Deck 6: Pages of Earths Past: Sedimentary Rocks

Question 1

Which transport medium carries the largest particles?

A) ice
B) water
C) wind

Answer 1

A

Question 2

The majority of the rocks that occur at the surface of Earth are ____________.

A) intrusive igneous rocks
B) extrusive igneous rocks
C) sedimentary rocks
D) metamorphic rocks

Answer 2

C

Question 3

Biochemical limestones are dominated by carbonate mud and fragments of ____________.

A) siliceous shells of planktonic diatoms and foraminifera
B) calcitic and aragonitic skeletons of marine invertebrates
C) the phosphatic bones of fish
D) the organic breakdown products of wood from trees

Answer 3

B

Question 4

The breakdown of exposed rock into small fragments and dissolved ions is termed ____________.

A) deposition
B) erosion
C) weathering

Question 5

Clastic sedimentary rocks are primarily classified on the basis of ____________.

A) grain size
B) degree of sorting
C) angularity
D) mineral composition

Question 6

Consult the figure below.The difference between breccia and conglomerate is that conglomerate ____________.

A) is finer grained than breccia
B) is coarser grained than breccia
C) possesses more angular grains than breccia
D) possesses more rounded grains than breccia

Question 7

A fine-grained clastic rock that splits into thin sheets is ____________.

A) mudstone
B) shale
C) sandstone
D) arkose

Question 8

A clastic rock comprised of sand-sized grains derived from the physical weathering of granite and containing a sizable proportion of feldspar is termed ____________.

A) metasandstone
B) lithosandstone
C) graywacke
D) arkose

Question 9

Two major sources of energy,coal and oil shale,are considered ____________ sedimentary rocks.

A) clastic
B) biochemical
C) organic
D) chemical

Question 10

If a geologist were to find a limestone deposit consisting of coral fragments,which of the following would NOT be something he or she could deduce from this discovery?

A) that the source material was formed in a shallow marine environment
B) the composition of the ocean water during the time of growth of the corals
C) the original geographic location of the source material
D) the age of the coral reef complex

Question 11

Unlike physically precipitated chert,biochemical chert ____________.

A) is bedded (layered)
B) is made up of the skeletons of radiolaria and foraminifera
C) does not occur as small nodules within bodies of limestone
D) All of the above are correct.

Question 12

Which of the following would NOT be a source for beach material?

A) pieces of rock weathered from a cliff
B) pebbles transported along a stream
C) calcium carbonate shells
D) salt deposits known as evaporites

Question 13

Physically precipitated (chemical)limestone that forms in caves is termed ____________.

A) agate
B) dolostone
C) jasper
D) travertine

Question 14

Lithified detritus (breakdown products of preexisting rocks)forms which kind of sedimentary rock?

A) biochemical
B) chemical
C) clastic
D) organic

Question 15

Compaction and cementation of grains occurs during ____________.

A) erosion
B) lithification
C) transport
D) weathering

Question 16

Cemented shells of marine organisms form which kind of sedimentary rock?

A) biochemical
B) clastic
C) organic

Question 17

Grains become rounded primarily during ____________.

A) weathering at outcrop
B) erosion
C) transportation
D) deposition

Question 18

The removal of detritus from weathered rock at an outcrop is termed ____________.

A) deposition
B) erosion
C) weathering

Question 19

Chemical weathering takes place most rapidly in environments that are ____________ and ____________.

A) cool; dry
B) cool; wet
C) warm; dry
D) warm; wet

Question 20

It is unusual for ____________ to carry grains larger than sand.

A) ice
B) water
C) wind

Question 21

Which of the following might cause a scientist to be unsure as to whether he or she was looking at a package of rocks from a formerly terrestrial environment?

A) the presence of red beds
B) the presence of layered beds deposited by water
C) the presence of a fan or triangle-shaped package of sediment
D) the presence of well-sorted sandstone

Question 22

Ripples,dunes,and cross bedding are sedimentary structures that can be used to help determine _____________.

A) wind direction
B) current direction
C) past environments
D) All of the above are correct.

Question 23

Glacial till is composed of ____________ sized particles.

A) clay- to boulder-
B) mostly boulder-
C) mostly clay-
D) mostly sand-

Question 24

What do hot springs,the immense salt layers beneath the Mediterranean Sea,and Native American tools and weapons have in common?

A) Their creation was aided by biologic activity.
B) They formed chemical reactions in water solutions.
C) They formed from the evaporation of water solutions.
D) They formed from the precipitation of minerals from water solutions.

Question 25

Asymmetric ripples indicate unidirectional flow,such as in a river,whereas symmetric ripples are indicative of flow in multiple directions,such as when waves wash back and forth in shallow water.

Question 26

Physical precipitation of gypsum due to evaporation of seawater produces which kind of sedimentary rock?

A) biochemical
B) chemical
C) clastic
D) organic

Question 27

Which environment would most likely produce sedimentary deposits characterized by very well-sorted,very well-rounded grains that are nearly pure quartz?

A) river
B) glacier
C) beach
D) alluvial fan

Question 28

If evidence of cross bedding was discovered on a barren planet such as Mars,what could you assume was once occurring on the planet?

A) fluvial action
B) glacial migration and retreat
C) high winds
D) movement of water

Question 29

If a geologist found preserved mud cracks,he or she could conclude that the environment in which they formed ____________.

A) was once covered in wet mud
B) was once covered in hexagonal plates of mud with curled-up edges
C) has been covered in sediment
D) All of the above are correct.

Question 30

Consult the figure below.Graded beds tell a geologist that a _____________.

A) turbidity current deposited these beds, depositing finer material first
B) turbidity current deposited these beds, depositing coarser material first
C) slurry deposited these beds with little sorting
D) density current deposited these beds, depositing coarser material first

Question 31

When limestone becomes chemically altered so that half of the calcium atoms are replaced by magnesium,the resultant rock is termed ____________.

A) agate
B) dolostone
C) jasper
D) travertine

Question 32

Sedimentary deposition is a continuous process: rivers,lakes,and the ocean deposit sediments nonstop at a fairly constant rate.

Question 33

As compared to arkose,quartz sandstone ____________.

A) is more mature
B) does not contain significant amounts of feldspar
C) is likely to be found farther away from weathering granitic source rock
D) All of the above are correct.

Question 34

Chemical and biochemical rocks are classified primarily on the basis of ____________.

A) grain size
B) degree of sorting
C) angularity
D) mineral composition

Question 35

If a series of graded beds was discovered in the rock record,which of the following could NOT be concluded?

A) that the event that caused the grading occurred more than once
B) the direction of the turbidity current
C) whether the package was deposited underwater or on land
D) that an earthquake, storm, or other large event occurred

Question 36

Consult the figure below.Distinct internal laminations that are inclined at an angle to the boundary of the main sedimentary layer are called ___________.

A) graded beds
B) cross beds
C) horizontal beds

Question 37

Geologists call individual layers of sedimentary rocks _____________,whereas several of them together are called ____________.

A) beds; strata
B) strata; beds

Question 38

Stratification refers to ____________.

A) the development of layering within sedimentary rocks
B) the act of deposition of sediment that will ultimately form sedimentary rock
C) physical and chemical alterations, including compaction and cementation, that occur as sediment is transformed into rock

Question 39

If water is the transport mechanism of sediment,the grain size of sedimentary deposits most closely indicates the ____________.

A) geographic extent of the weathering source rock at outcrop
B) average velocity of the water from the time of erosion until deposition
C) velocity of the water at the moment the sediment settled to the bottom

Question 40

Which of the following is NOT a reason why Native Americans used chert as flint?

A) It could be easily found in the ocean.
B) The way it broke created sharp edges.
C) It could be used to create a variety of tools and weapons.
D) Crypocrystalline quartz made it strong.

Question 41

In which of the following phenomena are sediment records NOT preserved?

A) transgression
B) regression

Question 42

Consult the figure below.Breccia and conglomerate most likely formed from deposits in a ______________.

A) desert
B) lake
C) mountain stream

Question 43

Pulling a block of clay apart,resulting in the middle portion thinning and sinking,is an adequate analogy for ___________.

A) passive margins and subsidence
B) foreland basins and diagenesis
C) rift basins and subsidence
D) intercontinental basins and diagenesis

Question 44

Which of the following would NOT be definitive evidence that a geologist was looking at a package of rocks from a formerly marine environment?

A) the presence of chert
B) medium-grained sandstone
C) sediment composed of predominantly calcium carbonate
D) evidence of worms and mollusks

Question 45

Swamps,channels,floodplains,and submarine slopes all play a role in the development of ____________.

A) deltas
B) marine deltas
C) alluvial fans

Question 46

What effect would plants have on a sand dune environment?

A) encourage sand movement
B) deter sand movement
C) Plants have no effect on a sand dune environment.

Question 47

Waves cause beach sand to be ____________.

A) well rounded
B) poorly sorted
C) well sorted
D) Both a and b are correct.
E) Both a and c are correct.

Question 48

What type of sediment is found in lake bottoms?

A) gravel
B) sand
C) silt
D) clay

Question 49

Which environment would most likely produce sedimentary deposits characterized by poorly to moderately sorted,angular to subangular grains that consist of feldspar,quartz,and lithics (rock fragments)?

A) river
B) glacier
C) beach
D) alluvial fan

Question 50

Topset,foreset,and bottomset beds are indicative of ____________.

A) alluvial fans
B) lake bottoms
C) deltas
D) deep-marine settings

Question 51

Siltstone or mudstone containing marine fossils likely formed in a ___________ environment.

A) shallow-marine
B) deep-marine
C) marine-delta
D) coastal-beach

Question 52

What is the difference between the ways in which chalk and chert form?

A) depositional environment
B) source material
C) Both a and b are correct.
D) None of the above are correct.

Question 53

Because the velocity of sediment settling (deposition)is positively related to grain size for waterborne sediments,fluvial deposits are more likely than glacial deposits to ____________.

A) be well sorted
B) include coarse grains, such as cobbles
C) include fine grains, such as clay
D) have angular grains

Question 54

Sea level rises locally,and marine sediments are deposited on top of terrestrial sediments during events termed ____________.

A) regressions
B) transgressions
C) divarications

Question 55

Consult the figure below.Limestone is most likely formed in which of the following environments?

A) shallow-marine clastic
B) shallow-marine carbonate
C) marine delta
D) deep marine

Question 56

What causes the formation of an alluvial fan?

A) load capacity
B) friction
C) decreased velocity
D) All of the above are correct.

Question 57

Diagenesis refers to ____________.

A) the development of layering within sedimentary rocks
B) the act of deposition of sediment that will ultimately form sedimentary rock
C) physical and chemical alterations, including compaction and cementation, that occur as sediment is transformed into rock

Question 58

Similar sediment and depositional thickness can be found in all sedimentary basins.

Question 59

A well-sorted sandstone with asymmetric ripples was most likely deposited as sand by a(n)____________.

A) river
B) glacier
C) beach
D) alluvial fan

Question 60

Which of the following would NOT be definitive evidence that a geologist was looking at a package of rocks from a formerly coastal environment?

A) rippled sedimentary structures
B) medium-grained sandstone
C) sediment composed of predominantly calcium carbonate
D) coal deposits

Question 61

What is the foremost requirement for the accumulation of sediment?

A) a source of sediment
B) sinking of a portion of the Earth's surface
C) the presence of sedimentary rocks
D) erosive action

Question 62

Beach sediments would travel ___________ the ocean during a transgression and ___________ the ocean during a regression.

A) toward; away from
B) away from; toward

Question 63

If a geologist were to dig below the current beach and find offshore sediments underlain by beach and swamp deposits,then he or she could conclude that ____________ has occurred.

A) transgression
B) regression

Question 64

Diagenesis requires ____________.

A) deep burial
B) high temperatures and pressures
C) warm groundwater
D) All of the above are correct.

Question 65

As compared with metamorphism,diagenesis ____________.

A) means exactly the same thing
B) takes place at lower temperatures and pressures
C) takes place at higher temperatures and pressures
D) takes place at greater depths that are well within the mantle

Question 66

Death Valley,part of the Basin and Range Province,has been sinking partially due to the weight of continuously accumulating sediment shed from the Black and Panamit Mountains that border the valley.What phenomenon is this an example of,and what depositional environment is created by the sediment deposition?

A) regression and deltas
B) subsidence and deltas
C) regression and alluvial fans
D) subsidence and alluvial fans