Geology Exam 2 DSM & Quiz Questions
What is the average spreading rate along the Mid-Atlantic and the Mid-Indian ridges? a.1 to 5 centimeters per year b.1 to 5 meters per year c.1 to 5 kilometers per year d.1 to 5 millimeters per year
a.1 to 5 centimeters per year
Approximately how much more energy is released in a 6.5 Richter magnitude earthquake than in one with magnitude 5.5? a.32 times b.3200 times c.3.2 times d.320 times
a.32 times
What is a transform fault? a.A strike-slip fault that forms the boundary between tectonic plates b.A dip-slip fault connecting an anticline with a syncline c.A reverse fault that steepens into a thrust fault d.Rift bounding faults on a mid-ocean ridge
a.A strike-slip fault that forms the boundary between tectonic plates
What is a horst? a.An uplifted block bounded by two normal faults b.A downdropped block bounded by two reverse faults c.An uplifted block bounded by two reverse faults d.A downdropped block bounded by two normal faults
a.An uplifted block bounded by two normal faults
Where in the oceans are biological communities thriving without sunlight? a.Around seafloor hot spring vents b.In shallow-water coral reefs c.In muds of deep-ocean trenches d.Around fissure vents for flood basalts
a.Around seafloor hot spring vents
Why are mid-ocean ridges elevated compared to the surrounding ocean floor? a.Because newly formed lithosphere is hotter and therefore less dense than the surrounding rocks b.Because the older, colder lithosphere is less dense and tends to rise c.Because the mantle is pushing up the lithosphere along the ridge d.Because of the shield volcanoes that develop due to seafloor spreading
a.Because newly formed lithosphere is hotter and therefore less dense than the surrounding rocks
Which of the following foundation materials is most stable during earthquake shaking? a.Bedrock b.Unconsolidated moist soil c.Water-saturated soil d.Sand and mud
a.Bedrock
Visualize five horizontal, sedimentary strata exposed in a cliff or canyon wall identified by consecutive numbers, 1 being the lowest bed and 5 being the highest. Which of the following statements concerning the strata are true? a.Beds 1 and 3 are older than bed 4. b.Bed 5 is the oldest. c.Bed 4 is older than bed 2. d.Bed 3 is older than beds 2 and 4.
a.Beds 1 and 3 are older than bed 4.
The percent of remaining parent isotope in a radioactive decay process is 40 percent. How many half-lives have elapsed since the material was 100 percent parent atoms? a.Between one and two b.Less than one c.More than three d.Between two and three
a.Between one and two
Where is the continental rise located? a.Between the abyssal plain and the continental slope b.In shallow-water coral reefs c.At the top of the continental slope d.At the seaward edge of a deep-ocean trench
a.Between the abyssal plain and the continental slope
What major change occurs during metamorphism of limestone to marble? a.Calcite grains increase in size. b.Clays crystallize to micas, forming a highly foliated, mica-rich rock. c.Limestone grains react to form quartz and feldspars. d.Calcite grains are dissolved leaving only quartz crystals.
a.Calcite grains increase in size.
Which of the following results from thrust faulting? a.Earth's crust is shortened and thickened. b.Grabens develop on the footwall blocks. c.Horizontal, tensional stresses drive the deformation. d.The hanging wall blocks slip downward along the thrust fault.
a.Earth's crust is shortened and thickened.
Which of the following denotes the divisions of the geologic time scale in correct order of decreasing lengths of time beginning with the longest time interval and ending with the shortest? a.Eon, era, period, and epoch b.Eon, era, epoch, and period c.Era, period, epoch, and eon d.Eon, epoch, period, and era
a.Eon, era, period, and epoch
What term describes a strong, parallel alignment of coarse mica flakes and/or of different bands in a metamorphic rock? a.Foliation b.Rock cleavage c.Stress fractures d.Lineation
a.Foliation
Of the following rock types, which is characterized by the segregation of light- and dark-colored minerals into thin layers or bands? a.Granitic gneiss b.Garnet schist c.Slate d.Quartzite
a.Granitic gneiss
What factor produces the largest lateral ground displacement in an earthquake? a.Horizontally vibrating surface waves b.First P arrival reflecting from the inner-outer core boundary c.The S wave reflected from the core-mantle boundary d.Vertically vibrating P waves refracted across the Moho
a.Horizontally vibrating surface waves
What nonfoliated metamorphic rock forms during contact metamorphism of a shale or mudstone? a.Hornfels b.Schist c.Marble d.Gneiss
a.Hornfels
What fundamental concept states that, "in a horizontal sequence of conformable sedimentary strata, each higher bed is younger than the bed below it"? a.Law of superposition b.Law of original horizontality c.Principle of cross-cutting relationships d.Principle of uniformitarianism
a.Law of superposition
Why was the Marina District of San Francisco heavily damaged in the 1906 earthquake and the 1989 Loma Prieta quake? a.Liquefaction and foundation failures were common. b.The epicenters of both quakes were under the district. c.Shaking was no more extensive than elsewhere in the city, but the whole district burned following each quake. d.The area is built on consolidated rock, causing the shaking to be amplified.
a.Liquefaction and foundation failures were common.
Which two Paleozoic periods used in North America are combined into the Carboniferous period in Europe and elsewhere? a.Mississippian and Pennsylvanian b.Triassic and Jurassic c.Cambrian and Ordovician d.Permian and Pennsylvanian
a.Mississippian and Pennsylvanian
What type of faults are the products of horizontally directed, extensional stresses? a.Normal faults b.Thrust faults c.Reverse faults d.Strike-slip faults
a.Normal faults
What is the best evidence of Earth having a solidified inner core? a.P waves travel faster in the inner core than in the outer core. b.S waves do not pass directly through the core. c.S waves are slower in the inner core than in the outer core. d.S waves are focused at the center of the P-wave shadow zone.
a.P waves travel faster in the inner core than in the outer core.
What foliated, metamorphic rock is texturally intermediate between slate and schist? a.Phyllite b.Fault breccia c.Quartzite d.Gneiss
a.Phyllite
Which of the following best describes the conditions of contact metamorphism? a.Pressures are fairly low, the rock may be in the upper part of the crust, and heat is supplied from a nearby magma body such as a pluton, dike, or sill. b.Pressures are very high, the rock is deeply buried, and temperatures are raised by Earth's internal heat. c.Heat is generated by shearing and mechanical movements along faults. d.Depths are fairly shallow, but temperatures and pressures are so high that the rocks begin to partially melt.
a.Pressures are fairly low, the rock may be in the upper part of the crust, and heat is supplied from a nearby magma body such as a pluton, dike, or sill.
What is the most widely accepted explanation for the mechanism that generates earthquakes? a.Reid's elastic rebound theory b.Dow's recovery theory c.Dupont's plastic-slip theory d.Richter's wave-snap theory
a.Reid's elastic rebound theory
What fault in California is the boundary between the North American and Pacific plates? a.San Andreas strike-slip fault b.Sierra Nevada frontal fault c.San Luis Obispo thrust fault d.San Francisco normal fault
a.San Andreas strike-slip fault
What type of foliation results from the parallel alignment of abundant, coarse-grained, mica flakes in a metamorphic rock? a.Schistosity b.Gneissic banding c.Slaty cleavage d.Phyllitic structure
a.Schistosity
Which of the following statements concerning slate is not true? a.Slate has abundant, coarse-grained mica. b.Slate forms from shales and mudstones. c.In slate, rock cleavage is common. d.Sedimentary features may be visible in slates.
a.Slate has abundant, coarse-grained mica.
What structure in Earth is thought to be caused by a change in the mineral structure of olivine? a.The 660-km-depth discontinuity or transition zone b.The "D" layer c.The low-velocity zone d.The mesosphere
a.The 660-km-depth discontinuity or transition zone
Of the following, which have a crust about twice as thick as normal? a.The Himalayan Range and the Tibetan Plateau in northern India and southwestern China b.The Coast Ranges and the Sierra Nevada in California c.The Blue Ridge Mountains in the southeastern United States d.The Basin and Range Province in Arizona and Nevada
a.The Himalayan Range and the Tibetan Plateau in northern India and southwestern China
Which one of the following statements concerning foci and epicenters is correct? a.The epicenter is at the surface directly above the focus, which is where the earthquake occurs. b.The focus is the faulted point on the surface directly above the epicenter. c.The fault first cracks at the epicenter and breaks through to the surface at the focus. d.The earthquake starts at the focus and the rupture extends down to the epicenter.
a.The epicenter is at the surface directly above the focus, which is where the earthquake occurs.
Which of the following geologic observations would not bear directly on interpreting the sequence of geologic events in an area? a.The feldspar and quartz content of a granite b.Inclusions of sandstone in a granite pluton c.A well-exposed dike of basalt in sandstone d.Unconformity between a granite and sandstone
a.The feldspar and quartz content of a granite
What happens in a normal fault? a.The hanging wall block above an inclined fault plane moves downward relative to the lower footwall block. b.The hanging wall block below an inclined fault plane moves downward relative to the other block. c.The footwall block below an inclined fault plane moves downward relative to the other block. d.The footwall block above an inclined fault plane moves upward relative to the other block.
a.The hanging wall block above an inclined fault plane moves downward relative to the lower footwall block.
What happens in a reverse fault? a.The hanging wall block has moved up relative to the footwall block along an inclined fault. b.The block above the fault plane has moved backwards with respect to the other block. c.One block has moved downward and the other moved horizontally along a vertical fault. d.Both blocks have moved horizontally in opposite directions along an inclined fault.
a.The hanging wall block has moved up relative to the footwall block along an inclined fault.
In the names of geologic eras, what does the suffix "zoic" mean? a.The suffix "zoic" means life (i.e., living things). b.The suffix "zoic" means rocks (i.e., lithified strata). c.The suffix "zoic" means time (i.e., recording of events). d.The suffix "zoic" means places (i.e., geographic references).
a.The suffix "zoic" means life (i.e., living things).
What is the maximum possible damage designation on the Mercalli scale? a.There is total damage; objects are thrown into the air. b.Few structures remain standing, bridges are destroyed, and rails are bent greatly. c.Well built wooden structures are destroyed, most masonry and frame structures are destroyed, and rails are bent. d.The earthquake is felt indoors by many and outdoors by few; it awakens people at night.
a.There is total damage; objects are thrown into the air.
Which of the following is not true of deep-ocean trenches? a.They are geologically very stable. b.They are long and narrow depressions. c.They are sites where oceanic plates plunge back into the mantle. d.They may act as sediment traps.
a.They are geologically very stable.
How did the mountains and valleys of the Basin and Range Province of the western United States form? a.They formed from tensional stresses and normal-fault movements. b.They formed from strike-slip faulting and hanging wall block uplifts. c.They formed from reverse faults and large displacement (thrust faults). d.They formed from normal faulting that resulted from horizontal compression.
a.They formed from tensional stresses and normal-fault movements.
What feature in distorted layered sedimentary rocks are evidence for horizontal compression and shortening? a.Tight folds b.Normal faults c.Strike-slip faults d.Horsts and grabens
a.Tight folds
Which of the following best characterizes an angular unconformity? a.Tilted strata that lie below the unconformity; bedding in younger strata above is parallel to the unconformity. b.Horizontal lava flows lie below the unconformity and horizontal sedimentary strata lie above. c.Older strata lie around and above an intrusive body of granite. d.Horizontal strata lie under a lava flow.
a.Tilted strata that lie below the unconformity; bedding in younger strata above is parallel to the unconformity.
What is the name of a thick accumulation of sediments and small, tectonic blocks formed of material scraped off a descending lithospheric plate? a.Accretionary-wedge complex b.Mass-movement complex c.Continental shelf terrain complex d.Subterranean-accumulation complex
a.accretionary-wedge complex
What is the name of the gently sloping, submerged surface extending from the shoreline toward the deep ocean? a.Continental shelf b.Continental slope c.Continental rise d.Submarine canyon
a.continental shelf
Which of the following forces creates backarc regions? a.extension b.compression c.shearing d.uplift
a.extension
What type of basin is characterized by thick sequences of relatively undeformed sedimentary rocks? a.forearc b.backarc c.transform fault d.evaporite
a.forearc
Which of Earth's layers is marked at its top by the Mohorovičić discontinuity? a.Mantle b.Inner core c.Outer core d.Crust
a.mantle
Which layer of Earth transmits P earthquake waves but not S earthquake waves? a.Outer core b.Inner core c.Crust d.Mantle
a.outer core
The __________ is used to record ground shaking and the earthquake-magnitude scale was invented by __________. a.seismograph; Richter b.rayoscope; Mercalli c.vibroscope; Rector d.polygraph; Freud
a.seismograph; Richter
Which of the following statements best describes topographically high-standing mountainous areas? a.they are generally underlain by greater-than-average thickness of lower-density crustal rocks b.they subside rapidly to compensate for erosion c.they have thicker, higher-density mantle rocks beneath them at shallow depths d.they experience rapid erosion that thins the crust and causes the area to subside
a.they are generally underlain by greater-than-average thicknesses of lower-density crustal rocks
Which of the following includes the zone called the "asthenosphere" (the "weak sphere")? a.Upper mantle b.Inner core c.Outer core d.Crust
a.upper mantle
Who discovered the crust-mantle seismic discontinuity? In what year? a.Beno Gutenberg, 1936 b.Andrija Mohorovičić, 1909 c.Alfred Wegener, 1915 d.Charles Richter, 1888
b.Andrija Mohorovičić, 1909
Which of the following rocks are closest to the average chemical composition of the oceanic crust? a.Granite and limestone b.Basalt and gabbro c.Andesite and granite d.Rhyolite and diorite
b.Basalt and gabbro
Which of the following is not a very long-lived, radioactive isotope? a.U-238 b.C-14 c.K-40 d.Rb-87
b.C-14
By what metamorphic process are basaltic rocks of the oceanic crust altered by heated seawater moving through fractures? a.Regional metamorphism b.Hydrothermal metamorphism c.Contact metamorphism d.Diagenesis
b.Hydrothermal metamorphism
What city in central United States was struck by three major earthquakes during the winter and spring months of the years 1811-1812 and experienced a quake as recently as 2008? a.Nome, Alaska b.New Madrid, Missouri c.Los Angeles, California d.Charleston, South Carolina
b.New Madrid, Missouri
Who made the first clear statement of the law of superposition? When? a.John Wesley Powell, 19th century b.Nicolas Steno, 17th century c.William Smith, 19th century d.Joseph Priestly, 18th century
b.Nicolas Steno, 17th century
Which earthquake was accompanied by extensive fire damage from ruptured natural gas lines and electrical lines? a.Anchorage, 1964 b.San Francisco, 1906 c.Mexico City, 1985 d.Yerevan, Armenia, 1988
b.San Francisco, 1906
Which of the following rock types form during the highest grade of regional metamorphism? a.Hornfels b.Schist c.Slate d.Phyllite
b.Schist
What term describes the zone of contact metamorphism that surrounds an intrusive magma body? a.amphibole b.aureole c.augite d.aerosol
b.aureole
What is the upper layer of the lithosphere called? a.Inner core b.crust c.Mantle d.Outer core
b.crust
The __________ is the point of origination for an earthquake. a.fault point b.focus c.seismic centroid d.epizone
b.focus
Which layer of Earth is very dense and solid and consists most likely of an iron-rich alloy? a.mantle b.inner core c.crust d.outer core
b.inner core
What is the final stable breakdown product of the radioactive isotopes uranium-238, uranium-235, and thorium-232? a.iron b.lead c.argon d.strontium
b.lead
What is the name given to material that loses all internal cohesion during earthquake shaking? a.slurrying b.liquefaction c.Motion slip d.Seismoflowage
b.liquefaction
What layer of Earth causes plate subduction because it, not the oceanic crust, is denser than the underlying asthenosphere? a.outer core b.lithospheric mantle c.seafloor sediments d.trailing continent
b.lithospheric mantle
What metamorphic rock forms during the metamorphism of limestone or dolostone? a.migmatite b.marble c.amphibolite d.quartzite
b.marble
How were the Ural Mountains (in Russia) formed? a.An active volcanic arc, similar to the present-day Aleutian Islands, rose along the Eurasian plate. b.Marine strata in a basin between the former Asian and European plates were squeezed, folded, and uplifted as the two plates joined to form the Eurasian plate. c.Large fault blocks of Archean igneous and metamorphic rocks rose as the former Asian and European plates joined to form Eurasia. d.Active, normal faulting elevated large mountain blocks above the level of the vast plains on both sides of the range.
b.marine strata in a basin between the former Asian and European plates were squeezed, folded, and uplifted as the two plates joined to form the Eurasian plate
Which rock type listed below is probably closest in chemical composition to the upper mantle? a.granite b.peridotite c.shale d.andesite
b.peridotite
Which type of wave moves the fastest and thus will reach the seismograph first? a.secondary waves b.primary waves c.Surface waves d.Refracted S waves
b.primary waves
In what type of fault does the hanging wall block move up with respect to the footwall block? a.normal b.reverse c.strike-slip
b.reverse
What term describes the zone where two continents collide, often preserving slivers of oceanic lithosphere between the colliding plates? a.passive margin b.suture c.ophiolite d.terrane
b.suture
Which of the following is not a feature found in subduction zones? a.deep-ocean trenches b.suture zones c.forearc basins d.volcanic arcs
b.suture zones
Which of the following are not layers that comprise the oceanic crust? .a.gabbro b.turbidites c.sheeted dike complexes d.pillow basalts
b.turbidites
What types of rocks make up the cores of the ranges of the central and southern rocky mountains? a.paleozoic and mesozoic sedimentary rocks that were elevated and compressed into tight folds; the deeper, harder rocks of the continental crust were pulled apart by tensional stresses b.uplifted blocks that typically have cores of Proterozoic igneous and metamorphic rocks c.thick sections of highly folded, Paleozoic marine strata d.layers of rocks that developed in response to a continent-continent collision
b.uplifted blocks that typically have cores of Proterozoic igneous and metamorphic rocks
What is the age of Earth accepted by most scientists today? a.4.5 million years b.6.4 million years c.4.6 billion years d.6.4 billion years
c.4.6 billion years
Complex, invertebrate life forms are common as fossils beginning with marine strata of Cambrian age. How long ago did the Cambrian period begin? a.54 million years b.65.4 million years c.542 million years d.6 billion years
c.542 million years
Approximately how much of Earth's surface is covered by ocean? a.50 percent b.90 percent c.70 percent d.10 percent
c.70 percent
What is the maximum limit on carbon-14 dating? a.700,000 and 750,000 years b.7 million years and 7.5 million years c.70,000 and 75,000 years d.7,000 and 7,500 years
c.70,000 and 75,000 years
Which of the following best describes a thrust fault? a.A vertical, normal fault b.A near vertical, strike-slip fault c.A low-angle, reverse fault d.A steeply inclined, oblique-slip fault
c.A low-angle, reverse fault
Which of the following properly describes a seamount? a.A seamount can form only in the Pacific Ocean. b.A seamount is a submarine canyon found near Australia. c.A seamount is a volcano that forms on the ocean floor. A seamount is a special type of oceanic trench.
c.A seamount is a volcano that forms on the ocean floor.
What type of unconformity is an erosional contact between tilted, older strata below and horizontal, younger strata above? a.A non-conformity b.A disconformity c.An angular unconformity
c.An angular unconformity
In which setting would regional metamorphism be most likely? a.At shallow depths along major transform faults in the continental crust b.At shallow depths beneath the seafloor where water pressures are immense c.At great depths in the crust where two continents are colliding d.At shallow depths below an oceanic ridge or rift zone
c.At great depths in the crust where two continents are colliding
Which one of the following statements concerning Earth's magnetic field is true? a.Earth's magnetism is generated by magnetic, crystalline iron grains in the mantle. b.Earth is dipolar with the two poles centered near the equator. c.At high latitudes, the force lines intersect Earth's surface at steep angles. d.Magnetic poles are not fixed and move freely across Earth.
c.At high latitudes, the force lines intersect Earth's surface at steep angles.
What type of metamorphic facies associated with the subduction of oceanic crust and sediments forms at very high pressure but moderately low temperature? a.Migmatite b.Biotite marble c.Blueschist d.Mylonite
c.Blueschist
What tectonic feature is exemplified by East Africa, the Rhine Valley, and the Baikal in Siberia? a.Continental margins b.Passive continental margins c.Continental rifts d.Ophiolites
c.Continental rifts
Which of the following situations would promote brittle deformation instead of plastic deformation? a.Warm temperatures b.Shallow depths c.Cool temperatures d.High confining pressures
c.Cool temperatures
Which of the following investigative processes do geologists use to identify and match sedimentary strata and other rocks of the same ages in different areas? a.Inclusions b.Fossil succession c.Correlation d.Cross-cutting
c.Correlation
What types of movement are characteristic in normal and reverse faults? a.Horizontal slip b.Bedding-plane slip c.Dip-slip d.Strike-slip
c.Dip-slip
Which of the following describes Earth's magnetic field? a.Earth's magnetic field results from self-induction of rising magmas in the asthenosphere. b.Earth's magnetic field is permanent and is caused by magnetized, iron-rich mineral grains in the oceanic lithosphere. c.Earth's magnetic field is a self-generating and self-reversing dynamo in the outer core. d.Earth's magnetic field is a high-temperature superconductor in the inner core.
c.Earth's magnetic field is a self-generating and self-reversing dynamo in the outer core.
What metamorphic environment produces tektites? a.Very high pressures and temperatures associated with deep subduction b.High temperatures and shearing stresses in an oceanic-crust transform fault c.High temperatures associated with meteorite impacts d.Low pressure and high temperature associated with volcanism
c.High temperatures associated with meteorite impacts
Which one of the following is consistent with deformation by folding? a.The crust is stretched and elongated. b.Horizontal distance perpendicular to fold axes is lengthened. c.Horizontal distance is shortened perpendicular to the axes of the folds. d.The crust is thinned.
c.Horizontal distance is shortened perpendicular to the axes of the folds.
Which one of the following situations results in folding of flat-lying, sedimentary strata? a.Horizontally directed, extensional stresses b.Vertically directed, compressional stresses c.Horizontally directed, compressive stresses d.Vertically directed, extensional or stretching stresses
c.Horizontally directed, compressive stresses
How does the Mercalli Scale rate earthquakes? a.1 to 10, rating the energy released by an earthquake b.I to X, rating the total energy released during the main quake and all aftershocks c.I to XII, ranging from little damage to total destruction d.1 to 12, rating the energy required for faulting to occur
c.I to XII, ranging from little damage to total destruction
Which of the following best describes the Great Rift Valley of East Africa? a.Mainly thrust faulting as Africa collides with Arabia b.Mainly anticlinal and synclinal folding as Africa collides with Madagascar c.Mainly normal faulting as East Africa begins to fragment d.Mainly transform faulting along zones connecting the rift with the Red Sea
c.Mainly normal faulting as East Africa begins to fragment
What platy, parallel mineral grains are the most visual aspect of foliated metamorphic rocks? a.Carbonates b.Quartz c.Micas d.Feldspars
c.Micas
Why was building damage so extensive in the 1985 Mexico City earthquake? a.The Richter magnitude was 8.8, and the focus was only 10 miles below the city. b.The steel frame buildings were rigid and lacked the flexibility to withstand lateral swaying during even a moderate magnitude quake. c.Much of the city is built on filled-in, shallow lakes and swampland. d.The epicenter was directly in the city.
c.Much of the city is built on filled-in, shallow lakes and swampland.
Which of the following best characterize the tectonic development of fault-block mountains? a.Normal faults; crustal shortening and plastic flowage of the upper crust b.Reverse faults; crustal shortening and plastic flowage of the lower crust c.Normal faults; crustal stretching and brittle failure of the upper crust d.Reverse faults; crustal stretching and brittle failure of the lower crust
c.Normal faults; crustal stretching and brittle failure of the upper crust
Why did the 1988 Armenian earthquake (in the Armenian Republic, then part of the former Soviet Union) result in an estimated 25,000 deaths? a.The quake hit at rush hour; thousands of motorists were killed when freeways collapsed. b.The area was densely populated and right at the epicenter of a magnitude 8.5 quake. c.Numerous, poorly constructed, top-heavy concrete slab buildings collapsed. d.The buildings were constructed on unconsolidated, water-saturated lakebeds; foundation failures were common.
c.Numerous, poorly constructed, top-heavy concrete slab buildings collapsed.
With which of the following oceanic features are "black smokers" associated? a.Metal-rich sulfide deposits b.Hot water c.Oceanic ridges, metal-rich sulfide deposits, and hot water d.Oceanic ridges
c.Oceanic ridges, metal-rich sulfide deposits, and hot water
What concept states that "ancient life forms succeeded each other in a definite, evolutionary pattern and the contained assemblage of fossils can determine the geologic age of the strata"? a.Principle of inclusions b.Principle of original horizontality c.Principle of faunal succession d.Principle of correlation
c.Principle of faunal succession
What metamorphic rock forms from sandstone? a.Slate b.Amphibolite c.Quartzite d.Schist
c.Quartzite
What causes the P-wave shadow zone? a.Lower P-wave velocities in the mantle than in the crust b.Reflection of P waves at the boundary between the inner and outer cores c.Refraction of P waves crossing the mantle-outer core boundary d.Reflection of P waves from the inner core-outer core boundary
c.Refraction of P waves crossing the mantle-outer core boundary
The elastic rebound theory for the origin of earthquakes was first proposed by __________ following the __________ earthquake. a.Richter; 1989 Loma Prieta b.Mohorovicic; 1964 Anchorage c.Reid; 1906 San Francisco d.Alfred Wegener; 1910 Sicilian
c.Reid; 1906 San Francisco
Which of the following is/are not part of an ophiolite complex? a.Intrusive, coarse-grained gabbro b.Steeply inclined, basaltic dikes c.Residual, unmelted, crustal lithosphere d.Basaltic lavas and pillow lavas
c.Residual, unmelted, crustal lithosphere
Which of the following best describes jointing in rocks? a.Structures formed where normal and reverse faults intersect b.The hinge lines connecting two limbs of an anticline or syncline c.Roughly parallel fractures separating blocks that show no displacement d.Closely spaced, parallel faults along which the blocks have moved in opposite directions
c.Roughly parallel fractures separating blocks that show no displacement
Which one of the following statements regarding rock deformation and strength is correct? a.Elastic deformation is accomplished through internal flow of material. b.When rocks are subjected to stress for long time periods, very small, plastic deformations accumulate to produce large, permanent, elastic deformations. c.Rupture and plastic deformation occur when stresses exceed the elastic limit of a material. d.Rocks undergo plastic deformation less readily as temperatures and pressures increase.
c.Rupture and plastic deformation occur when stresses exceed the elastic limit of a material.
Which one of the following statements is correct? a.P and S waves travel through liquids, but P waves do not travel through solids. b.P and S waves travel through liquids, but S waves do not travel through solids. c.S waves travel through solids and P waves travel through solids and liquids. d.P waves travel through solids; S waves do not.
c.S waves travel through solids and P waves travel through solids and liquids.
Which of the following lists foliated metamorphic rocks in the order of increasing grain size and increasing grade of metamorphism? a.Schist, slate, and phyllite b.Slate, schist, and phyllite c.Schist, slate, and phyllite d.Slate, schist, and phyllite
c.Schist, slate, and phyllite
What North American mountains are a geologically old mountain range that was folded and deformed during the Paleozoic? a.The Cascades in the northwestern United States b.The Rockies in the western United States c.The Appalachians in the eastern United States d.The Alps in Europe
c.The Appalachians in the eastern United States
Sandstone strata and a mass of granite are observed to be in contact. Which of the following statements is correct? a.The sandstone is younger if it shows evidence of contact metamorphism. b.The granite is older if it contains inclusions of sandstone. c.The granite is older if the sandstone contains pebbles of the granite. d.The sandstone is younger if the granite contains sandstone inclusions.
c.The granite is older if the sandstone contains pebbles of the granite.
Which of the following is an essential characteristic of an index fossil? a.The fossils are exceptionally abundant and well preserved. b.The fossils occur in deep-water marine sediments, but the organism actually lived in the sunlit, surface layer of the ocean. c.The organism only lived for a short period of geologic time over a broad area. d.The organism lived only in specific environments such as beaches or estuaries.
c.The organism only lived for a short period of geologic time over a broad area.
During metamorphism, what is the major effect of chemically active fluids? a.They prevent partial melting so solid rocks can undergo very high-temperature regional metamorphism. b.They facilitate the formation of schistosity and gneissic banding in hornfels and slates. c.They aid in the movement of dissolved silicate constituents and facilitate growth of the mineral grains. d.They increase the pressures in deeply buried, regional-metamorphic zones.
c.They aid in the movement of dissolved silicate constituents and facilitate growth of the mineral grains.
Which one of the following best characterizes tsunami? a.They are faster than seismic surface waves. b.They are easily seen at sea but are lost in the swell and breaking waves along a coast. c.They have relatively small amplitudes compared to their very long wavelengths. d.They cause the land to ripple and oscillate.
c.They have relatively small amplitudes compared to their very long wavelengths.
Which one of the following is true regarding tsunami? a.Their wave heights decrease and wavelengths increase as they move into shallower water. b.They are started by fault-induced, horizontal shifts in the seafloor that suddenly propel great masses of water in opposite directions. c.They occur in the open ocean; their wavelengths are many miles or kilometers and their wave heights are only a few feet. d.They travel as deep-water waves at speeds greater than surface seismic waves but slower than S waves.
c.They occur in the open ocean; their wavelengths are many miles or kilometers and their wave heights are only a few feet.
What causes Earth's magnetic field? a.Weak electrical currents associated with hot, rising, mantle plumes cause Earth's magnetic field. b.Magnetic mineral grains in the inner core cause Earth's magnetic field. c.Weak electrical currents associated with fluid motions of molten iron in the outer core causes Earth's magnetic field. d.Magnetization of oxygen and nitrogen atoms in the atmospheric ozone layer by solar radiation causes Earth's magnetic field.
c.Weak electrical currents associated with fluid motions of molten iron in the outer core causes Earth's magnetic field.
Which layer of Earth has the smallest volume? a.Mantle b.Inner core c.Crust d.Outer core
c.crust
Which of the following are not associated with a mid-ocean ridge? a.Very thin, ocean-floor sediment layers b.Submarine basaltic lava eruptions c.Deep-ocean trenches d.Shallower depths than abyssal plains
c.deep-ocean trenches
What concept shows that rocks of the crust and upper mantle are floating in gravitational balance? a.ecstasy b.isotrophy c.isostasy d.isometrics
c.isostasy
What techniques do modern oceanographers use to measure water depths and seafloor topography? a.Computerized, satellite-mounted parallel transponder systems b.Satellite-linked laser reflector systems c.ship-mounted echo sounders d.ship-mounted optical-fiber satellite uplink systems
c.ship-mounted echo sounders
Which one of the following is an example of an isostatic movement? a.stream downcutting following a drop in sea level b.arching of strata at the center of a dome c.uplift of areas recently covered by thick continental ice sheets d.numerous aftershocks associated with deep-focus earthquakes
c.uplift of areas recently covered by thick continental ice sheets
What types of materials are characteristic of volcanism along a continental arc? a.all of the listed options b.rhyolitic pyroclastic materials and lavas c.basaltic lava flows d.andesitic lavas and pyroclastic materials
d. andesitic lavas and pyroclastic materials
Which of the following describes a syncline? a.A fold in which the strata dip away from the axis b.A fold with only one limb c.A fold characterized by recumbent limbs d.A fold in which the strata dip toward the axis
d.A fold in which the strata dip toward the axis
Which of the following best describes a graben? a.A hanging wall block that has moved up between two reverse faults b.A footwall block that has moved up between two normal faults c.A footwall block that has moved down between two reverse faults d.A hanging wall block that has moved down between two normal faults
d.A hanging wall block that has moved down between two normal faults
Which of the following situations would result in the largest area of ground-shaking damage? a.A deep-focus quake off the coast of North Africa b.A shallow-focus quake along the San Andreas Fault c.A very deep-focus quake beneath the Aleutian Islands d.A shallow-focus quake along the Mississippi Valley fault zone
d.A shallow-focus quake along the Mississippi Valley fault zone
Which one of the following best characterizes the asthenosphere? a.A layer of soft, solid magnesium silicates and molten iron droplets at the base of the mantle b.A zone of hardened, silicate rock at the base of the oceanic crust c.The zone in the mantle from which hot-spot magmas are melted d.A zone of softened peridotite in the upper mantle
d.A zone of softened peridotite in the upper mantle
Which of the following is directly related to the Richter earthquake-magnitude rating? a.Average of the highest and lowest Mercalli intensity ratings b.Distance between the receiving station and the epicenter c.Time interval between the first P-wave arrival and the first P wave reflected from the crust-mantle discontinuity d.Amplitude of the seismic waves
d.Amplitude of the seismic waves
Which one of the following is not likely to be genetically associated with impact of an asteroid or large meteorite? a.Tektites b.Coesite c.Impact crater d.Blueschists
d.Blueschists
What is the source of natural carbon-14? a.Nuclear fission of the heavy, radioactive elements uranium and thorium b.Fusion of hydrogen and helium in the Sun and eruption of solar flares c.Leakage of radioactive gases from the liquid, outer core d.Cosmic ray collisions and neutron-capture involving atmospheric nitrogen
d.Cosmic ray collisions and neutron-capture involving atmospheric nitrogen
Which of the following situations would exhibit sheared and mechanically fragmented rocks? a.Intense compression in a deep-seated, regional metamorphic zone b.Heating of shales and mudstones near a pluton c.Regional metamorphism of pyroclastic volcanic rocks d.Fault movements at shallow depths
d.Fault movements at shallow depths
Which rock layers dating from the Appalachian orogeny consist of North American continental shelf strata deposited prior to the late Paleozoic collision with Africa? a.Metamorphic and igneous rocks of the Blue Ridge b.Igneous and regionally metamorphosed rocks of the Piedmont c.Cretaceous and Tertiary strata of the coastal plain and continental shelf d.Folded sedimentary rocks of the Valley and Ridge Province
d.Folded sedimentary rocks of the Valley and Ridge Province
Which ship was commissioned in the 1870s to conduct the first far-reaching, comprehensive study of Earth's oceans? a.H.M.S. Moonbeam b.H.M.S. Bismarck c.H.M.S. Brit d.H.M.S. Challenger
d.H.M.S. Challenger
What is the major source of heat for contact metamorphism? a.Deep burial and heat from Earth's interior b.Heat from grinding and shearing on faults c.Heat from the spontaneous decomposition of micas and feldspars d.Heat from a nearby magma body
d.Heat from a nearby magma body
Assume that man's recorded history can be stretched back to 4600 years before the present. This is approximately what fraction of geologic time? a.One ten-thousandth b.One billionth c.One hundred-thousandth d.One millionth
d.One millionth
The __________ magnitude scale is a measure of the energy released. It does not directly measure the extent of building damage. a.Gutenberg b.Reid c.Mercalli d.Richter
d.Richter
What are seismic gaps? a.Seismic gaps are slices of land bounded by active, strike-slip faults on all sides. b.Seismic gaps are inactive faults that cut across high ridges and water gaps. c.Seismic gaps are segments of active faults with creep rates of up to 2 cm/yr. d.Seismic gaps are unusually quiet zones along known active faults.
d.Seismic gaps are unusually quiet zones along known active faults.
Which low-grade metamorphic rock, composed of extremely fine-sized mica and other mineral grains, typically exhibits well developed rock cleavage? a.Schist b.Hornfels c.Quartzite d.Slate
d.Slate
Which one of the following would not be a characteristic of the San Andreas fault zone? a.Sag ponds b.Deformed, broken, and pulverized bedrock c.Laterally offset stream channels d.Steep, near vertical, dip-slip fault scarps
d.Steep, near vertical, dip-slip fault scarps
What type of waves will show the highest amplitudes on a typical seismogram? a.P waves b.S waves c.Body waves d.Surface waves
d.Surface waves
What happens to create an accretionary wedge? a.The base of a passive continental margin meets the seafloor. b.An oceanic plate moves along a transform fault. c.Oceanic plate volcanoes are fed by long-lived hot spots in the mantle. d.The edge of the overriding plate faces a subduction zone.
d.The edge of the overriding plate faces a subduction zone.
What happened to create an unconformity? a.There was a fault or fracture with older rocks above and younger rocks below. b.There was a fault or fracture with younger strata above and older strata below. c.The younger strata below were eroded with older strata laid above. d.The older strata below were eroded before the younger layers were laid down.
d.The older strata below were eroded before the younger layers were laid down.
What does an echo sounder measure? a.The time for a light beam to travel from a satellite at a known altitude to the sea bottom and back b.The time for a radar beam to travel from a harbor patrol boat to a speeding yacht c.The time for a radar beam to travel from a ship to the seafloor and back d.The time for a sound pulse to travel from the ship to the seafloor and back
d.The time for a sound pulse to travel from the ship to the seafloor and back
What is the direct measure of the distance from a seismic receiving station to the focus of a distant earthquake? a.The magnitude of the ground acceleration of surface wave passing a receiving station b.The time elapsed between the first P-wave arrivals from the first and last aftershocks c.The time interval between the first P wave and the last surface wave d.The time interval between the arrivals of the first P and S waves
d.The time interval between the arrivals of the first P and S waves
Which of the following best characterizes how the diameter of Earth's core and the nature of the outer core were discovered? a.Through analysis of crystalline iron found in lavas erupted from the deepest known hot spots b.By studying P-wave speeds, which are higher in the outer core than in the lower mantle c.By using the ratio of iron meteorites to stony meteorites to deduce the relative diameters of the core and mantle d.Through analysis of the P-wave and S-wave shadow zones
d.Through analysis of the P-wave and S-wave shadow zones
Which of the following is the result of convection within the mantle? a.Warm rock rises as tabular sheets. b.Cool rock rises as vertical, pipe-like masses. c.Cool rock rises as tabular sheets. d.Warm rock rises as narrow pipe-like plumes.
d.Warm rock rises as narrow pipe-like plumes.
What physiographic feature of the ocean floor lies at the base of the continental slopes? a.Offshore shelf b.Off-slope reef c.Continental rift d.continental rise
d.continental rise
Which of the following are probably major components of Earth's inner core? a.Solid iron silicates and magnesium silicates b.Liquid iron-nickel-sulfur alloy c.Solidified uranium and other very heavy elements d.crystalline iron and nickel
d.crystalline iron and nickel
What feature of the ocean floor develops where the oceanic lithosphere bends downward and sinks into the mantle? a.Submarine canyons b.Abyssal seamounts c.Rift valleys on mid-ocean ridges d.deep-ocean trenches
d.deep-ocean trenches
Where does seafloor spreading occur along relatively narrow areas at the crests of oceanic ridges? a.In trenches b.In submarine canyons c.In seamounts d.in rift zones
d.in rift zones
Which term refers specifically to geologic mountain building? a.Ontogeny b.Orthorhombic c.origami d.orogeny
d.orogeny
Where does Earth's magnetic field originate? a.Inner core b.Mantle c.Crust d.outer core
d.outer core
Which layer of Earth does not transmit S waves? a.Outer mantle b.Inner crust c.Deep mantle d.outer core
d.outer core
In which process of fossilization are the internal cavities and pores of the original organism filled with mineral matter? a.Replacement b.Carbonization c.Impression d.petrification or petrifaction
d.petrification or petrifaction
What type of rocks dominate the Valley and Ridge Province of the Appalachian Mountains of North America? a.crustal stretching as Africa and Eurasia migrated away from North America b. stratovolcanoes above a volcanic arc c.deeply eroded, late Paleozoic fault-block mountains and valleys d.sedimentary strata folded in late Paleozoic time
d.sedimentary strata folded in late Paleozoic time