Deck 3: Rocks

Question 1

Multiple Choice Which of the following is not a true statement about rocks?

A) Soil is an example of rocks because it is unconsolidated aggregate of materials
B) If you pick up a rock, it will be considered a rock if it is made up of a solid aggregate of one or more minerals
C) Igneous rocks form a few hundred kilometers beneath the surface because high enough temperatures are there to melt rock into magma
D) Magma rises slowly towards the Earth's surface because it is less dense than the surrounding rock

Answer 1

A

Question 2

Which of the following is not a true statement?

A) Sedimentary rocks form processes of weathering on pre-existing rocks on the Earth's surface
B) Metamorphic rocks form when a rock is heated to the point it melts into magma
C) Metamorphic rocks are formed when heat, pressure, or hot water alters any preexisting rock
D) Igneous rocks form from magma
E) A rock you find in nature is likely not going to be permanently in its current state over all of geologic time due to the rock cycle

Answer 2

B

Question 3

Which of the following would not true about igneous rock chemistry?

A) Igneous rocks are classified based on the percentage of silica that is in the rock
B) Felsic igneous rocks contain high percentages of silica
C) Mafic igneous rocks contain low percentages of silica but high amounts of iron and magnesium
D) Ultramafic igneous rocks contain very low percentages of iron and magnesium
E) Intermediate igneous rocks contain intermediate percentages of silica

Answer 3

D

Question 4

Which of the following is not a true statement?

A) If you find a piece of rhyolite in the field, it should be light in color because it high in quartz and feldspars
B) If you find a piece of basalt in the field, it should be a very light gray color because contains an intermediate level of quartz and feldspars
C) If you find a piece of andesite in the field, it should be a gray color
D) If you find a piece of ultramafic rock in the field, it will be noticeable more dense than other rocks because it is high in iron and magnesium

Question 5

Which of the following is a true statement about weathering?

A) Weathering process can make dissolved ions such as sodium, calcium, and chloride
B) Weathering of solid rock can cause some of the minerals in it to change or dissolve our of a rock
C) Most of the dissolved ions from rock travel via rivers to the ocean where marine organisms use the ions to make shells or other hard parts of their bodies
D) If you find a rock called limestone, you have found a very rare rock because the geologic conditions to form limestone are very rare

Question 6

Which of the following would not be a true statement?

A) If you witness a highly explosive volcanic eruption, its chemistry would higher in silica minerals and lower in temperature
B) If you witness a flowing, running lava eruption in Hawaii, its chemistry would be lower in silica and higher in temperature
C) The higher temperature for mafic lavas help decrease its density and prevent silica minerals from forming
D) All of the above are true statements

Question 7

Which of the following is not a true statement?

A) If you were to witness a volcanic eruption, the igneous rocks that would be formed are plutonic rocks
B) Volcanic igneous rocks form when magma/lava reach the Earth's surface and cool at the surface
C) Plutonic igneous rocks form when magma cools and crystallizes inside the Earth and do not get deposited as lava on the Earth's surface
D) Lava cools off in a few days or a few years unless it comes in contact with cold water or ice where it may cool off in hours

Question 8

Which of the following is not true regarding the rock cycle

A) A rock can be impacted by rain or the hydrosphere
B) A rock can be impacted by air or the atmosphere
C) A rock can be impacted by chemicals secreted plants or the biosphere
D) As a solid rock is decomposed by processes of weathering, the end result is the formation of sand that can get into rivers and streams
E) As a solid rock is decomposed by processes of weathering, clay and other minerals get washed by rain into rivers and are deposited into sedimentary basins

Question 9

Which of the following is not a true statement about the hardness of a mineral?

A) If you owned a drilling operation that was drilling into the Earth, you would find out that the temperature within the crust rises approximately 30°C for every kilometer you drill in depth
B) Melting of rocks can occur between depths of 100 and 350 kilometers causing magma to form
C) The depth of magma melting is important to the minerals that form and ultimately to the chemistry of the igneous rock that is formed
D) Quartz crystallizes at temperatures around 1100°C so it is not a common igneous mineral since super hot magma temperatures are currently rare on Earth

Question 10

Which of the following is not a true statement?

A) Rhyolite is very dense and does not weather fast
B) Granite is very dense and does not weather fast
C) Granite forms steep sheer cliffs in many mountain ranges
D) Most obsidian forms from felsic composition
E) Yellowstone Volcano has produced multiple felsic eruptions over the past 2.1 million years

Question 11

Which of the following is not a true statement?

A) Bedrock is the rock material which exists beneath the soil
B) The rock that is already in a region and has been cut into by intrusive igneous rocks is referred to as the country rock
C) Basement rock that exists beneath the sedimentary rock layers at the Earth's surface
D) All of the above are true statements

Question 12

Which of the following is not a true statement about the rock cycle?

A) A sedimentary rock can be buried to depths that cause it to metamorphose
B) A metamorphic rock can be buried to depths inside the Earth that the rock is melted into an igneous rock
C) An igneous rock can form inside the Earth as it crystallizes and cools off or it can be deposited on the Earth's crust as lava where it crystallizes and cools off
D) All of the above are true statements about elements

Question 13

If you find a rock in a creek bed, which of the following is true about that rock?

A) The rock you found has likely been recycled via weathering and erosion at the Earth's surface
B) The rock you found has been the same rock and has not experienced any changes for all of geologic time
C) Weathering breaks down rocks into smaller fragments
D) Sands on a beach represent weathered down sediments but are not considered rocks

Question 14

Which of the following is a true statement about the rock cycle?

A) The Earth's internal heat only produces igneous rocks
B) Sedimentary rocks deposited in a basin sink under new overlying rocks and the deeper layers can become metamorphosed by the Earth's heat
C) Sedimentary rocks deposited in a basin can be buried deep enough that the rocks become too hot and turn into magma
D) Magma may not reach the Earth's surface where it crystallizes and turns into a rock like granite
E) Magma may reach the Earth's surface as lava where it crystallizes and turns into lava such as basalt

Question 15

Which of the following is not a true statement?

A) If you find a piece of granite, you have discovered a plutonic igneous rock that contains mostly quartz and feldspar
B) If you find a piece of rhyolite, you have discovered a volcanic igneous rock that contains mostly quartz and feldspar
C) Granite and rhyolite represent the same igneous chemistry
D) Granite and rhyolite are different not in their chemistry but in how and where they crystallized and cooled off
E) An igneous rock that contains coarse-grained crystals would be considered a volcanic rock

Question 16

Which is not a true statement?

A) Andesite is a volcanic rock which has an intermediate chemistry between basalt and granite so is typically gray in color
B) Basalt is a volcanic rock which has a mafic chemistry and it is typically black in color
C) Every type of asbestos is a potent carcinogen regardless if it can blow around or it is woven into a cloth
D) Andesite was named after the Andes Mountain Range in South America that has a large concentration of intermediate igneous volcanic rocks
E) Diorite is chemically the same as Andesite but it is the plutonic equivalent rock has larger interlocking crystals like granite and gabbro

Question 17

Which of the following is not a true statement about igneous rocks?

A) When magma rises slowly through the Earth's crust before erupting, crystals can form when the rest of the magma remains molten
B) The igneous rock texture described in "A" is called porphyry
C) If a rock has a porphyry texture, it will have interlocking crystals because it cooled for a long period of geologic time
D) Another term of volcanic is extrusive igneous rocks

Question 18

Which is not a true statement?

A) The most violent and most catastrophic volcanic eruptions in Earth's history involved felsic magmas
B) The least violent volcanic eruptions in Earth's history involved ultra-mafic magmas
C) The more silica a magma contains, the more viscous or thick it becomes creating a violent eruption because internal pressure builds up inside the volcano
D) The less silica a magma contains, the magma remains molten and does not create a violent eruption
E) A mafic eruption would be thick and viscous allowing for internal pressure to build up inside the volcano

Question 19

Which of the following is not a true statement?

A) Basalt is a mafic igneous rock that contains equal amounts of plagioclase feldspar and pyroxene
B) Basalt makes up the oceanic crust while granite makes up the continental crust
C) Gabbro is the intrusive or plutonic equivalent of basalt because it has equal amounts of plagioclase feldspar and pyroxene but has interlocking crystals like granite
D) Gabbro is common in the deeper parts of the oceanic crust where mafic magma crystallize
E) All of the above are true statements

Question 20

Which of the following is not a true statement about plutonic rocks?

A) A plutonic rock takes a hundred years to cool and crystallize
B) Plutonic rocks are medium to coarsely crystalline meaning that there are interlocking crystals that grew over hundreds of thoughts or even millions of years
C) Granite is a plutonic igneous rock that formed inside the Earth's crust
D) Granite has interlocking crystals that are clearly visible

Question 21

Which of the following properties would be the most effective means of mineral identification for the mineral hematite?

A) If you discover a piece of sandstone that is well sorted by size, that would tell you that the sands were deposited in an environment with high levels of waver energy such as a beach
B) Crossbedding is a sedimentary structure that tells a geologist about ancient wind and water conditions from geologic past
C) A ripple mark is a sedimentary structure that tells a geologist shallow water currents from geologic past
D) A mud crack is a sedimentary structure that tells a geologist that mud dried up after being deposited in water at some point in geologic past
E) A graded bed is an uncommon sedimentary structure but it tells a geologist that all sizes of sediment were abruptly deposited at the same time

Question 22

If you find a piece of granite or rhyolite, it will primarily contain quartz but may contain small amounts of biotite or hornblende which gives it a speckled appearance.

Question 23

If you find a rock with a dominance in quartz minerals, that should tell you as a geologist that the magma chamber in which the quartz crystallized was around 500°C.

Question 24

Which of the following is not a true statement?

A) Mudstone is made up of tiny clay minerals but is still considered a clastic sedimentary rock
B) If you were in a swamp where a lot of peat was forming, this material could turn into coal over geologic time with heat and pressure
C) Chert is an organic sedimentary rock made up of very finely crystallize quartz
D) If you found halite in the field, you have discovered a chemical sedimentary rock that is an evaporite
E) All limestone rocks are clastic sedimentary rocks

Question 25

Which is not a true statement? A) 75 percent of the continents are covered with sedimentary rocks
B) Sedimentary rocks comprise over 15 percent of the Earth's crust
C) If you find a conglomerate sample in the field, you have discovered a clastic sedimentary rock
D) If you find a coal layer in the field, you have discovered an organic sedimentary rock
E) If you find rock salt in the field, you have discovered a chemical sedimentary rock
F) If you find a limestone rock in the field, you have discovered a bioclastic sedimentary rock

Question 26

Which of the following is not a true statement?

A) Any limestone sample you find will be calcareous meaning the rock contains an abundance of the mineral calcite or aragonite
B) No limestone sample you find will contain skeletal bris from broken-down shells and other marine organisms with hard body parts
C) A good way to test a sample you think is limestone is to place some diluted acid on the rock to see if it fizzes or effervesces
D) Limestone reacts to diluted acid because it contains calcite

Question 27

If you find a piece of obsidian in the field, you have discovered an intrusive, plutonic igneous rock meaning it crystallized inside the Earth over a long period of geologic time.

Question 28

If you find a rock with a dominance in olivine minerals, that should tell you as a geologist that the magma chamber in which the quartz crystallized was greater than 1100°C.

Question 29

The vast amount of sandstone found in Utah tells a geologist that ancient sand dunes once existed in the region.

Question 30

Granite and rhyolite are chemically the same but the location of where the crystallized determines if the rock has a coarse texture or a fine texture.

Question 31

Which is not a true statement?

A) Limestone rock contains a substantial amount of carbon dioxide gas
B) Atmospheric carbon dioxide dissolves in seawater and combines with dissolved calcium to form limestone
C) The formation of limestone removes carbon dioxide from both the sea and the air
D) If humans use limestone at the surface for making cement, this can cause the carbon dioxide gas to be released back to the atmosphere
E) All of the above are true statements

Question 32

Which is not a true statement?

A) Burial metamorphism occurs when sedimentary rocks are buried in a basin that is greater than 5 kilometers in depth
B) Temperature and pressure increase within the deeper layers until metamorphism begins
C) Burial metamorphism occurs with deformation
D) Burial metamorphism will yield nonfoliated metamorphic rocks

Question 33

Since marine fossils have been documented at the top of Mount Everest, that tells a geologist that marine or oceanic rocks layers with these fossils have been uplifted to the highest point in the Himalayas.

Question 34

The rock cycle states that all rocks undergo changes from igneous, sedimentary, and metamorphic states to another but that most rocks are permanent over geologic time in one of these states.

Question 35

If you want to find a lot of basalt in North America, a good place to go visit is Columbia River Plateau Basalts located in the Pacific Northwest.

Question 36

Which is not a true statement?

A) Ultramafic rocks are commonly made by hot volcanoes in modern time
B) Most ultramafic rocks were formed when the first crust of the Earth began to form around 4 billion years ago
C) If you find a sample of komatiite in the field, you have discovered an ultramafic lava
D) If you find a sample of peridotite in the field, you have discovered an ultramafic plutonic rock that is like granite meaning it has interlocking crystals the cooled under the Earth's surface
E) Ultramafic rocks are rich in magnesium and iron and this type of igneous rock makes up most of the upper mantle but is rare in the crust

Question 37

Which is not a true statement about minerals?

A) Clastic sedimentary rocks are classified in order of increasing particle size
B) Pore space in clastic rocks can be important to humans because water, petroleum, and natural gas can fill those pore spaces
C) As sediment accumulates and is buried, this allows for the layer to be compressed by the weight of the overlying layers and this process is called compaction
D) Lithification is the process of hardening a rock
E) Conglomerate, breccia, sandstone, siltstone, and shale are all examples of clastic sedimentary rocks

Question 38

If you find a piece of granite, you have discovered a rock that is high in iron and magnesium.

Question 39

Which is not a true statement about metamorphic rocks?

A) Contact metamorphism occurs when hot magma intrudes cooler rock
B) If you find a low-grade piece of marble, that means the marble you found was very close to the magma chamber
C) Contact metamorphism commonly occurs without deformation
D) The highest grade metamorphic rocks form the contact point

Question 40

Which is not a true statement?

A) Regional dynamothermal metamorphism would occur where active mountain building is happening
B) Regional dynamothermal metamorphism refers to rocks that are deformed and heated simultaneously
C) Regional dynamothermal metamorphism is the least common type of metamorphism because it involves large-scale regional areas where mountain building has occurred
D) If you find a regional dynamothermal metamorphic rock such as gneiss, the sample will likely be foliated

Question 41

Completion
If you discover a piece of slate, it represents what specific level of metamorphic grade? ________

Question 42

Completion
If you were making a clay vase, you would need to heat up the clay material to around 1000°C allowing for what minerals, _________, to decompose and also promoting the growth of new minerals all without melting the solid material.

Question 43

Completion
If you moved to an urban area in Utah such as Salt Lake City, what sedimentary mining resource would be essential for you to build a home?   ______________________________

Question 44

Completion
If you find a fossil such as a tracks, trails, and burrows, you have discovered what type of fossil ____________________

Question 45

If you wanted to find an abundance of halite, you would want to find places where ancient evaporites formed.

Question 46

Completion
Cross-sections of ___________ show a well-developed concentric internal structure resulting from the layer-by-layer precipitation of the carbonate minerals ?

Question 47

Completion
Which sedimentary structure is the most common and represents layers of sediment that have deposited in a similar depositional environment? ____________________.

Question 48

Completion
If you discover a piece of gneiss, it represents what specific level of metamorphic grade? ________

Question 49

Completion
If you see a sand and gravel operation near where you live, you have observed one of ________ active operations based on business data collected in 2016.

Question 50

Completion
If you visited the Great Barrier Reef of Australia, you would be observing a modern-day coral reef environment where _________-forming organisms exist.

Question 51

If you want to find a lot of andesite in North America, a good place to go visit would be the Cascade Mountains of the Pacific Northwest.

Question 52

If you visited the Sierra Nevada region where Yosemite National Park exists, the type of metamorphism that created these rocks would have been what? ___________________

Question 53

If you find a metamorphic rock in the field that contains mica crystals that have grown with their flat surfaces perpendicular to the direction of squeezing, what type of metamorphic texture would your rock have?

Question 54

In order to qualify as a sedimentary rock, it must be lithified which means it has been compacted and cemented.

Question 55

Completion
If you find a rock in which the coarsest clasts are in its base and the smallest size clasts are on its top, what specific sedimentary structure have you found? ______________________

Question 56

Completion
___________ form in a quiet water environment as compared to ooids that require agitation to roll the grain around.

Question 57

If you discover a clastic sedimentary rock in the field, you have found the least common type of sedimentary rock known to man.

Question 58

You can find numerous places in North America to see ultramafic rocks because these rocks are still being made today in very hot magma chambers.

Question 59

What type of metamorphic grade occurs in the depth of less than 10 kilometers and causes the rock to heat up to 300°C to 400°C? _________________

Question 60

What type of metamorphic grade occurs between 40 and 55 kilometers before the Earth's surface allowing a rock to come close to its melting point? _________________

Question 61

Explain why a geologist would expect to find more basalt on ocean floors as compared to granite.

Question 62

Short Answer
Explain what a parent rock is and how that relates to metamorphism.

Question 63

Explain how excessive mining of gravels could pose a risk to future construction needs of humans.

Question 64

Explain how clastic and chemical sedimentary rocks are formed differently.

Question 65

Explain why magma rises toward the Earth's surface and how that contributes to the formation of volcanoes.

Question 66

Essay
Explain why a geologist would expect to find more granite on continents as compared to basalt.

Question 67

Discuss how a plutonic mafic rock forms and how a volcanic mafic rock forms. Correlate the location of where the rock crystallizes to its extrusive or plutonic status.

Question 68

Short Answer
Explain why the oceanic crust is dominated by basalt.

Question 69

Short Answer
Explain why a low-grade metamorphic rock would not form in depths of 10 kilometers or greater.

Question 70

Short Answer
Explain what specific dominance of minerals you would expect to find in granite and identify how the higher percentage of silica contributes to a more explosive volcanic eruption.

Question 71

Short Answer
Explain what testing a rock with diluted acid tells a geologist about the type of rock she or he has found.

Question 72

Explain why there is an extrusive equivalent to a plutonic igneous rock for each igneous rock chemistry group such as rhyolite and granite.

Question 73

Short Answer
Explain why regional dynamothermal metamorphism creates foliated metamorphic rocks.

Question 74

Short Answer
Explain why conglomerate and shale are both considered to be clastic sedimentary rocks.

Question 75

Explain why ultramafic rocks are no longer made on the Earth's surface. Correlate that information to why ancient ultramafic volcanoes would not have erupted violently.

Question 76

Short Answer
Explain how a ripple mark forms and what it tells a geologist when she or he discovered an ancient ripple mark in the field.

Question 77

Short Answer
Explain the steps for forming a sedimentary rock.

Question 78

Short Answer
Explain how chalk limestone forms.

Question 79

Explain why Yellowstone Volcano has produced multiple felsic eruptions which violently erupted over the past 2.1 million years and correlate that information to the location of the magma chamber to the surface of the Earth.

Question 80

Explain how a rock you find in the field could have undergone multiple changes in the rock cycle over geologic time.