Studied by 50 peopleWhich physical property was responsible for determining how earth materials separate into interior layer at the time of earths formation
density
What is a mineral phase change
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
differentiation
What is the major difference between the inner core and the outer core
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
seismic waves
What will happen to a seismic wave when it is reflected
the wave will be bounced back toward the source
what will happen to a seismic wave when it is refracted
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 earths interior layers
P and S waves
Which of the following materials will allow for the fastest transmission of seismic waves
rigid, less compressible material
what is diffraction
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
their velocities are changed because of increasing pressure with depth
a relatively weak layer in the earth due to temperature is known as the _______
asthenosphere
where is the thinnest continental crust in north America
basin and range region
where is oceanic crust generated
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
moho boundary
the ______ layer is thought to have large variations in composition as well as temperature
D"
Which layer or layers are believed to have convection cells
mantle and outer core
which layer is thought to be the birthplace of deep mantle plumes
D" layer
the inner core is believed to rotate independently from the outer layers of earth. why is this possible
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 earths interior
at mid ocean ridges
______ is a technique to view three-dimensional changes in composition and density by seismology
seismic tomography
how is the shape of earth affected by its rotation
the equator is further from the center of the earth than the poles
which of the following materials would cause the greatest gravity anomaly
metallic ore
a ______ occurs when an iron-rich fluid in the core is electrically charged and flowing, which generates a magnetic field
geodynamo
______ are responsible for the heat generated in the interior today
short-lived radioactive isotopes
why is conduction not an efficient way to move heat through most of the earth
rocks are poor conductors of heat
what physical property of continents makes them difficult to subduct
low density
which process is responsible for earths magnetic field? In which layer does this process occur
convection; outer core
which of the following factors contributed toward the early increase in temperature in the earths interior
impact from planetesimals
If the outer core is cooler than the inner core, why is it in a liquid state
it is under less pressure than the inner core
The measurement of ocean depth and the topography of the ocean floor are known as _______
bathymetry
which of the following groups contains all three major topographic provinces oceanographers use to define the seafloor
continental margins, mid-ocean ridges, and deep-ocean basins
what are the two types of continental margins
passive and active
which of the following is associated with a passive continental margin
no tectonic boundaries nearby
which of the following is associated with an active continental margin
convergent boundaries
which region is surrounded by an active continental margin
pacific ocean
which of the following scenarios would likely result in the development of a passive continental margin
continental blocks rifting apart and becoming separated by seafloor spreading
the continental shelf is composed of what materials
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
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
lowest part of continental slope
what is the definition of turbidity current
submarine landslide
which part of a passive continental margin is built up by repeated deposition from turbidity currents
continental rise
submarine canyons found cutting into the continental shelf and slope are believed to have been created ______
by rivers during the ice age
What is the definition of subduction erosion
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
challenger deep
along which tectonic boundary are deep ocean trenches found
convergent
volcanic island arcs are found near which features on the seafloor
deep ocean trenches
what is the source of flood basalts associated with oceanic plateaus
the melting of the head of a mantle plume
volcanic islands such as the Hawaiian islands form as a result of _______
mantle plumes
submarine volcanoes, called _______ may rise hundreds of meters above the surrounding seafloor
seamounts
where do rift valleys form along the oceanic ridge system
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
basalt
what generates the magma necessary for seafloor spreading
partial melting
which of the following materials or features are not found at mid-ocean ridges
deep submarine trenches
the oceanic crust is composed almost entirely of _____ rocks that are underlain by _____ rocks, which makes up the lithospheric mantle
mafic; ultramafic
the sheeted dike complex is layer _____ of the ocean floor
3
which of the following is not an example of a continental rift
Appalachia, united states
thermal springs known as _____ are often associated with oceanic ridges, where hot water containing dissolved minerals gushes from the seafloor
black smokers
which process, common near black smokers, uses hot water circulating through the crust to alter olivine and pyroxene into chlorite and serpentine
hydrothermal metamorphism
why do mantle plumes tend to concentrate beneath supercontinents such as Pangea?
A large landmass acts as an insulating blanket to trap heat in the mantle
most mountain ranges are the result of _____ stress
compressional
Which of the following terms describes the increasing downward force on basal rocks as a mountain continues to grow
gravitational collapse
How would the angle of subduction of a tectonic plate influence the location of a volcanic arc
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)
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
forearc region
put the four regions of a subduction zone in order from the convergent boundary landward toward the continental interior
deep-ocean trench, forearc region, volcanic arc, back-arc region
which factor(s) will most influence the depth of deep-ocean trenches
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
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
steep angle of subduction leads to a narrow forearc basin
what is the source of the sediments in a forearc basin
continental sediments and pyroclastic materials
If a back-arc basin is associated with a volcanic island arc, what tends to develop there
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
trench rolls back as the old, dense subducting plate sinks
which of the following is an example of a volcanic island arc
Aleutian volcanoes
In ocean-continental convergence, a volcanic arc is created on the _____ and is the result of _____ rising up from a subducting plate
continental plate; magma
a ______ will form as sediment collects between the accretionary wedge and the volcanic arc
back-arc basin
a divergent boundary will be characterized by what feature
a rift zone
which of the following locations is a remnant of a forearc basin
great valley CA
what is an accretionary wedge
sediments and ocean crust fragments being scraped off a subduction plate
which type of volcanic material will dominate the eruptions along a continental volcanic arc
mafic lavas
a _____ is a crustal fragment that has been transported by plate tectonics and has adhered to an overriding plate
terrane
which of the following locations is composed largely of accreted terranes
california
what is a suture
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
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
taconic, acadian, alleghanian
which of the following describes the events of the taconic orogeny
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
geologically distinct, microcontinent-sized fragments and terraces accreted to the continent
what are fault block mountains
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
basin and range province
which of the following is a real-world example of isostatic adjustment
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
each terrane is geologically distinct, but also highly deformed
_____ is the downslope movement of rock, regolith, or soil under the direct influence of gravity
mass wasting
what term is commonly used to describe a sudden event in which large volumes of rock move down steep slopes
rockslide
which of the following locations would be most likely to see large-scale, rapid mass wasting
the rocky mountains
which of the following factors does not influence mass wasting
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
narrow valleys with vertical walls
which region would be most likely to produce a catastrophic landslide
steep, geologically young mountains
what is the controlling force of mast wasting
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
trigger
which of the following scenarios would lead to a mass wasting event due to an over steepened slope
construction of buildings on slopes
what is the angle of repose
the steepest angle at which a material remains at rest
Note
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