Deck 5: Formation of Sediment and Sedimentary Rocks

Question 1

Why is carbonic acid the most abundant acid in chemical weathering?

A) Carbon dioxide is present in the atmosphere and in soil; it combines with water vapor in the atmosphere and water percolating through soil to produce weak carbonic acid.
B) Carbon dioxide easily breaks down to carbonic acid.
C) Carbonic acid is so good at chemical weathering that it appears all the time.
D) Acetic acid is rare, so carbonic acid is common.

Answer 1

A

Question 2

What process would cause the weathering of olivine and subsequent formation of limonite, clay, and ions in solution?

A) physical weathering
B) volcanic eruptions
C) earthquakes
D) chemical weathering

Answer 2

D

Question 3

What happens when dissolution occurs between halite and water?

A) Halite crystals break into sodium and calcium ions, which exist invisibly between water molecules.
B) Halite crystals disappear and only water molecules end up being present.
C) Water molecules break into hydrogen and oxygen ions, which exist invisibly between halite crystals.
D) Water molecules disappear and only halite crystals end up being present.

Answer 3

A

Question 4

Plutonic and metamorphic rocks are particularly susceptible to oxidation reactions when they are exposed on Earth's surface.

Question 5

Which resource is not usually obtained from sedimentary rocks?

A) gem crystals
B) coal
C) water
D) oil

Question 6

What occurs during dissolution?

A) Minerals soak up water molecules.
B) Both the minerals and the water are consumed resulting in new minerals.
C) Mineral molecules break apart, and these molecules then disperse in water.
D) Oxidation occurs.

Question 7

The strongest acid in chemical weathering forms from mixing carbon dioxide and water.

Question 8

The following equation is what type of chemical reaction? 2 KalSi3O8(s) + 11 H2O --> 2 K+(aq) + 2 OH-(aq) + 4 H4SiO4 (aq) + Al2Si2O5(OH)4(s)

A) acid-base
B) dissolution
C) oxidation
D) hydrolysis

Question 9

What occurs during hydrolysis?

A) Oxidation occurs.
B) Mineral molecules break apart, and these molecules then disperse in water.
C) Both the minerals and the water is consumed, resulting in new minerals.
D) Minerals soak up water molecules.

Question 10

What occurs during hydrolysis?

A) A mineral dissolves in water.
B) A mineral reacts with water to produce a new mineral and ions in solution.
C) A mineral breaks down into smaller minerals.
D) A mineral is submerged into the ocean.

Question 11

What do pores allow for in rock forming processes?

A) Magma seeps through pores, resulting in igneous rock.
B) Hydrothermal energy seeps through pores, allowing for the production of electricity.
C) Water seeps through pores, resulting in dissolution.
D) Minerals precipitate from the water into pores, cementing grains together.

Question 12

Why are oxygen and water the two main components involved in chemical weathering?

A) They are extremely rare.
B) They are among the most abundant and easily bonding molecules on earth.
C) They are very good at it, so they do it a lot.
D) Nothing else can chemically alter minerals.

Question 13

Which option describes the process of exfoliation?

A) Fractures and cracks are formed when the rock forms by the cooling of lava.
B) Cracks open up parallel to the ground when surface rock expands slightly outward.
C) Bedding in sedimentary rocks causes planar breaks in the rock.
D) Stresses in the crust from plate tectonics cause fractures in many directions.

Question 14

Identify the products in the following chemical reaction. 2 KalSi3O8(s) + 11 H2O --> 2 K+(aq) + 2 OH-(aq) + 4 H4SiO4 (aq) + Al2Si2O5(OH)4(s)

A) potassium ion, hydroxyl ion, silicic acid, kaolinite
B) kaolinite ion, hydronic ion, salicic acid, caolinite
C) potassium feldspar, water
D) potassium feldspar, basic ion, silicate, kaolinite

Question 15

Sedimentary rocks are the most common rocks on Earth's surface.

Question 16

Natural water is pure H₂O.

Question 17

Which statement is false?

A) Sedimentary rocks experience physical changes such as dissolving and crystallization.
B) Sedimentary rocks may undergo chemical changes such as organic material changing into coal.
C) Sedimentary rocks may undergo radioactive changes that result in one element changing into another.
D) Sedimentary rocks may change into other kinds of rocks under forces of heat and pressure.

Question 18

Why does hematite cause the rusty red color observed in many surface rocks?

A) Hematite is a carbon-oxide, giving rocks the red color (even if in small amounts).
B) Hematite contains pyrite, giving rocks the red color (even if in small amounts).
C) Hematite is an iron-oxide, giving rocks the red color (even if in small amounts).
D) Carbonic acid weathers hematite, giving rocks the red color (even if in small amounts).

Question 19

Which statement about iron oxidation is false?

A) Oxidation of iron helps to protect rocks against weathering.
B) Limonite is an iron hydroxide mineral.
C) Hematite is the most common red iron oxide mineral.
D) Iron is one of the most abundant minerals in Earth's crust, and iron oxidation is a common reaction in chemical weathering on Earth.

Question 20

What is the chemical relationship between rock and the sediments rock is weathered into?

A) They have the same chemical composition.
B) The sediments consist of all the same minerals, divided into separate flakes.
C) Most of the rock minerals dissolve; only a few harder minerals form sediment.
D) Most of the same minerals are present in both.

Question 21

Why is cementation such an important process?

A) It is the final step in metamorphism.
B) It is the final step in the lithification process.
C) It results in the compaction of rock fragments.
D) It joins together rock particles by heating.

Question 22

Why is calcite such a common sedimentary cementing material?

A) Calcite precipitates and forms cement readily at depth due to elevated temperatures.
B) Calcite is very common.
C) Calcite dissolves in water faster than halite does.
D) Calcite is the most abundant material in the earth's crust.

Question 23

A blocky clastic sedimentary rock composed of mud would be called a

A) siltstone.
B) mudstone.
C) claystone.
D) shale.

Question 24

Why are sedimentary rocks not a component of soil?

A) Components of broken down sedimentary rocks, like weathered rock residue, are present in soil, not sedimentary rocks.
B) Sedimentary rocks do not break down quickly enough to become soil.
C) Sedimentary rocks' chemical composition makes them impossible to ever become soil.
D) Sedimentary rocks are too rare.

Question 25

A blocky clastic sedimentary rock composed of clay would be called a

A) siltstone.
B) mudstone.
C) claystone.
D) shale.

Question 26

What is a property of a conglomerate?

A) composed of rounded gravel
B) igneous rock
C) secreted from shelled animals
D) extremely rare

Question 27

How is coal produced?

A) with natural gas
B) the same way oil is produced
C) Obsidian and water are mixed together and buried for hundreds of years.
D) Plant organic matter is compressed into rock under elevated heat and pressure during burial.

Question 28

Minerals with covalent bonds are more resistant to weathering than minerals with ionic bonds.

Question 29

A blocky clastic sedimentary rock composed of silt would be called a(n)

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

Question 30

Why do silicate ions cement into quartz as they rise toward the surface?

A) The pressure decreases.
B) The temperature decreases.
C) They come into contact with the other ions they need to precipitate.
D) They get access to air as they near the surface.

Question 31

What are the important processes involved in lithification?

A) metamorphism and crystallization
B) crystallization and weathering
C) weathering and metamorphism
D) compaction and cementation

Question 32

Choose the option that matches the pore particles with the cement it forms upon reaction with water.

A) Feldspar grains become hematite; iron-silicate grains form quartz.
B) Silicate grains become clay; iron-oxide grains form hematite.
C) Pyroxene grains become clay; carboN-silicate grains form hematite.
D) Feldspar grains become clay; iron-silicate grains form hematite.

Question 33

A clastic sedimentary rock composed of mud and splits into sheets would be called a

A) shale.
B) mudstone.
C) claystone.
D) siltstone.

Question 34

A clastic sedimentary rock composed of sand-size grains (10% feldspar, 65% quartz and 25% rock fragments) would be called a

A) mixed sandstone.
B) lithic sandstone.
C) rock fragment sandstone.
D) low quartz sandstone.

Question 35

Choose the option that correctly orders the minerals from most easily weathered to most weather resistant.

A) quartz, halite, biotite
B) gypsum, pyroxene, feldspar
C) olivine, calcite, quartz
D) amphibole, feldspar, quartz

Question 36

What occurs during compaction?

A) A machine takes the sediment and stomps it down as much as possible.
B) Sediment is heated up which causes it to condense.
C) Additional layers of sediment accumulate and press down on the layers underneath them.
D) Sediment crystallizes which causes it to condense.

Question 37

What occurs during cementation?

A) Additional layers of sediment accumulate and press down on the layers underneath them.
B) Sediment is heated up, causing them to cement together.
C) Minerals precipitate from water in the pore spaces between sediment particles and cement them together into rock.
D) Sediment crystallizes, causing them to cement together.

Question 38

Which statement about compaction is false?

A) Grains of sand are crushed into a smaller volume.
B) Spaces between grains are decreased.
C) Flakes of minerals are broken.
D) Compaction may be caused by the weight of overlying sediment.

Question 39

Why can volcanic rocks occasionally contain fossils?

A) Lava does not melt bones.
B) Volcanic ash, if builds quickly enough, can preserve the remains of organisms.
C) Magma cools so quickly that fossils get trapped inside.
D) Organisms were often attracted to volcanoes and fell inside them by accident.

Question 40

All weathered rock is represented by clastic particles.

Question 41

Coal is

A) a very rare fossil fuel.
B) a chemical or biogenic sedimentary rock consisting of plant organic matter.
C) an inorganic form of energy.
D) a mafic igneous rock.

Question 42

A chemical or biogenic sedimentary rock consisting of gypsum is called

A) chert.
B) rock salt.
C) rock gypsum.
D) dolostone.

Question 43

Which of the following is true of dolomite, calcite and silica?

A) Dolomite is not secreted by invertebrate animals for shells.
B) It is not different in any way from calcite, but its molecules are arranged more tightly than silica's.
C) It is not different in any way from silica, but its molecules are arranged more tightly than calcite's.
D) They are all the same.

Question 44

Which is not one of the three main types of sediment grain?

A) clastic
B) biogenic
C) conglomeratic
D) chemical

Question 45

What do the three ingredients of sedimentary-rock texture include?

A) the mineralogy of the grains
B) the rounding of the grains
C) the dominant grain size
D) the degree of sorting, rounding of grains, and dominant grain size

Question 46

Why are grain size and composition often used to name sedimentary rocks?

A) These are indicators of what type of volcano the rocks came from.
B) These are indicators of how deep within the earth the rocks formed.
C) They are easily observed and easily distinguishable.
D) These are indicators of how deep within the sea the rocks formed.

Question 47

In order to produce sand-size rock fragments the crystal- or grain-size in the weathered rock must be larger than 2 mm.

Question 48

Limestone, composed mainly of calcite, can form by both inorganic and biologic processes.

Question 49

A clastic sedimentary rock composed of sand (85%) and silt (15%) would be called a

A) silty sandstone.
B) siltstone.
C) sandstone.
D) sandy siltstone.

Question 50

A clastic sedimentary rock composed of pebbles (20%) and sand (80%) would be called a

A) sandy pebblestone.
B) pebbly sandstone.
C) sandy conglomerate.
D) conglomeratic sandstone.

Question 51

All clay-size grains in a clastic sedimentary rock are clay minerals.

Question 52

A chemical or biogenic sedimentary rock consisting of microscopic quartz is called

A) limestone.
B) rock gypsum.
C) chert.
D) dolostone.

Question 53

All clay-mineral grains in a clastic sedimentary rock are clay size.

Question 54

A clastic sedimentary rock composed of pebbles (40%), cobbles (25%), boulders (10%) and sand (25%; even amounts of quartz and feldspar) would be called a(n)

A) sandy pebblestone.
B) conglomeratic pebblestone.
C) arkose.
D) sandy conglomerate.

Question 55

Chert, composed mainly of quartz, forms only by inorganic processes.

Question 56

A clastic sedimentary rock composed of sand (90%) and mud (10%) would be called a

A) sandy mudstone.
B) muddy sandstone.
C) siltstone.
D) sandy shale.

Question 57

A chemical or biogenic sedimentary rock consisting of calcite is called

A) limestone.
B) rock salt.
C) chert.
D) rock gypsum.

Question 58

A chemical or biogenic sedimentary rock consisting of halite is called

A) limestone.
B) rock salt.
C) chert.
D) dolostone.

Question 59

A quartz sandstone and an arkose were both produced from the weathering of a granite. Which rock's sediments experienced a greater degree of weathering than the other?

A) The sediments in the quartz sandstone experienced a greater degree of weathering than the sediments in the arkose.
B) The sediments in the arkose experienced a greater degree of weathering than the sediments in the quartz sandstone.
C) The sediments in the arkose and the quartz sandstone both experienced the same degree of weathering.
D) There is not enough information to answer this question.

Question 60

A chemical or biogenic sedimentary rock consisting of dolomite is called

A) limestone.
B) rock salt.
C) rock gypsum.
D) dolostone.

Question 61

Read carefully through the paragraph below, and decide which of the options is correct. A shallow sea existed in North America approximately 425 million years ago. This ancient geography was interpreted based on the sedimentary rocks in the region of that age. Mudstone, limely shale and shaley sandstone mark the location of the shallow sea. Sandstone occurred near the ancient shoreline and conglomerate occurred near the source area. Clasts of volcanic and plutonic rocks in the conglomerate imply the uplift and erosion of igneous rocks of nearby mountains.

A) The word "igneous" should be replaced by "metamorphic".
B) The word " mudstone" should be replaced by " limestone".
C) The word "shale" should be replaced by " sandstone".
D) The word " shallow" should be replaced by "deep".

Question 62

What could indicate that quartz sandstone and arkose may form from the weathering of granite?

A) the composition of clastic sedimentary rocks
B) the texture of clastic sedimentary rocks
C) the size of grains in sedimentary rocks
D) the igneous composition

Question 63

How does loose sediment become sedimentary rock? (5.3)

Question 64

What conditions during the formation of coal may reduce its quality for industrial use?

A) Very high heat and pressure are applied.
B) Clay and silt wash periodically through the swamp that formed the coal.
C) The swamp that formed the coal floods.
D) The coal is formed of mostly green plants and contains very few woody trees.

Question 65

Which phenomenon does not usually cause graded beds?

A) turbidity currents
B) river floods
C) storm waves
D) tides

Question 66

Choose the option that correctly matches all rock types with their source environments.

A) conglomerate: lake bottoms; limestone: sea floor; evaporites: stream deltas
B) conglomerate: river bottoms; limestone: lake bottoms; mudstone: lake bottoms
C) limestone: river bottoms; conglomerate: sea floor; evaporites: ocean beaches
D) limestone: sea floor; evaporites: lake shores; conglomerates: stream deltas

Question 67

Judge the following sentence according to the criteria given below: When studying alternating sandstone and shale beds prior to 1900, sedimentologists interpreted that the sediment did not quietly settle out to the seafloor because they saw scoured bases on the graded beds and current-formed cross-beds.

A) The assertion and the reason are both correct, and the reason is valid.
B) The assertion and the reason are both correct, but the reason is invalid.
C) The assertion is correct but the reason is incorrect.
D) The assertion is incorrect but the reason is correct.
E) Both the assertion and the reason are incorrect.

Question 68

Which type of rock is abundant in older rock formations but more rare in newer formations, may contain oil or gas, and is formed by a reaction with a previous sedimentary rock?

A) anthracite
B) bituminous coal
C) chert
D) dolostone

Question 69

What conditions during the formation of coal may increase its quality for industrial use?

A) Very high heat and pressure are applied.
B) Clay and silt wash periodically through the swamp that formed the coal.
C) The swamp that formed the coal floods.
D) The coal is formed of mostly green plants and contains very few woody trees.

Question 70

The direction of moving water and air currents that transport sediment can be determined by the study of

A) bedding.
B) mudcracks.
C) cross-beds.
D) graded beds.

Question 71

Arkose contains

A) sandstone, mica, and silicates.
B) feldspar, quartz, mica, and silicates.
C) feldspar, biotite, and mica.
D) sandstone, biotite, mica, and silicates.

Question 72

How are sedimentary rocks classified? (5.4)

Question 73

Why are fossils found in sedimentary rock? (5.5)

Question 74

In the field, a student finds a sedimentary rock that contains angular fragments of white rock embedded in a darker rock. This rock is possibly

A) arkose sandstone.
B) breccia.
C) conglomerate.
D) lithic mudstone.

Question 75

A student scoops a bucket of water and sediment from the side of a stream. A second student scoops a bucket of water and sediment from the center of the stream. What is the most probable outcome?

A) The first student would have large rocks and boulders because the stream flow sweeps these out of the way and to the sides. The second student might have small rocks and pebbles because the stream wears the rocks down where it flows quickly in the middle.
B) The first student would have mud and small rocks because the stream flows slowly at the sides. The second student might have mostly mud because mud settles to the bottom.
C) The first student would have mud and small rocks because the stream flows slowly at the sides. The second student might have large rocks and pebbles because the stream probably flows more quickly in the middle.
D) The first student would have mud and medium-to-large size rocks that get stuck in the mud at the sides. The second student might have pebbles.

Question 76

How and why do rocks disintegrate to form sediment? (5.1)

Question 77

What is the link between weathering and making sediment? (5.2)

Question 78

Which location would contain the most well-rounded rocks?

A) a beach shore
B) an avalanche site
C) a fast-flowing river
D) a quiet lake shore

Question 79

A muddy sedimentary environment exposed to the air allowing the sediment to dry out will result in

A) ripples.
B) mudcracks.
C) cross-beds.
D) graded beds.

Question 80

How do evaporites occur?

A) Evaporation turns rock to smaller fragments.
B) They are extremely rare; the sun and moon must be aligned.
C) Volcanic rock combines with sedimentary rock.
D) Extensive evaporation allows precipitation of halite and gypsum.