Deck 7: Metamorphism and Metamorphic Rocks

Question 1

Which of the following statements is false about an anastomosing stream?

A) have deep, interwoven, multiple channels
B) channels shift frequently
C) resemble braided streams
D) channels are separated by stable vegetated islands

Answer 1

B

Question 2

Which one of the following statements is correct?

A) Sea level drops when evaporation rates increase over the oceans and when this extra, atmospheric moisture falls on land as rain.
B) Sea level drops in glacial times when increasing amounts of water are stored in expanding continental glaciers.
C) Sea level rises when water is added to the oceans through increased rainfall and increased inflow from rivers.
D) Sea level drops with new mid- ocean ridge formation because of the rifting and infiltration of water into the new ocean crust.

Answer 2

B

Question 3

Which of the following statements best characterizes alluvial fans?

A) They develop where a low- gradient stream leaves a wide valley and deposits in a canyon.
B) They develop where a high- gradient stream leaves a narrow mountain valley and deposits on a flat area.
C) They develop where a low- gradient tributary meets the main stream.
D) They develop where a high- gradient tributary splits when it enters a flat area.

Answer 3

B

Question 4

describes the particle transport mode in streams intermediate between suspension and rolling along the bottom?

A) Saltation
B) Skippity- doo- dah
C) Alluviation
D) Siltation

Question 5

A(n) is a curved lake on a low gradient floodplain formed from the abandoned channel after a meander loop is cut off.

A) oxbow
B) drooping johnson
C) gooseneck
D) snakebelly

Question 6

is the product of the average flow velocity and the area of the channel cross section (velocity × area).

A) Hydrocapacity
B) Runoff gradient
C) Stream discharge
D) Stream load factor

Question 7

The river has the largest discharge at its mouth.

A) Mackenzie
B) Yukon
C) Mississippi
D) Columbia

Question 8

Which statement below best describes how narrow valleys form?

A) Streams tend to flow down abandoned mine shafts.
B) Stream cuts vertically, but valley sides cave in due to weathering and mass wasting.
C) Stream water dissolves the bedrock along a narrow swath of soluble bedrock.
D) Stream cuts vertically along soft fault gouge.

Question 9

If you found yourself "up the yazoo without a paddle" you'd likely be .

A) in a meander cutoff oxbow lake across the cutbank from the main channel
B) going up a low capacity parallel tributary on the other side of the levee from the main channel
C) vainly wishing that you had read the textbook a little more closely
D) following the wrong distributary upstream, never to intersect the main channel

Question 10

Which of the following statements is false about braided streams?

A) Sand and gravel bars between channels are covered with vegetation.
B) Braided streams comprise complex networks of converging and diverging channels.
C) Sand and gravel bars between channels are unstable.
D) Braided channels are temporary and shift frequently.

Question 11

Which deposits form during flood stage on a subaerial delta plain?

A) foreset beds
B) bottomset beds
C) distributary channels
D) topset beds

Question 12

describes the amount of water flowing past a certain point at any given time.

A) Competence
B) Discharge
C) Hydro- load factor
D) Capacity

Question 13

A natural, meandering, river channel is modified into a more or less straight and smooth, canal- like channel. Which of the following statements is correct?

A) The straight channel has a higher gradient and more friction than the natural channel.
B) The natural channel had a lower gradient and less friction than the modified channel.
C) The natural channel had a lower gradient and higher friction than the straight channel.
D) There was no change in gradient or friction.

Question 14

are characteristics of downcutting streams and a youthful stage of valley evolution.

A) Meandering channels and natural levees
B) Rapids and whitewater
C) Wide floodplains
D) U- shaped, cross- valley profiles

Question 15

What is the drop in water surface elevation divided by the distance the water flows?

A) stream gradient
B) stream discharge
C) hydrologic resistance
D) hydraulic capacity

Question 16

Which of the following is the correct definition of stream gradient?

A) the increase in discharge of a stream per unit drop in elevation
B) the drop in elevation of a stream divided by the distance the water travels
C) the distance travelled by water in a channel times a drop in elevation
D) the water pressure at the bottom of the stream divided by the stream's width

Question 17

Entrenched meanders are evidence for what sequence of geologic events?

A) Lateral cutting by streams was followed by subsidence of the land.
B) Stream downcutting was followed by a rise in base level.
C) Land uplift was followed by stream downcutting.
D) A sea level rise was followed by stream downcutting.

Question 18

Many larger rivers in the Colorado Plateau region meander in deep, narrow canyons and have no floodplains. How could this happen?

A) As the Colorado Plateau rose, the original, new- age streams became wiser.
B) Original, high gradient, youthful streams continued to downcut as the land rose.
C) As sea level dropped, the original youthful streams matured into old- age streams.
D) Original, low gradient, old age streams downcut as the land gradually rose.

Question 19

generally constitutes the highest percentage of the annual sediment load moved by a stream.

A) Bed load
B) Suspended load
C) Saltation load
D) Dissolved load

Question 20

are components of the hydrologic cycle that release water vapour directly to the atmosphere.

A) Precipitation and runoff
B) Discharge and transportation
C) Runoff and infiltration
D) Evaporation and transpiration

Question 21

Which of the following features characterize wide streams and valleys?

A) natural levees; broad floodplains
B) V- shaped valley cross- sections
C) waterfalls; entrenched meanders
D) rapids; channel bed potholes

Question 22

The greatest erosion and sediment transport in rivers happens .

A) near the mouth where the discharge is the greatest
B) during floods because capacity and competence are at their maxima
C) during winter freeze up because of velocity changes below the ice
D) at ordinary discharge but at particular locations where the gradient decreases

Question 23

Which of the following are not methods of flood control?

A) channelization
B) artificial levees
C) flood- control dams
D) demolishing dams

Question 24

In a typical stream, the suspended sediment load .

A) weighs less than its total dissolved constituents
B) usually includes fine sand, silt, and clay
C) saltates along the bottom
D) decreases greatly during floods

Question 25

A stream begins at an elevation of 200 m and flows a distance of 400 km to the ocean. What is the average gradient?

A) 0.5 km/in
B) 2 km/m
C) 0.5 m/km
D) 2 m/km

Question 26

In the absence of cutoff, how does a river meander loop behave over time?

A) The gradient is raised as the loop shortens, and the channel migrates away from the cut or outer bank of the loop.
B) The gradient is lowered as the channel lengthens and migrates toward the cut or outer bank of the loop.
C) The gradient is lowered as the loop shortens, and the channel migrates toward the shallow inner bank of the loop.
D) The gradient is raised as the loop lengthens, and the channel migrates toward the cut or inner bank of the loop.

Question 27

Where would you find clays and silts in delta sediments?

A) distributary channels
B) topset beds
C) bottomset beds
D) foreset beds

Question 28

describes the maximum particulate size that a stream can transport.

A) Competence
B) Hydro- load factor
C) Capacity
D) Discharge

Question 29

Which of the following must result in a lower base level for rivers and streams?

A) sea level drops; land subsides to below sea level as in rifts like the Dead Sea and Death Valley
B) sea level falls; land rises
C) sea level rises; land rises
D) sea level rises: land subsides

Question 30

A stream pattern is developed only on growing mountains like volcanoes or where the land surface is tectonically doming upward as over intrusions or salt diapirs.

A) dendritic
B) boreal
C) trellis
D) radial

Question 31

Which one of the following statements is true concerning natural levees?

A) Erosional features are left behind when meander cutoff occurs.
B) They form the high, steep banks of a downcutting stream.
C) Depositional features formed at times of low discharge.
D) Mostly fine sand and silt build up during overbank floods.

Question 32

What would cause a river to have a series of terraces lying at different elevations, all above its modern floodplain?

A) incision due to uplift or lowered base level
B) deranged drainage patterns
C) agrarian alien visitors in the geologic past constructing paddies
D) progressive decreases in rainfall in its headwaters

Question 33

describes the maximum solid particulate sediment load transported by a stream.

A) Hydro- load factor
B) Capacity
C) Competence
D) Discharge

Question 34

is an abandoned, cutoff, meander loop.

A) A horsetail
B) A yazoo
C) An oxbow
D) A gatorback

Question 35

Where is erosion concentrated along a meandering stream?

A) at the unconsolidated point bars
B) on the outer parts of the meander loops or bends
C) on the straight channel segments that connect the meander loops
D) on the inner banks of the meander loops

Question 36

make up the suspended loads of most rivers and streams.

A) Dissolved salts
B) Silt and clay- sized, detrital grains
C) Coarse sand and gravel that move during floods
D) Dissolved ions and fine sand

Question 37

A(n) stream pattern develops where the same bedrock or regolith layer forms the land surface so that erosion rates are relatively uniform throughout the area.

A) dendritic
B) trellis
C) radial
D) elliptical

Question 38

A water gap is _ .

A) a short segment of canyon formed where a river flows across the outcrop area of a resistant, ridge-forming rock layer
B) a low sag between adjoining segments of a natural levee
C) the narrow strip of land separating two meander loops
D) a vertical-walled canyon resulting from very rapid stream downcutting

Question 39

In a drainage pattern that is generally developed in areas underlain by tilted or folded strata, tributary streams flow along outcrop areas of the softer strata.

A) rectangular
B) dendritic
C) radial
D) trellis

Question 40

At the head of a delta, the major channel splits into smaller channels that follow different paths to the sea. These smaller channels are known as .

A) cotributaries
B) distributaries
C) exotributaries
D) endotributaries

Question 41

When did Lakes Michigan, Huron, and Superior drain via the Nipissing spillway to the Ottawa River and the St. Lawrence?

A) in the Archean, prior to 2.5 b.y. ago as recorded by bedrock lithologies
B) in the Early Holocene between 10,500 and 5,500, prior to glacial isostatic rebound
C) prior to the 1930s when the waters were diverted to run hydroelectric stations and create the tourist attraction of Niagara Falls
D) in the 1920s by damming the rivers to make paths for the early log drives

Question 42

Why is a bird-foot delta like that of the present-day Mississippi below New Orleans likely to change naturally toward one with the shape of an equilateral triangle like the upper-case Greek letter delta (O)?

A) Increased sediment loads since the mid-19th century have caused the major distributaries to be filled with sand.
B) Present-day distributaries have higher gradients than potential new ones.
C) Potential, new, distributary channels have higher gradients, causing downcutting of the existing channels.
D) Potential, new, major distributary channels have steeper gradients than existing channels.

Question 43

A dam and reservoir are constructed on a graded river. What will happen?

A) deposition upstream from the dam; channel downcutting below
B) channel downcutting upstream and downstream from the dam
C) deposition upstream and downstream from the dam
D) channel downcutting upstream from the dam; deposition below

Question 44

The river has the largest discharge of any in the world.

A) Nile
B) Congo
C) Amazon
D) Mississippi

Question 45

is not part of the hydrologic cycle.

A) Water infiltrating into the soil and bedrock
B) Water evaporating from a lake
C) Calcium carbonate dissolving in or precipitating from soil water and groundwater
D) Water moving into creeks and streams following a rainstorm

Question 46

How does urbanization (buildings, paving, lawns etc.) affect runoff and infiltration in a small, previously forested, drainage basin?

A) Runoff decreases; infiltration increases.
B) Both increase.
C) Infiltration decreases; runoff increases.
D) Both decrease.

Question 47

in a delta are essentially cross strata inclined toward deeper water.

A) Bottomset beds
B) Foreset beds
C) Topset beds
D) Backset beds

Question 48

Which one of the following best fits with floodplain widening?

A) youthful stream; downcutting and waterfall retreat
B) mature stream; lateral cutting and point bar deposition
C) old age stream; rapid erosion of a delta
D) stream rejuvenation; downcutting and meandering

Question 49

The describes the movement of water through Earth's hydrosphere.

A) precipitation cycle
B) aqualytic cycle
C) aquatic cycle
D) hydrologic cycle

Question 50

Which one of the following is true concerning a major river system?

A) Channel bed roughness and turbulence generally increase downstream.
B) Discharge decreases below junctions with perennial tributaries.
C) Upstream tributaries generally have higher competencies than the major river.
D) Upstream tributaries generally have lower gradients than the major river.

Question 51

Which one of the following statements is true concerning natural levees?

A) form the high, steep banks of a downcutting stream
B) erosional features left behind when meander cutoff occurs
C) depositional features formed at times of low discharge
D) mostly fine sand and silt that build up during floods

Question 52

At the head of a delta, the major river divides into numerous, smaller channels. What are these smaller channels?

A) cutoff chutes
B) outflow channels
C) intradeltaic rills
D) distributaries

Question 53

Which one of the following best describes how urbanization affects small- stream watersheds?

A) Infiltration and lag time between storms and peak runoff increase.
B) Infiltration decreases; lag time between storms and peak runoff is shortened.
C) Infiltration is reduced; lag time between storms and peak runoff is increased.
D) Infiltration increases slightly; lag time between storms and peak runoff decreases.

Question 54

Where would you expect to find the coarsest particle size in delta sediments?

A) distributary channels
B) foreset beds
C) bottomset beds
D) topset beds

Question 55

A stream pattern develops on lands underlain by tilted or folded, alternating hard and soft, sedimentary strata.

A) dendritic
B) trellis
C) rectangular
D) radial

Question 56

Which one of the following does not apply to stream turbulence and average velocity?

A) channel shape; bed roughness
B) stream gradient; channel roughness
C) discharge; stream gradient
D) laminar flow; dissolved load

Question 57

Which one of the following statements correctly describes how stream terraces can form?

A) Base level rises; the stream downcuts, and the old floodplain is left well above the elevation of the present- day channel.
B) A temporary base level is eliminated; the stream builds its channel upstream from the old temporary base level, and the former floodplain is left well above the present elevation of the stream.
C) A temporary base level is eliminated; the stream downcuts upstream from the old temporary base level, and the former floodplain is left well above the present elevation of the stream.
D) Base level drops; the stream aggrades its channel, and the former floodplain is left below the present elevation of the stream.

Question 58

A radial drainage pattern would most likely develop .

A) in areas underlain by horizontal strata
B) on an active, growing volcano
C) in areas of folded and tilted strata with varying resistances to erosion
D) in areas where the bedrock is cut by sets of fractures at right angles

Question 59

Which of the following is not a type of flood?

A) flash flood
B) gradual flood
C) ice- jam flood
D) regional flood

Question 60

Which one of the following would cause stream rejuvenation?

A) the land is uplifted
B) sea level rises
C) a shift from downcutting to lateral cutting
D) when unstable distributaries in a delta are abandoned

Question 61

is the quantity of water flowing past a certain stream cross section per unit time.

Question 62

The bottom of a stream's channel is called its .

Question 63

What stream characteristic is measured by the size of the largest particle that a stream can move?

Question 64

streams have interconnecting channels around unstable sandy bars.