.

If we mentally align the continents to fit Wegener's concept of Pangaea,evidence of late Paleozoic glacial deposits ____________.

The oldest sediments on the ocean floor are about ____________ years old.

Most of the pushing force that drives plate motion is produced ____________.

The deep ocean floor is flat and nearly featureless.

The apparent polar-wander paths for continents that were not connected over some span of geologic history will likely ____________ concerning the positions of the ancient magnetic pole.

The Earth in Context

Patterns in Nature: Minerals

Up From the Inferno: Magma and Igneous Rocks

The Wrath of Vulcan: Volcanic Eruptions

Pages of Earths Past: Sedimentary Rocks

Metamorphism: a Process of Change

A Violent Pulse: Earthquakes

Crags, cracks, and Crumples: Crustal Deformation and Mountain Building

Deep Time: How Old Is Old

A Biography of Earth

Riches in Rock: Energy and Mineral Resources

Unsafe Ground: Landslides and Other Mass Movements

Running Water: the Geology of Streams and Floods

Restless Realm: Oceans and Coasts

A Hidden Reserve: Groundwater

Dry Regions: the Geology of Deserts

Amazing Ice: Glaciers and Ice Ages

Global Change in the Earth System

Filters