GLY 101 Exam 3 (ch 12-17

Which physical property was responsible for determining how earth materials separate into interior layers at the time of earth's formation?
A) density
B) color
C) tensile strength
D) molecular charge

A) density

What is a mineral phase change?
A) Atoms in a mineral are rearranged into a denser and more stable structure
B) The exterior of a mineral weathers and changes color
C) a mineral melts from a solid state to a liquid state
D) a mineral changes density because of the addition of water

A) atoms in a mineral are rearranged into a denser and more stable structure

______ is the process when materials separate into different layers due to density.
A) Phase change
B) differentiation
C) tensional stress
D) shearing

B) differentiation

What is the major difference between the inner core and the outer core?
A) the outer core is solid while the inner core is liquid
B) the inner core is mostly iron and magnesium while the outer core is mostly silicon and oxygen
C) the outer core is mostly iron and magnesium while the inner core is mostly silicon and oxygen
D) the inner core is solid while the outer core is liquid

D) the inner core is solid while the outer core is liquid

What is the primary method scientists use to determine the layering of the interior of the earth?
A) drill cores
B)seismic waves
C) volcanic rocks
D) sonar

B) seismic waves

What will happen to a seismic wave when it is reflected?
A) the wave will undulate
B) the wave will be bounced back toward its source
C) the wave will be bent
D) nothing will change the wave

B) the wave will be bounced back toward its source

what will happen to a seismic wave when it is refracted?
A) the wave will be bounced back toward its source
B) the wave will be bent when passing into a material of differing density
C) the wave will undulate
D) nothing will change the wave

B) the wave will be bent when passing into a material of differing density

which seismic waves would be most useful in determining the extent and thickness of the earth's interior layers?
A) P and S waves
B) P and L waves
C) L and G waves
D) S and L waves

A) P and S waves

Which of the following materials will allow for the fastest transmission of seismic waves?
A) partially molten material
B) molten material
C) material that has been slightly heated
D) rigid, less compressible material

D) rigid, less compressible material

what is diffraction?
A) a seismic wave is bent when moving from one material to another
B) a seismic wave is bent when it passes by a curved surface
C) seismic waves are separated by liquids
D) a seismic wave is bounced back toward its source

B) a seismic wave is bent when it passes by a curved surface

why do seismic waves follow strongly curved paths as they move through the interior?
A) their velocities are altered by changes in chemistry
B) their paths are altered by changes in temperature
C) their velocities are changed because of increasing pressure with depth
D) their paths are altered by reflection off dense materials

C) their velocities are changed because of increasing pressure with depth

a relatively weak layer in the earth due to temperature is known as the _______
A) crust
B) mantle
C) lithosphere
D) asthenosphere

D) asthenosphere

where is the thinnest continental crust in north America?
A) Mississippi River Valley
B) Colorado Plateau
C) Appalachian Mountains
D) Basin and Range region

D) basin and range region

where is oceanic crust generated?
A) where magma bodies are emplaced deep in the crust
B) where continents collide
C) where volcanic lava meets the sea
D) along divergent plate boundaries

D) along divergent plate boundaries

the _____ is a seismic boundary between the crust and the mantle where there is a dramatic increase in seismic wave velocity.
A) Moho boundary
B) greenschist facies
C) schrodinger discontinuity
D) low-velocity pathway

A) moho boundary

the ______ layer is thought to have large variations in composition as well as temperature.
A) A"
B) B"
C) C"
D) D"

D) D"

Which layer or layers are believed to have convection cells?
A) outer core and inner core
B) mantle and outer core
C) inner core
D) mantle

B) mantle and outer core

which layer is thought to be the birthplace of deep mantle plumes?
A) D" layer
B) transition zone
C) outer core
D) shadow zone

A) D" layer

the inner core is believed to rotate independently from the outer layers of earth. why is this possible?
A) radioactive decay generates spin
B) the immense interior pressure generate rotation
C) frictional drag pushes the inner core at a different rate than the rest of the planet
D) the inner core is separated from the mantle by the liquid outer core and can spin freely

D) the inner core is separated from the mantle by the liquid outer core and can spin freely

where is the highest rate of heat flow escaping the earth's interior?
A) at mountain ranges
B) at volcanoes
C) at mid-ocean ridges
D) at subduction zones

C) at mid-ocean ridges

______ is a technique to view three-dimensional changes in composition and density by using seismology.
A) magnetometry
B) chemical convection
C) seismic tomography
D) paleomagnetism

C) seismic tomography

how is the shape of earth affected by its rotation?
A) earth is perfectly spherical
B) the equator is further from the center of the earth than the poles
C) the earth is more elongated at 45 degrees north and south latitude as compared with elsewhere
D) the poles are further from the center of the earth than the equator

B) the equator is further from the center of the earth than the poles

which of the following materials would cause the greatest gravity anomaly?
A) quartz
B) granite
C) water
D) metallic ore

D) metallic ore

a ______ occurs when an iron-rich fluid in the core is electrically charged and flowing, which generates a magnetic field.
A) geophysical anomaly
B) geotherm
C) geosyncline
D) geodynamo

D) geodynamo

______ are responsible for the heat generated in the interior today.
A) nuclear reaction
B) magma plutons
C) meteorite impacts
D) short-lived radioactive isotopes

D) short-lived radioactive isotopes

why is conduction not an efficient way to move heat through most of the earth?
A) molecules are too far apart to transfer heat via that method
B) radiation is the most efficient way to move heat through the interior
C) rocks are poor conductors of heat
D) radioactive decay generates too much hear

C) rocks are poor conductors of heat

what physical property of continents makes them difficult to subduct?
A) low density
B) age
C) temperature
D) thickness

A) low density

which process is responsible for earth's magnetic field? In which layer does this process occur?
A) radiation; upper mantle
B) subduction; lower mantle
C) crystallization; inner core
D) convection; outer core

D) convection; outer core

which of the following factors contributed toward the early increase in temperature in the earth's interior?
A) radioactive decay and impact from planetesimals
B) impact from planetesimals
C) friction between landmasses and radioactive decay
D) friction between landmasses

B) impact from planetesimals

If the outer core is cooler than the inner core, why is it in a liquid state?
A) it has greater water content than the inner core
B) it has higher density materials than the inner core
C) it has more radioactivity than the inner core
D) it is under less pressure than the inner core

D) it is under less pressure than the inner core

The measurement of ocean depth and the topography of the ocean floor are known as _______.
A) bathymetry
B) geophysics
C) topographic surveying
D) seismic tomography

A) bathymetry

which of the following groups contains all three major topographic provinces oceanographers use to define the seafloor?
A) continental margins, mid-ocean ridges, and deep-ocean basins
B) submarine trenches, mid-ocean ridges, and turbidity currents
C) mid-ocean ridges, continental shelves, and divergent boundaries
D) deep ocean basins, active margins, and passive margins

A) continental margins, mid-ocean ridges, and deep-ocean basins

what are the two types of continental margins?
A) passive and active
B) transform and divergent
C) continental shelves and slopes
D) trenches and rifts

A) passive and active

which of the following is associated with a passive continental margin?
A) transform boundaries
B) convergent boundaries
C) divergent boundaries
D) no tectonic boundaries nearby

D) no tectonic boundaries nearby

which of the following is associated with an active continental margin?
A) transform boundaries
B) divergent boundaries
C) convergent boundaries
D) no tectonic boundaries nearby

C) convergent boundaries

which region is surrounded by an active continental margin?
A) Atlantic Ocean
B) Arctic Ocean
C) Indian Ocean
D) Pacific Ocean

D) pacific ocean

which of the following scenarios would likely result in the development of a passive continental margin?
A) two tectonic plates sliding past each other, rotating part of the crust
B) A mantle plume creating a chain of volcanic islands across the seafloor
C) Continental blocks rifting apart & becoming separated by seafloor spreading
D) two tectonic plates colliding, creating, a submarine trench

C) continental blocks rifting apart and becoming separated by seafloor spreading

the continental shelf is composed of which material(s)?
A) Basaltic crust
B) Ophiolites
C) Granitic crust covered with sedimentary rocks
D) clay sediments and sands

A) basaltic crust

although many areas of the continental shelves are relatively featureless, there are some locations on the shelves that have received extensive glacial deposits and significant dissection by streams. How would this have been possible?
A) glaciers and streams were powerful enough to shape the shelf underwater
B) as the continents collided in the past, the shelves were lifted above sea level and became exposed to the elements
C) the shelves were once above sea level but have since dropped below sea level due to tectonic activity
D) the sea level dropped during the last glacial episode because water was stored in large ice sheets, exposing the shelves

D) the sea level dropped during the last glacial episode because water was stored in large ice sheets, exposing the shelves

Which of the following will mark the furthest extent of a continent?
A) the lowest part of the continental slope
B) the crest of the continental slope
C) the shoreline
D) tidal flats exposed during low tide

B) the crest of the continental slope

what is the definition of turbidity current?
A) submarine landslide
B) focused jet of water blasting across the shelf from a surface stream
C) fast-moving water created by density differences
D) subsidence of the seafloor

A) submarine landslide

which part of a passive continental margin is built up by repeated deposition from turbidity currents?
A) continental shelf
B) continental rise
C) continental slope
D) abyssal plain

B) continental rise

submarine canyons found cutting into the continental shelf and slope are believed to have been created ______.
A) by rivers during the ice age
B) by tectonic rifting
C) by icebergs
D) by subduction

A) by rivers during the ice age

What is the definition of subduction erosion?
A) diverging tectonic plates will cause rocks to slide downward along normal faults
B) sediments from the ocean floor are scraped off a subducting tectonic plate and adhere to the overring plate
C) glaciers extending off the continent will scour deep grooves in continental shelves
D) sediment and rock are scraped off the bottom of an overriding plate and transported into the mantle by a descending plate

D) sediment and rock are scraped off the bottom of an overriding plate and transported into the mantle by a descending plate

where is the deepest place on earth?
A) Kuril Trench
B) mid-continent rift
C) Peru-Chile trench
D) challenger deep

D) challenger deep

along which tectonic boundary are deep ocean trenches found?
A) transform
B) convergent
C) divergent

B) convergent

volcanic island arcs are found near which features on the seafloor?
A) coral atolls
B) abyssal plains
C) deep-ocean trenches
D) rift zones

C) deep ocean trenches

what is the source of flood basalts associated with oceanic plateaus?
A) partial melting associated with subduction
B) decompression melting associated with seafloor spreading
C) impact heating from a meteorite strike
D) the melting of the head of a mantle plume

D) the melting of the head of a mantle plume

volcanic islands such as the Hawaiian islands form as a result of _______.
A) rifting
B) subduction
C) mantle plumes
D) batholith emplacement

C) mantle plumes

submarine volcanoes, called _______ may rise hundreds of meters above the surrounding seafloor.
A) trench plateaus
B) abyssal ridges
C) hot spots
D) seamounts

D) seamounts

where do rift valleys from along the oceanic ridge system?
A) along the axis of some ridge segments where the rift is down-faulted
B) transecting the ridge where transform boundaries exist
C) where the seafloor plunges back into the mantle as the plate is consumed
D) along the flanks of the continent where the slope levels out to meet the seafloor

A) along the axis of some ridge segments where the rift is down-faulted

what rock would you expect to find associated with a mid-ocean ridge?
A) basalt
B) sandstone
C) limestone
D) granite

A) basalt

what generates the magma necessary for seafloor spreading?
A) partial melting
B) subduction
C) decompression melting
D) mantle plumes

A) partial melting

which of the following materials or features are not found at mid-ocean ridges?
A) deep submarine trenches
B) basaltic lava eruptions emitted along the ridge
C) stands higher above the surrounding seafloor
D) thin layers of sediments

A) deep submarine trenches

the oceanic crust is composed almost entirely of _____ rocks that are underlain by _____ rocks, which makes up the lithospheric mantle.
A) felsic; sediments
B) intermediate; felsic
C) mafic; ultramafic
D) sedimentary; mafic

C) mafic; ultramafic

the sheeted dike complex is layer _____ of the ocean floor.
A) 1
B) 2
C) 3
D) 4

C) 3

which of the following is not an example of a continental rift?
A) rhine valley, Europe
B) Appalachia, United States
C) lake baikal, Siberia
D) East Africa

B) Appalachia, united states

thermal springs known as _____ are often associated with oceanic ridges, where hot water containing dissolved minerals gushes from the seafloor.
A) geysers
B) ophiolites
C) hot springs
D) black smokers

D) black smokers

which process, common near black smokers, uses hot water circulating through the crust to alter olivine and pyroxene into chlorite and serpentine?
A) decompression melting
B) hydrothermal metamorphism
C) thermal contraction
D) partial melting

B) hydrothermal metamorphism

why do mantle plumes tend to concentrate beneath supercontinents such as Pangea?
A) concentrations of radioactive materials build up as continents assemble
B) friction from converging landmasses heats up the mantle
C) a large landmass acts as an insulating blanket to trap heat in the mantle
D) partial melting from subduction concentrates large volumes of magma

C) A large landmass acts as an insulating blanket to trap heat in the mantle

most mountain ranges are the result of _____ stress.
A) shear
B) compressional
C) tensional

B) compressional

Which of the following terms describes the increasing downward force on basal rocks as a mountain continues to grow?
A) accretion
B) isostacy
C) delamination
D) gravitational collapse

D) gravitational collapse

How would the angle of subduction of a tectonic plate influence the location of a volcanic arc?
A) the steeper the angle, the closer the arc would form to the trench
B) the shallower the angle, the closer the arc would form to the trench
C) the angle of subduction doesn't affect the location of the volcanic arc
D) the steeper the angle, the further the arc would form to the trench

D) the steeper the angle, the further the arc would form to the trench

In which location on a continent would one be likely to find young mountain belts (less than 100 million years old)?
A) on the stable platform
B) along the margins of the continent
C) in the center of the continent
D) on the continental shield

B) along the margins of the continent

which of the following regions of a subduction zone is characterized by thick sequences of relatively undeformed sedimentary rocks?
A) suture
B) volcanic island arc
C) transform fault
D) forearc region

D) forearc region

put the four regions of a subduction zone in order from the convergent boundary landward toward the continental interior.
A) volcanic arc, deep-ocean trench, forearc region, back-arc region
B) forearc, back-arc, deep-ocean trench, volcanic arc
C) back-arc region, volcanic arc, forearc, deep-ocean trench
D) deep-ocean trench, forearc region, volcanic arc, back-arc region

D) deep-ocean trench, forearc region, volcanic arc, back-arc region

which factor(s) will most influence the depth of deep-ocean trenches?
A) temperature and density of the plate
B) density and composition of the mantle beneath
C) rate of convection
D) compressive force

A) temperature and density of the plate

the Cascadia subduction zone off the coast of Washington and Oregon famously lacks a well-defined deep-ocean trench. Why might this be the case?
A) the descending plate is warm and buoyant, so it subducts shallowly
B) there is a shallow angle of plate subduction, as well as large quantities of sediment infill
C) compression from the convergent boundary has squeezed any potential trench closed
D) there is a massive amount of sediment fill from the Columbia River basin

B) there is a shallow angle of plate subduction as well as large quantities of sediment infill

How does the angle of subduction affect the dimensions of the forearc basin?
A) shallow angle of subduction leads to a wide forearc basin
B) steep angle of subduction leads to a wide forearc basin
C) steep angle of subduction leads to a narrow forearc basin
D) shallow angle of subduction closes the forearc basin

C) steep angle of subduction leads to a narrow forearc basin

what is the source of the sediments in a forearc basin?
A) continental sediments and pyroclastic materials
B) glacial sediments
C) carbonate reefs
D) sediments washed from the landmasses

A) continental sediments and pyroclastic materials

If a back-arc basin is associated with a volcanic island arc, what tends to develop there?
A) long, linear sea
B) rift valley
C) wide continental shelf
D) submarine trench

A) long linear sea

if a back-arc basin is a region related to a subduction zone, how can such an extensional basin form near a boundary defined by compression?
A) trench rolls back as the old, dense subducting plate sinks
B) rising magma is softening the crust, allowing it to stretch
C) a plate subducting at an extremely shallow angle is pushing against the back-arc region
D) compression ceases before extension takes over

A) trench rolls back as the old, dense subducting plate sinks

which of the following is an example of a volcanic island arc?
A) Andean Volcanoes
B) Aleutian Volcanoes
C) Hawaiian Volcanoes
D) Cascade Volcanoes

B) Aleutian volcanoes

In ocean-continental convergence, a volcanic arc is created on the _____ and is the result of _____ rising up from a subducting plate.
A) continental plate; magma
B) oceanic plate; sediment
C) oceanic plate; magma
D) continental plate; sediment

A) continental plate; magma

a ______ will form as sediment collects between the accretionary wedge and the volcanic arc.
A) forearc basin
B) continental shelf
C) back-arc basin
D) deep-ocean trench

C) back-arc basin

a divergent boundary will be characterized by what feature?
A) a trench
B) a back-arc basin
C) a rift zone
D) a forearc basin

C) a rift zone

which of the following locations is a remnant of a forearc basin?
A) great valley, CA
B) snake river plain, ID
C) lake baikal, Siberia
D) death valley, CA

A) great valley CA

what is an accretionary wedge?
A) sediments and ocean crust fragments being scraped off of a subducting plate
B) fault blocks that are slipping down due to extension in a back-arc basin
C) deformed and thrust-faulted continental lithosphere
D) a fan of sediments at the bottom of a deep-ocean trench

A) sediments and ocean crust fragments being scraped off of a subduction plate

which type of volcanic material will dominate the eruptions along a continental volcanic arc?
A) a mix of felsic and ultramafic lavas
B) lavas of intermediate or felsic composition
C) felsic lavas
D) mafic lavas

D) mafic lavas

a _____ is a crustal fragment that has been transported by plate tectonics and has adhered to an overriding plate
A) guyot
B) xenolith
C) terrain
D) terrance

D) terrane

which of the following locations is composed largely of accreted terranes?
A) colorado
B) Illinois
C) California
D) Hawaii

C) california

what is a suture?
A) the zone where two continents are welded together
B) the region of a mid-ocean ridge where it is bisected by a transform boundary
C) a fold-and-thrust belt created through convergence
D) a landmass accreted to a continent through subduction

A) the zone where two continents are welded together

as India is colliding with Asia, the margin of Asia is experiencing significant deformation. What is happening to the rocks that are being deformed?
A) they are being displaced to the southeast to make up southeast Asia
B) they are breaking off to form microcontinents
C) they are being subducted into the mantle
D) they are being melted to become magma plutons

A) they are being displaced to the southeast to make up southeast Asia

put the three orogenic events of the Appalachian in order from oldest to youngest.
A) laramide orogeny, taconic, alleghanian orogeny
B) taconic orogeny, acadian orogeny, allenghanian orogeny
C) taconic orogeny, laramide orogeny, acadian orogeny
D) alleghanian orogeny, taconic orogeny, acadian orogeny

B) taconic, acadian, alleghanian

which of the following describes the events of the taconic orogeny?
A) closing of the marginal sea caused a volcanic arc to be thrust over the continent
B) the sea along north America closed completely as Africa collided with north America
C) the rifting of Pangaea opened the modern Atlantic Ocean
D) north America collided with a microcontinent as the marginal sea continued to close

A) closing of the marginal sea caused a volcanic arc to be thrust over the continent

which of the following statements best characterizes the geology of western north America, starting in California and extending through British Columbia and up into Alaska?
A) geologically distinct, microcontinent-sized fragments and terraces accreted to the continent
B) metamorphosed accretionary wedges
C) divergent rifting creating deep, wide valleys with garbens
D) collision of a massive subcontinent of old igneous and metamorphic rocks, resulting in fold-and-thrust mountains that are still growing

A) geologically distinct, microcontinent-sized fragments and terraces accreted to the continent

what are fault block mountains?
A) mountains formed through crustal extension and normal faulting
B) mountains consisting of exposed batholiths
C) mountains formed through folding and thrusting of the crust
D) mountains that form by erosion of streams

A) mountains formed through crustal extension and normal faulting

which US region is made up of a series of high-angle normal faults producing nearly parallel mountain ranges?
A) valley and ridge province
B) colorado plateau
C) basin and range province
D) Appalachian mountains

C) basin and range province

which of the following is a real-world example of isostatic adjustment?
A) downwarping of the continent in Illinois due to subduction of slabs of oceanic lithosphere
B) African continent bulging upward when moving over a mantle plume
C) rebound of the landmass around Hudson Bay after glacial ice sheets have retreated
D) continental margin of north America extending to create a forearc basin in California

C) rebound of the landmass around hudson bay after glacial ice sheets have retreated

why would geologic mapping be difficult in an area dominated by accreted terranes?
A) isostatic rebound would result in gravitational collapse to make them indistinct
B) the geology is so similar that it would be difficult to determine terrane boundaries
C) each terrane is geologically distinct, but also highly deformed
D) terranes are very old and terribly eroded

C) each terrane is geologically distinct, but also highly deformed

_____ is the downslope movement of rock, regolith, or soil under the direct influence of gravity.
A) erosion
B) mass wasting
C) weathering
D) dissolution

B) mass wasting

what term is commonly used to describe a sudden event in which large volumes of rock move down steep slopes?
A) carbonization
B) lahar
C) mass wasting
D) rockslide

D) rockslide

which of the following locations would be most likely to see large-scale, rapid mass wasting?
A) the rocky mountains
B) Florida everglades
C) Mojave desert
D) central Illinois

A) the rocky mountains

which of the following factors does not influence mass wasting?
A) water
B) geologic age
C) vegetation
D) gravity

B) geologic age

stream valleys are produced through combined effects of mass wasting and running water. If running water alone were responsible for creating stream valleys, how would they appear?
A) wide valleys with flat bottoms
B) u-shaped valleys
C) narrow valleys with vertical walls
D) v-shaped valleys

C) narrow valleys with vertical walls

which region would be most likely to produce a catastrophic landslide?
A) flat-lying floodplains along a stream
B) steep, geologically young mountains
C) old, eroded, worn-down mountains
D) v-shaped stream valley with gentle slopes

B) steep, geologically young mountains

what is the controlling force of mast wasting?
A) friction
B) gravity
C) water
D) hydration

B) gravity

a _____ is not the sole cause of a mass wasting event, but the last of many causes that initiate the downslope movement of materials
A) trigger
B) slide
C) repose angle
D) debris flow

A) trigger

which of the following scenarios would lead to a mass wasting event due to an oversteepened slope?
A) baking of surface materials during a wildfire
B) heavy rains saturate slope materials
C) trees are planted on a slope
D) construction of buildings on slopes

D) construction of buildings on slopes

what is the angle of repose?
A) the angle of plunge into the interior
B) the angle of the slip plane from a slide
C) the steepest angle at which a material remains at rest
D) the angle of an inclined rock layer measured from a horizontal line

C) the steepest angle at which a material remains at rest