chapter 17,18,19,20
7. A(n) _____ continental margin usually lacks a continental rise and an abyssal plain and is associated with convergent plate boundaries. A. active B. passive C. transform D. subducting E. remote
a
8. In some mountain belts the crust breaks into fault-bounded blocks resulting in _____ mountain ranges. A. fault-block B. extremely high C. extensional D. isostatically adjusted E. metamorphic
a
At a pressure equivalent to a depth of 670 km the mineral olivine collapses to form ____. A. perovskite B. quartz C. mica D. calcite E. zircon
a
Because _____ can be accurately calculated, the size and shape of the core can be determined. A. P-wave paths B. surface wave paths C. gravitational anomalies D. heat flow conditions E. magnetic anomalies
a
Harry Hess proposed that the _______. A. sea floor moves B. continents drift C. magnetic field reverses D. magnetic poles wander E. the core is liquid
a
In plate tectonics, intense geologic activity occurs at ____. A. plate boundaries B. ocean floor C. continental interiors D. along coastlines E. along mountain ranges
a
Oceanic crust is _____ continental crust. A. thinner than B. thicker than C. the same thickness as D. the same composition as E. the same seismic velocity as
a
22. Many guyots and seamounts are aligned in chains (for example the Hawaiian Islands and Emperor seamounts) that form major _____. A. trench systems B. aseismic ridges C. Benioff zones D. mid-ocean ridges E. continental rises
b
27. Project FAMOUS used submersibles to study ______. A. trenches B. mid-ocean ridges C. guyots D. reefs E. continental rises
b
10. A _____ is a group of closely spaced mountains or parallel ridges that may show a history of intrusive tectonic activity. A. volcano B. mountain range C. back-arc basin D. spreading center E. any uplifted region
b
10. _____ are major lines of weakness in Earth's crust that cross the mid-oceanic ridge at right angles. A. Abyssal fans B. Fracture zones C. Submarine canyons D. Transform faults E. Fold belts
b
11. The continental crust is _______ beneath mountain belts than under the craton. A. thinner B. thicker C. the same thickness D. more felsic E. more dense
b
12. The ____ is a shallow submarine platform at the edge of a continent. A. abyssal plain B. continental shelf C. aseismic ridge D. rise E. trench
b
13. Extension and normal faulting take place in a mountain range ____. A. during their early stage of formation B. when rock at high level flows outward C. before folding and metamorphism D. randomly throughout the range's history E. and is always related to late stage intrusions
b
17. Most geologists think that the flat summits of seamounts ___. A. are uplifted sea floor B. were eroded flat by wave action C. are fault surfaces D. are remnants of the continental shelf E. are remnants of plateau basalts
b
21. Terranes that can be shown to have traveled great distances are known as _____ terranes. A. accreted B. exotic C. suspect D. cratonic E. shield
b
13. A(n) _____ is a great mass of sediment-laden water that is pulled downward by gravity along the continental slope. A. avalanche B. underwater landslide C. turbidity flow D. mudflow E. gravity slide
c
18. The crests of mid-oceanic ridges are associated with ____. A. pelagic sediments B. barrier reefs C. rift valleys D. abyssal plains E. Benioff zones
c
22. Late stage normal faulting in a mountain range is a result of _______. A. volcanism B. igneous intrusions C. vertical uplift or extension D. sea-floor spreading E. geosyncline formation
c
23. _____ are rounded masses of rock that form when molten lava erupts into cold water. A. Gabbro mountains B. Sheeted dikes C. Pillow lava D. Dunite dikes E. Columnar basalts
c
28. In a passive continental margin, there is a lack of _______. A. seamounts B. guyots C. earthquakes, volcanoes, and young mountain belts D. no riverine discharge E. sediments
c
The basic idea of ______ is that the Earth's surface is divided into a few large plates that move slowly relative to one another. A. continental drift B. sea floor spreading C. mantle plumes D. plate tectonics E. isostasy
d
The study of ancient magnetic fields is called ____. A. paleontology B. old magnetism C. Curie point D. paleomagnetism E. magnetic polarities
d
Alternating positive and negative polarity magnetic anomalies in the crust form a stripe- like pattern parallel to _____. A. lines of longitude B. the equator C. continental margins D. aseismic ridges E. mid-oceanic ridges
e
As lava cools below the _____ point, a record of the Earth's magnetic field is permanently trapped in the rock. A. freezing B. burning C. boiling D. melting E. Curie
e
Hess's original hypothesis was that sea-floor spreading is driven by deep mantle ____. A. contraction B. spreading centers C. convergent boundaries D. transform faults E. convection
e
High _____ is usually an indication of a magma body or still-cooling pluton near the surface. A. geothermal gradient B. heat loss C. convection D. conduction E. heat flow
e
Marine geologists can predict the age of igneous rocks of the sea floor by measuring _____. A. the percent of iron-rich minerals in the rock B. their grain size C. the velocity of earthquake waves D. their density E. magnetic anomalies
e
Plumes form ______ that are related to areas of active volcanism such as Iceland, Yellowstone and Hawaii. A. converging plate boundaries B. trenches C. aseismic ridges D. failed rifts E. hot spots
e
The average temperature increase in the shallow crust (the geothermal gradient) is about ______ degrees C per kilometer. A. 2 B. 5 C. 10 D. 15 E. 25
e
The boundary between the core and the mantle is marked by great changes in ____. A. seismic velocity B. density C. temperature D. Both seismic velocity and density are correct. E. Seismic velocity, density, and temperature are all correct.
e
The portion of a fracture zone between two offset portions of ridge crest is called a ____. A. normal fault B. strike-slip fault C. convergence zone D. Benioff zone E. transform fault
e
11. Geologists' ideas about the composition of ocean crust are greatly influenced by the study of ____. A. ophiolites B. continental volcanoes C. chert D. the Mohorovicic discontinuity E. the asthenosphere
a
16. The _____ crust of the sea floor is covered in many places with layers of sediment. A. basalt B. granite C. rhyolite D. serpentine E. andesite
a
20. If the San Andreas Fault remains active, Los Angeles will continue northward and crash into ___. A. Alaska B. Japan C. the Imperial Valley D. British Columbia E. Hawaii
a
21. Seismic surveys of the sea have shown the oceanic crust to be divided into _______ major layers. A. 3 B. 6 C. 5 D. 2 E. 7
a
25. _____ is the detachment of part of the mantle portion of the lithosphere beneath a mountain belt. A. Delamination B. Mantle convection C. Terrane shift D. Isostatic adjustment E. Craton formation
a
26. Most seamounts are ______. A. extinct volcanoes B. granitic intrusions C. submerged reefs D. fault block grabens E. ophiolites
a
26. _____ faults in the Tibetan plateau indicate that gravitational collapse is taking place. A. Normal B. Reverse C. Thrust D. Strike-slip E. High-angle thrust
a
31. Divergent plate boundaries can occur where spreading occurs under a continent, for example ___. A. the Red Sea B. the Himalayan Mountains C. the Alps D. the Gulf of Mexico E. the Mediterranean Sea
a
31. Oceans cover _____ percent of the Earth's surface. A. 70 B. 90 C. 80 D. 60 E. 50
a
32. Thick deposits of sediment called _____ are found at the base of many submarine canyons. A. abyssal fans B. continental rises C. continental slopes D. continental shelves E. guyots
a
33. The present ________ represent rejuvenation following uplift in Late Tertiary time. A. Appalachian Mountains B. Alps C. Himalayan Mountains D. Ural Mountains E. Sierra Nevada Mountains
a
37. __________ is the name applied to hot springs on the seafloor where 350 degree Celsius metal-rich solutions are discharged into the cold waters of the ocean. A. Black smokers B. Fumaroles C. Ophiolites D. Andesite E. Hot spots
a
38. Most of the _____ of the United States has/have a very thin blanket - only 1000 to 2000 meters - of sedimentary rock layers. A. craton B. Gulf Coast C. Rocky Mountain region D. Oregon-Washington coast E. Blue Ridge Mountains
a
4. In many mountainous regions are found ____, which are characterized by large thrust faults stacked one upon another. A. fold and thrust belts B. numerous rock types C. evidence of intrusions D. patterns of deformation E. volcanic landforms
a
40. A(n) _________ mountain range, such as the Basin and Range and Tetons, implies a horizontal extension strain. A. fault block B. erosional C. volcanic D. fold E. strike-slip.
a
40. _____ parallel the shore, but are separated from it by wide, deep lagoons. A. Barrier reefs B. Atolls C. Patch reefs D. Guyot reefs E. Fringing reefs
a
Recently, geologists have been analyzing ____ generated by tidal friction, ocean waves, and storms to gain an even more detailed image of the crust and upper mantle. A. energy waves B. light sources C. water movement D. evaporation E. ocean currents
a
The P-wave shadow zone can be explained by the refraction of P-waves at the ___. A. core-mantle boundary B. asthenosphere-lithosphere boundary C. Moho D. inner core-outer core boundary E. 670 km depth limit
a
The Rift Valley in East Africa is an example of a _____. A. diverging plate boundary B. converging plate boundary C. transform plate boundary D. back arc spreading center E. continental rise
a
The ____ is a low velocity seismic zone. A. asthenosphere B. lower crust C. core D. outer core E. Mohorovicic discontinuity
a
The bending of seismic waves as they pass from one material to another is called seismic ____. A. refraction B. reflection C. deflection D. attenuation E. waves don't bend when they pass through different materials.
a
The crust and upper mantle form the ____. A. lithosphere B. athenosphere C. core D. outer core E. Moho discontinuity
a
The inner wall of a trench consists of a(n) _____ of thrust-faulted and folded marine sediment and pieces of oceanic crust. A. accretionary wedge B. subduction wedge C. large amount of sea D. active volcano consisting E. a gap
a
The isotopic ages of Hawaiian Island basalts increase regularly to the ____. A. northwest B. east C. north D. south E. northeast
a
The rise of the crust after removal of ice is called ____. A. crustal rebound B. tectonic uplift C. upheaval D. subduction E. dynamic adjustment
a
The rock record for tens of millions of years indicates that the Earth's magnetic field ____. A. reverses polarity about every 500,000 years B. is constant in strength and polarity C. did not come into existence until about 1 million years ago D. is a monopole magnet E. has steadily weakened and will be gone in another 10 million years
a
The study of _____ rocks, sediment, and topography provided most of the information that led to the concept of plate tectonics. A. seafloor B. ocean boundaries containing C. continental interior D. mid-oceanic ridge E. abyssal plains
a
_____ is the return of some of the energy of a seismic wave to the Earth's surface after it bounces off a rock boundary. A. Seismic reflection B. Seismic refraction C. Seismic attenuation D. Seismic adjustment E. Seismic shadow zone
a
_____ predicts that the higher a mountain range extends above sea level the deeper it extends into the mantle. A. Isostatic adjustment B. Crustal rebound C. Mantle convection D. Mohorovicic discontinuity E. Subducting oceanic lithosphere
a
27. ________ beneath the Basin and Range helps to explain the extensive rhyolitic and basaltic eruptions that occurred tens of millions of years after the last orogeny. A. Obduction B. Delamination C. Wilson Cycles D. Subduction E. Thickening of the continental crust by "rooting"
b
28. The cycle of splitting of a supercontinent, opening of an ocean basin, followed by closing of the basin and collision of the continents, is known as a ________. A. Wegener plan B. Wilson Cycle C. delamination plan D. Hess Process E. Vine-Mathews system
b
29. A ______ is the source of sedimentary and volcanic material accumulating along a convergent boundary. A. subduction zone B. magmatic arc C. suspect terrane D. mid-oceanic ridge E. folded mountain range
b
3. The once deep-seated roots of former Precambrian mountain belts are the _____ rock for the now stable, central part of the continent. A. cratonic B. basement C. core D. platform E. isostatic
b
31. Major mountain belts with higher mountain ranges tend to be geologically ___________ relative to those where the mountains are lower. A. the same age B. younger than C. random in age D. older than
b
32. Plate motion can be measured directly using ____. A. FBI B. GPS C. USGS D. NOAA E. GIS
b
34. The system approach regards mountains as the products of three closely interdependent components. Which of the following is not one of those components? A. plate tectonics B. meteor impacts C. climate D. erosion
b
36. _____ are V-shaped valleys that run across continental shelves and down continental slopes. A. Rift valleys B. Submarine canyons C. Submarine trenches D. Guyots E. Fracture zones
b
38. The continental shelf is part of the ____. A. abyssal plain B. continents C. mid-oceanic ridge D. island arc system E. true ocean basin
b
7. Geologists believe that when the thick and high part of a mountain belt becomes too high and gravitationally unstable _____ occurs. A. massive landslides B. gravitational collapse and spreading C. volcanic eruptions D. rapid downcutting E. basalt flows
b
9. Mid-oceanic ridges are often marked by lines of _____ that carry and precipitate metals. A. ocean currents B. hot springs C. seismic ridges D. submarine volcanoes E. ocean trenches
b
A divergent boundary on the sea floor is associated with ______. A. submarine trenches B. mid-oceanic ridges C. transform faults D. aseismic ridges E. guyots
b
A region of magnetic force, called the ______ surround Earth. A. magnetic force B. magnetic field C. magma field D. magnetic poles E. magnetism
b
Heat flow ______ the crest of the mid-oceanic ridges. A. increases away from B. decreases away from C. does not change relative to D. is unknown on E. is the highest on Earth on
b
In this hypothesis the two sides of the mid-oceanic ridge are moving in opposite directions like slow conveyor belts. A. plate tectonics B. sea floor spreading C. continental drift D. continental collisions E. plate spreading
b
Iron-nickel meteorites are an important source of information regarding the composition of Earth's ______. A. oceanic crust B. core C. mantle D. asthenosphere E. continental crust
b
One kind of convergent plate boundary is ____. A. rift valley convergence B. continent-continent convergence C. transform convergence D. subduction zone convergence
b
Sea-floor spreading implies that sea-floor rocks should be ______________. A. the same age throughout B. youngest on the crest of mid-ocean ridges C. younger as water become colder D. younger toward the trench E. youngest on the continental shelf
b
Seismic P-waves _____ through continental crust relative to oceanic crust. A. travel faster B. travel slower C. stay the same velocity D. are refracted E. are reflected
b
The boundary that separates the crust from the mantle is the ____. A. mantle discontinuity B. Mohorovicic discontinuity C. lithospheric discontinuity D. athenospheric discontinuity E. shadow zone
b
The magnetic poles are displaced about ______ degrees from the geographic poles. A. 5.5 B. 11.5 C. 16.5 D. 30.5 E. 45.5
b
These machines can take geologists to many parts of the sea floor to observe, photograph, and sample rock and sediment. A. deep sea drilling platforms B. submersibles C. sonar D. echo sounder E. multibeam sonar
b
These plate boundaries are marked by shallow-focus earthquakes in a narrow zone for a single fault or in a broad zone for a group of parallel faults. A. divergent B. transform C. ocean-continent convergence D. subduction E. ocean-ocean convergence
b
Wegener reassembled the continents to form the super continent _____. A. Asia B. Pangea C. Laurasia D. Gondwanaland E. Madagascar
b
_____ is a circulation pattern in which low-density material rises and high-density material sinks. A. Conduction B. Convection C. Density flow D. Refraction E. Reflection
b
_______ is a balance or equilibrium of adjacent blocks of brittle crust floating on the upper mantle. A. Density adjustment B. Isostasy C. Gravity adjustment D. Inertial adjustment E. Thermohaline flow
b
10. ____ volcanoes can be found along subducting plate boundaries. A. Shield B. Cinder cone C. Andesitic D. Basaltic E. Pegmatitic
c
30. Continents grow bigger as _______. A. accretionary wedges form at the margins B. gravitational collapse and spreading widens the craton C. mountain belts evolve along their margins D. uplift and block-faulting takes place E. isostacy lifts them up
c
33. The Peru-Chile trench is moving over the ________ Plate as South America moves west. A. North American B. Australian C. Nazca D. South American E. Antarctic
c
34. The continental rise typically ends at a(n) _______ at a depth of about 5 kilometers. A. slope B. trench C. abyssal plain D. mid-oceanic ridge E. continental slope
c
36. A(n) __________ is an episode of intense deformation of the rocks of a region. A. isostatic adjustment B. geosyncline C. orogeny D. buoyancy event E. basin to dome event
c
37. The Grand Canyon, Ozark dome, Black Hills, and Adirondacks expose ________. A. a fold and thrust belt B. ophiolites C. a Precambrian basement D. an ancient magmatic arc E. the result of delamination
c
5. Turbidity currents are great masses of sediment-laden water that are pulled downhill by ____. A. landslides B. submarine canyons C. gravity D. earthquakes, storms, volcanic eruptions E. Earth's rotation
c
5. ____, intermixed granitic and metamorphic rock, may represent those parts of mountain belts that were once at even deeper levels of the crust. A. Pegmatites B. Sutures C. Migmatites D. Extensional fabric E. Subduction patterns
c
9. The _____ is(are) the product of oceanic-continental convergence and Earth's second highest mountain belt. A. Appalachians B. Himalayas C. Andes D. Basin and Range E. Sierra Nevada
c
A cavity or body of low-density material causes a _____ pull on a gravity meter relative to average crust. A. stronger B. greater than the surrounding rock C. weaker D. rapidly increasing E. Gravity can't be measured.
c
A deviation from average reading is called a(n) ____. A. deviant B. negative C. anomaly D. above or below average E. positive
c
A gravity reading lower than the normal regional gravity indicates that a region is ____. A. actively being uplifted B. under a high magnetic field C. being held down D. a good prospect for an ore deposit E. undergoing elastic rebound
c
Continental crust is ___ relative to oceanic crust. A. the same thickness B. thinner C. thicker D. hotter E. of unknown relation
c
During extension in divergent plate boundaries a rift valley forms as a central ____. A. horst B. strike-slip fault C. graben D. mountain range E. subduction zone
c
Hot mantle rock rising slowly by convection under parts of the ocean explains ____. A. mid-oceanic ridges B. underwater volcanoes C. the unexpectedly high heat flow under the oceans D. the thickness of the continents
c
One possible mechanism for plate tectonic drive is ____. A. meteor impacts B. earthquake energy C. slab pull D. gravity sliding E. Benioff drive
c
The Himalayan Mountains are thought to have formed ____. A. by continent-ocean convergence B. by ocean-ocean convergence C. by continent-continent convergence D. at a spreading center E. at a transform fault
c
The San Andreas Fault is _________ in California. A. a normal fault B. an oblique fault C. a transform fault D. a thrust fault E. a reverse fault
c
The ___ includes rocks of the crust and uppermost mantle. A. true ocean basin B. asthenosphere C. lithosphere D. ophiolites E. Moho
c
The ____ is the transition zone at the core-mantle boundary. A. Moho B. asthenosphere C. D layer D. perovskite zone E. unnamed surface
c
The downward plunge of cold rock at convergent boundaries accounts for the existence of _____. A. continental shelves B. submarine hot springs C. oceanic trenches D. the Earth's core E. the abyssal plains
c
The gradual loss of heat through the Earth's surface is called ___. A. thermal decay B. cooling trend C. heat flow D. thinning of the heat E. convection
c
The head of large plumes that form "hot spots" may cause uplift and ____. A. andesitic volcanoes B. transform faults C. vast fields of flood basalt D. spreading centers E. subduction zones
c
The upper mantle consists of _______. A. granite B. basalt C. ultramafic rocks D. metamorphic rocks E. sedimentary rocks
c
This type of plate boundary the two plates can consist of ocean-ocean, ocean-continent, or continent-continent crust. A. divergent B. strike-slip C. convergent D. transform E. transverse
c
____ is the idea that continents move freely over Earth's surface, changing their positions relative to one another. A. Plate tectonics B. Sea floor spreading C. Continental drift D. Continental collisions E. Plate spreading
c
_____ is the branch of geology that applies physical laws and principles to study Earth. A. Earthquakology B. Physicalogy C. Geophysics D. Palentology E. Environmental geology
c
14. The region of a continent that has been structurally stable for a long period of time is called the ______. A. dome B. basin C. Precambrian shield D. craton E. mountain range
d
14. Turbidity currents flow down the continental slope until they come to rest on ___. A. the continental shelf B. the mid-oceanic ridge C. a guyot D. the abyssal plain E. a submarine trench
d
15. The _____ resulted from the collision of Asia and Europe. A. Alps B. Pyrenees C. Caledonide Mountains D. Ural Mountains E. Himalayan Mountains
d
17. Volcanic rocks, mostly _______, accumulate near a convergent plate boundary. A. shales B. sandstones C. granites D. andesites E. marbles
d
19. A basic tool for indirectly studying the sea floor is the ____, which measures water depth. A. drilling ship B. rock dredge C. submersible D. echo sounder E. gravimeter
d
2. During the last couple of decades, geologist have used a _____ approach to gain insight into the growth and wearing away of mountains. A. tectonic B. erosional C. weathering D. system E. climatic
d
23. Migmatites must have been transported much higher in the crust during and after ____. A. normal faulting B. volcanism C. emplacement of plutons D. an orogeny E. subduction
d
24. A ______ is a bottom flowing current that flows parallel to the slopes of the continental margins. A. density flow B. surface current C. turbidity current D. contour current E. coriolis current
d
29. The abyssal plains are formed of _____. A. sediment from meteoric dust B. pillow basalts C. mid-oceanic ridges D. horizontal layers of sediment E. volcanic ash
d
29. _______ proposed an explanation for magnetic anomalies. A. Charles Plummer B. Harry Hess C. Alfred Wegener D. Vine and Matthews E. Diane Carlson
d
3. This instrument works on essentially the same principles as echo sounder but can penetrate the bottom of the sea floor and provides more information. A. multibeam sonar B. single beam sonar C. seismic refraction profiler D. seismic reflection profiler E. sonar profiler
d
34. Magma heated by ocean-continent convergence may form a(n) _____ such as the Aleutian Islands. A. mantle diapir B. convection uplift C. abyssal plain D. magmatic arc E. hot spot
d
35. Of the two major mountain belts in North America, the _______ are in the West. A. Urals B. Himalyan C. Appalachians D. North American Cordillera E. Andes
d
35. The continental shelves of the world are typically covered by relatively young sediments derived from ___________. A. contour currents B. mid-oceanic ridges C. turbidity currents D. land E. continental shelves
d
37. Young mountain belts with their associated igneous intrusions, metamorphism, and fold- thrust belts form at _______. A. divergent boundaries B. continental rifts C. transform fault boundaries D. convergent boundaries E. hot spots
d
38. Pangea initially separated into two parts, the southern part is called ____. A. Rodinia B. Laurasia C. Panthallasia D. Gondwanaland E. Atlantis
d
39. ______ proposed that the three types of coral reefs are related to each other by subsidence of a central volcanic island. A. Isaac Newton B. Charles Plummer C. George Bush D. Charles Darwin E. Diane Carlson
d
8. Earthquakes, volcanoes, Benioff seismic zones, and island arcs are all associated with this sea floor feature. A. guyots B. passive margin C. seamounts D. oceanic trench E. abyssal plains
d
A _____ plate boundary is where plates are moving away from each other. A. convergent B. shear C. transform D. divergent E. transverse
d
A gravity meter registers _____ over ore bodies. A. zero gravity readings B. constant gravity C. decreased gravity D. increased gravity E. You can't explore for metallic deposits with a gravity meter.
d
Detailed images provided by _____ suggest that the mantle is heterogeneous, probably due to variations in temperature, composition, and density. A. p-waves B. shadow zone C. deep drill holes D. seismic reflection E. seismic tomography
d
In the early 1900s the German meteorologist _____ made a strong case for continental drift. A. Charles Plummer B. George Bush C. Ben Franklin D. Alfred Wegener E. Diane Carlson
d
Measured rates of sea-floor spreading range from ______ cm/year. A. 0.1 to 1 B. 100 to 1000 C. 1000 to 10,000 D. 1 to 24 E. 0.01 to 0.1
d
One widely accepted hypothesis is that the Earth's magnetic field is created by electric currents within the ______. A. asthenosphere B. crust C. lower mantle D. liquid outer core E. sun
d
What is the asthenosphere? A. It is the surface that separates the crust from the mantle. B. It is the zone that separates the continental crust from the oceanic crust. C. It is in the surface that separates the inner and outer core. D. It is the zone of weakness in the mantle on which the lithosphere moves. E. It is the same as the Gutenberg Discontinuity.
d
___ indicates that the core of the Earth is a liquid. A. Density calculations B. Studies of meteorites C. The P-wave shadow zone D. The S-wave shadow zone E. The Earth's heat flow
d
_____ currents are bottom currents that flows parallel to the slopes of the continental margin. A. Turbidity B. Gulf Stream C. Newfoundland D. Contour E. Abyssal
d
1. _____ are chains thousands of kilometers long composed of numerous mountain ranges. A. Mid-oceanic ridge B. Volcanic arcs C. Back arcs D. Valley and Ridge Province E. Mountain belts
e
12. Most of the world's mountains existing today are a result of ____. A. intense deformation B. isostasy C. weathering and erosion D. intense deformation and isostasy E. intense deformation, isostasy, and weathering and erosion
e
15. Shallow focus earthquakes on the sea floor are associated with ___. A. trenches B. abyssal rises C. guyots D. abyssal plains E. mid-ocean ridge crests
e
16. The sedimentary sequences that form on passive margins are predominantly ____. A. shale B. limestone C. sandstones D. andesitic flows E. shale, limestone, and sandstones
e
18. The Himalayan Mountains formed as the result of ______ convergence. A. ocean-continent B. arc-continent C. ocean-ocean D. arc-ocean E. continent-continent
e
19. A _____ terrane has rock types and ages that do not seem to be related to the rest of the geology of a mountain belt. A. mixed B. coupled C. partial D. integrated E. suspect
e
20. Water depth increases over a continental shelf to the outer edge depth of _____ to ____ meters. A. 500; 600 B. 400; 500 C. 300; 400 D. 200; 300 E. 100; 200
e
24. At the close of the Paleozoic, eastern North America was attached to what is now _______. A. Europe and Asia B. China and South America C. India and Antarctica D. Africa and China E. Europe and Africa
e
25. _______ is an island on a mid-oceanic ridge. A. Madagascar B. Japan C. Cuba D. Hawaii E. Iceland
e
30. Oceanic trenches are marked by _______. A. no seismicity B. shallow depths C. positive gravity anomalies D. high heat flow E. low heat flow
e
30. The most common type of transform faults offset oceanic ____. A. abyssal plains B. microcontinents C. continental shelves D. trenches E. ridge crests
e
32. Geologists regard most bodies of ultramafic rock as being _______. A. intrusions formed during the accumulation stage B. due to gravitational collapse and spreading C. due to lithospheric delamination D. areas left by block faulting and uplift E. mantle material faulted into the crust during orogeny
e
33. The Grand Banks cable breaks of 1929 are interpreted to be the result of earthquake- caused ____. A. earthquakes B. contour currents C. tsunamis D. underwater volcanic eruptions E. turbidity currents
e
35. The apparent movement of the magnetic poles through geologic time is called _____. A. mantle plume motion B. polar drift C. sea-floor spreading D. continental drift E. polar wandering
e
36. Evidence in support of continental drift includes ____. A. glacial striation patterns B. fossil distribution on different continents C. fit of continental margins D. matching of geologic patterns on continents E. all of the choices are correct
e
39. According to the concept of ____, lighter less dense continental crust "floats" higher on the mantle than denser oceanic crust. A. delamination B. gravitational collapse C. geosynclines D. block faulting E. isostacy
e
6. Frequent earthquakes, offshore trenches, and active volcanoes perched on top of older rock are all indications of ____. A. old mountain belts B. stable craton C. platform D. Precambrian shield E. active mountain ranges
e
A ____ is a tool used to study the gravitational attraction between Earth and a mass within the instrument. A. seismic reflection study B. sonograph C. gravitation recorder D. seismograph E. gravity meter
e
Abyssal fans are made up of _____ sediment that has moved down submarine canyons A. abyssal B. continental slope C. deep sea D. marine pelagic E. land-derived
e
