eas 2600 test 2
When tensional forces act on a fault plane, they produce _________.
normal faults
What is the name for a basaltic lava flow that has a ropy, folded surface?
pahoehoe
Basaltic lava that cools under water forms distinct _________ features.
pillow lava
A fold that has a non-horizontal fold axis is called a(n) ________ fold. This is typically represented by a U or slightly V- shaped exposure of the rock layers as viewed from the surface.
plunging
Which of the following forces, when applied to the edges of a layer, will not produce a fold?
pulling apart
Over the past 2000 years, which of the following volcanic hazards has caused the most fatalities?
pyroclastic flows
Solidified fragments of volcanic material ejected into the air are called
pyroclasts
If a sediment started out with equal proportion of quartz and feldspar, then which of the following sediment compositions will have been transported the furthest?
quartz/feldspar = 3/1
Which of the following metamorphic rocks is INCORRECTLY paired with its parent rock?
quartzite -granite
The average time between large earthquake events along a fault is known as the ______ interval.
recurrence
Seismic waves that bounce off a boundary between two different materials are said to be ________, whereas seismic waves that cross the boundary and are bent are said to be ________.
reflected; refracted
The two "kinks" in the seismic wave path are examples of seismic __________.
refraction
What type of metamorphism is caused by high temperature and high pressure imposed over a large volume of crust?
regional
What type of volcano has the largest and most violent eruptions?
resurgent calderas
Rocks that undergo elastic deformation will _____________.
return to their original shape once the stress is released
Which of the following lavas will flow downhill slowest?
rhyolite
What types of lavas are erupted at ocean-continent convergent plate boundaries?
rhyolites, andesites, basalts
After melting of a continental ice cap, the surface of the continent will tend to ______.
rise
Up-Down
s wave
A clastic sedimentary rock composed of medium-grained (1 mm across) particles is called a ______.
sandstone
The parent rock of quartzite is
sandstone
Which of the following is an example of a clastic sedimentary rock?
sandstone
Which of the following sets of processes is written in order of increasing temperature?
sedimentation, diagenesis, metamorphism
Energy waves that are released during an earthquake are called __________.
seismic waves
Which set(s) of waves is/are P waves?
set A
Look at the seismogram attached to the back of your exam. Which set of waves represent the surface waves?
set C
Which set(s) of waves travels through the Earth's interior?
sets A and B
The area on the surface of the Earth where P waves and S waves are not recorded by seimograms following an earthquake event are referred to as _______.
shadow zones
Which of the following rocks is composed of clay-sized clastic sediment?
shale
Which of the following sedimentary rock groups are MOST abundant?
shales
In a thickened lithosphere you expect to see
shallower geothermal gradients
Which of the following correctly links the tectonic force with the expected type of faulting?
shear + compression = oblique-slip faulting
What type of seismic waves are S waves?
shear waves
What kind of metamorphism would you expect to see in the rocks at a meteorite impact site?
shock
Which of the following elements is more abundant in Earth's crust than in Earth as a whole?
silicon
Sedimentary particles that are abraded will become
smaller and more rounded
What powers Earth's external heat engine?
solar energy
The Earth's magnetic field shields the surface of the Earth from _________.
solar winds
The tendency for variations in current velocity to segregate sediments on the basis of particle size is called ______.
sorting
Calculations suggest that the inner core __________.
spins at a faster rate than the rest of the Earth
Near a subduction zoneyou expect to see
steeper geothermal gradients
What type of metamorphism would follow a relatively high pressure-low temperature path?
subduction
What type of seismic wave causes the MOST building damage?
surface waves
What type of seismic wave causes the most building damage?
surface waves
Which of the following types of seismic waves are the slowest?
surface waves
Coal is produced from the diagenesis of
swamp vegetation
Coal is produced from the diagenesis of ______.
swamp vegetation
Which of the following sedimentary structures suggests the presence of a back-and-forth current?
symmetric ripple marks
What determines whether a rock deforms in a brittle fashion versus a ductile fashion?
temperature, rock type, rate of deformation
Analysis of fault mechanisms indicates ___________ at divergent boundaries and _______ at transform boundaries.
tension; shear
The modified Mercalli intensity scale measures ____________.
the amount of destruction caused by an earthquake
An earthquake's Richter magnitude is based on ______.
the amount of ground movement caused by seismic waves
The moment magnitude of an earthquake is proportional to_____________.
the area of the fault break and the seismic energy released during the rupture
As the distance to an earthquake increases, __________.
the elapsed time before the S waves arrive increases
What type of information do seismographs give about an earthquake?
the fault mechanism, the location, the magnitude
Which of the following measurements collected from seismograph stations gives scientists information regarding the type of faulting that occurred during an earthquake?
the first motion of the P waves
Which of the following Earth systems powers the Earth's magnetic field?
the geodynamo system
Which of the following regions is hottest?
the inner core
If erosion stripped the top off a dome, one would find __________.
the oldest rocks exposed in the center
43. Which layer in the Earth does not transmit S waves?
the outer core
Which layer in the Earth does nottransmit S waves?
the outer core
What is metasomatism?
the parallel alignment of minerals in a metamorphic rock
68. Which of the following factors remains constant and does not vary depending on tectonic setting?
the rate of pressure increase with depth
Geologic maps are used to depict
the strike and dip
Which of the following regions in the Earth consists primarily of olivine and pyroxene?
the upper mantle
Which of the following processes is responsible for the recording of the magnetic reversals on the seafloor?
thermoremanent magnetism
How many seismograph stations are needed to locate the epicenter of an earthquake?
three
Based on seismic tomographic images, how deep do subducting slabs extend?
to the core-mantle boundary
Body Waves
travel through the earth
Tsunamis can be generated by
undersea earthquakes, the eruption of an oceanic volcano, or undersea landslides.
How fast do tsunamis travel across the ocean?
up to 800 kilometers per hour
Which of the following is typically not a factor used to estimate seismic risk in a given region?
vegitation
Diatremes are a type of
volcanic neck material
Which of the following gases is the main constituent of volcanic gas?
water vapor
25. During metasomatism, hydrothermal fluids can remove all _____ from an affected rock.
water-soluble chemical elements
Evidence for the internal structure of the Earth is mostly based on __________.
waves generated by earthquakes
Evidence for the internal structure of Earth is mostly based on
waves generated by earthquakes.
What is the average rate at which temperature increases with depth in Earth's crust?
30°C/km
Approximately how far away from the seismograph station was the earthquake?
5000 km
Which of the following environments is an example of a shoreline environment?
delta
Which of the following terms describes the alteration of sediments to sedimentary rocks after deposition?
diagenesis
54. Shiprock, New Mexico, is an example of a
diatreme (volcanic neck)
Directed pressure is also sometimes called
differential stress or differential pressure
An overturned fold is characterized by two limbs _________.
dipping in the same direction, with one limb tilted beyond vertical
Where does seafloor metamorphism take place?
divergent plate boundaries
Point B is called the earthquake __________.
epicenter
Granoblastic (nonfoliated or massive) metamorphic rocks generally contain minerals that are _______ in shape.
equant
Which of the following is NOT a clastic sedimentary environment?
evaporate
Which of the following is not a clastic sedimentary environment?
evaporite
The process whereby metamorphic rocks rise to the Earth's surface is called _______.
exhumation
The retrograde part of a metamorphic P-T path occurs during __________.
exhumation and cooling
In response to deformation brittle materials will _____ whereas ductile materials will ____.
fault; fold
Find the correct volcano/volcanic product match.
fissure/basalt
During metamorphism pressure will ____ the rocks in the direction a force is applied and ____ in the direction perpendicular to that same force.
flatten; elongate
Point A, where slip initiated during the earthquake, is called the __________.
focus
The parallel alignment of mica in a metamorphic rock is an example of
foliation
The parallel alignment of mica in a metamorphic rock is an example of ______.
foliation
Small vents on volcanoes that emit gas fumes and steam are called
fumaroles.
Metamorphic mineral assemblages that can be used as pressure gauges are referred to as _________.
geobarometers
A diagram representing a vertical slice through Earth's crust is called a
geologic cross section
A diagram representing a vertical slice through the Earth's crust is called a _________.
geologic cross section
The graphical curve that describes how temperature changes with depth in the Earth is called the ___________.
geotherm
Which of the following rocks represents the highest metamorphic grade?
gneiss
Which of the following sequences describes the metamorphic changes in a shale with DECREASING metamorphic grade?
gneiss, schist, slate
Light-colored rocks with coarse bands of segregated light and dark minerals are called ______.
gneisses
Which of the following correctly lists the three rock types in order of increasing P-wave velocity?
granite → gabbro → peridotite
What is the porosity of newly deposited mud?
greater than 50%
Which of the following minerals precipitates directly from water in evaporite deposits?
gypsum
Which of the following is deposited only by non-biological, chemical precipitation?
halite
In which of the following subsystems is Earth's magnetic field generated?
hydrologic system
Confining pressure is pressure applied _________.
in all directions
Where do P waves travel fastest?
in the lower mantle
The inner core is solid relative to the outer core because of a(n)
increase in pressure with depth.
Seismic wave speeds increase with __________.
increasing density and decreasing temperature
Burial of sediments results in
increasing pressure and increasing temperature.
Different pressure-temperature zones within a belt of regionally metamorphosed rock are defined by the presence of
index minerals
Which of the following statements best describes the behavior of rocks during deformation?
Brittle materials deform by faulting, whereas ductile materials deform by folding.
Earth's core is made up primarily of
iron
A torrential mudflow of wet volcanic debris is called a(n)
lahar
changes in the size or shape of a rock body
Deformation
Point on the surface, directly above the focus
Epicenter
the place within Earth where earthquake waves originate
Focus
Minerals are in a parallel alignment
Foliated texture
Which of the following statements about convection is TRUE?
Hot material flows upward and displaces cool material
Given that the P wave velocities are related to rock density, choose the sequence that shows the rocks in terms of increasing P wave speeds. Rock densities are: rock I = 2.9 gm/cc, rock II = 2.6 gm/cc, and rock III = 3.3 gm/cc.
II, I, III
Continental crust is ________ oceanic crust.
less dense than
What is the most abundant nonclastic sedimentary rock?
limestone
What are the plates of plate tectonics made up of?
lithosphere
During metamorphism a rock will not
loose its solid form
The oceanic crust consists mostly of ______.
mafic rocks
Which of the following metamorphic rocks cannot form from a shale?
marble
Which of the following rocks has a non-foliated granular texture?
marble
Fault mechanisms at subduction zones are called ___________.
megathrusts
Takes place where preexisting rock is subjected to temperatures and pressures unlike those in which it formed
metamorphic
What metamorphic rock could also be considered a transitional rock between igneous and metamorphic?
migmatite
An underground igneous body
Pluton
Which set of waves would be used to determine Richter Magnitude?
Set C
Which of the following statements about transportation of sediment is FALSE?
Smaller particles settle faster than larger particles
travel on the surface of the earth
Surface Waves
downfolded, youngest rock in center
Syncline
What is the relationship between metamorphic foliation and sedimentary bedding?
There is no general angular relationship between sedimentary bedding and metamorphic foliation.
Abrasion of sediment particles results in which of the following?
They become smaller and more rounded.
What sort of sedimentary environments are floodplains?
alluvial
In what type of environment did the ripples depicted below most likely form?
alluvial (stream)
The modified Mercalli intensity scale measures the
amount of destruction caused by an earthquake
Which of the following marks the boundary between the crust and the mantle?
an increase in P-wave velocity and a change in rock type
Which of the following processes will cause metamorphism?
an increase in temperature, pressure, and interaction with hydrothermal fluids
What sort of fault type is likely to form where shear forces combine with compressive or tensional forces?
an oblique-slip fault
Metamorphic rocks may form from
any of the major rock types.
In a deep mine, temperatures increase at the rate of ______.
approximately 25°C per kilometer
How thick is the oceanic crust?
approximately 7 km
Which of the following types of sandstones is most likely to form by the rapid mechanical weathering of a granite?
arkose
Which of the following relationships is CORRECT?
asthenosphere = crust + upper mantle
Sedimentary processes take place
at or near Earth's surface
Sedimentary processes take place ____________.
at or near the Earth's surface
The surface that divides a fold into two symmetrical halves is called the __________.
axial plane
How do rock particles move during the passage of an S wave through the rock?
back and forth at right angles to the direction of wave travel
How do rock particles move during the passage of an P wave through the rock?
back and forth parallel to the direction of wave travel
Mantle plumes generate large volumes of ________ magmas.
basaltic
22. The largest forms of igneous intrusions are called
batholiths
Why is the average elevation of the continents higher than the average elevation of the seafloor?
because oceanic crust is composed of denser rocks than the continental crust
What type of material undergoes smooth, continuous plastic deformation?
brittle, cataclastic, ductile
The prograde part of a metamorphic P-T path occurs during
burial and heating
The prograde part of a metamorphic P-T path occurs during __________.
burial and heating
Which of the following factors remains constant and does not vary depending on tectonic setting?A)the geothermal gradientB)the thickness of the lithosphereC)the rate of pressure increase with depthD)the depth to the 1300°C isotherm
c
Which mineral is commonly used to determine a metamorphic P-T path?
calcite
The most abundant chemical/biochemical sedimentary rocks are ______.
carbonates
What causes the sharp increases in the velocity of S waves at 400 and 660 kilometers depth in the mantle?
changes in the mineral structures
What causes the sharp increases in the velocity of S waves at a depth of 400 and 660 km in the mantle?
changes in the mineral structures
Which of the following sedimentary rocks is composed of biochemically precipitated silica?
chert
Which sedimentary rock consist of microcrystalline quartz?
chert
What type of sediments are accumulations of solid fragments produced by weathering?
clastic or detrital sediments
The P wave shadow extends from roughly __________ to 142° distance from an earthquake's focus.
100
The ground motion during a Richter magnitude 8 earthquake is ______ times greater than the ground motion during a Richter magnitude 6 earthquake.
100
The energy released during a magnitude 8 earthquake is approximately ______ times larger than the energy released during a magnitude 6 earthquake.
1000
The P wave shadow extends from roughly ___ to roughly ____ distance from an earthquake's focus.
100°; 140°
The S-wave shadow zone extends from ____ to 180° angular distance from the earthquake focus.
105°
What is the approximate temperature of sediment that is buried to a depth of 4 km?
120 C
The P wave shadow extends from 105° to roughly __________distance from an earthquake's focus.
140
Which of the following processes occurs during lithification?
All of these may occur during lithification
upfolded, oldest rock in center
Anticline
What type of seismic wave is depicted in the diagram above?
P wave
Which of the following types of waves is a compressional wave?
P waves
Which of the following correctly lists the order in which seismic waves arrive at a seismograph station?
P waves → S waves → surface waves
Which of the following statements about the metamorphism of a shale is FALSE?
With increasing metamorphism, the grain size of the rock gets smaller
A geothermometer is ___________.
a mineral assemblage that reveals the maximum temperature attained by a rock
A fault plane strikes north-south and dips steeply to the west. Geologic observations indicate that most of the fault movement was dip-slip and that the younger rocks occur east of the fault and older rocks occur west of the fault. What type of fault is this?
a reverse fault
Which of the following types of tectonic forces causes faulting?
compressive forces, shear forces, tensional forces
A clastic sedimentary rock composed of poorly sorted large and small particles is called a
conglomerate
Which of the following lists is written in order of decreasing particle size?
conglomerate, sandstone, siltstone
In which of the following sedimentary rocks would it be easiest to determine the type of rocks from which the sediment was derived?
conglomerates
What type of metamorphism would follow a relatively low pressure-high temperature path?
contact
What type of metamorphism is caused by igneous intrusions?
contact metamorphism
The major environments for sedimentary deposition are often grouped into __________.
continental, shoreline, and marine
Earthquakes that originate at depths greater than 100 km are associated with ______ plate boundaries.
convergent
The largest earthquakes occur at
convergent boundaries
Shallow, intermediate, and deep focus earthquakes occur at
convergent plate boundaries
Shallow earthquakes, less than 20 km deep, are associated with ___________.
convergent plate boundaries, transform plate boundaries, divergent plate boundaries
Which of the following of Earth's layers contains the least amount of iron?
crust
As seismic waves travel through the Earth, they generally __________.
curve upward
