Earth Science unknowns
53) Mountain building in the western margin of North America records a history of both ________. A) continental collision and terrane accretion B) Andean type subduction and terrane accretion C) Andean type subduction and continental collision D) none of the above
B
55) Which of the following is not a significant volcanic hazard? A) injury or death by inhalation of air heavily laden with volcanic ash B) being overrun by a basaltic lava flow C) being caught in a river valley and being overcome by a volcanic mudflow/lahar D) a tsunami generated by a massive submarine volcanic eruption
B
64) When the differential stress exceeds the strength of the material, the material will begin to undergo ________. A) brittle deformation B) elastic strain C) overturned faulting D) reverse faulting
B
22) In a(n) ________ fault, the hanging wall block moves up with respect to the footwall block. A) normal B) strike slip C) reverse D) abnormal
C
30) Given enough time, what factor is typically most important in soil formation? A) bedrock type B) slope direction C) climate D) months of snow cover
C
31) A volcanic deposit comprised of red to black lapilli-sized pyroclastic material associated with pahoehoe lava flows was probably deposited on ________. A) a large composite volcano B) a shield volcano C) a cinder cone D) a satellite shield volcano on a rhyolitic caldera
C
36) Shield volcanoes form from what type of magma? A) high viscosity aa basaltic magmas B) low viscosity rhyolitic magmas C) low viscosity basaltic magmas D) high viscosity rhyolitic magmas
C
4) The release of water vapor to the atmosphere by plants is called ________. A) evaporation B) degassing C) transpiration D) infiltration
C
73) ________ would have the largest capacity to naturally remove sewage pollutants. A) Fractured granite B) Well-sorted, coarse gravel C) Slightly clayey sand D) Limestone with solution channels and caverns
C
13) Monoclines, anticlines, synclines and domes are all examples of ________. A) faulting B) jointing C) flow D) foliation
D
45) The Himalayas and Tibet are the archetypical example of a(n) ________ mountain belt. A) Andean B) continental rift C) transform D) collisional
D
7) Which of these is considered to be "storage" part of the hydrologic cycle? A) addition to a glacier B) condensation C) evaporation D) infiltration E) transpiration
A
40) Digging downward through a soil profile, how deep would you have to go before you found recognizable fragments of the parent rock for the soil? A) A B) B C) C D) E
B
109) What is the most abundant, naturally produced, weak acid involved in chemical weathering and soil formation? A) carbonic B) hydraulic C) hydrogen chloride D) sulfuric
A
113) ________ is the basic force that moves or accelerates soil and regolith down a slope. A) Gravity B) Mass wasting C) Slope D) Trigger
A
14) If the glacial budget is balanced (accumulation equals wastage), then ________. A) the terminus of the glacier is stationary B) the ice front will retreat C) the glacier will not flow downhill D) the ice front will advance
A
21) As a stream changes from its headwaters to its mouth, which of the following is not likely to occur? A) Flow velocity decreases. B) The channel gets wider downstream. C) Sediment size gets smaller downstream. D) The channel gets smoother. E) The volume of water increases.
A
26) A(n) ________ is a deposit created by a former meltwater channel or tunnel in glacial ice that was filled with sand and gravel. A) esker B) yazoo ridge C) valley plain D) kettle
A
3) Which statement about the May, 1980, eruption of Mount St. Helens is false? A) During the eruptive period, the mountain peak was substantially built up by new lava flows and pyroclastic debris. B) Plumes of ash rose high into the atmosphere during the major eruptive events. C) Mudflows accompanied the major eruptive events. D) The most powerful explosive event was preceded by a massive landslide.
A
41) In what part of a subduction margin might you find rocks deposited on the abyssal plain, far from land? A) Accretionary Wedge B) Volcanic Arc C) Forearc Basin D) Cratonic Basin
A
47) The boundary between two terranes or two continents that have collided is called a ________. A) suture B) join C) weld D) stitch
A
51) Folded limestones that are exposed high elevations in the Himalayas were originally deposited as sediments in a ________. A) marine basin between India and Eurasia B) Cenozoic fault basin between Africa and Arabia C) deep ocean trench along the southern margin of India D) late Paleozoic syncline north of the Tibetan Plateau
A
54) The loess deposited in many parts of the Midwest ________. A) was once glacial outwash deposits B) is in the form of transverse dunes C) is uniformly thick D) had its source in desert regions
A
54) Which of the following features characterize meandering streams and valleys? A) natural levees; broad floodplains B) rapids; channel bed potholes C) waterfalls; entrenched meanders D) V-shaped valley cross sections
A
67) Terrane accretion generally occurs along a ________ boundary between a continental plate and a(n) ________ plate. A) convergent; continental B) convergent; oceanic C) divergent; continental D) divergent; oceanic
A
67) Terrane accretion generally occurs along a ________ boundary between a continental plate and a(n) ________ plate. A) convergent; continental B) convergent; oceanic C) divergent; continental D) divergent; oceanic
A
79) Bajadas develop from ________. A) coalescence of alluvial fans B) deflation of blowouts C) deposition of playa lakes D) erosion of inselbergs
A
89) Gradients usually ________ downstream in a major river system. A) decrease B) increase C) stay the same D) become highly variable
A
9) Clay minerals formed from gabbro or diorite bedrock illustrate which kind of weathering? A) chemical B) proactive C) syntropical D) mechanical
A
92) Quartz is quite resistant to weathering and is an important component of ________. A) clays in swamps B) feldspars on beaches C) mud in deltas D) sands in riverbeds
A
1) When subjected to a differential stress, a very "brittle" material, like glass, will ________. A) not bend at all. It will only break B) deform by breaking or elastic bending C) flow or shear if the stress is large enough D) flow under low to moderate stress conditions
B
11) A dendritic (tree-like) drainage pattern develops in regions where the underlying material is relatively uniform so the major control on the water movement is ________. A) vegetation B) slope C) saturation D) climate E) sediment load
B
11) Burial of rocks increases the confining pressure so that deeply buried rocks are more likely to ________ than shallow rocks. A) fracture B) fold C) deform D) shear
B
112) ________ denotes the downslope movement of soils and regolith. A) Gravity B) Mass wasting C) Slope D) Trigger
B
122) Highly impermeable layers such as compacted clay or shale are known as ________. A) aquifers B) aquitards C) perched water tables D) pressure surfaces
B
15) Laminar flow, where water moves in approximately straight-line paths, characterizes ________. A) fast-moving streams B) slow-moving streams C) the edges of channels D) the bottoms of channels E) all of the above
B
16) In the movie "Volcano" basaltic lava flows are shown running down flat streets at speeds faster than humans could run. From your knowledge of magma viscosity, is this realistic? A) Yes, the viscosity of basalt magma is similar to water so it would flow at comparable rates. B) No, the viscosity of basaltic magma is much higher than water, and thus would flow much slower than water. C) No, the viscosity of basaltic magma is much higher than water, and thus, would flow much faster than water. D) There is no way of knowing because basaltic magmas can have viscosities similar to water or higher depending on temperature and fluids, and thus there isn't enough information.
B
65) Orogenesis refers to the formation of ________. A) accretionary wedges B) fault planes C) mineral deposits D) mountains
D
17) Under similar warm, moist climatic conditions, why would basalt and gabbro generally have higher chemical weathering rates than rhyolite and granite? A) The quartz in the gabbro and basalt decomposes very quickly. B) The ferromagnesian minerals in the gabbro and basalt are subject to oxidation and chemical breakdown. C) The plagioclase feldspars in the granite and rhyolite decompose readily to clay minerals and iron oxides. D) The potassium feldspars and quartz in the rhyolite and granite are more susceptible to cracking by frost wedging.
B
22) If you were to examine the profile of a typical river, you would probably find that the gradient is ________. A) steepest near the mouth B) steepest near the head C) the same at both the head and mouth D) none of these
B
23) In thrust faulting, ________. A) grabens develop on the footwall block B) the crust is shortened and thickened C) horizontal, tensional stresses drive the deformation D) the hanging wall block slips downward along the thrust fault
B
32) Island arcs and Andean type mountains are both examples of mountains formed by ________. A) collisional tectonics B) subduction C) rifting/oceanic spreading D) transform faults
B
33) Which of the following volcano types are short lived volcanoes that last a few days to months and then shut down? A) shield volcano B) cinder cone C) lava dome D) composite volcano
B
41) Paricutin volcano in Mexico is an example of a ________. A) shield volcano B) cinder cone C) lava dome D) composite volcano
B
41) Which soil horizon represents the lowest part of the zone of accumulation, also referred to as the subsoil? A) A B) B C) C D) E
B
42) The major difference between floods in humid regions and in dry regions is ________. A) in dry regions, flooding is a very slow process because there is less water B) in dry regions, flooding is a very fast process because there are fewer plants C) in dry regions, flooding lasts much longer than in humid regions because the water cannot soak into the baked desert soil D) in dry regions, flooding does not really occur because there is almost no water
B
46) A river is flowing in a broad, alluvial valley and the river is silt-laden but also moves sand and a small amount of gravel. The government decides to build a dam across the valley for power and flood control. What will happen to the river, upstream of the dam? A) The river will downcut. B) The river will start to deposit sand and gravel, frequently spilling out of its channel. C) The river will not change. D) The river will respond to the new temporary base level and cut laterally outside its valley, widening the valley.
B
46) Island arc systems now on the Tibet plateau record subduction prior to the collision of India with Eurasia. Geologists would map these pre-collisional arc rocks as ________. A) hot spot tracks B) terranes C) rift zones D) pre-collisional transform zones
B
46) The steep, upper slopes of composite volcanoes are generally produced by ________. A) large landslides B) high-viscosity, low-volume silicic magmas that are erupted from the summit C) satellite or parasitic cones that push up the top of the volcano to steep slopes D) tilting of the summit by intrusion of high-viscosity magma directly below the summit
B
52) The Appalachian Mountains may have once been as lofty as the Himalayan-Tibetan Mountain belt is today. Why are they not this high now? A) They developed a dense crustal root following collision, and isostasy forced them to sink to their present elevation. B) They formed long ago, and erosion has beveled them to their present low elevation. C) The mountains cooled following the collision, which increased the density of the of the rocks by cooling, and isostasy forced the mountains to sink. D) Opening of the North Atlantic Ocean converted lithosphere to asthenosphere beneath eastern North America, forcing eastern North America to sink to low elevations.
B
53) A natural levee is ________. A) an erosional feature B) a depositional feature C) perpendicular to its stream channel D) found inside the stream channel
B
60) In the interior of continents the earth's crust is typically about 40km thick and the elevation is near sea level. Most earth materials expand when heated, lowering their density. During rifting continental margins are heated but cool as sea floor spreading moves offshore from the continent. Thus, basic isostasy suggests that after rifting, a continental margin will ________. A) uplift B) subside C) remain near sea level D) rise slowly as erosion removes uplifted rocks
B
70) Which of the following best describes melting of the mantle at subduction zones that leads to island arc volcanoes? A) Heat is carried downward with the subducting plate and melts the mantle above the downgoing plate. B) Water released from the subducting plate decreases the melting temperature in the mantle above the downgoing plate to generate magmas from the overlying mantle wedge. C) The subducting plate is cooled as it is carried to depth and the subducted oceanic crust melts. D) The subducted plate subsides into the mantle and allows magma from the lower mantle magma ocean to rise toward the surface.
B
75) How does a permeable sandstone compare to a karst limestone in terms of groundwater flow? A) Flow is faster in the limestone so pollution is less of a threat. B) Flow is faster in the limestone so pollution is more of a threat. C) Flow is faster in the sandstone so pollution is less of a threat. D) Flow is faster in the sandstone so pollution is more of a threat.
B
8) Chemical weathering rates are highest in ________. A) hot dry climates B) hot wet climates C) cold wet climates D) cold dry climates
B
87) Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern. A) frost wedging B) mass wasting C) sheeting D) oxidation
B
93) Magmas are generated at mid-ocean ridges by ________ melting. A) compression B) decompression C) hot spot D) subductional
B
100) ________ can be a temporary base level for a river. A) A cavern B) A mountain summit C) Another river D) Sea level
C
110) Most caves and caverns originate by ________ and ________. A) deposition; limestone B) deposition; sandstone C) dissolving; limestone D) dissolving; sandstone
C
117) Which process of mass wasting occurs primarily in permafrost regions? A) debris flows B) rockslides C) solifluction D) slumps
C
22) Which of the following is not a major factor controlling glacial erosion? A) ice thickness B) rate of glacial ice movement C) altitude of the glacial ice D) character of the surface beneath the glacier
C
24) The greater the channel roughness, the ________ the stream. A) higher gradient there is in B) more sediment laden C) slower flowing D) straighter
C
24) Which one of the following statements concerning volcanic blocks and bombs is true? A) The top of the lava flow cools slower than the middle of the lava flow. B) Orange represents the cooler parts, which are below the surface. C) The surface cools faster than the lava below, and is black in appearance. D) The black part is aa, while the orange is pahoehoe.
C
25) Mountain building uplifts rocks against the force of gravity raising their potential energy, which requires work by the earth system. Based on the relative motion of fault blocks, what type of fault would you expect to require more energy than the others? A) normal B) strike-slip C) thrust D) There is no way of knowing based on information data given.
C
28) ________ make up the suspended loads of most rivers and streams. A) Dissolved ions and sand B) Dissolved salts C) Silt and clay-sized, detrital grains D) Sand and gravel that move during floods
C
35) A(n) ________ is a thick accumulation of sediments and small tectonic blocks formed of material scraped off subducting oceanic lithosphere at a convergent margin. A) mass movement complex B) continental shelf, terrain complex C) accretionary-wedge complex D) subterranean-accumulation complex
C
40) Permanent streams in desert regions are rare, and when they do occur, ________. A) they originate in a glacier region B) they have numerous tributaries to keep them supplied with water as they cross the desert C) they originate outside of the desert region and have few tributaries in the desert D) they get their water from wadis and arroyos
C
40) What type of basin would be most likely to contain large amounts of sediments derived from a volcanic source? A) a continental interior basin B) a passive continental margin C) a forearc basin D) a strike-slip basin
C
50) What type of volcano would be most likely to generate large landslides? A) shield volcano B) cinder cone C) composite volcano D) caldera
C
52) Most stream valleys have a V shaped cross section because ________. A) water washing down the slope makes straight channels B) vegetation on the slopes forces this profile C) mass wasting of weathered rocks on the slope maintain an angle of repose slope D) none of the above
C
66) A ________ is a near surface, intrusive igneous rock body that results from local inflation of a horizontal sill. A) batholith B) dike C) laccolith D) volcanic neck
C
67) An artesian well is one in which ________. A) the water is warm, fairly saline, and recharged by an affluent stream B) pressurized groundwater rises from a deep, unsaturated aquifer C) water rises above the top of the aquifer without any pumping D) the well is horizontal and the water table is perched
C
86) Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern. A) rockslide B) debris flow C) creep D) slump
C
89) Quartz weathers readily to ________ minerals. A) aluminum-rich clay B) ferromagnsian C) silicate D) sulfurouos
C
90) If two streams are otherwise identical, the stream with the smaller gradient would have the ________. A) greatest load B) largest discharge C) lowest velocity flow D) smoothest channel.
C
92) Stream discharge is defined as the ________ of water flowing past a specific channel location per unit time. A) gradient B) load C) quantity D) velocity
C
1) Approximately how much of Earth's water supply is saline? A) 20% B) 43% C) 67% D) 98% E) 100%
D
114) ________ is the boundary line separating adjacent stream drainage basins. A) A drainage basin B) A meander C) A natural levee D) A stream divide
D
13) As magma approaches the surface, water contributes to the explosive potential of the eruption because ________. A) water has a large heat capacity, which allow it to keep the magma hot enough to explode B) water dissociates to hydrogen and oxygen at high temperatures but reacts violently at decreasing pressures to produce explosive eruptions C) water has a lower density in its solid phase than its liquid phase which makes it explode when pressure decreases D) water dissolved in magma flashes to steam as pressure decreases, and the volume increase leads to an explosive potential
D
14) Which one of the following statements concerning mechanical weathering is not true? A) reduces grain sizes of rock particles B) allows for faster rates of chemical weathering C) is important in the formation of talus slopes D) involves a major change in the mineral composition of the weathered material
D
15) Volcano A erupts rocks with SiO2 content ranging from 49% to 52% whereas volcano B, 100km away, erupts materials with SiO2 content of 62-68%. Which statement best characterizes these two volcanoes? A) Both volcanoes are shield type volcanoes that are characterized by quiescent eruptions. B) Both volcanoes are violent, explosive volcanoes that spread ash continent wide. C) Volcano A is likely to be a supervolcanoes with violent eruptions, whereas volcano B is probably a shield volcano with quiescent eruptions. D) Volcano A is probably a shield volcano with typically quiescent eruptions, whereas Volcano B is likely a stratovolcano characterized by violent, explosive eruptions.
D
21) In which area would weathering by frost wedging probably be most effective? A) in a moist, tropical forest B) in cool high desert areas C) where the subsoil is permanently frozen D) in moist, temperate climates
D
25) The main power of water in a channel is related to its ________. A) velocity and temperature B) viscosity and velocity C) discharge and viscosity D) slope and discharge E) slope and temperature
D
25) The term drift ________. A) refers only to alpine glaciers B) refers only to moraines C) is synonymous with the term till D) means any sediments of glacial origin
D
32) The most dangerous of the volcano types is the ________. A) cinder cone B) fissure eruption C) shield volcano D) stratovolcano
D
33) Most granitic batholiths represent ________. A) a deeply exhumed passive continental margin B) a deeply exhumed forearc rock assemblage C) magmas generated in a rift system, prior to development of a passive margin D) the exhumed roots of a subduction related magmatic arc
D
36) Which of the following best describe the E soil horizon? A) regolith zone B) erosion zone C) residual zone D) leaching zone
D
37) You are walking on the beach along the south-coast of Alaska. You see rocks cut by numerous faults that consist of basalt with evidence of eruption in the ocean, deep-water chert, mudstone, and sandstones with abundant volcanic material. What tectonic setting would you assign to these rocks? A) passive continental margin sequence B) forearc basin C) continental interior basin D) accretionary wedge
D
38) Granitic batholiths typically form over time intervals of ________. These are normally formed below the surface of the earth. A) tens of thousands of years B) hundreds of thousands of years C) millions of years D) billions of years
D
45) Most of the deserts and steppes that occur at middle latitudes do so because of ________. A) subsiding air currents B) rising air currents C) high temperatures D) mountains that block the moisture and long distances from the oceans
D
45) Mount Pelée on Martinique is an example of a ________. A) shield volcano B) cinder cone C) lava dome D) composite volcano
D
48) Which of the following is not a typical stage in the evolution of a Basin and Range type region? A) Water erodes the mountains and deposits sediment in the adjacent basins. B) Alluvial fans and bajadas form along the mountain fronts. C) Salt flats or playas and occasional playa lakes form. D) Sediment moves downhill to the sea.
D
49) Inselbergs are ________. A) insulated icebergs floating in a playa lake B) blowouts cut from bedrock in mountainous areas C) lithified rock formed by cementation of wind-deposited dune sands D) bedrock hills in a highly eroded desert landscape
D
50) A meandering river is flowing in a broad, alluvial valley and the river is silt-laden but also moves sand and a small amount of gravel. The government decides to build a dam across the valley for power and flood control. What will happen to the river downstream of the dam? A) The river will start to deposit sand and gravel, frequently spilling out of its channel. B) The river will not change. C) The river will respond to the new temporary base level and cut laterally outside its valley, widening the valley. D) The trapping of silt in the reservoir will change the river to a braided stream because it will only have sand and gravel in its sediment load.
D
51) Which of the following mass movements is most likely to occur in a geologic setting where the rock strata are inclined? A) debris flow B) slump C) creep D) rockslide
D
55) The Tibetan plateau is high above sea level because ________. A) there are many active faults across Tibet that produce internal crustal thickening and uplift B) the extrusion of East Asia has produced structures that thicken the crust under Tibet, producing regional uplift C) a giant fault beneath Tibet raises it up relative to adjacent areas D) crustal thickening over millions of years has produced a thick crust that stands high due to Isostasy
D
57) Most geologists think the elevation of mountains above sea level is limited by earth's gravity because ________. A) rocks can never reach escape velocity B) rock cliffs are subject to gravity failure and can only be about 1km high C) the earth's mantle is too weak to support the load of large mountains D) thickening of the crust in mountain belts produces a weak deep crust the spreads by gravity collapse, limiting the elevation
D
61) Permeable rock strata or sediment that transmit groundwater freely are called ________. A) perched water tables B) aquitards C) springs D) aquifers
D
62) A ________ is the largest discordant body of intrusive, igneous rock. A) lopolith B) laccolith C) pluton D) batholith
D
63) In the above diagram what type of mountain range exists at letter C? A) collisional mountain chain B) island-volcanic arc C) fault block mountain D) continental volcanic arc
D
64) Which of the following is emplaced over millions of years to form a composite intrusive complex? A) dike B) sill C) laccolith D) batholith
D
65) A ________ is an intrusive, igneous rock body that is tabular and concordant. A) laccolith B) dike C) pluton D) sill
D
67) Which of the following best describes the bedrock in the Sierra Nevada Mountains in California? A) Batholiths crystallize below the surface but then flow upwards towards the surface. B) Batholiths crystallize below the surface but were later exposed by way of erosion of overlying material. C) Batholiths crystallize at the surface, so they are simply still in place. D) The batholiths were washed downhill from distant mountains and deposited here.
D
71) Moraines are glacial deposits composed of ________. A) ice B) loess C) stratified drift D) till
D
97) Alluvium refers to ________, mainly sand and gravel. A) backswamps B) bed load C) natural levees D) stream deposits
D
68) Changes in the shape of a rock body in response to a differential stress is called ________.
Deformation
27) The type and amount of material carried in the suspended load of a stream depends on ________. A) turbulence and viscosity B) source accessibility and slope C) ground cover and channel shape D) flow velocity and discharge E) settling and flow velocities
E
