Deck 5: A Surface Veneer: Sediments and Sedimentary Rocks

Question 1

Glacial till is composed of ______________ particles.

A)mud-sized
B)sand-sized
C)boulder-sized
D)all sizes of

Answer 1

D

Question 2

Lithification occurs

A)in the shallow subsurface.
B)at the surface of Earth.
C)deep under the ground
D)high in the mountains

Answer 2

A

Question 3

If a geologist found preserved polygonal cracks in a sedimentary rock, he or she could conclude that the environment in which they formed

A)was once covered in wet mud.
B)was once covered by a glacier.
C)has been subjected to a major climate change event.
D)was the site of a mass extinction event.

Answer 3

A

Question 4

Compaction and cementation of grains occur during

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

Question 5

Compared with metamorphism, diagenesis

A)is 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 6

The process by which solid material is ground away by glaciers, rivers, wind, or waves is called

A)deposition.
B)erosion.
C)weathering.
D)lithification

Question 7

Cementation of sediments occurs when minerals __________ the spaces between sediment grains.

A)swell into
B)pass through
C)precipitate in
D)dissolve in

Question 8

Geologists call individual layers of sedimentary rocks _________, whereas several of them together are called __________.

A)beds; strata
B)strata; beds
C)laminations; graded beds
D)graded beds; laminations

Question 9

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.
D)the natural process of separating sediment by grain size.

Question 10

If water is the primary transport mechanism for a given sediment, the grain size 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.
D)climate conditions at the time of deposition.

Question 11

What type of sediment is typically found in lake bottoms?

A)gravel
B)sand
C)pebbles
D)clay/mud

Question 12

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

A)deposition.
B)erosion.
C)weathering.
D)lithification

Question 13

Which of the following processes involves the creation of ions in solution?

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

Question 14

The elevation of a mountain could be slowly decreased by weathering and

A)lithification.
B)sedimentation.
C)erosion.
D)deposition

Question 15

A gravel bar in a river is an example of a landform created by

A)deposition.
B)erosion.
C)transportation.
D)lithification.

Question 16

Topset, foreset, and bottomset beds found together are indicative of ________ environments.

A)alluvial fan
B)lake bottom
C)Delta
D)deep-marine

Question 17

Lithification, the process by which sediments are turned into sedimentary rocks, includes

A)erosion and transportation.
B)transportation and cementation.
C)erosion and deposition.
D)compaction and cementation.

Question 18

Grains become rounded primarily during

A)weathering at the outcrop.
B)lithification.
C)transportation.
D)deposition.

Question 19

Consult the figure below. Here, distinct internal laminations are inclined at an angle to the boundary of the main sedimentary layers. This is termed __________ bedding.

A)graded
B)cross
C)horizontal
D)tilted

Question 20

Precipitation of gypsum caused by evaporation of seawater produces which kind of sedimentary rock?

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

Question 21

Clastic sedimentary rocks are primarily classified on the basis of

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

Question 22

What type of sedimentary rocks form from once-separate grains that have been packed together and then cemented to one another (lithified)?

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

Question 23

Most of the rocks that are formed at the surface of Earth are ________ rocks.

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

Question 24

Which of the following is FALSE? Compared with arkose, quartz sandstone

A)contains more angular grains.
B)does not contain significant amounts of feldspar.
C)is likely to be found farther away from weathering granitic source rock.
D)is considered to be more compositionally mature.

Question 25

Which of the following does NOT reflect transport distance?

A)angularity
B)type of cement
C)rounding
D)mineral content

Question 26

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

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

Question 27

Graded beds are an indicator of

A)submarine landslides.
B)quiet, still water.
C)arid environments.
D)current flow.

Question 28

The primary difference between breccia and conglomerate is that conglomerate _______ than breccia.

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

Question 29

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 30

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

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

Question 31

How are chalk and chert different?

A)They have different grain sizes.
B)They are made of different source materials.
C)Chalk is terrestrial; chert is marine.
D)Chalk is biochemical; chert is chemical.

Question 32

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 33

Lake deposits tend to be composed of finely laminated mudstones, indicative of

A)quiet water.
B)oscillating waves.
C)bioturbation.
D)current flow.

Question 34

Large layers of cross-bedded sand can be indicative of a ____________ environment.

A)submarine
B)beach
C)desert
D)fluvial

Question 35

Coal and oil shale are considered __________ sedimentary rocks.

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

Question 36

The image below shows an outcrop of coarse-grained sedimentary rock. Note the rock hammer for scale. What is an appropriate name for this rock?

A)sandstone
B)shale
C)breccia
D)conglomerate

Question 37

The image below shows a series of graded beds. How many full sets of graded beds are shown?

A)1
B)3
C)12
D)15

Question 38

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

A)river (far from source).
B)glacier.
C)river (near source).
D)alluvial fan.

Question 39

Biochemical limestones are dominated by carbonate mud and fragments of

A)siliceous shells of planktonic diatoms and foraminifera.
B)skeletons of marine invertebrates made of calcite and aragonite.
C)the phosphate-rich bones of fish.
D)the organic breakdown products of wood and leaves from trees.

Question 40

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

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

Question 41

Describe the difference between lithification and diagenesis.

Question 42

What is a soil profile?

Question 43

If a geologist finds thick accumulations of fossiliferous limestone, in what type of basin might they have been formed?

A)passive-margin
B)intracontinental
C)rift
D)foreland

Question 44

What type of basins contain the largest accumulation of marine sediments?

A)rift
B)passive-margin
C)foreland
D)intracontinental

Question 45

Thick accumulations of sediments and fossils in the deep ocean tend to be ___________-sized because of the low amounts of energy.

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

Question 46

What is an alluvial fan? How is it different from a marine delta?

Question 47

Describe the depositional environment that can account for the red bed sandstones in this picture.

Question 48

The image below shows a layer of ________, which is an accumulation of dead plant material.

A)limestone
B)coal
C)sandstone
D)chalk

Question 49

What attributes would a clastic sedimentary rock have if it had traveled far from its source and was carried in a current with uniform energy? What environment would this be?

Question 50

Limestone can be either a biochemical or a chemical sedimentary rock. Explain how both types of limestone are formed. Make sure to describe the environments in which they were formed.

Question 51

In which type of basin would it be possible to find oil forming and why?

Question 52

Basins that form on the continental side of mountain ranges are called _________ basins.

A)rift
B)passive-margin
C)foreland
D)intracontinental

Question 53

How are a marine transgression and regression different?

Question 54

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

A)transgressions.
B)regressions.
C)turbidity currents.
D)cross bedding.

Question 55

Shorelines migrate _________ during a transgression and _________ during a regression.

A)seaward; inland
B)inland; seaward
C)parallel to the shore; perpendicular to the shore
D)perpendicular to the shore; parallel to the shore

Question 56

Sedimentary basins are often subject to ___________, which allows them to fill with thick accumulations of sediments.

A)erosion
B)diagenesis
C)uplift
D)subsidence

Question 57

What are the steps involved in the formation of a clastic sedimentary rock?

Question 58

Which of the following is FALSE about regressions?

A)They are not typically well preserved in the sedimentary record.
B)They can occur when the climate warms and continental ice sheets melt.
C)They occur when the land is uplifted by tectonic processes.
D)Coastal environments will migrate seaward.

Question 59

Shallow-marine deposits tend to have abundant fossils because of their proximity to

A)reefs.
B)beaches.
C)deltas.
D)rivers.

Question 60

What is the difference between chemical and physical weathering?