Which of the following lithospheric plates is not included among the seven largest?
THE PHILIPPINE PLATE
Earth's lithospheric plates are composed of crust and which of the following layers?
The outermost portion of the mantle.
Which of the following processes can be observed at the margins of lithospheric plates?
FAULTINGEARTHQUAKES, VOLCANOES, MOUNTAIN BUILDING (All of the ABOVE)
In studies of rock obtained from ocean basins all over Earth, the oldest ages obtained are approximately 200 million years before the present. Why have no older oceanic rocks been discovered?
DUE TO TECTONIC ACTIVITY, ROCKS ON THE OCEAN FLOOR ARE CONTINUALLY RECYCLED.
Which of the following regions was not part of the large Southern Hemisphere continent of Gondwana?
Which of the following techniques can be used to recreate the configuration of supercontinents that existed before Pangaea?
apparently wandering polar paths
During the breakup of Pangaea, volcanic island arc systems may have formed that no longer exist. What likely happened to these arcs?
They may have been accreted onto continents after their formation.
What geologic process initiated the breakup of Pangaea approximately 165 million years ago?
Since the breakup of Pangaea approximately 165 million years ago, a new supercontinent cycle has begun with the collision of which of the following continents?
India and Asia
When oceanic and continental crust collide at a subduction zone, one plate is forced under the other. The angle at which the subducting plate descends is due to what?
The density of the plate being sub ducted and the age of the plate being subducted. Older crust subducts at a steeper angle because something about the plate changes over time.
As oceanic crust is subducted below continental crust, what factors most directly drives the melting that will fuel volcanoes at the surface?
When oceanic crust is sub ducted below continetal crust, partial melting can occur. Which of the following best explains why the resultant magma rises through the crust toward the surface?
The magma is less dense than the surrounding solid rock.
A volcanic arc is formed when which of the following conditions exists?
A piece of oceanic crust is subducted below continental crust.
What type of stress is most directly associated with convergent boundaries?
Although new crust is being formed at divergent boundaries, Earth remains the same size. What is the reason for this?
An equal volume of crust is being consumed at convergent boundaries.
As oceanic crust is subducted, it melts, forming a body of magma. When this magma rises and interacts with the overlying continetal crust, what change occurs in the composition of the magma?
The silica content of the magma increases.
The formation of the Himalaya and the Tibetan Plateau was caused by which of the following events?
There was a collision of two pieces of continental crust at a subduction zone.
What is convection?
a cycle of moving material formed by the rise of less-dense material and the sinking of denser material
What is the relationship between temperature and density?
In general, warmer materials are less dense, and colder materials are denser.
What is a plume?
a zone of upwelling material originating at the outer core-mantle boundary
What features at the surface provide evidence of plumes?
What is the relationship between the crust and the lithosphere?
All of the crust is contained within a larger layer called the lithosphere.
What is the relationship between the mantle and the lithosphere?
Some of the mantle is contained within a smaller layer called the lithosphere.
What is the relationship between the mantle and the asthenosphere?
All of the asthenosphere is contained within a larger layer called the mantle.
What surface feature provides evidence for the location of hot spots?
volcanoes within tectonic plates
When will a hot spot volcano become extinct?
when the volcano is carried away from the hot spot by the tectonic plate
What surface feature would you expect to form if both a hot spot and a tectonic plate are stationary?
a single volcano
Plates move apart at __________ boundaries, move together at __________ boundaries, and move side-by-side at __________ boundaries.
Which geologic features are associated with divergent boundaries?
mid-ocean ridges and continental rift valleys
Which geologic features are associated with convergent boundaries?
ocean trenches and volcanoes
Where is the youngest ocean floor found?
Along the crest of mid-ocean ridge
What would happen to Earth if ocean floor were created at divergent boundaries at a faster rate than it is destroyed at convergent boundaries?
The Earth would increase in volume.
What is a volcanic arc?
a row of volcanoes that forms on the overriding plate near a subduction zone
Which of the following mountain ranges are examples of continental arcs?
Andes and Cascades
What is a terrane?
a slice of lithosphere that has been added to the margin of a continent during plate collision
Where does most terrane accretion occur?
in association with a continental-oceanic subduction zone
Why are terranes added to continental margins, rather than subducting under them?
Terranes are too buoyant to subduct.
Which of the following statements about terranes is most accurate?
The margins of many continents have grown through the accretion of terranes.
Which feature would you expect to find at the mouth of a submarine canyon?
A deep sea fan
Which coast represents an active continental margin?
the west coast of South America.
Moving off the east coast of North America, identify the sequence of environments you would encounter as you move deeper into the Atlantic Ocean?
continental shelf, continental slope, continental rise, abyssal plain
Which statement best explains the formation of seamounts?
They represent volcanoes situated over mantle plumes that have since moved away from their source of magma and subsided
Which response best explains the absence of volcanoes and earthquakes at a passive continental margin?
No earthquake or volcanoe can occur due to the distance from any active boundaries
Which one of the following is an important fundamental assumption underlying the plate tectonic theory?
Earth's diameter has been essentially constant overtime
The continental drift hypothesis was rejected primarily because Alfred Wegener could not __________.
Identify a mechanism capable of moving continents.
Deep-focus earthquakes are associated with ________ plate boundaries.
A transform plate boundary is characterized by _____________.
a deep, vertical fault along which two plates slide past one another in opposite directions
Which one of the following would most likely be covered with thick turbidite layers?
Deep-sea fan at the base of a continental slope
Deep ocean trenches are surficial evidence for ____________.
Sinking of oceanic lithosphere into the mantle at a subduction zone
"Black smokers" are associated with ____________.
a. oceanic ridge b. mineral-rich waters c. hot water d. all of these (ALL OF THESE)
______ marks the edge of a continent.
The lowest part of the continental slope
All of the following are layers that comprise oceanic crust except for?
Which of the following best characterizes the tectonic development of fault-block Mountains?
Normal faults; crustal stretching and brittle failure of the upper crust
Oceanic ridges are elevated compared to the surrounding ocean floor because ________.
Newly formed lithosphere is hotter and therefore less dense than the surrounding rocks
Which of the following best describes the geology of the Pacific coastal regions of western North America including Alaska?
Geologically different, micro continent-sized fragments and terranes, formed elsewhere, were tectonically accreted to North America.
The ________ are a geologically old mountain range folded and deformed during the Paleozoic.
Appalachians in the eastern United States
Folded limestone's that occur high in the Himalayas were originally deposited as sediments in a ________.
Marine basin between India and Eurasia
Volcanism along a continental arc is dominated by the eruption of ________.
Andesitic lavas and pyroclastic materials
Which one of the following operates primarily in areas of permafrost?
Of the following, which one would most likely be triggered by an earthquake?
All of the following are factors affecting mass wasting except for ________.
Why was the Alaskan pipeline built above ground and insulated?
To protect the pipeline against damage due to thawing ground and to keep the crude oil hot and fluid
Which of the following statements concerning mudflows is not true?
a. Mudflows may be caused by heavy rains or melting snow.
b. In hilly areas, mudflows move down the canyons and stream valleys.
c. Mudflows deposit talus slopes.
d. Mudflows can move and carry very large boulders and other coarse debris.
c. Mudflows deposit talus slopes.
As an erosional process, how is mass wasting unique from wind, water, and ice?
Mass wasting does not require a transporting medium.
Most dry lands lie between ________ degrees north and south of the equator.
20 and 30
In which area would surface water most effectively infiltrate into the local groundwater system?
A. a stream in a steep-sided, bedrock canyon in the mountains
B. streams flowing in the numerous channels of an alluvia fan
C. a playa lake with a thick mud bottom
D. all of these would promote infiltration.
B. streams flowing in the numerous channels of an alluvia fan
Which one of the following statements about sand dunes is correct?
A. A dune migrates in the direction of inclination of the slip face.
B. the more gently sloping surface is the leeward slope of the dune.
C. sand is blown up the slip face and rolls down the more gently sloping flank of the dune.
D. in a sand dune, the more gently inclined strata lie parallel to the slip face.
A. A dune migrates in the direction of inclination of the slip face.
Which one of the following will effectively limit further deflation in a given area?
Which of the following is determined by the angle of repose for dry sand?
Inclination angle of a dunce slip face
Which of the following responses are examples of how water can promote mass wasting? B,D,E
A. Water can infiltrate sediment, partially filling the pore spaces between grains and reducing slope integrity.
B. Waves and streams can undercut banks and cliffs, causing them to fail.
C. Water enhances the ability of vegetation to grow on weathered particles.
D. When water is added to weathered particles, the mass of the sediment is increased, which can promote mass wasting.
E. Water can saturate sediment, reducing the integrity of the slope and allowing it to move.
When dry sediment accumulates, the angle of repose represents what property of the deposit?
The steepest angle at which those sediments can accumulate and remain stable.
When sediment accumulates, the angle of repose can be increased by changing which of the following conditions? D
A. undercutting by waves and streams
B. removing all the moisture from the sediment (drying)
C. removal of vegetation
D. slight addition of water to the sediment
E. earthquake activity
Of the following types of mass wasting, which tends to be the fastest moving and most destructive?
Which of the following examples of mass wasting is characterized by a crescent-shaped scarp or cliff at its head?
Which of the following types of mass wasting is extremely slow and occurs when saturated soil flows downslope?
During the eruption of Mount St. Helens on May 18, 1980, snow and glacial ice on the mountain melted and rushed down the Toutle River. What is the name given to this specific type of mass wasting?
Which of the following statements about deserts is true? C
A. Deserts are dominated by sand dunes.
B. Deserts are lifeless.
C. Water is the most significant agent of erosion in deserts.
D. Deserts are always hot.
Which of the following statements characterizes ephemeral streams? E
A. Ephemeral streams generally depend on groundwater in the desert to flow year round.
B. Ephemeral streams flow all the time in the desert.
C. Ephemeral streams are streams that flow through deserts, but have their origins outside of the desert.
D. Ephemeral streams don't have any life in them.
E. Ephemeral streams flow only at certain times of the year.
In the desert environment, how are ventifacts created?
Ventifacts are produced on the surface of a rock by the continued impact of very small particles carried by the wind.
When desert pavement is produced in a desert, why do the larger particles accumulate on the surface? A
A. The wind can move particles of only a very specific size and it takes away these small particles, concentrating the larger ones.
B. Particles are cemented together as water evaporates.
C. Running water carries away all the smaller material.
D. Large particles fall from the nearby slopes due to mass wasting.
E. Wind is capable of moving the large particles to a site where they are deposited.
Which of the following statements is the best explanation for the occurrence of the Great Basin Desert in the western United States? E
A. Snow in the mountains surrounding the Great Basin melts very slowly.
B. The Great Basin Desert exists because descending high-pressure air masses do not contain any moisture.
C. Water is removed from the Colorado River before it gets to the Great Basin, causing it to be dry.
D. Storms from the east rarely make it to the Great Basin while they still have moisture in them.
E. The Great Basin Desert exists because it is a rain shadow desert
With the noted increases in global temperature, what changes will be associated with Earth's climatic regions?
Deserts will expand into steppe and humid regions of the globe.
Which of the following provides the best explanation for the abundance of desert areas in the low latitudes?
? In these regions, air is cooled and compressed, which precludes the transport of water in the atmosphere.
Fan-shaped cones deposited at the mouth of a canyon in a desert are known as _____________.
Which of the following terms best describes long, sinuous bed forms that develop perpendicular to the prevailing wind direction in desert environments? E
A. Star dunes
B. barchan dunes
C. Parabolic dunes
D. Longitudinal dunes
E. Transverse dunes
The majority of the loess deposits on the Great Plains owe their accumulation to which of the following explanations?
Loess in the Great Plains accumulated as fine sediments blown from outwash deposits adjacent to the retreating continental ice sheet.
What are cross beds?
Inclined layers in sediment or sedimentary rocks that reveal the direction of wave or wind transport
What do cross beds represent?
The moving front of a ripple or dune
What is the relationship between water currents and cross beds?
Cross beds sit at an angle to current direction
Why do desert dunes migrate?
Wind erodes material on the back side of the dune and deposits it on the front side of the dune.
How do pieces of rock move under the influence of wind?
Rolling, sliding, bouncing, suspension
What property of a piece of material will most directly determine how it is carried by wind?
What is dust?
The particles carried in suspension by wind
Which of the following features would you expect to find on the outside bank of a stream meander loop? A: a cut bank
a yazoo tributary
an oxbow lake
a cut bank
a very gentle slope
a point bar
When the local gradient of a stream changes as it goes from a mountainous area to a large flat-lying area, which of the following features could form?
A alluvial fan
In a delta, sedimentary layers deposited under circumstances that appear to violate the Principle of Original Horizontality are found in which of the following circumstances?
Which of the following choices does not directly affect stream velocity?
location of the drainage divide
The amount of meandering that occurs in a stream influences the gradient is which of the following ways?
With more Meanders, the stream gradient decreases.
While working on a stream in your field study area, you find that the channel with is 20 meters, the channel depth is 2 meters, and the velocity is 1.2 meters/ sec. What is the discharge of the stream?
What is a floodplain?
A flat surface next to a river channel
What is a natural levee?
a ridge of flood deposits next to a river channel
How does the formation of a natural levee impact flooding?
Natural levees raise the height of the stream channel, reducing the amount of flooding that will occur on the floodplain.
How can pieces of rock in contact with a stream bed move?
Rolling, sliding, bouncing
Complete this analogy: Bouncing is to sand as suspension is to_____________.
which are part of the bed load?
What are the three types of loads carried by streams?
dissolved load, suspended load, and bed loads
What is suspended load?
the fine-grained particles that travel in the water column above the stream bed
What is the dominant fluvial process in a clear, sediment-poor stream moving down a steep slope?
Where do deposition and erosion of material occur along a meander
Deposition occurs on the inside of the meander, whereas erosion occurs on the outside
How are oxbow lakes formed?
Oxbow lakes form when one meander erodes into another, cutting off water to part of the stream channel.
Which of the following zones is the location of the most biological activity?
the zone of soil moisture
In terms of freshwater storage, groundwater is second only to which of the following sources?
The majority of ground water is stored within which of the following zones?
the zone of saturation
During a summer with little rainfall, your house on a hill slope experiences an interval during you well runs dry. You have to borrow water from your neighbor who lives downslope from you. Why does you neighbor have water when you don't?
as the water table drops due to the lack of precipitation, it goes below the base of your well.
The quantity of groundwater that can be stored within sedimentary material is most directly controlled by which of the following parameters?
the porosity of the material
The permeability of a material is directly related to which of the following parameters?
the grain size of the material
Rock, such as shale or clay, or other unlithified sediment can produce layers that are well sorted, but do not allow water to move through them. Which of the following terms is most accurate for this type of layer?
An agricultural company purchased a large tract of land adjacent to your property and built a group of large commercial greenhouses on it. This company uses a lot of water to keep the plants green and healthy. During a particularly dry summer, the amount of water available to your well starts to decrease. Since you are utilizing the same aquifer, what has this company done to the water supply?
The company has compromised the aquifer and is essentially mining the water from it.
As a hydrogeologist looking for a source of water for a housing development, which of the following attributes would you look for in a layer of sediment or sedimentary rock?
High porosity, high permeability, extent over a large geographic area
How would the water table be affected if Earth were made up of uniform, permeable material?
The water table would not exist.
Why does groundwater discharge to Earth's surface?
Earth's surface is irregular, and permeability decreases with depth within Earth.
Which of the following would produce a lower water table?
an increase in the amount of discharge to surface water, a decrease in the amount of recharged to ground water
How does the use of water by humans affect the water table
use of water by humans increases discharge, resulting in lowered water table
Which of the following statements characterize the activity of glaciers and their impact on the landscape? Glacial activity can change the position of sea level relative to present conditions, glaciers are capable of oversteepening slopes, glaciers are capable of moving large amounts of sediment, glaciers can disrupt the hydrologic cycle
All answers are relevant
Compared with the amount of ice that existed during the last glacial maximum, how much exists today?
You are working in a field area that you think at one time contained valley glaciers. What evidence would you look for to determine this?
You would look for rounded, U shaped valleys
Which is the best definition of glacial snow line
the line dividing zones of accumulation and melting of ice at the surface of a glacier
Under what conditions will the front of a glacier remain stationary?
Glacial fronts remain stationary when melting and snow accumulation are equal.
Which way does ice flow in a glacier retreating uphill?
How would a snow line on a glacier move as a glacial front is advancing?
The snow line would move downslope
How would you expect the front of a glacier to move if it undergoes a period of net accumulation, followed by net wastage, and finally a period of net accumulation?
The glacier's front would move forward, backward, and then forward again.
Which one of the following statements is correct? A
A: Sea level drops when water is stored in expanding ice sheets and continental glaciers.
B. Sea level rises when water is added to the oceans through increased rainfall and increased inflow from rivers.
C. Sea level drops when evaporation rates increase over the oceans and when this extra, atmospheric moisture falls on land as rain.
D. Sea level rises when water is stored in expanding ice sheets and continental glaciers.
In the absence of cutoff, how does a river meander loop behave over time?
The gradient is lowered as the channel lengthens and migrates toward the cut or outer bank of the loop.
________ are components of the hydrologic cycle that release water vapor directly to the atmosphere.
Evaporation and transpiration
Which of the following features characterize wide streams and valleys
Natural levees; broad
________ are characteristics of down cutting streams and a youthful stage of valley evolution.
Rapids and lots of whitewater
Which one of the following statements is true concerning natural levees?
mostly fine sand and silt that build up during floods
The water table is ________.
a boundary between saturated rock below and unsaturated rock above
________ controls the ease (or difficulty) of groundwater transmission through a porous material.
An aquifer is ________.
a saturated, porous, and permeable layer or stratum
Which one of the following applies to a valley glacier that lengthens (extends its terminus down slope) over a period of many years?
Accumulation exceeds wastage.
________ account for the largest usage of groundwater in the United States.
Agriculture and irrigation
________ is the volume of voids or open space in a rock or unconsolidated material.
________ are erosional features produced by valley/alpine glaciers.
A(n) ________ represents a former meltwater channel or tunnel in glacial ice that was filled with sand and gravel.
A drumlin is a ________.
smooth, tapering ridge of till; formed and shaped beneath a continental ice sheet
Which eon translates to "visible life" from the Greek?
Which is the shortest interval of geologic time?
The subdivisions of the Geologic Time Scale were based on which criteria or characteristics?
types of fossils within the units
Which event is generally used to indicate the beginning of the Phanerozoic eon
widespread occurrence of hard parts
While working in the field, you find some sedimentary rocks that include hundreds of fossils of crinoids, numerous brachiopods, and a few trilobites. Realizing that these organisms are not similar to any living today and knowing what you do about the history of life on Earth, to which unit of geologic time would you place these rocks?
What does the term unconformity mean?
a missing rock layer in a sequence that represents a period of erosion or nondeposition
Which of the following statements about relative and absolute age dating is most accurate?
Relative age dating places rocks and events in chronological order but does not provide information about absolute
What is the principle of original horizontality?
Sedimentary rocks are close to horizontal when deposited.
What is the principle of superposition? .
Within a sequence of rock layers formed at Earth's surface, rock layers lower in the sequence are older
What is the principle of cross-cutting relationships?
Geologic features that cut through rocks must form after the rocks that they cut through.
Five layers of rock are cut by two faults. Both faults cut through all five layers of rock. Fault A breaks through to the surface, whereas fault B does not. Which of the following statements about faults A and B is most accurate?
Faults A and B are about the same age, and both are younger than the five layers of rock
Which principle of relative age dating is important for determining the relative age of igneous rock that has intruded into overlying rock?
the principle of cross-cutting relationships
Evidence of photosynthetic primordial life in the Hadean is in the form of?
It is believed that most of the anerobic bacteria was killed off in the Proterozoic due to? .
the onset of oxygen-producing bacteria
Fossils resembling modern day _____ are found in the middle Archaen?
Banded iron formations identify cycles of?
low and high oxygen availability.
The Burgess Shale provides evidence of?
an explosion of diverse fauna.
There was twenty to thirty five times more _____ during the Cambrian Period than today.
The first evidence of land plants and fungi occurs in?
the Ordovician Period.
Concordant fossils change color as a function of the temperature of?
the surrounding rock that the fossils are trapped within.
Plants that possess vascular tissue allow the plants?
to grow larger.
The first amphibians are represented as fossils in rocks from the? Devonian Period.
The Carboniferous Period is best known for?
What percentage of life became extinct at the end of the Permian Period?
What is believed to be the reason for the first appearance of terrestrial dinosaurs in the Jurassic Period?
none of the above
The first birds and lizards are represented in the fossil record from the?
The first flowering plants and placental mammals are represented in the fossil record from the?
What evidence is found at the KT boundary that is thought to be responsible for the great extinction at that time?
iridium from an asteroid impact
Why did mammals begin to flourish during the Paleocene Epoch?
filled a void left behind by the extinction of the dinosaur
How did the many forests of the Miocene Epoch impact the Earth?
Removed large quantities of atmospheric carbon dioxide
Which epoch contains fossil evidence of the first homo habilis?