Deck 7: Sedimentary Environments and Rocks

Question 1

If you were designing a rock that resisted weathering,which of the following characteristics would it have?

A)closely spaced fractures
B)a soluble chemical composition
C)a quartz-rich rock
D)a rock composed of abundant loose pieces

Answer 1

C

Question 2

Which of the following environments would most likely consist of sand and/or rounded cobbles?

A)beach at A
B)lagoon at B
C)coral reef at C
D)deep seafloor at D
E)tidal flat at E

Answer 2

A

Question 3

Which of the following sites would most likely have turbidity currents?

A)beach at A
B)lagoon at B
C)coral reef at C
D)deep seafloor at D
E)tidal flat at E

Answer 3

D

Question 4

If you were designing a rock that would be easily weathered,which of the following characteristics would it have?

A)closely spaced fractures
B)a soluble chemical composition
C)a limestone in a wet climate
D)a rock composed of abundant pieces
E)all of these

Question 5

What is the best explanation for the shape of these clasts?

A)they are composed of relatively soft,soluble materials
B)they accumulated on a steep slope
C)they have been moved by the wind and rounded by blowing sand in sand dunes
D)they have been transported a significant distance

Question 6

Which of the following sites would have sand and silt deposited by slowing of the current?

A)mountains at A
B)glacial streams at B
C)braided river at C
D)delta at D
E)lake at E

Question 7

Large,angular clasts are most likely at:

A)mountains at A and glaciers at B
B)glaciers at B and braided river at C
C)braided river at C and delta at D
D)delta at D and lake at E

Question 8

Which of the following sites would have the slowest moving or least energetic current?

A)mountain streams at A
B)glacial streams at B
C)braided river at C
D)delta at D
E)lake at E

Question 9

What is the geologic setting of Vancouver,British Columbia?

A)it is surrounded by low-lying hills
B)it is along the Fraser River and its delta
C)it is on a large but scenic island in the ocean
D)it is on a large but scenic island in a lake
E)none of these

Question 10

Fine-grained sediment would most likely be present at:

A)the beach at A and lagoon at B
B)the lagoon at B and coral reef at C
C)the coral reef at C and deep seafloor at D
D)the beach at A and coral reef at C
E)the lagoon at B and deep seafloor at D

Question 11

Which of the following attributes does NOT apply to these sediments?

A)angular clasts
B)cobbles and boulders
C)well sorted
D)composed of gravel

Question 12

Which of the following environments would most likely form limestone?

A)beach at A
B)lagoon at B
C)coral reef at C
D)deep seafloor at D
E)tidal flat at E

Question 13

Which of the following processes produce sedimentary clasts?

A)fracturing of bedrock that results in angular pieces
B)breaking of round cobbles as they are transported
C)scouring and abrasion of bedrock along rivers
D)decomposition of granite into quartz grains and clay
E)all of these

Question 14

Which of the following processes is NOT considered to be chemical weathering?

A)dissolution
B)thermal expansion
C)oxidation
D)hydrolysis
E)reaction with acids from decaying plants

Question 15

Which of the following sites would contain the finest grained sedimentary deposits?

A)mountains at A
B)glaciers at B
C)braided river at C
D)delta at D
E)lake at E

Question 16

Which of the following environments would most likely have sediment formed by evaporation of seawater?

A)beach at A
B)lagoon at B
C)coral reef at C
D)deep seafloor at D
E)tidal flat at E

Question 17

Sediments with a large amount of sand are most likely at:

A)mountains at A and glaciers at B
B)glaciers at B and braided river at C
C)braided river at C and delta at D
D)delta at D and lake at E

Question 18

Which of the following processes is NOT considered physical weathering?

A)near-surface fracturing
B)frost wedging
C)prying by plant roots
D)thermal expansion
E)oxidation

Question 19

What sedimentary environments dominate the area around Vancouver,British Columbia?

A)deposition of sediment carried by a braided river
B)large landslides that blocked a narrow ocean channel
C)large ocean waves that carry large boulders far inland
D)a scenic offshore reef that protects the coastline from large waves

Question 20

What type of weathering is best expressed in this weathered limestone?

A)oxidation
B)dissolution
C)hydrolysis
D)biologic activity

Question 21

What type of rock would you form in this plant-rich swamp?

A)rock salt and other evaporite minerals
B)limestone
C)coal
D)chert
E)iron formation

Question 22

What typically happens to the size,shape,and sorting of clasts as they are transported from steep mountains toward more gentle settings?

A)the size of the clasts increases
B)the clasts become more rounded
C)the sediment becomes more poorly sorted
D)all of these

Question 23

What type of rock is shown in this photograph?

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

Question 24

Which of the following is NOT a common type of cement in sedimentary rocks?

A)calcite
B)pyroxene
C)silica
D)iron-oxide minerals

Question 25

Which of the following environments would likely have clasts smaller than sand?

A)a weak current
B)steep slopes
C)dunes formed by wind
D)all of these

Question 26

Which of the following characteristics are NOT used to classify and name clastic sediments?

A)the size of the clasts
B)the amount of sorting of clasts
C)the shape of the clasts
D)the climate in which the clasts are produced
E)all of these are used

Question 27

What type of rock would you form in this environment,showing a dried up lake bed?

A)rock salt and other evaporite minerals
B)limestone
C)coal
D)chert
E)iron formation

Question 28

How does gypsum form?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 29

What type of rock is shown in this photograph?

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

Question 30

What is the main difference between conglomerate and breccia?

A)the size of the clasts
B)the shape of the clasts
C)the sorting of the clasts
D)the kind of cement
E)all of these

Question 31

Which of the following is NOT involved in turning some sediment into sedimentary rock?

A)burial
B)compaction
C)cementation
D)metamorphism
E)all of these are involved

Question 32

Which of the following environments would likely have large clasts?

A)a weak current
B)steep slopes
C)dunes formed by wind
D)all of these

Question 33

Which of the following situations would result in angular clasts?

A)transport of the clasts over long distance
B)working of clasts by waves on a beach
C)steep slopes in a mountain
D)dunes formed by wind

Question 34

What type of rock is shown in this photograph?

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

Question 35

This photograph shows chalk.How is it formed?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 36

Which of the following statements is NOT true about clastic sedimentary rocks?

A)Clasts in a conglomerate or breccia can be different rock types or can be all the same rock type.
B)To be called a sandstone,quartz must make up more than 95 percent of the grains.
C)The amount of pore space decreases as a sand is compacted into sandstone.
D)Siltstone is coarser than shale.

Question 37

What type of rock would you form in this coral reef?

A)rock salt and other evaporite minerals
B)limestone
C)coal
D)chert
E)iron formation

Question 38

If a rock is poorly sorted,this means the rock contains:

A)mostly sand
B)a great variety of rock types as clasts
C)some angular and some rounded clasts
D)some parts that are reddish and others that are not
E)a wide range in the size of clasts

Question 39

What type of rock is shown in this photograph?

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

Question 40

Which of the following rocks is composed of the smallest sedimentary clasts?

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

Question 41

The large cross beds in these rocks indicate that the sediment was deposited:

A)deep in the ocean
B)in a lake with a gently sloping bottom
C)by the wind or a water current
D)by a debris flow
E)all of these

Question 42

Which environment is most likely to deposit a breccia?

A)sand dunes
B)braided river
C)meandering river
D)debris flow
E)none of these are likely to deposit a breccia

Question 43

Which of the following is most likely to deposit a conglomerate?

A)landslide
B)braided river
C)steep mountain front
D)sand dunes
E)lagoon

Question 44

What do the characteristics of the rock in this photograph tell you about its environment?

A)deposited by the wind
B)transported a short distance
C)transported a long distance or worked by waves
D)deposited in a lake

Question 45

This sandstone consists of well-sorted sand grains,was deposited on land,and locally contains large cross beds.What is the most likely environment in which it formed?

A)sand dunes
B)river
C)beach next to a sea
D)deep-water turbidity currents

Question 46

How does a graded bed form?

A)an abrupt change in the composition of the sediment
B)a gradual decrease in the strength of the current over time
C)piling of sediment down the front of a dune or ripple
D)a gradual change in the climate of the region
E)a gradual change in global climate

Question 47

Gradational boundaries between different sedimentary rock types can form from:

A)slowing of the current over time
B)a progressive change from one environment to another
C)a gradual rise or fall in sea level
D)all of these

Question 48

What can you infer from this contact between an overlying conglomerate and underlying sandstone?

A)The conglomerate was deposited by the wind.
B)There was a gradual switch from marine to nonmarine conditions.
C)There was a gradual switch from nonmarine to marine conditions.
D)There was an abrupt event,such as a flood.

Question 49

Which environment is least likely to deposit a breccia?

A)debris flow
B)landslide
C)steep mountain front
D)meandering river
E)glacier

Question 50

Which way was the current (either wind or water)moving during deposition of this section of rocks?

A)toward the left
B)toward the camera
C)toward the right
D)away from the camera
E)there is no way to tell

Question 51

What do the characteristics of the rock in this photograph tell you about its environment?

A)deposited by the wind
B)transported a short distance
C)transported a long distance or worked by waves
D)deposited in a lake

Question 52

This photograph shows chert.How does it form?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 53

Which of the following does NOT correctly match a rock with a possible environment in which that rock forms?

A)salt-evaporation of water
B)gypsum-evaporation of water
C)coal-deep-sea organic-rich black shale
D)chert-accumulation of tiny silica-rich creatures
E)chert-mixing of seawater and groundwater

Question 54

This photograph shows an iron formation.How does it form?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 55

Which of the following does NOT help define layers in some sedimentary rocks?

A)a change in mineral composition
B)a change in grain size
C)a change in color
D)a sharp contact between two rock types
E)all of these are ways that can define layers in sedimentary rocks

Question 56

How does chalk form?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 57

Which of the following is NOT a way to form layers in a sedimentary rock?

A)occurrence of a discrete event like a flood
B)a change in the strength of the current
C)a change in the supply of sediment
D)a change in climate of the region
E)all of these are ways to form layers

Question 58

How does a cross bed form?

A)an abrupt change in the composition of the sediment
B)a gradual decrease in the strength of the current over time
C)piling of sediment down the front of a dune or ripple
D)a gradual change in the climate
E)two glaciers that cross

Question 59

How does iron formation form?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 60

How does chert form?

A)evaporation of water in a lake or sea
B)accumulation of microscopic organisms composed of calcium carbonate
C)precipitation from seawater early in Earth's history
D)accumulation of silica-rich organisms or mixing of seawater and groundwater

Question 61

Which of the following is a common characteristic of carbonate rocks?

A)they commonly have a dissolved appearance
B)they are commonly black and shiny
C)they are commonly reddish
D)they do not form cliffs
E)all of these

Question 62

Which of the following is a characteristic of fine-grained clastic rocks?

A)most clasts are visible with the unaided eye
B)the rocks are poorly sorted
C)the cobbles directly rest on one another without much matrix
D)the rocks tend to be easily eroded

Question 63

Which environment is a setting that can deposit sand?

A)landslide
B)evaporating lake
C)deep ocean away from land
D)turbidity currents along a continental slope
E)all of these

Question 64

This sandstone includes shells of marine creatures that live in shallow water.What is the most likely environment in which it formed?

A)sand dunes
B)river
C)beach next to a sea
D)deep-water turbidity currents

Question 65

Which of the following are NOT common in landscapes formed by carbonate rocks?

A)sinkholes
B)fractures widened by dissolution
C)well-defined layers (beds)
D)outcrops with pits or holes
E)all of these are common in carbonate landscapes

Question 66

Which of the following is NOT a way in which sandstones are commonly expressed in the landscape?

A)as thick massive cliffs with little variation in grain size
B)as rocks with abundant layers defined by variations in color,grain size,or composition
C)as outcrops that can contain cross beds
D)as outcrops that show evidence of being dissolved during weathering

Question 67

This sandstone includes small rounded pebbles and was deposited far from the ocean.What is the most likely environment in which it formed?

A)sand dunes
B)river
C)beach next to a sea
D)deep-water turbidity currents

Question 68

Which of the following is NOT a type of carbonate rock?

A)limestone
B)travertine
C)dolostone
D)shale
E)a rock formed from a coral reef

Question 69

In this section,a lower gray rock is successively overlain by beach sandstone,lagoon mudstone,and limestone.What is the best interpretation of what was going on?

A)the area was experiencing a transgression
B)sea level was stable but the temperatures were getting colder
C)sea level was stable but the temperatures were getting warmer
D)none of these

Question 70

Which of the following is a typical way in which siltstone and shale are expressed in the landscape?

A)soft slopes covered by small,loose chips
B)slopes covered by loose debris from overlying rocks
C)valleys and other low areas carved into the landscape
D)badlands
E)all of these

Question 71

Imbricated clasts in this river means that:

A)the wind was blowing from left to right
B)the rocks have been shuffled by ground shaking during an earthquake
C)the rocks have slid downhill to the right
D)the current flowed from right to left

Question 72

Which of the following is a good interpretation of the environmental significance of an attribute of a sedimentary rock?

A)Fossils indicate that sediment was deposited on land.
B)Large cross beds in well-sorted sandstone usually indicate deposition by wind.
C)Mudcracks are formed in deep-water environments where sand and mud can be deposited in thin layers.
D)Large,angular,poorly sorted clasts reflect a large amount of transport.
E)None of these.

Question 73

Which of the following is a good interpretation of the environmental significance of an attribute of a sedimentary rock?

A)Red rocks typically form in deep oceans.
B)Thick bedding implies rapidly changing conditions.
C)Fossils indicate that sediment was deposited in water.
D)Graded beds indicate that the strength of the current decreased through time.
E)None of these.

Question 74

Which environment is least likely to deposit sand?

A)sand dunes along a beach or in a desert
B)channel of a meandering river
C)beach along the ocean or lake
D)delta along an ocean or lake
E)open ocean away from land

Question 75

These sandstone beds are interlayered with dark marine shales.What is the most likely environment in which the sandstone formed?

A)sand dunes
B)river
C)beach next to a sea
D)deep-water turbidity currents

Question 76

Which of the following is characteristic of a regression?

A)the seas move in,covering more land
B)sand dunes and river sediments can be deposited over marine deposits
C)marine sedimentary facies move toward the land
D)erosion surfaces on land can be covered by beach sand
E)all of these

Question 77

Which of the following environments is NOT a setting in which limestone forms?

A)coral reefs
B)deposition of calcite near springs
C)some lakes
D)accumulation of the remains of microscopic organisms
E)all of these are environments in which limestone forms

Question 78

Which environment is least likely to deposit siltstone or shale?

A)calm waters in a lagoon
B)shallow continental seas
C)bottoms of lakes
D)channel of a braided river
E)open ocean away from land

Question 79

Which of the following is characteristic of a transgression?

A)the seas move out,uncovering more land
B)sand dunes and river sediments can be deposited over marine deposits
C)marine sedimentary facies move toward the land
D)all of these

Question 80

In this section,a lower limestone is successively overlain by lagoon mudstone and a beach sandstone.What is the best interpretation of what was going on?

A)the areas was experiencing a transgression
B)sea level was stable but the temperatures were getting colder
C)sea level was stable but the temperatures were getting warmer
D)none of these