Eas Test 1

Front 1

The composition of the inner core of Earth is thought to be ________.

A) liquid iron-manganese alloy

B) solid iron-nickel alloy

C) peridotite

D) liquid iron-nickel alloy

E) solid iron-manganese alloy

Back 1

B) solid iron-nickel alloy

Front 2

Which one of the following best describes volcanism in the East Africa (Kenya, Tanzania)?

A) related to plate subduction

B) related to deep, transform faults

C) related to a mid-oceanic ridge system

D) related to a mantle hot spot

E) related to a continental rift zone

Back 2

E) Related to a continental rift zone

Front 3

Which of the following combinations should favor folding rather than faulting?

A) high temperature and low confining pressureB) high confining pressure and low temperatureC) low confining pressure and low temperatureD) high temperature and high confining pressureE) All of the above

Back 3

D) high temperature and high confining pressure

Front 4

Linear, magnetic patterns associated with mid-ocean ridges are configured as ________.A) normal magnetizations along the rift valleys and reverse magnetizations along the ridgeB) normal and reversed magnetized strips roughly parallel to the ridgeC) reversed magnetizations along the rift valleys and normal magnetizations along the ridgeD) concentric circles about a rising plume of hot mantle rocks and magmaE) normal and reversed magnetized strips roughly perpendicular to the ridge axis

Back 4

B) Normal and reversed magnetized strips roughly parallel to the ridge

Front 5

The lithosphere is defined as ________.A) a plastic layer composed mainly of mantle materialB) a rigid layer of mantle materialC) a rocky layer having a relatively uniform chemical compositionD) a rocky layer composed mainly of crustal rocksE) none of the above

Back 5

E) None of the above

Front 6

Which one of the following shows the correct order from left to right of the lavas that have the lowest tohightest silicon contents.A) rhyolite, andesite, basaltB) basalt, andesite, rhyoliteC) basalt, rhyolite, andesiteD) andesite, basalt, rhyolite,E) andesite, rhyolite, basalt

Back 6

B) basalt, andesite, rhyolite

Front 7

Which of the following is true about tsunamis?A) They are associated with large earthquakes on transform faultsB) They have less than 10 meter wavelengths in the open oceanC) They are associated with mantle hotspotsD) They travel at about the speed of a jet airplane.E) none of the above

Back 7

D) They travel at about the speed of a jet airplane

Front 8

The average composition of the continental crust most closely approximates that of ________.A) peridotite B) basalt C) rolandite D) leaverite

E) granite

Back 8

E) Granite

Front 9

Which type of basaltic lava flow would typically have the lowest viscosity?A) contrafluereB) pailanaC) ryehoeliteD) a'aE) pahoehoe

Back 9

E) pahoehoe

Front 10

Moment magnitude isA) a silly term made up by the class professorB) a measure of volcanic intensityC) a measure of earthquake sizeD) the time delay between P and S wavesE) none of the above

Back 10

C) a measure of earthquake size

Front 11

Atolls form byA) granulometric volcanic eruptions in the oceanB) meteorite impacts into areas of continental crustC) meteorite impacts into areas of ocean crustD) coral reefs growing upward at approximately the same rate as an extinct volcano under the reef issinkingE) thrust faulting in convergent tectonic settings

Back 11

D) coral reefs growing at approximately the same rate as an extinct volcano under the reef is sinking

Front 12

The mantle is mostly composed of ____________.A) carbonatesB) silicatesC) sulfatesD) phosphatesE) metal alloys

Back 12

B) silicates

Front 13

Which of the following is associated with a divergent plate boundary?A) riftingB) earthquakesC) normal faultsD) volcanismE) all of the above

Back 13

E) All of the above

Front 14

Transmission of S waves through a substance require the substance to haveA) high rheoplasticityB) a high Mercalli scale ratingC) a low Mercalli scale ratingD) no shear strengthE) high shear strength

Back 14

E) high shear strength

Front 15

At what type of plate boundary do the deepest earthquakes occur?A) convergent B) transform C) strike-slip D) dip-slip E) divergent

Back 15

A) convergent

Front 16

Which one of the following is an example of an isostatic movement?A) uplift of mountain ranges undergoing erosionB) arching of strata at the center of a domeC) numerous aftershocks associated with deep-focus earthquakesD) stream downcutting following a drop in sea levelE) none of the above

Back 16

A) uplift of mountain ranges undergoing erosion

Front 17

________ most effectively outline the edges of asthenospheric plates.A) Lines of active stratovolcanoesB) Lines of earthquake epicentersC) The locations of deep mantle hot spotsD) Gravitational anomaliesE) None of the above

Back 17

E) None of above

Front 18

The Earth's magnetic field originates by ________.A) magnetic mineral grains in the inner coreB) weak electrical currents associated with fluid motions in the inner coreC) weak electrical currents associated with hot, rising, mantle plumesD) magnetization of oxygen and nitrogen atoms in the atmospheric ozone layer by solar radiationE) none of the above

Back 18

E) none of the above

Front 19

Which of the following best describes Shiprock, a famous volcanic feature in New Mexico?A) a shield volcanoB) the eroded remains of a volcanic pipe and radiating dikesC) an extinct, massive, rhyolitic shield volcanoD) an extinct, highly symmetrical, composite shield volcanoE) a very recently active, basaltic cinder cone

Back 19

B) The eroded remains of a volcanic pipe and radiating dikes

Front 20

In correct order from the center outward, Earth includes which units or regions?A) inner core, lithosphere, lower mantle, asthenosphere, crustB) inner core, outer core, lower mantle, asthenosphere, crustC) inner core, outer core, lithosphere, mantle, asthenosphereD) inner core, inner mantle, outer core, asthenosphere, crustE) inner core, outer core, lower mantle, astrosphere, crust

Back 20

B) inner core, outer core, lower mantle, asthenosphere, crust

Front 21

________ refers to the tendency for a foundation material to lose its internal cohesion and fail mechanicallyduring earthquake shaking.A) Motion slipB) LiquefactionC) SeismoflowageD) SlurryingE) Occultation

Back 21

B) liquefaction

Front 22

When did India begin to collide with Asia to form the HimalayasA) about 500 million years agoB) about 50 thousand years agoC) about 500 thousand years agoD) about 50 million years agoE) about 50 billion years ago

Back 22

D) 50 million years ago

Front 23

The Wasatch Fault in Utah is an example ofA) a normal fault formed in a region of tectonic compressionB) a reverse fault formed in a region of tectonic compressionC) a normal fault formed in a region of tectonic extensionD) a transform fault formed in a region of tectonic torsionE) a reverse fault formed in a region of tectonic extension

Back 23

C) a normal fault formed in a region of tectonic extension

Front 24

Which one of the following statements is incorrect?A) P waves have lower velocities than S wavesB) P and S waves travel through solidsC) S waves do not travel through liquids and P waves travel through solids.D) P waves travel through liquids, but S waves do not travel through liquids.E) Both C and D

Back 24

A) P waves have lower velocities than S waves

Front 25

Approximately how much more energy is released in a 4.0 Richter magnitude earthquake than in one withmagnitude 3.0?A) 10 times B) 3 times C) 32 times D) 100 times E) 1000 times

Back 25

C) 32 times

Front 26

Surface manifestations of hydrothermal activity associated with volcanoes include:A) aquiventsB) nerozonesC) fumarolesD) pyroclinesE) all of the above

Back 26

C) fumaroles

Front 27

In thrust faulting, ________.A) the crust is shortened and thickenedB) grabens develop on the footwall blockC) the hanging wall block slips downward along the thrust faultD) horizontal, tensional stresses drive the deformationE) none of the above

Back 27

A) the crust is shortened and thickened

Front 28

The Aleutian Islands occur at a ________.A) convergent boundary where ocean crust subducts beneath ocean crustB) convergent, continental margin with uplifted fault blocks, much like those of the Basin and RangeProvinceC) transform boundary where North America has moved towards AlaskaD) divergent boundary where shield volcanoes are formingE) deep mantle hot spot

Back 28

A) Convergent boundary where ocean crust subducts beneath ocean crust

Front 29

Pick the earthqauke wave below that travels by squeezing and expanding the rocks it travels through.A) Surface wavesB) Love wavesC) P wavesD) S wavesE) Rayleigh waves

Back 29

C) P waves

Front 30

Partial melting of a mafic rock typically creates a magma thatA) is enriched in Si, Na and K relative to the mafic rockB) is depleted in Si, Na and K relative to the mafic rockC) is nearly identical in composition to the mafic rockD) none of the above

Back 30

A) is enriched in Si, Na, and K relative to the mafic rock

Front 31

Rhyolitic magmas are most likely produced from partially meltedA) peridotiteB) mantleC) continental crustD) coreE) ocean crust

Back 31

C) continental crust

Front 32

Volcanic bombs originate ________.A) as blocks of mantle rock ejected from an erupting volcanic craterB) as laser-guided, granite blocks launched from a supersonic jetC) as erupted lava blobs that partly congeal before falling to the groundD) as ash particles that join together in the eruptive plume and fall as cobble-sized objectsE) none of the above

Back 32

C) As erupted lava blobs that partly congeal before falling to the ground

Front 33

The term that describes the processes that collectively produce mountain belts is___A) monteformaB) montegenesisC) orogenesisD) montepartumE) none of the above

Back 33

C) orogenesis

Front 34

Scientists use which of the following as clues to the composition of the Earth's core and mantle?A) High pressure and temperature experimentsB) Seismic wave velocities and behaviorC) Meteorite compositionD) Strength and movement of the Earth's magnetic fieldE) All of the above

Back 34

E) all of the above

Front 35

The recent (geologically) volcanic activity in Yellowstone National Park is ________.A) related to plate subductionB) related to a transform plate boundaryC) related to a divergent plate boundaryD) related to intraplate, hot spot volcanismE) none of the above

Back 35

D) related to the intraplate, hot spot volcanism

Front 36

When rocks elastically rebound after an earthquake, theyA) are displaced by the fault and remain deformedB) undergo teleseimic reformationC) are displaced by the fault and return to their original undeformed dimensionsD) lose their ability to transmit S wavesE) lose their ability to transmit P waves

Back 36

C) are displaced by the fault and return to their original undeformed dimensions

Front 37

Mount St. Helens is ________.A) an explosive ultramafic stratovolcanoB) an explosive andesitic stratovolcanoC) an explosive basaltic cinder coneD) an explosive basaltic shield volcanoE) an exposive andesitic shield volcano

Back 37

B) an explosive andesitic stratovolcano

Front 38

The continental drift hypothesis was rejected primarily because Alfred Wegener could not ________.A) disprove competing theories that were more accepted by scientistsB) identify a mechanism capable of moving continentsC) find paleontological similarities on different continentsD) find geologic similarities on different continentsE) all of the above

Back 38

B) identify a mechanism capable of moving continents

Front 39

Tectonic feculence isA) lithospheric plate rebound after a seismic eventB) athenospheric plate rebound after a seismic eventC) a process commonly observed in convergent zonesD) a silly term made up by the class professorE) a process commonly observed in divergent zones

Back 39

D) a silly term made up by the class professor

Front 40

________ are usually the most abundant gases emitted during basaltic volcanism.A) Water and carbon dioxideB) Carbon dioxide and sulfur dioxideC) Carbon dioxide and hydrogen sulfideD) Chlorine and ammoniaE) Nitrogen and oxygen

Back 40

A) water and carbon dioxide

Front 41

On a geologic map you see patterns showing concentric circular sedimentary layers with the oldest layersexposed in the center, what is this geologic structure?A) domeB) antistratumC) synclineD) basinE) posistratum

Back 41

dome

Front 42

Cinder cones ________.A) sometimes have associated lava flowsB) consist largely of pyroclasticsC) are usually less than 300 meters (1000 feet) highD) have very steep slopesE) all of the above

Back 42

E) all of the above

Front 43

Which of the following is not a type of geologic stress?A) geopressureB) shearC) tensionD) compressionE) none of the above

Back 43

A) geopressure

Front 44

A region is charaterized by numerous synclines and anticlines. There are also several faults present thatappear to have formed at the same time as the folding. Without knowing any other details, what type offaults would you assume them to be?A) normal B) teleseismic C) strike slip D) transform E) reverse

Back 44

E) reverse

Front 45

On a seismogram taken near an earthquake focus, ________ will show the highest amplitudes.A) Rosby wavesB) S wavesC) surface wavesD) P wavesE) body waves

Back 45

C) surface waves

Front 46

The average composition of the oceanic crust is thought to approximate that of ________.A) leaverite B) granite C) basalt D) peridotite E) andesite

Back 46

C) basalt

Front 47

Mount Vesuvius in Italy is ________.A) an explosive ultramafic stratovolcanoB) an explosive andesitic stratovolcanoC) an exposive andesitic shield volcanoD) an explosive basaltic shield volcanoE) an explosive basaltic cinder cone

Back 47

B) an explosive andesitic stratovolcano

Front 48

Which of the following statements best describes the big Hawaiian volcanoes?A) are situated above a mantle hot spot that produces basaltic magmaB) lie directly above a transform plate boundary that cuts deeply into the mantleC) lie along the crest of the East Pacific Rise, a mid-ocean ridge or spreading centerD) lie directly above an active subduction zone where the Pacific plate is sinking into the mantleE) none of the above

Back 48

A) are situated above a mantle hot spot that produces basaltic magma

Front 49

The city of Pompeii wasA) destroyed by a tsunamiB) destroyed by flows of basaltic lavaC) destroyed by a magnitude 8.1 earthquakeD) destroyed by a plinian volcanic eruptionE) none of the above

Back 49

D) destroyed by a plinian volcanic eruption

Front 50

You are buying a house in an earthquake prone region, which of the following is most likely to withstand anearthquake.A) A wood frame house built on unconsolidated sedimentB) A solid brick house built on unconsolidated sedimentC) A wood frame house built on a hard solid rock surfaceD) A solid brick house that is built over a fault lineE) House construction and underlying geology make almost no difference

Back 50

C) a wood frame house built on a hard solid rock surface

Front 51

________ most effectively outline the edges of the lithospheric plates.A) Magnetic field anomaliesB) Gravitational anomaliesC) Lines of earthquake epicentersD) The locations of deep mantle hot spotsE) Lines of active stratovolcanoes

Back 51

C) lines of earthquake epicenters

Front 52

Solidified fragments of volcanic material ejected into the air are called _________A) ahuluB) areteC) vesiclesD) pillow basaltsE) pyroclasts

Back 52

E) pyroclasts

Front 53

The composition of the mantle is thought to be ________.A) ultramafic, silicateB) felsic, silicateC) iron-nickel alloyD) iron-manganese alloyE) all of the above

Back 53

A) ultramafic, silicate

Front 54

A typical rate of seafloor spreading in the Pacific Ocean is ________.A) 1.8 to 2.5 centimeters per yearB) 6.4 to 15.0 centimeters per yearC) 35.0 to 150.0 centimeters per yearD) 64.0 to 150.0 centimeters per yearE) 276 to 325 centimeters per year

Back 54

B) 6.4 to 15cm per year

Front 55

A syncline is ________.A) a fold in which the strata dip away from the axisB) a fold in which the strike of the strata trend toward the axisC) a fold characterized by recumbent limbsD) a fold in which the strike of the strata trend away from the axisE) a fold in which the strata dip toward the axis

Back 55

E) a fold in which the strata dip toward the axis

Front 56

The modern-day Red Sea is explained by plate tectonics theory because it is ________.A) a tiny remnant of a once immense ocean that was closed as Africa moved toward AsiaB) a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separateC) a subduction zone where the African continental plate is sinking under the Arabian continental plateD) the site of a transform fault along which Arabia is moving away from AfricaE) none of the above

Back 56

B) a rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate

Front 57

Which of the following correctly lists the layers from least dense to most dense.A) continental crust, ocean crust, mantle, outer coreB) continental crust, mantle, ocean crust, outer coreC) ocean crust, continental crust, mantle, outer coreD) ocean crust, continental crust, outer core, mantleE) none of the above

Back 57

A) continental crust, ocean crust, mantle, outer core

Front 58

The position on Earth's surface directly above the earthquake source is called the ________.A) epicenterB) seismic zoneC) focusD) focal centerE) inertial point

Back 58

A) epicenter

Front 59

Unconsolidated, finely ground material that is sometimes found in fault zones is termed___________.A) seismoliths B) basalt C) tuff D) gouge E) ahulu

Back 59

D) gouge

Front 60

Which one of the following shows the correct order (left to right) of decreasing magma viscosity (in otherwords, list from left to right the least to most fluid lavas)?A) rhyolite, andesite, basaltB) basalt, andesite, rhyoliteC) andesite, rhyolite, basaltD) andesite, basalt, rhyolite,E) basalt, rhyolite, andesite

Back 60

A) rhyolite, andesite, basalt

Front 61

Scientists use which of the following as clues to the composition of the Earth's core and mantle?A) High pressure and temperature experimentsB) Strength and movement of the Earth's magnetic fieldC) Meteorite compositionD) Seismic wave velocities and behaviorE) All of the above

Back 61

E) all of the above

Front 62

________ tend to increase the explosive potential of a magma body beneath a volcano.A) Low silica content, low dissolved gas contentB) High viscosity, low dissolved gas contentC) Low viscosity, low dissolved gas contentD) Low silica content, low viscosityE) High viscosity, high dissolved gas content

Back 62

E) High viscosity, high dissolved gas content

Front 63

Why are isochrons on the Pacific seafloor more widely spaced than isochrons on the Atlantic seafloor?A) The Pacific seafloor is younger than the Atlantic SeafloorB) The Pacific seafloor is older than the Atlantic SeafloorC) The Pacific seafloor is more felsic than the Atlantic SeafloorD) The Pacific seafloor is formed at a slower spreading rate than the Atlantic SeafloorE) The Pacific seafloor is formed at a faster spreading rate than the Atlantic Seafloor

Back 63

E) The pacific seafloor is formed at a faster spreading rate than the Atlantic Seafloor

Front 64

Tensional forces normally cause which one of the following?A) reverse faultsB) thrust faultsC) normal faultsD) strike-slip faultsE) anticlines

Back 64

D) strike-slip faults

Front 65

On a geologic map the symbol for a thrust fault appears asA) a plain dark line with small parallel arrows pointing in opposite directions on either side of the lineB) a dark line with triangular teeth on one side pointing in the direction of fault dipC) a dark line with triangular teeth on both sides pointing in the direction of fault movementD) a plain dark lineE) none of the above

Back 65

B) a dark line with traingular teeth on one side pointing in the direction of the fault dip

Front 66

) The Earth's magnetic field originates by ________.A) weak electrical currents associated with fluid motions in the outer coreB) magnetization of oxygen and nitrogen atoms in the atmospheric ozone layer by solar radiationC) weak electrical currents associated with hot, rising, mantle plumesD) magnetic mineral grains in the inner coreE) none of the above

Back 66

A) weak electrical currents associated with fluid motions in the outer core

Front 67

) The Andes mountains on the west coast of South America are ________.A) blocks of cratonic material uplifted by transform fault activityB) built on a continental margin above a sinking slab of oceanic lithosphereC) young, active, shield volcanoes built as western South America moved over a hot spot deep in themantleD) old, deeply eroded stratovolcanoes built before the Pacific Ocean existedE) built on a continental margin above a sinking slab of continental lithosphere

Back 67

B) built on a continental margin above a sinking slab of oceanic lithosphere

Front 68

A good example of a present-day, passive continental margin is the ________.A) east coast of the Japanese IslandsB) east coast of North AmericaC) south coast of the Aleutian IslandsD) west coast of South AmericaE) north flank of the East Pacific Rise

Back 68

B) east cost of North America

Front 69

78) The most violent volcanic activity is associated with ________.A) cinder conesB) shield volcanoesC) fissure eruptionsD) basaltic volcanoesE) composite cones

Back 69

E) composite cones

Front 70

Rhyolitic magmas are most likely produced from partially meltedA) peridotiteB) continental crustC) mantleD) coreE) ocean crust

Back 70

B) continental crust

Front 71

Which of the following best describes the bedrock in the Sierra Nevada Mountains in California?A) peridotite; batholithB) andesite; laccolithsC) gabbro; plutolithsD) basalt; dikesE) granite; batholiths

Back 71

E) granite, batholiths

Front 72

Large circular downwarped structures are called ________.A) anticlinesB) synclinesC) horstsD) basinsE) domes

Back 72

D) basins