Geology Chapters 4-7

What is the major component of stratovolcano?

A mix

What is concordant tabular intrusion?

A sill

What is a residual soil?

A soil that formed over parent material.

What type of chemical sedimentary rock is found in petrified wood? A. Chert B. Shale C. Limestone D. Dolostone E. Coquina

A. Chert

Why is coal different from other sedimentary rocks? A. It is made of almost entirely of organic matter. B. It forms from pieces of igneous rocks. C. It is a valuable economic resource. D. It forms in a marine environment. E. Compaction is an important part of the rock-forming process.

A. It is made of almost entirely of organic matter.

When a rock is mechanically weathered, A. the surface area of the rock is increased, which allows a greater amount of chemical weathering to occur. B. the volume of the rock is increased, which allows a greater amount of chemical weathering to occur. C. the surface area of the rock is increased, which hinders chemical weathering. D. the surface area of the rock is decreased, which allows a greater amount of chemical weathering to occur. E. the volume of the rock is decreased, which hinders chemical weathering to occur.

A. the surface area of the rock is increased, which allows a greater amount of chemical weathering to occur.

A dike is mostly likely to be composed of which of the following igneous rocks? A. diorite B. basalt C. peridotite D. gabbro E. granite

B. basalt

Which type of plate boundary generates the greatest quantity of magma? A. transform B. divergent C. continental-continental convergent D. oceanic-oceanic convergent E. continental-oceanic convergent

B. divergent

What is a dark gray, fine-grained rock?

Basalt

Which of the following would decrease soil erosion? CHOOSE ALL THAT APPLY. A. Removing all vegetation B. Vegetation planted perpendicular to the slope C. Adding terraces to a slope D. Steepening a slope E. Vegetation planted parallel to the slope

C. Adding terraces to a slope E. Vegetation planted parallel to the slope

Where do you raise the heat to generate magma?

Continental-Continental Collisions Above mantle plumes that have cooled

Why is the left hand side of Bowen's reaction series called a discontinuance?

Crystallization never continues.

Why do rainforest soils lack nutrients? A. Rainforest soils lack bacterial activity. B. Rainforest soils have high concentrations of calcium carbonate. C. Rainforest soils are the result of extreme mechanical weathering. D. Rainforest soils are heavily leached. E. Rainforest soils lack iron oxide.

D. Rainforest soils are heavily leached.

Why are soils in tropical rain forests not well suited for farming? A. The vegetation that already exists in the rain forest increases the rate at which the soil erodes. B. There are not enough oxides in the soil. C. There is too much humus in the soil. D. Soluble materials such as calcium carbonate are severely leached from the soil. E. The soils in rain forests chemically weather very slowly.

D. Soluble materials such as calcium carbonate are severely leached from the soil.

Which of the examples below shows how carbon moves from the geosphere directly to the atmosphere? A. When land animals die, they release carbon dioxide into the atmosphere. B. When certain small marine organisms die, their calcium carbonate skeletons fall to the ocean floor and eventually become sedimentary rock. C. During photosynthesis, plants absorb carbon dioxide. D. The burning of fossil fuels (e.g., coal) releases carbon dioxide directly into the atmosphere. E. Carbon dioxide combines with water vapor to make carbonic acid, which rains and weathers rocks on Earth's crust.

D. The burning of fossil fuels (e.g., coal) releases carbon dioxide directly into the atmosphere

How are chemical rocks identified, and how does this differ from how detrital rocks are identified? A. Chemical rocks are primarily identified by their overall textures, whereas detrital rocks are primarily identified by their compositions. B. Chemical rocks are primarily identified by their compositions, whereas detrital rocks are identified primarily by their grain rounding. C. Chemical rocks are primarily identified based on their particle sizes, whereas detrital rocks are primarily identified based on their compositions. D. Chemical rocks are primarily identified based on the minerals they are composed of, whereas detrital rocks are primarily identified based on their grain sorting. E. Chemical rocks are primarily identified based on their compositions, whereas detrital rocks are primarily identified based on their particle sizes.

E. Chemical rocks are primarily identified based on their compositions, whereas detrital rocks are primarily identified based on their particle sizes.

Which type of sedimentary structure is characteristic of sand dunes? A. bedding plane B. ripple marks C. mud cracks D. graded beds E. cross-bedding

E. cross-bedding

Scientists monitor volcanoes in an attempt to A. reduce the number of volcanic eruptions that occur. B. prevent volcanic eruptions. C. study volcanic eruptions that happened long ago in geologic past. D. pinpoint precisely when a volcano will erupt next. E. discover precursors that may warn of an impending or imminent eruption.

E. discover precursors that may warn of an impending or imminent eruption.

In which depositional environment would breccia form? A. sand dunes B. deep marine C. playa lakes D. alluvial fan E. glacial deposits

E. glacial deposits

Chemical sedimentary rocks form from ___. A. the carbon-rich remains of planktonic algae B. the compaction of sediments C. compacted pieces of decaying plant material D. compacted ash from volcanoes E. the precipitation of ions in solution

E. the precipitation of ions in solution

Soil in good condition for plant growth will be composed of ____. A. less than 1 percent water B. ~95 percent organic matter C. ~50 percent water D. less than 1 percent air E. ~45 percent mineral matter

E. ~45 percent mineral matter

What are some examples of Mechanical Weathering?

Frost Wedging Sheeting Salt Crystal Growth Root Wedging

What is the least hazardous volcanic hazard?

Gases

How is the material that forms chemical sedimentary rock transported?

In solution

Where is the third most common place for volcanic activity?

Interplate Volcanic Activity (Hawaiian Islands)

How does magma differentiate?

Magma Mixing Assimilation Crystal settling

What is a fine-grained, light colored rock?

Rhyolite

What type of magma(s) give you explosive eruptions?

Rhyolitic Intermediate Andesitic

What are the three categories of sedimentary rocks?

Detrital Chemical Organic

What is a discordant tabular intrusion?

Dike

What is a coarse-grained rock that looks like salt and pepper? (equal amounts of dark and light)

Diorite

What are some examples of Chemical Weathering?

Dissolution Oxidation Hydrolosis Spheroidal Weathering

Where do you get lower pressure to generate magma?

Divergent Plate Boundaries

Where does most of the volcanic activity take place?

Divergent Plate Boundaries

Explain why some volcanic eruptions are explosive?

They have high viscosity magma

What is a transported soil?

A soil that has been formed from material that has been transported

How have human activities affected the rate of soil erosion? A. Humans have increased the rate of soil erosion by removing vegetation through activities such as farming, logging, and construction. B. Humans have decreased the rate of soil erosion by removing vegetation through activities such as farming, logging, and construction. C. Humans have increased the rate of soil erosion by adding vegetation through activities such as farming, logging, and construction. D. Humans have increased the rate of soil erosion by creating grassed waterways. E. Humans have increased the rate of soil erosion by farming on terraces on steep slopes.

A. Humans have increased the rate of soil erosion by removing vegetation through activities such as farming, logging, and construction.

Joints in rock promote weathering by A. allowing water to penetrate the rock at depth and begin the weathering process. B. allowing solid ice to penetrate the rock at depth and begin the weathering process. C. allowing solid salts to penetrate the rock at depth and begin the weathering process. D. weakening the overall rock so that it breaks more easily when a force pushes on it. E. allowing more fractures to form within the joint.

A. allowing water to penetrate the rock at depth and begin the weathering process.

What process(es) used to generate magma?

Decompression melting Addition of water Increase in temperature

An exfoliation dome forms as a result of A. sheeting, where concentric slabs of rock break loose in reaction to the unloading of pressure. B. sheeting, where concentric slabs of rock are pushed loose in reaction to the addition of weight on top of the rock. C. the growth of salt crystals within fractures around the perimeter of the rock, which eventually grow so large that they break of rock pieces, leaving behind a dome-shaped mass. D. water eroding rock at higher rates around its perimeter and lower rates at the top. E. water infiltrating between rock layers, freezing, and breaking away the topmost layers of rock.

A. sheeting, where concentric slabs of rock break loose in reaction to the unloading of pressure.

What is the single most common and characteristic feature of sedimentary rocks? A. cross-bedding B. horizontal strata or beds C. mud cracks D. ripple marks E. graded bedding

B. horizontal strata or beds

How does climate influence the weathering of rock? A. Areas with high temperatures and scarce moisture will generally have the highest rates of chemical weathering. B. Areas with high temperatures and abundant moisture will generally have the highest rates of chemical weathering. C. Areas with high temperatures and abundant moisture will generally have the lowest rates of chemical weathering. D. Areas with low temperatures and abundant moisture will generally have the highest rates of chemical weathering. E. Areas with frequently occurring, forceful winds will have the highest rates of chemical weathering.

B. Areas with high temperatures and abundant moisture will generally have the highest rates of chemical weathering.

What is the difference between cross-bedding and graded bedding? A. Cross-bedding occurs when sediments are layered at an angle inclined to the horizontal, whereas graded bedding occurs when smaller sediments are deposited at the bottom of the layer, gradually changing to large sediments at the top. B. Cross-bedding occurs when sediments are layered at an angled inclined to the horizontal, whereas graded bedding occurs when larger sediments are deposited at the bottom of the layer, gradually changing to fine sediments at the top. C. Cross-bedding occurs when larger sediments are deposited at the bottom of the layer, gradually changing to fine sediments at the top, whereas graded bedding occurs when sediments are layered at an angled inclined to the horizontal. D. Cross-bedding occurs when small sediments are deposited at the bottom of the layer, gradually changing to large sediments at the top, whereas graded bedding occurs when large sediments are deposited at the bottom of the layer, gradually changing to small sediments at the stop. E. Cross-bedding occurs when sediments are layered at an angle inclined to the horizontal, whereas graded bedding occurs when thinner sedimentary layers are overlain by increasingly thicker sedimentary layers.

B. Cross-bedding occurs when sediments are layered at an angled inclined to the horizontal, whereas graded bedding occurs when larger sediments are deposited at the bottom of the layer, gradually changing to fine sediments at the top.

Where are most sediments and sedimentary rocks found? CHOOSE ALL THAT APPLY. A. At mid-ocean ridges B. On the ocean floor C. On the surface of continents D. At the base of Earth's crust E. In the mantle

B. On the ocean floor C. On the surface of continents

What is the raw material for coal, and how does it accumulate? A. calcium carbonate B. Plants are the raw material for coal; to form coal plants must accumulate in oxygen deficient swamp water. C. Plants are the raw material for coal; to form coal plants must accumulate in highly oxygenated water. D. Lignite is the raw material for coal; it accumulates through the shallow burial of organic material. E. Peat is the raw material for coal; it accumulates through the partial decomposition of plant remains

B. Plants are the raw material for coal; to form coal plants must accumulate in oxygen deficient swamp water.

What is an everyday example of mechanical weathering? CHOOSE ALL THAT APPLY. A. A car rusting B. Potholes forming in the street C. Tree roots cracking a sidewalk D. A log burning E. Paint colors fading

B. Potholes forming in the street C. Tree roots cracking a sidewalk

Why are sedimentary rocks important? A. Sedimentary rocks are the only type of rocks that contains minerals used for production and manufacturing. B. Sedimentary rocks provide geologists with information necessary to study the history of Earth and also hold various resources of economic importance. C. Because sedimentary rocks are far less abundant in Earth's crust than igneous and metamorphic rocks, they are considered very rare. D. Dynamics in sedimentary rocks are the primary cause for the movement of crustal plates. E. Sedimentary rocks are the only sources for all igneous rocks and metamorphic rocks on Earth.

B. Sedimentary rocks provide geologists with information necessary to study the history of Earth and also hold various resources of economic importance.

How does the volume of sedimentary rocks in Earth's crust compare with the volume of igneous and metamorphic rocks? A. Sedimentary rocks represent roughly 50 percent of Earth's crust, while igneous rocks and metamorphic rocks combined represent the other 50 percent of Earth's crust. B. Sedimentary rocks represent 5 to 10 percent of the crust, whereas igneous rocks and metamorphic rocks combined represent 90 to 95 percent of Earth's crust. C. Sedimentary rocks represent 70 to 75 percent of Earth's crust, whereas igneous rocks and metamorphic rocks combined represent 25 to 30 percent of Earth's crust. D. Sedimentary rocks represent 90 to 95 percent of Earth's crust, whereas igneous rocks and metamorphic rocks combined represent 5 to 10 percent of Earth's crust. E. Sedimentary rocks, igneous rocks, and metamorphic rocks each represent roughly 33 percent of Earth's crust.

B. Sedimentary rocks represent 5 to 10 percent of the crust, whereas igneous rocks and metamorphic rocks combined represent 90 to 95 percent of Earth's crust.

How does regolith differ from soil? A. Regolith contains water, whereas soil does not. B. Unlike regolith, which consists only of weathered rock and mineral fragments, soil also contains organic matter, water, and air. C. Regolith consists of organic material, which is not found in soil. D. Unlike soil, which consists only of weathered rock and mineral fragments, regolith also contains organic matter, water, and air. E. Regolith consists of weathered rock and mineral fragments, neither of which is found in soil.

B. Unlike regolith, which consists only of weathered rock and mineral fragments, soil also contains organic matter, water, and air.

Which three minerals are especially susceptible to oxidation? A. olivine, calcite, and biotite B. biotite, olivine, and pyrite C. potassium feldspar, olivine, and calcite D. quartz, pyrite, and biotite E. pyrite, calcite, and biotite

B. biotite, olivine, and pyrite

What are the three broad categories of sedimentary environments with an example of each? A. marine environments, such as deep-sea fans; transitional environments, such as lakes; continental environments, such as caves B. marine environments, such as deep ocean floors; continental environments, such as deserts; transitional environments, such as tidal flats C. marine environments, such as swamps; continental environments, such as deserts; transitional environments, such as beaches D. marine environments, such as salt flats; continental environments, such as swamps; transitional environments, such as beaches E. marine environments, such as deep ocean floors; continental environments, such as estuaries; transitional environments, such as tidal flats

B. marine environments, such as deep ocean floors; continental environments, such as deserts; transitional environments, such as tidal flats

An igneous rock with a ______ texture solidified deep within Earth. A. aphanitic B. phaneritic C. glassy D. porphyritic E. vesicular

B. phaneritic

Which group of minerals makes up most igneous rocks? A. sulfates B. silicates C. carbonates D. halides E. oxides

B. silicates

What is diagenesis? A. the chemical and physical change of a sedimentary rock to a metamorphic rock B. the chemical, physical, and biological changes that take place after sediments have been deposited and during and after sediment lithification C. the chemical, physical, and biological changes that take place before sediments are weathered from the parent material D. the chemical, physical, and biological changes that take place while sediments are being weathered E. the chemical, physical, and biological changes that take place as sediments are being eroded

B. the chemical, physical, and biological changes that take place after sediments have been deposited and during and after sediment lithification

What is an intrusion with a surface exposure over 100 square kilometers?

Batholith

What is Mechanical Weathering?

Breaking down the rock into smaller and smaller pieces.

During the process that forms sedimentary rocks, how does compaction affect sediment? A. It decreases the amount of calcite in the sediment. B. It changes the shape of sand grains. C. It decreases the ion concentration in groundwater. D. It decreases the volume of pore spaces. E. It decreases the size of interlocking crystals.

D. It decreases the volume of pore spaces.

By what process do sediments become well sorted, and by what process do sediments become poorly sorted? A. Sediments that are transported over a rather short period of time tend to become well sorted, whereas sediments that are transported for a long, sustained time tend to be poorly sorted. B. Sediments that are rounded tend to be well sorted, whereas sediments that are angular tend to be poorly sorted. C. Sediments that are transported for a long, sustained time tend to become well sorted, whereas sediments that are transported over a rather short period of time tend to be poorly sorted. D. Sediments that are angular tend to be well sorted, whereas sediments that are rounded tend to be poorly sorted. E. Sediments of softer minerals tend to be poorly sorted, whereas sediments of hard minerals tend to be well sorted.

C. Sediments that are transported for a long, sustained time tend to become well sorted, whereas sediments that are transported over a rather short period of time tend to be poorly sorted.

Which type of weathering produces an exfoliation dome? A. Salt crystal growth B. Oxidation C. Sheeting D. Biological activity E. Frost wedging

C. Sheeting

How can an angular mass of rock become a spherical boulder? A. Tree roots grow in a circular pattern into joints in the rock; when the roots grow, they break off pieces of the rock. B. Material on top of the rock unloads extremely quickly, which causes edges and corners of the rock to sheet off quickly. C. Water enters joints in the rock, where it preferentially weathers the corners and edges of the rock into a roughly spherical shape. D. The edges and corners of a rock fracture more easily than its planar surfaces. E. The entire rock is continuously pushed and rolled along by a force such as water or wind until its corners and edges wear away, giving the rock a more spherical shape.

C. Water enters joints in the rock, where it preferentially weathers the corners and edges of the rock into a roughly spherical shape.

How do chemical weathering and the formation of biochemical sediment remove carbon from the atmosphere and store it in the geosphere? A. When carbon dioxide in the atmosphere combines with water, it creates bicarbonate ions that precipitate and then chemically weathers the rocks on Earth. The result of this ultimately ends up in the oceans and is used by marine organisms to make their shells. When these organisms die, their skeletons settle to the ocean floor and eventually become a rock layer containing the carbon dioxide. B. When carbon dioxide in the atmosphere combines with water, it creates calcium carbonate acid, which precipitates and chemically weathers the rocks on Earth. The result of this weathering is bicarbonate, which ultimately ends up in the oceans and is used by marine organisms to make their shells. When these organisms die, their skeletons settle to the ocean floor and eventually become a rock layer containing the carbon dioxide. C. When carbon dioxide in the atmosphere combines with water, it creates carbonic acid, which precipitates and chemically weathers the rocks on Earth. The result of this weathering is bicarbonate, which ultimately ends up in the oceans and is used by marine organisms to make their shells. When these organisms die, their skeletons settle to the ocean floor and eventually become a rock layer containing the carbon dioxide. D. When carbon dioxide in the atmosphere combines with water, it creates carbonic acid, which precipitates and chemically weathers the rocks on Earth. The result of this weathering is silica, which ultimately ends up in the oceans and is used by marine organisms to make their shells. When these organisms die, their skeletons settle to the ocean floor and eventually become a rock layer containing the carbon dioxide. E. When carbon dioxide in the atmosphere combines with water, it creates carbonic acid, which precipitates and mechanically weathers the rocks on Earth. The result of this weathering is bicarbonate, which ultimately ends up in the oceans and is used by marine organisms to make their shells. When these organisms die, their skeletons settle to the ocean floor and eventually become a rock layer containing the carbon dioxide.

C. When carbon dioxide in the atmosphere combines with water, it creates carbonic acid, which precipitates and chemically weathers the rocks on Earth. The result of this weathering is bicarbonate, which ultimately ends up in the oceans and is used by marine organisms to make their shells. When these organisms die, their skeletons settle to the ocean floor and eventually become a rock layer containing the carbon dioxide.

What is Chemical Weathering?

Changing the chemical composition of a rock. Changing the material to something else.

What is the smallest volcano?

Cinder cone

How is carbonic acid formed in nature? A. Iron oxidizes. B. Limestone dissolves in water, creating carbonic acid. C. Potassium feldspar is chemically weathered. D. Atmospheric carbon dioxide dissolves in raindrops. E. Pyrite decomposes.

D. Atmospheric carbon dioxide dissolves in raindrops.

Differentiate between the formation of biochemical rocks and the formation of inorganic chemical rocks. A. Biochemical rocks form only from organisms that were once alive that can be seen by the naked eye, such as shells in a coquina, whereas inorganic chemical sediments form from non-biological processes, such as salt that is left behind when a lake evaporates. B. Biochemical rocks form from things that used to be alive, such as oolitic limestone, whereas inorganic chemical rocks form strictly from non-biological processes, such as travertine in caves. C. Biochemical rocks form from the compression of organic matter, such as coal, whereas inorganic chemical rocks form from non-biological processes, such as dripstones that form in caves. D. Biochemical rocks form from organisms that were once alive, such as limestone from marine shells, whereas inorganic chemical rocks form from non-biological processes, such as salt that is left behind when a lake evaporates. E. Biochemical rocks form from organisms that were once alive, such as limestone from marine shells, whereas inorganic chemical rocks form strictly from non-biological processes, such as chalk.

D. Biochemical rocks form from organisms that were once alive, such as limestone from marine shells, whereas inorganic chemical rocks form from non-biological processes, such as salt that is left behind when a lake evaporates.

Which type of chemical weathering is very efficient at weathering limestone? A. Biological activity B. Exfoliation C. Root wedging D. Dissolution E. Oxidation

D. Dissolution

Which answer correctly distinguishes among limestone, dolostone, and chert? A. Limestone, which is composed of calcium-magnesium carbonate, forms by both chemical and biochemical means; dolostone, which is composed of calcium carbonate, forms strictly by chemical means; chert, which is composed of microcrystalline quartz, forms most often chemically and to a lesser extent biochemically. B. Limestone, which is composed of calcium carbonate, forms strictly by chemical means; dolostone, which is composed of calcium-magnesium carbonate, forms strictly by chemical means; chert, which is composed of microcrystalline quartz, forms most often chemically and to a lesser extent biochemically. C. Limestone, which is composed of microcrystalline quartz, forms by both chemical and biochemical means; dolostone, which is composed of calcium-magnesium carbonate, forms strictly by chemical means; chert, which is composed of calcium carbonate, forms most often chemically and to a lesser extent biochemically. D. Limestone, which is composed of calcium carbonate, forms by both chemical and biochemical means; dolostone, which is composed of calcium-magnesium carbonate, forms strictly by chemical means; chert, which is composed of microcrystalline quartz, forms most often chemically and to a lesser extent biochemically. E. Limestone is composed of calcium carbonate; dolostone is composed of calcium-magnesium carbonate; chert is composed of microcrystalline quartz. All three rock types are strictly inorganic chemical rocks.

D. Limestone, which is composed of calcium carbonate, forms by both chemical and biochemical means; dolostone, which is composed of calcium-magnesium carbonate, forms strictly by chemical means; chert, which is composed of microcrystalline quartz, forms most often chemically and to a lesser extent biochemically.

Which of the choices below lists the successive stages in coal formation from first step to last? A. anthracite coal formation, bituminous coal formation, lignite formation, peat formation, accumulation of plant remains B. accumulation of plant remains, peat formation, bituminous coal formation, anthracite coal formation, lignite formation C. accumulation of plant remains, peat formation, lignite formation, anthracite coal formation, bituminous coal formation D. accumulation of plant remains, peat formation, lignite formation, bituminous coal formation, anthracite coal formation E. accumulation of plant remains, lignite formation, peat formation, bituminous coal formation, anthracite coal formation

D. accumulation of plant remains, peat formation, lignite formation, bituminous coal formation, anthracite coal formation

Which of the choices below correctly describes three types of common cements in sedimentary rocks? A. calcite (which gives rocks a reddish color), silica (which produces the hardest sedimentary rocks), and iron (which effervesces in dilute acid) B. calcite (which produces the hardest sedimentary rocks), silica (which effervesces in dilute acid), and iron (which gives rocks a reddish color) C. silica (which produces the hardest sedimentary rocks), coal (which is high in carbon), and iron (which gives rocks a reddish color) D. calcite (which effervesces in dilute acid), silica (which produces the hardest sedimentary rocks), and iron (which gives rocks a reddish color) E. calcite (which effervesces in dilute acid), silica (which produces the hardest sedimentary rocks), and evaporites

D. calcite (which effervesces in dilute acid), silica (which produces the hardest sedimentary rocks), and iron (which gives rocks a reddish color)

Which sedimentary rock from the list below could resemble an igneous rock? A. breccia B. shale C. conglomerate D. chert E. sandstone

D. chert

The three basic sedimentary rock categories are A. detrital rocks, which are composed of solid particles; organic rocks, which are composed of ions that precipitated from solution; and chemical rocks, which form from the carbon-rich remains of organisms B. detrital rocks, which are composed of solid particles; chemical rocks, which are composed of ions that precipitated from solution; and carbonate rocks, which form from the carbon-rich remains of organisms C. chemical rocks, which are composed of solid particles; detrital rocks, which are composed of ions that precipitated from solution; and organic rocks, which form from the carbon-rich remains of organisms D. detrital rocks, which are composed of solid particles; chemical rocks, which are composed of ions that precipitated from solution; and organic rocks, which form from the carbon-rich remains of organisms E. weathered rocks, which are composed of solid particles; chemical rocks, which are composed of ions that precipitated from solution; and organic rocks, which form from the carbon-rich remains of organisms

D. detrital rocks, which are composed of solid particles; chemical rocks, which are composed of ions that precipitated from solution; and organic rocks, which form from the carbon-rich remains of organisms

Which of the following releases CO2 into the atmosphere? A. formation of limestone B. hydrolysis of granite C. formation of coal D. dissolution of limestone E. formation of sandstone

D. dissolution of limestone

Evaporites, such as _____. A. chert and halite, form when minerals that were previously dissolved in water are deposited as the water evaporate B. gypsum and halite, form when minerals that were previously dissolved in water precipitate on the substrate C. chert and travertine, form when minerals that were previously dissolved in water precipitates to the substrate D. gypsum and halite, form when minerals that were previously dissolved in water are deposited as the water evaporates E. chert and travertine, form when minerals that were previously dissolved in water are deposited as the water evaporates

D. gypsum and halite, form when minerals that were previously dissolved in water are deposited as the water evaporates

Which are two most common minerals in detrital rocks? A. quartz and sand B. feldspar and calcite C. quartz and calcite D. quartz and feldspar E. sand and mud

D. quartz and feldspar

Which choice lists events in soil erosion from first to last? A. raindrop impact, sheet erosion, gullies, rills, stream B. stream, gullies, rills, sheet erosion, raindrop impact C. raindrop impact, rills, gullies, stream, sheet erosion D. raindrop impact, sheet erosion, rills, gullies, stream E. rills, gullies, sheet erosion, raindrop impact, stream

D. raindrop impact, sheet erosion, rills, gullies, stream

How are conglomerate and breccia different? A. Conglomerate has angular grains; breccia has rounded grains. B. The grains within a conglomerate can range from pebble-sized or larger; the largest grains within a breccia are sand-sized. C. Conglomerate is poorly sorted; breccia is well sorted. D. Conglomerate is well sorted; breccia is poorly sorted. E. Conglomerate has rounded grains; breccia has angular grains.

E. Conglomerate has rounded grains; breccia has angular grains.

How do the products of the two categories of weathering differ from each other? A. Mechanical weathering results in smaller pieces of the original whole, whereas chemical weathering always results in the phase change if the original material (e.g., it turns a solid to liquid). B. Chemical weathering results in broken pieces that are of the same composition of the original material, whereas mechanical weathering alters the composition of the material. C. Mechanical weathering changes the size of the original material, whereas chemical weathering changes only the shape of the original material. D. Mechanical weathering always results in the phase change of the original material (e.g., it turns a solid to liquid), whereas chemical weathering alters the composition of the material. E. Mechanical weathering results in broken pieces that are of the same composition as the original material, whereas chemical weathering alters the composition of the material.

E. Mechanical weathering results in broken pieces that are of the same composition as the original material, whereas chemical weathering alters the composition of the material.

What region of the world has the greatest concentration of composite volcanoes? A. the volcanic field near Flagstaff, Arizona B. Italy C. Japan D. the Hawaiian Islands E. Ring of Fire

E. Ring of Fire

Which of the processes listed below would transform an exposure of granite in the mountains into sedimentary rocks? A. The granite would mechanically weather into small particles, which would be deposited, travel down the slope of the mountain via mass wasting, and undergo diagenesis when the sediments are buried under younger layers of rock. B. The granite would mechanically weather into small particles, which would travel down the slope of the mountain via mass wasting, be deposited, and undergo erosion when the sediments are buried under younger layers of rock. C. The granite would mechanically weather into small particles, which would travel down the slope of the mountain via mass wasting, be deposited, and undergo diagenesis when the sediments are buried under older layers of rock. D. The granite would chemically weather into small particles, which would travel down the slope of the mountain via mass wasting, be deposited, and undergo diagenesis when the sediments are buried under younger layers of rock. E. The granite would mechanically weather into small particles, which would travel down the slope of the mountain via mass wasting, be deposited, and undergo diagenesis when the sediments are buried under younger layers of rock.

E. The granite would mechanically weather into small particles, which would travel down the slope of the mountain via mass wasting, be deposited, and undergo diagenesis when the sediments are buried under younger layers of rock.

In the above picture, why have the headstone on the right and the headstone on the left weathered differently? A. The headstone on the left was constructed significantly later than the headstone on the right. B. The headstone on the left is made of granite, which is composed of calcite, whereas the headstone on the right is made of marble, which is composed of quartz and feldspar. C. The headstone on the right is located in a warmer place on Earth than the headstone on the left. D. The headstone on the right is located in a more humid place on Earth than the headstone on the left. E. The headstone on the left is made of granite, which is composed mostly of quartz and feldspar, whereas the headstone on the right is made of marble, which is composed of calcite.

E. The headstone on the left is made of granite, which is composed mostly of quartz and feldspar, whereas the headstone on the right is made of marble, which is composed of calcite.

Why is texture an important soil property? A. The texture of soil indicates which rocks its content of mineral material came from. B. The soil's texture indicates what types of nutrients it holds. C. The majority of soils in the world uniformly contain particles of the exact same size, so that many soils can be studied by studying one soil. D. Soil texture determines how well plants can grow in the soil based on the nutrients that it contains. E. The texture of soil strongly influences the soil's ability to transmit water and air.

E. The texture of soil strongly influences the soil's ability to transmit water and air.

What type of detrital sedimentary rock forms from sediment transported and deposited by energetic mountain streams? A. sandstone B. mudstone C. siltstone D. shale E. conglomerate

E. conglomerate

Aside from the loss of topsoil, what are two detrimental effects of soil erosion? A. the land cannot support livestock, and it is unusable as a park or recreation area B. the land cannot support livestock, and it cannot be built upon C. a lower quality of crops and fewer areas of land that can support homes or buildings D. fewer areas of land that can support homes or buildings and lower agricultural income E. lower agricultural productivity and a lower quality of crops

E. lower agricultural productivity and a lower quality of crops

What is a coarse-grained, light colored rock?

Granite

Why is the right hand side of Bowen's reaction series called a continuance? What is different?

It grows layers.

What is an intrusion that looks like a mushroom?

Laccolith

What is the most hazardous volcanic hazard?

Lahar

What are the major component of shield volcanoes?

Lava flows

What are the two main categories of weathering?

Mechanical and Chemical

Does a concordant/discordant intrusion mean horizontal or vertical?

No

What soil horizons form the "true soil"?

O and A

What are the stages in the formation of coal?

Plant material Peat and Lignite Bituminous coal

What is the major component of cinder cones?

Pyroclastic material

What are 3 categories of material extruded during an explosion?

Pyroclastic material Lava Gases

On Bowen's reaction series, what is the last mineral to crystallize?

Quartz

Which is the largest volcano?

Shield

What is the shape of a cinder cone?

Steep sides

What is another name of a composite volcano?

Stratovolcano

Where do you add water to generate magma?

Subduction Zones

Where is the second most common place for volcanic activity?

Subduction zones (Ring of Fire)

What is the shape of a stratovolcano (composite)?

Symmetrical cone

What is the shape of a shield volcano?

Very broad and dome shaped

Name major volcano hazards

Volcanic Ash Tsunamis induced by volcanoes Lahars Volcanic Gases

What do mud cracks and ripple marks indicate about the geologic past? A. Mud cracks indicate that the sediment was deposited in an area that was alternately wet and dry, whereas ripple marks indicate that the sediment was deposited by directional currents in water or air. B. Mud cracks show that water moved over them in the paths that are now marked by cracks in the rock, and ripple marks indicate that water moved perpendicular to their axes. C. Mud cracks and ripple marks both indicate that water over the sediment had a directional movement. D. Mud cracks indicate that water over the sediment had a directional movement, whereas ripple marks indicate that water over the sediment had no directional movement. E. Mud cracks indicate that the sediment was deposited in an area that was constantly wet, whereas ripple marks indicate that the sediment was deposited by water or air that was moving over the ground.

What do mud cracks and ripple marks indicate about the geologic past? A. Mud cracks indicate that the sediment was deposited in an area that was alternately wet and dry, whereas ripple marks indicate that the sediment was deposited by directional currents in water or air.

Which of the following can be a product of a composite volcano eruption? CHOOSE ALL THAT APPLY. A. ash B. andesitic lava C. gases D. cinders E. volcanic bombs

A. ash B. andesitic lava C. gases D. cinders E. volcanic bombs

How do the crystallization and settling of the earliest formed minerals affect the composition of the remaining magma? A. After the earliest formed minerals have settled, the resulting magma will be more felsic than the original magma. B. After the earliest formed minerals have settled, the resulting magma will be less felsic than the original magma. C. After the earliest formed minerals have settled, the resulting magma will become richer in iron and magnesium than the original magma. D. After the earliest formed minerals have settled, the resulting magma will be denser than the original magma.

A. After the earliest formed minerals have settled, the resulting magma will be more felsic than the original magma.

Why does partial melting result in a magma having a composition different from the rock from which it was derived? A. Because different minerals melt at different temperatures, minerals that melt at lower temperatures will melt from the rock first, creating a magma formed from the minerals that melted first. B. Because different minerals melt at different temperatures, minerals that melt at higher temperatures will melt from the rock first, creating a magma formed from the minerals that melted first. C. Because different minerals solidify at different temperatures, minerals that solidify at lower temperatures will be removed from the melt first, leaving behind only the minerals that solidify at higher temperatures. D. Because different minerals all melt at the same temperature, minerals that are closer to the Earth's surface will melt first, creating a magma composed of minerals that are closer to the Earth's surface. E. Because different minerals solidify at different temperatures, minerals that solidify at higher temperatures will be removed from the melt first, leaving behind only the minerals that solidify at lower temperature

A. Because different minerals melt at different temperatures, minerals that melt at lower temperatures will melt from the rock first, creating a magma formed from the minerals that melted first.

What is the difference between extrusive igneous rocks and intrusive igneous rocks? A. Extrusive igneous rocks cool and solidify on the Earth's surface, whereas intrusive igneous rocks cool and solidify beneath the Earth's surface. B. Extrusive igneous rocks cool and solidify beneath the Earth's surface, whereas intrusive igneous rocks cool and solidify on the Earth's surface. C. Intrusive igneous rocks can form volcanic island chains such as Hawaii, whereas extrusive igneous rocks cannot. D. Extrusive igneous rocks are made from the cooling of magma, whereas intrusive igneous rocks are made from the cooling of lava. E. Another name for extrusive igneous rocks is plutonic rocks, and another name for igneous intrusive rocks is volcanic rocks.

A. Extrusive igneous rocks cool and solidify on the Earth's surface, whereas intrusive igneous rocks cool and solidify beneath the Earth's surface.

How is magma generated along convergent plate boundaries? A. The subducting slab drives water and carbon dioxide into the mantle, which reduces the temperature at which it melts, allowing mantle rock to melt and rise. B. The subducting slab pushes mantle rock upwards, where it reaches the surface through the trench. C. The subducting slab pushes mantle rock upwards, which decompresses as it rises. This decompression allows the mantle rock to melt. D. Friction from the subducting slab raises the temperature of the rock under which it subducts, melting this rock into magma. E. The collision of two continental slabs create enough heat to melt rock, thus producing magma.

A. The subducting slab drives water and carbon dioxide into the mantle, which reduces the temperature at which it melts, allowing mantle rock to melt and rise.

How did Crater Lake form, and how does it compare to the calderas of shield volcanoes? A. The summit of the composite volcano collapsed after an explosive eruption of silica-rich pumice and ash fragments; rainwater later filled this caldera. Had this volcano been a shield volcano, the collapse would have been a result of a gradual subterranean drainage of a central magma chamber. B. The summit of the composite volcano collapsed after an explosive eruption of silica-rich pumice and ash fragments; rainwater later filled this caldera. Had this volcano been a shield volcano, a large area would have collapsed as a result of the discharge of colossal volumes of silica-rich pumice and ash along ring fractures. C. A large area at the summit of the composite volcano collapsed as a result of the discharge of colossal volumes of silica-rich pumice and ash along ring fractures; rainwater later filled this caldera. Had this volcano been a shield volcano, the collapse would have been a result of a gradual subterranean drainage of a central magma chamber. D. The summit of the composite volcano collapsed as a result of a gradual subterranean drainage of a central magma chamber; rainwater later filled this caldera. Had this volcano been a shield volcano, a large area would have collapsed as a result of the discharge of colossal volumes of silica-rich pumice and ash along ring fractures. E. The summit of the composite volcano collapsed as a result of a gradual subterranean drainage of a central magma chamber; rainwater later filled this caldera. Had this volcano been a shield volcano, the collapse would have been a result of the collapse of the summit after an explosive eruption of silica-rich pumice and ash fragments.

A. The summit of the composite volcano collapsed after an explosive eruption of silica-rich pumice and ash fragments; rainwater later filled this caldera. Had this volcano been a shield volcano, the collapse would have been a result of a gradual subterranean drainage of a central magma chamber.

How do volcanic bombs differ from blocks of pyroclastic debris? A. Volcanic blocks are made of hardened lava, whereas volcanic bombs are made of incandescent lava. B. Volcanic blocks are greater than 64 mm long, whereas volcanic bombs range from 2 mm to 64 mm. C. Volcanic blocks are semi-molten, whereas volcanic bombs are completely solid. D. Volcanic blocks are made of incandescent lava, whereas volcanic bombs are made of hardened lava. E. Volcanic blocks are more streamlined than volcanic bombs.

A. Volcanic blocks are made of hardened lava, whereas volcanic bombs are made of incandescent lava.

How can water cause mechanical weathering? A. When water within fractures in a rock freezes, it expands, which applies pressure to the portions of rock immediately around it. This pressure breaks off pieces of the rock. B. Water in the fracture of a rock can dissolve and carry away the weaker minerals along the surfaces of the fracture. C. When water in a fracture of a rock evaporates, the water vapor expands against the walls of the fracture, breaking pieces off the rock. D. When water in a fracture of a rock freezes, it contracts, so that the rock around the fracture breaks when another force hits it. E. Water washes sediment off of rocks by a single grain at a time.

A. When water within fractures in a rock freezes, it expands, which applies pressure to the portions of rock immediately around it. This pressure breaks off pieces of the rock.

In addition to composite volcanoes, what other type of volcanic landform can generate pyroclastic flow? A. a lava dome B. a fumarole C. a fissure D. a parasitic cone E. a volcanic pipe

A. a lava dome

Which of the following would decrease the viscosity of magma? A. an increase in temperature B. a decrease in dissolved gases C. a decrease in water content D. an increase in silica content E. a decrease in the slope of the volcanic flank

A. an increase in temperature

What are the six major igneous rock textures? A. aphanitic, phaneritic, porphyritic, vesicular, glassy, and pyroclastic B. glassy, vesicular, aphanitic, crystalline, porphyritic, and pyroclastic C. aphanitic, porphyritic, vesicular, glassy, welded tuff, phaneritic, and vesicular D. phaneritic, phenocryst, vesicular, pyroclastic, aphanitic, and glassy E. obsidian, phaneritic, pyroclastic, aphanitic, and vesicular

A. aphanitic, phaneritic, porphyritic, vesicular, glassy, and pyroclastic

Which type of rock is most likely to form a ridge due to differential weathering? A. basalt B. gabbro C. granite D. peridotite E. marble

C. granite

In which two plate tectonic settings would one expect magma to be generated? A. at a mid-oceanic ridge and at an oceanic-continental convergent boundary B. at a transform boundary and at an oceanic-continental convergent boundary C. at a transform boundary and at a continental rift. D. at a transform boundary and at a continental-continental convergent boundary E. at a divergent boundary and at a transform boundary

A. at a mid-oceanic ridge and at an oceanic-continental convergent boundary

What three factors do volcanologists monitor in order to determine whether magma is migrating toward the Earth's surface? A. changes in the patterns of earthquakes caused by the movement of magma, inflation of the volcano, and the gases released from the volcano B. atmospheric temperature near the volcano, the total volume of lava ejected during every eruption, and changes in the depth of the magma itself C. the total volume of lava ejected during every eruption, changes in the patterns of earthquakes caused by the movement of magma, and the gases released from the volcano D. inflation of the volcano, atmospheric temperature near the volcano, and the gases released from the volcano E. changes in the patterns of earthquakes caused by the movement of magma, inflation of the volcano, and changes in the depth of the magma itself

A. changes in the patterns of earthquakes caused by the movement of magma, inflation of the volcano, and the gases released from the volcano

When contrasting lava from composite volcanoes to lava from shield volcanoes, A. composite volcanoes most often produce silica-rich lavas with high viscosities, whereas shield volcanoes produce basaltic lavas with low viscosities. B. composite volcanoes most often produce basaltic lavas with high viscosities, whereas shield volcanoes produce silica-rich lavas with low viscosities. C. composite volcanoes most often produce silica-rich lavas with low viscosities, whereas shield volcanoes produce basaltic lavas with high viscosities. D. composite volcanoes most often produce basaltic lavas with low viscosities, whereas shield volcanoes produce silica-rich lavas with high viscosities. E. both types of volcano produce silica-rich lavas, but the lavas of composite cones have low viscosities, whereas the lavas of shield volcanoes have high viscosities.

A. composite volcanoes most often produce silica-rich lavas with high viscosities, whereas shield volcanoes produce basaltic lavas with low viscosities.

Most magma on Earth is produced at ___ plate boundaries. A. divergent B. oceanic-oceanic convergent C. transform D. continental-oceanic convergent E. continental-continental convergent

A. divergent

Where do most shield volcanoes form? A. on the ocean floor B. at oceanic-oceanic divergent plate boundaries C. at continent-continent convergent boundaries D. in the middle of continents and at continent-continent convergent boundaries E. in the middle of continents

A. on the ocean floor

Which of the following is a characteristic of an igneous rock found in a batholith? A. phaneritic texture B. pyroclastic texture C. ultramafic composition D. glassy texture E. mafic composition

A. phaneritic texture

Which of these minerals would be the first to crystallize in a body of magma? A. pyroxene B. sodium-rich plagioclase C. quartz D. muscovite mica E. potassium feldspar

A. pyroxene

To what does the term "country rock" refer? A. the crustal rocks into which igneous bodies intrude B. the igneous bodies that intrude plutons C. the mantle rocks into which igneous bodies intrude D. the igneous bodies that intrude mantle rocks E. the igneous bodies that intrude crustal rocks

A. the crustal rocks into which igneous bodies intrude

What is the process that is thought to generate most granitic magmas? A. Rising basaltic magmas assimilate crustal rocks that tend to be silica-rich. B. A basaltic pond of magma becomes trapped below continental crust and partially melts this silica-rich crust into a granitic magma. C. A basaltic magma undergoes magmatic differentiation as it slowly moves through the continental crust. D. Peridotite partially melts to form granitic magma. E. Basaltic rocks partially melt to form granitic magma.

B. A basaltic pond of magma becomes trapped below continental crust and partially melts this silica-rich crust into a granitic magma.

Which of the following indicates that a volcanic eruption could be imminent? A. An increase in atmospheric temperature B. A change in the composition of gasses being released C. A decrease in surface temperatures D. A newly-formed depression in the volcano E. A decrease in seismic activity

B. A change in the composition of gasses being released

Fill in the blanks in this sentence using the terms below: Granite and rhyolite are both ____, but they differ in ____. A. crystal size; silica content B. felsic; crystal size C. phaneritic; composition D. intermediate; texture E. aphanitic; composition

B. felsic; crystal size

Distinguish among a conduit, a vent, and a crater. A. A vent is the circular path through which magma ascends to the crater, which is the surface opening of the vent. A conduit is a funnel-shaped depression around the crater. B. A conduit is the circular path through which magma ascends to the vent, which is the surface opening of the conduit. A crater is a funnel-shaped depression around the vent. C. A vent is the circular path through which magma ascends to the conduit, which is the surface opening of the vent. A crater is a funnel-shaped depression around the conduit. D. A conduit is the circular path through which magma ascends to the crater, which is the surface opening of the conduit. A vent is a funnel-shaped depression around the crater. E. A crater is the circular path through which magma ascends to the vent, which is the surface opening of the crater. A conduit is a funnel-shaped depression around the vent.

B. A conduit is the circular path through which magma ascends to the vent, which is the surface opening of the conduit. A crater is a funnel-shaped depression around the vent.

How do craters differ from calderas? A. Calderas only form as results of the summits of volcanoes collapsing, whereas craters only form as the results of explosive eruptions. B. Calderas, which have diameters of 1 km or more, are much larger than craters. C. Calderas are much smaller than craters, which have diameters of 1 km or more. D. Calderas are always composed of felsic material, whereas craters are always composed of mafic material. E. Calderas are always composed of mafic material, whereas craters are always composed of felsic material.

B. Calderas, which have diameters of 1 km or more, are much larger than craters.

Which statement describes the composition and viscosity of the lava associated with shield volcanoes? A. Lava from shield volcanoes is intermediate and has a very low viscosity. B. Lava from shield volcanoes is mafic and has a low viscosity. C. Lava from shield volcanoes is mafic and has a high viscosity. D. Lava from shield volcanoes is felsic and has a high viscosity. E. Lava from shield volcanoes is felsic and has a low viscosity.

B. Lava from shield volcanoes is mafic and has a low viscosity.

How does magma differ from lava? A. Magma does not cool to form igneous rocks, although lava cools to form igneous rocks. B. Magma exists strictly below Earth's surface, whereas lava is found on Earth's surface. C. Magma is found only on Earth's surface, whereas lava is found strictly below Earth's surface. D. Magma is the material that erupts from volcanoes, and lava is the material that flows along the ground. E. Magma ultimately cools to form igneous rocks, whereas lava does not.

B. Magma exists strictly below Earth's surface, whereas lava is found on Earth's surface.

Which component of magma includes mobile ions of silicon? A. Pegmatites B. Melt C. Water vapor D. Silicate mineral crystals E. Carbon dioxide

B. Melt

Contrast pahoehoe and aa lava flows. A. Aa flows exhibit smooth surfaces, are hotter, and are more fluid than pahoehoe flows, which exhibit jagged surfaces with sharp edges. B. Pahoehoe flows exhibit smooth surfaces, are hotter, and are more fluid than aa flows, which exhibit jagged surfaces with sharp edges. C. Pahoehoe flows exhibit jagged surfaces with sharp edges, are hotter, and are more fluid than aa flows, which smooth surfaces. D. Pahoehoe flows exhibit smooth surfaces, are cooler, and are less fluid than aa flows, which exhibit jagged surfaces with sharp edges. E. Pahoehoe flows exhibit smooth surfaces, are hotter, and are less fluid than aa flows, which exhibit jagged surfaces with sharp edges.

B. Pahoehoe flows exhibit smooth surfaces, are hotter, and are more fluid than aa flows, which exhibit jagged surfaces with sharp edges.

Which statement accurately describes a pyroclastic flow? A. Pyroclastic flows, which consist of basaltic lava infused with incandescent ash and lava fragments, can reach many miles away from their sources because they are nearly frictionless and are driven by gravity. B. Pyroclastic flows, which consist of basaltic lava infused with incandescent ash and lava fragments, can reach many miles away from their sources because they are nearly frictionless and are driven by gravity. C. Pyroclastic flows, which consist of felsic lava infused with incandescent ash and lava fragments, can reach many miles away from their sources because they are nearly frictionless and are driven by gravity. D. Pyroclastic flows, which consist of hot water infused with incandescent ash and lava fragments, can reach many miles away from their sources because they are nearly frictionless and are driven by gravity.

B. Pyroclastic flows, which consist of basaltic lava infused with incandescent ash and lava fragments, can reach many miles away from their sources because they are nearly frictionless and are driven by gravity.

The texture of an igneous rock describes: A. the appearance of a rock based on which minerals it contains. B. the appearance of a rock based on the size(s), shape(s), and arrangement on the mineral grains it contains. C. whether an igneous rock will exhibit cleavage or fracture. D. how a rock feels to the touch. E. the appearance of a rock based on how old it is.

B. The appearance of a rock based on the size(s), shape(s), and arrangement on the mineral grains it contains.

How does the composition of a typical lava dome differ from that of a typical fissure eruption? A. a lava dome's flow is basaltic and has a low viscosity, whereas a fissure eruption is silica-rich and has a high viscosity. B. a lava dome's flow is silica-rich and has a high viscosity, whereas a fissure eruption is basaltic and has a low viscosity. C. a lava dome's flow is silica-rich and has a low viscosity, whereas a fissure eruption is basaltic and has a high viscosity. D. a lava dome's flow is basaltic and has a high viscosity, whereas a fissure eruption is silica-rich and has a low viscosity. E. a lava dome's flow is silica-rich and has a high viscosity, whereas a fissure eruption is primarily made of pyroclastic materials.

B. a lava dome's flow is silica-rich and has a high viscosity, whereas a fissure eruption is basaltic and has a low viscosity.

Composite volcanoes generally consist of what materials? A. alternating layers of cinders and ash interbedded with basaltic lava flows B. alternating layers of cinders and ash interbedded with andesitic lava flows C. cinders and ash interbedded with andesitic lava flows D. cinders and ash mixed in basaltic lava flows E. alternating layers of felsic pyroclastic material interbedded with felsic lava flows

B. alternating layers of cinders and ash interbedded with andesitic lava flows

How can a magma body change its composition? CHOOSE ALL THAT APPLY. A. batholith emplacement B. crystal settling C. assimilation D. magma mixing E. magmatic differentiation

B. crystal settling C. assimilation D. magma mixing E. magmatic differentiation

Which of the choices below lists the four basic compositional groups of igneous rocks, ranging from the highest silica content to the lowest silica content? A. intermediate, mafic, ultramafic, felsic B. granitic, andesitic, basaltic, ultramafic C. ultramafic, basaltic, andesitic, granitic D. ultramafic, mafic, intermediate, felsic E. basaltic, granitic, andesitic, ultramafic

B. granitic, andesitic, basaltic, ultramafic

_____ is/are common in the final stages of growth of a typical shield volcano. A. low viscosity (basaltic) lava B. high viscosity (rhyolitic) lava C. lava tubes D. pillow lava E. pahoehoe lava

B. high viscosity (rhyolitic) lava

Which volcanic landform listed below is primarily composed of loose fragments of scoria? A. the Yellowstone caldera B. the Parícutin cinder cone C. the Deccan Traps flood basalts D. the Mauna Loa shield volcano E. the Fujiyama composite volcano

B. the Parícutin cinder cone

At a subduction zone, melting is triggered by _____. A. the presence of volcanism B. the introduction of water C. a decrease in pressure D. heating the crustal rocks E. stretching the continental crust

B. the introduction of water

Which of the following is a feature of an aa flow? A. Aa flows can develop lava tubes. B. Aa flows can produce pillow lavas. C. Aa flows have sharp, jagged edges. D. Aa flows can change into pahoehoe lava. E. Aa flows have low viscosity.

C. Aa flows have sharp, jagged edges.

Which of the following statements accurately describes the composition of a cinder cone? A. Cinder cones are composed of generally basaltic fluid magma. B. Cinder cones are composed of generally felsic liquid magma C. Cinder cones are composed of generally basaltic pyroclastic material and scoria. D. Cinder cones are composed of generally felsic pyroclastic material and scoria. E. Cinder cones are composed of generally felsic pyroclastic material and pumice.

C. Cinder cones are composed of generally basaltic pyroclastic material and scoria.

All types of volcanic cones share which feature? A. Pahoehoe lava B. Caldera C. Conduit D. Broad, gentle slopes E. Lava tubes

C. Conduit

How do the eruptions that created the Columbia Plateau differ from eruptions that create large composite volcanoes? A. Eruptions that created the Columbia Plateau ejected highly viscous magma from fissures, whereas eruptions that create large composite volcanoes eject magma that is low in viscosity from vents. B. Eruptions that created the Columbia Plateau ejected basaltic magma from volcanic vents, whereas eruptions that create large composite volcanoes eject silica-rich magma from fissures. C. Eruptions that created the Columbia Plateau ejected basaltic magma from fissures; eruptions that create large composite volcanoes eject silica-rich magma from vents. D. Eruptions that created the Columbia Plateau ejected silica-rich magma from fissures, whereas eruptions that create large composite volcanoes eject basaltic magma from vents. E. Eruptions that created the Columbia Plateau ejected silica-rich magma from volcanic vents, whereas eruptions that create large composite volcanoes eject basaltic magma from fissures.

C. Eruptions that created the Columbia Plateau ejected basaltic magma from fissures; eruptions that create large composite volcanoes eject silica-rich magma from vents.

Which of the following is the location of a currently active shield volcano? A. Mauna Kea in Hawaii B. Kohala in Hawaii C. Mauna Loa in Hawaii D. Mt. Rainier in Washington E. Sunset Crater in Arizona

C. Mauna Loa in Hawaii

What occurs when carbonic acid reacts with calcite-rich rocks such as limestone? A. The limestone oxidizes into rust. B. What happens to the dissolved limestone if the water is moving? C. The limestone is dissolved and carried away by underground water. D. The limestone dissolves, but is redeposited when the water that it dissolved into evaporates. E. Clay is created, most often as the mineral kaolinite.

C. The limestone is dissolved and carried away by underground water.

Are pyroclastic materials a significant component of shield volcanoes? A. No; pyroclastic materials are never ejected from shield volcanoes. B. No; during the final stage of shield volcano formation, eruptions become less sporadic, resulting in fewer pyroclastic materials being ejected. C. Yes; pyroclastic materials are more commonly ejected during the final stage of growth of a shield volcano, when eruptions become more sporadic. D. Yes; pyroclastic materials are more commonly ejected during the final stage of growth of a shield volcano, when eruptions become less sporadic. E. Yes; pyroclastic materials are more commonly ejected during the first stage of growth of shield volcanoes, thus forming a foundation for the volcano.

C. Yes; pyroclastic materials are more commonly ejected during the final stage of growth of a shield volcano, when eruptions become more sporadic.

How are basaltic magmas thought to be formed? A. from the partial melting of the intermediate rock andesite B. from the partial melting of the ultramafic rock gabbro C. from the partial melting of the ultramafic rock peridotite D. from the partial melting of the mafic rock gabbro E. from the partial melting of the felsic rock granite

C. from the partial melting of the ultramafic rock peridotite

The volcanoes in the Ring of Fire are generally described as A. having violent eruptions, as most of these volcanoes are composite cones which eject basaltic lava. B. having quiescent eruptions, as most of these volcanoes are composite cones which eject andesitic lava. C. having violent eruptions, as most of these volcanoes are composite cones which eject andesitic lava. D. having quiescent eruptions, as most of these volcanoes are shield volcanoes which eject basaltic lava. E. having violent eruptions, as most of these volcanoes are shield volcanoes which eject basaltic lava.

C. having violent eruptions, as most of these volcanoes are composite cones which eject andesitic lava.

The most abundant minerals found in granitic (felsic) igneous rocks include ______. CHOOSE ALL THAT APPLY. A. amphibole B. pyroxene C. quartz D. olivine E. potassium feldspar

C. quartz E. potassium feldspar

What is Bowen's reaction series? A. the order in which specific minerals melt within magma, from hottest to coolest B. the order in which specific minerals cool and form within melted magma, from coolest to hottest C. the order in which specific minerals cool and form within melted magma, from hottest to coolest D. the order in which specific rocks cool and form within melted magma, from hottest to coolest E. the order in which specific minerals melt within magma, from coolest to hottest

C. the order in which specific minerals cool and form within melted magma, from hottest to coolest

What factors influences the texture of an igneous rock? A. the amount of silica that is present in the magma from which it forms and the amount of dissolved gases present in said magma B. the age of the rock, the rate at which the rock cools, and the amount of silica that is present in the magma from which it forms C. the rate at which the rock cools, the amount of silica that is present in the magma from which it forms, and the amount of dissolved gases present in said magma D. the rate at which the rock cools and the amount of dissolved gases present in the magma E. the rate at which the rock becomes hotter, the amount of silica that is present in the magma from which it forms, and the amount of dissolved gases present in said magma

C. the rate at which the rock cools, the amount of silica that is present in the magma from which it forms, and the amount of dissolved gases present in said magma

Which of the below choices lists three volcanic hazards other than pyroclastic flows and lahars? A. volcanic gases' effects on respiration, nue´e ardentes, and volcanically generated tsunamis B. a mudflow formed by volcanic debris mixing with water, volcanically generated tsunamis, and atmospheric cooling C. volcanically generated tsunamis, atmospheric cooling from ejected ash, and sulfur dioxide ruining vegetation via the groundwater D. atmospheric warming from ejected ash, volcanically generated tsunamis, and sulfur dioxide ruining vegetation via the groundwater E. unsafe flying conditions due to ejected ash, volcanically generated tsunamis, and hydrogen dioxide ruining vegetation via the groundwater

C. volcanically generated tsunamis, atmospheric cooling from ejected ash, and sulfur dioxide ruining vegetation via the groundwater

Which of the following statements correctly describes a parasitic cone? A. A parasitic cone is a small cone within the caldera of a volcano that has formed during repeated conduit eruptions. B. A parasitic cone is a small cone on the side or base of a volcano that has formed as a result of the ejection of pyroclastic materials. C. A parasitic cone is a small cone on the side or base of a volcano; this cone's fissure only emits gases. D. A parasitic cone is a small cone on the side or base of a volcano that has formed during repeated flank eruptions. E. A parasitic cone is a small cone within the crater of a volcano that has formed during repeated conduit eruptions.

D. A parasitic cone is a small cone on the side or base of a volcano that has formed during repeated flank eruptions.

How do batholiths, stocks, and laccoliths differ? A. Batholiths are the largest type of igneous bodies and occur in a linear fashion with a distance of 100km or more; laccoliths are smaller than batholiths; stocks bend the sedimentary layers above them, whereas the sedimentary layers below remain relatively undeformed. B. Stocks are the largest type of igneous bodies and occur in a linear fashion with a distance of 100km or more; batholiths are smaller than stocks; laccoliths bend the sedimentary layers above them, whereas the sedimentary layers below remain relatively undeformed. C. Laccoliths are the largest type of igneous bodies and occur in a linear fashion with a distance of 100km or more; batholiths are smaller than laccoliths; stocks bend the sedimentary layers above them, whereas the sedimentary layers below remain relatively undeformed. D. Batholiths are the largest type of igneous bodies and occur in a linear fashion with a distance of 100km or more; stocks are smaller than batholiths; laccoliths bend the sedimentary layers above them, whereas the sedimentary layers below remain relatively undeformed. E. Stocks are the largest type of igneous bodies and occur in a linear fashion with a distance of 100km or more; laccoliths are smaller than stocks; batholiths bend the sedimentary layers above them, whereas the sedimentary layers below remain relatively undeformed.

D. Batholiths are the largest type of igneous bodies and occur in a linear fashion with a distance of 100km or more; stocks are smaller than batholiths; laccoliths bend the sedimentary layers above them, whereas the sedimentary layers below remain relatively undeformed.

Why is soil considered an interface within the Earth system? A. Soil forms the boundary between the land on Earth and the atmosphere. B. Soil forms the boundary between the land and the plants, animals, and other organisms that live on land. C. Changes in soil cause changes in the plants that live in it. D. Changes in the climate in the atmosphere create changes in soil texture and composition. Water from the hydrosphere that is added to soil from various sources allows the soil to be able to sustain plant life, which returns to the geosphere once it expires. E. Because soil receives water from various sources, it is capable of sustaining plant life.

D. Changes in the climate in the atmosphere create changes in soil texture and composition. Water from the hydrosphere that is added to soil from various sources allows the soil to be able to sustain plant life, which returns to the geosphere once it expires.

How do light-colored igneous rocks differ from dark-colored rocks? A. Light-colored rocks are called mafic, whereas dark-colored rocks are called felsic. B. Light-colored igneous rocks begin melting at a much higher temperature than dark-colored rocks. C. Light-colored igneous rocks have a higher iron and magnesium content than dark-colored rocks. D. Dark-colored igneous rocks have a higher iron and magnesium content than light-colored rocks. E. Dark-colored igneous rocks have a higher silica content than light-colored rocks.

D. Dark-colored igneous rocks have a higher iron and magnesium content than light-colored rocks.

Which of the following choices classifies the three listed rocks by composition and texture? A. Diorite is intermediate with an aphanitic texture; rhyolite is felsic with a phaneritic texture; basalt porphyry is mafic with a porphyritic texture. B. Diorite is felsic with a phaneritic texture; rhyolite is felsic with an aphanitic texture; basalt porphyry is mafic with a porphyritic texture. C. Diorite is intermediate with a phaneritic texture; rhyolite is felsic with an aphanitic texture; basalt porphyry is felsic with an aphanitic texture. D. Diorite is intermediate with a phaneritic texture; rhyolite is felsic with an aphanitic texture; basalt porphyry is mafic with a porphyritic texture. E. Diorite is intermediate with a phaneritic texture; rhyolite is mafic with an aphanitic texture; basalt porphyry is felsic with a porphyritic texture.

D. Diorite is intermediate with a phaneritic texture; rhyolite is felsic with an aphanitic texture; basalt porphyry is mafic with a porphyritic texture.

How do crystals in pegmatite grow so large? A. Large crystals in pegmatites are the result of a high percentage of the melt being composed of water, carbon dioxide, and other materials. These materials enhance ion migration, allowing the crystals to cool more quickly than usual. B. Large crystals in pegmatites are the result of a low percentage of the melt being composed of water, carbon dioxide, and other materials. These materials enhance ion migration, allowing the crystals to grow larger than usual. C. Large crystals in pegmatites are the result of a high percentage of the melt being composed of water, carbon dioxide, and other materials. These materials impede ion migration, allowing the crystals to grow larger than usual. D. Large crystals in pegmatites are the result of a high percentage of the melt being composed of water, carbon dioxide, and other materials. These materials enhance ion migration, allowing the crystals to grow larger than usual. E. Large crystals in pegmatites are the result of a high percentage of the melt being composed of already formed crystals, which ultimately aggregate into a single large crystal.

D. Large crystals in pegmatites are the result of a high percentage of the melt being composed of water, carbon dioxide, and other materials. These materials enhance ion migration, allowing the crystals to grow larger than usual.

What is scoria, and how does it differ from pumice? A. Scoria is an ejecta that is a smaller particle size than pumice. B. Scoria is a vesicular ejecta that is produced from felsic magma. Although pumice is also vesicular, it differs from scoria in that pumice is mafic. C. Scoria is a vesicular ejecta with a low iron content. Although pumice is also a vesicular ejecta, it has a high iron content. D. Scoria is a vesicular ejecta that is produced from mafic magma. Although pumice is also vesicular, it differs from scoria in that pumice is felsic. E. Scoria is an ejecta that is a larger particle size than pumice.

D. Scoria is a vesicular ejecta that is produced from mafic magma. Although pumice is also vesicular, it differs from scoria in that pumice is felsic.

What role do water and other volatiles play in the formation of magma? A. The addition of water and other volatiles to rock allows the rock to melt at lower pressures than if the volatiles had not been added. B. The addition of water and other volatiles to rock allows the rock to melt at higher temperatures than if the volatiles had not been added. C. The addition of water and other volatiles to rock allows the rock to melt at higher pressures than if the volatiles had not been added. D. The addition of water and other volatiles to rock allows the rock to melt at lower temperatures than if they had not been added. E. The addition of water and other volatiles to rock allows the rock to melt at a quicker rate than if the volatiles had not been added.

D. The addition of water and other volatiles to rock allows the rock to melt at lower temperatures than if they had not been added.

What does a porphyritic texture indicate about the cooling history of an igneous rock? A. The rock began cooling on the Earth's surface, but then was buried under the Earth's surface where it finished cooling. B. The rock cooled entirely underground, first forming the phenocrysts and then forming the groundmass out of different minerals. C. The rock cooled entirely on the Earth's surface in a region that regularly varied between high and low temperatures. D. The rock began cooling under the Earth's surface, but then was moved to above the Earth's surface where it finished cooling. E. The rock first began cooling under the Earth's surface, which formed the groundmass. It finished by solidifying the phenocrysts on the Earth's surface.

D. The rock began cooling under the Earth's surface, but then was moved to above the Earth's surface where it finished cooling.

What type of structure is Shiprock, New Mexico, and how did it form? A. Shiprock, New Mexico is the best known volcanic pipe in the world, as it is filled with diamond-bearing kimberlite. B. Shiprock, New Mexico is a lava dome that formed in the Crater of Mount St. Helens after an explosive eruption of silica-rich lava. C. Shiprock, New Mexico is a basaltic plateau that formed by the eruption of lava from fissures in the Deccan Traps. D. Shiprock, New Mexico is the rim of the Kilauea caldera. It formed as a result of the gradual drainage of a subterranean magma chamber. E. Shiprock, New Mexico is a volcanic neck that formed when the volcano itself eroded away, leaving the crystallized igneous rock piercing through the Mancos shale.

E. Shiprock, New Mexico is a volcanic neck that formed when the volcano itself eroded away, leaving the crystallized igneous rock piercing through the Mancos shale.

How does decompression melting occur? A. When hot, solid mantle rock ascends, it moves to areas of higher pressure. This increase in pressure allows the hot material to melt into a less compressed liquid phase. B. When hot, liquid mantle rock ascends, it moves to areas of lower pressure. This reduction in pressure allows the hot material to melt into a less viscous liquid phase. C. When hot, liquid mantle rock descends, it moves to areas of higher pressure. This increase in pressure allows the hot material to melt into a solid phase. D. When hot, solid mantle rock ascends, it moves to areas of lower pressure. This reduction in pressure allows the hot material to melt into a less compressed liquid phase. E. When hot, solid mantle rock descends, it moves to areas of lower pressure. This reduction in pressure allows the hot material to melt into a less compressed liquid phase.

D. When hot, solid mantle rock ascends, it moves to areas of lower pressure. This reduction in pressure allows the hot material to melt into a less compressed liquid phase.

How are igneous rocks classified? A. by their compositions and where they cooled B. by their ages and textures C. by the size of the overall rocks and their compositions D. by their textures and compositions E. by their textures and how they formed

D. by their textures and compositions

Comparing cinder cones to shield volcanoes, A. cinder cones have steeper flanks than shield volcanoes, but cinder cones occupy the same area of land as shield volcanoes. B. cinder cones have less steep flanks than shield volcanoes, and cinder cones occupy a smaller area of land than shield volcanoes. C. cinder cones have steeper flanks than shield volcanoes, and cinder cones occupy a larger area of land than shield volcanoes. D. cinder cones have steeper flanks than shield volcanoes, and cinder cones occupy a smaller area of land than shield volcanoes. E. cinder cones have less steep flanks than shield volcanoes, and cinder cones occupy a larger area of land than shield volcanoes.

D. cinder cones have steeper flanks than shield volcanoes, and cinder cones occupy a smaller area of land than shield volcanoes.

What is a way to limit soil erosion? A. remove trees and shrubs in windy areas B. plant crops in large masses on gentle slopes C. remove vegetation in dry areas D. create grassy waterways E. plant crops on steep slopes

D. create grassy waterways

What does a fumarole emit? A. fluid magma only B. gases and fluid magma C. fluid magma and pyroclastic material D. gases only E. pyroclastic material only

D. gases only

What is the source of magma for most intraplate volcanism? A. oceanic plateaus B. felsic pyroclastic material in a continental setting C. mid-ocean ridges D. mantle plumes E. fissures

D. mantle plumes

Which of the below is not weathering by biological activity? A. plant roots growing into rock fractures B. the destruction of rocks by humans for road construction C. animals moving fresh material to the surface D. salt crystal growth within rock fractures E. chemicals released from decaying animals

D. salt crystal growth within rock fractures

What results when carbonic acid reacts with potassium feldspar? A. quartz grains and silica B. calcium and bicarbonate C. evaporites D. the salt potassium bicarbonate and the mineral kaolinite E. limonite and silica

D. the salt potassium bicarbonate and the mineral kaolinite

Which type of volcanic hazard can decrease global temperatures? A. lava flow B. tsunami C. lahar D. volcanic ash E. pyroclastic flow

D. volcanic ash

How does the viscosity of the magma fed to volcanoes affect nearby life and property? A. A volcano that expels magma that is low in viscosity is a greater threat to life and property because bubbles of hot gas build up in the magma as the magma travels towards the Earth's surface. B. A volcano that expels magma that is low in viscosity is a greater threat to life and property because it is more explosive, and thus is more difficult or impossible to predict. C. A volcano that expels a highly viscous magma is a greater threat to life and property because the lava flows farther, which damages a greater area around the volcano. D. A volcano that expels magma that is low in viscosity is a greater threat to life and property because the iron content is more harmful to the environment than silica would be. E. A volcano that expels highly viscous magma is a greater threat to life and property because it is more explosive and thus is more difficult or impossible to predict.

E. A volcano that expels highly viscous magma is a greater threat to life and property because it is more explosive and thus is more difficult or impossible to predict.

How might the direction that a slope is facing influence soil formation? A. Different directions of slopes tend to receive different amounts of precipitation; therefore, the direction of the slope that receives the most precipitation will form soil the most easily. B. The direction the slope faces determines how much wind will hit the soil over the course of a year, which partially accounts for soil erosion. C. The orientation of the slope directly affects the slope's steepness. Very steep slopes cannot form soils on their surfaces. D. Plants only tend to grow on a single direction of slope. E. The direction the slope faces determines how much solar radiation that its soil will receive, which determines the soil's temperature and moisture content.

E. The direction the slope faces determines how much solar radiation that its soil will receive, which determines the soil's temperature and moisture content.

Choose the statement that describes two processes that alter the composition of magma. A. Assimilation occurs when magma that is injected into bedrock becomes incorporated into the bedrock around it, whereas magma mixing occurs when two ascending bodies of magma join and mix together into a composition that is intermediate to the two original magmas. B. Magma mixing occurs when magma that is injected into bedrock melts the rock directly surrounding it, incorporating it into the magma, whereas assimilation occurs when two ascending bodies of magma join and mix together into a composition that is intermediate to the two original magmas. C. Assimilation occurs when magma that is injected into bedrock melts the rock directly surrounding it, incorporating it into the magma, whereas magma mixing occurs when an ascending body of magma melts an already cooled unit of igneous rock, mixing the rock's composition in with the hot magma. D. Assimilation occurs when magma that is injected into bedrock melts the rock directly surrounding it, incorporating it into the magma, whereas magma mixing occurs when two static bodies of magma join and mix together into a composition that is intermediate to the two original magmas. E. Assimilation occurs when magma that is injected into bedrock melts the rock directly surrounding it, incorporating it into the magma, whereas magma mixing occurs when two ascending bodies of magma join and mix together into a composition that is intermediate to the two original magmas.

E. Assimilation occurs when magma that is injected into bedrock melts the rock directly surrounding it, incorporating it into the magma, whereas magma mixing occurs when two ascending bodies of magma join and mix together into a composition that is intermediate to the two original magmas.

Over what time span do most typical cinder cones form? A. Cinder cones are generally the product of a few periodic eruptions over a period of thousands of years, becoming taller and steeper with each eruption. B. Cinder cones are generally the product of hundreds of eruptions over a period of millions of years, becoming taller and steeper with each eruption. C. Cinder cones are generally the product of several eruptions over a period of decades, becoming taller and steeper with each eruption. D. Cinder cones are generally the product of several eruptions over a period of hundreds of years, becoming taller and steeper with each eruption. E. Cinder cones are generally the product of a single eruption and thus are constructed in less than a year or less than a month.

E. Cinder cones are generally the product of a single eruption and thus are constructed in less than a year or less than a month.

Select the correct description of dikes and sills. A. Dikes are tabular, concordant igneous intrusions whereas sills are massive, discordant igneous intrusions. B. Dikes are tabular, discordant igneous intrusions whereas sills are massive, concordant igneous intrusions. C. Dikes are massive, discordant igneous intrusions whereas sills are tabular, concordant igneous intrusions. D. Dikes are concordant igneous intrusions whereas sills are discordant igneous intrusions; both are tabular. E. Dikes are discordant igneous intrusions; sills are concordant igneous intrusions; both are tabular.

E. Dikes are discordant igneous intrusions; sills are concordant igneous intrusions; both are tabular.

Which of the following statements about soil formation is accurate? A. The primary source of organic material in soils is from animals. B. Soil that has been weathered for a long time closely resembles the parent rock. C. Thick, dark soils are often found on steep slopes. D. Climate is the least influential control on soil formation. E. Dissimilar soils can develop from the same parent material.

E. Dissimilar soils can develop from the same parent material.

Which of the following choices correctly classifies the four listed igneous rocks by composition? A. Gabbro is intermediate; obsidian is felsic; granite is felsic; andesite is intermediate. B. Gabbro is mafic; obsidian is mafic; granite is felsic; andesite is intermediate. C. Gabbro is felsic; obsidian is felsic; granite is mafic; andesite is intermediate. D. Gabbro is mafic; obsidian is felsic; granite is felsic; andesite is ultramafic. E. Gabbro is mafic; obsidian is felsic; granite is felsic; andesite is intermediate.

E. Gabbro is mafic; obsidian is felsic; granite is felsic; andesite is intermediate.

How do lava tubes form? A. Aa flows develop cave-like tunnels that were previously used for carrying lava from an active vent to the flow's leading edge. B. Aa flows change into pahoehoe flows, which develop cave-like tunnels that were previously used for carrying lava from an active vent to the flow's leading edge. C. Pahoehoe flows change into aa flows, which develop cave-like tunnels that were previously used for carrying lava from an active vent to the flow's leading edge. D. A mix of aa flows and pahoehoe flows develop cave-like tunnels that were previously used for carrying lava from an active vent to the flow's leading edge. E. Pahoehoe flows develop cave-like tunnels that were previously used for carrying lava from an active vent to the flow's leading edge.

E. Pahoehoe flows develop cave-like tunnels that were previously used for carrying lava from an active vent to the flow's leading edge.

Fill in the blanks using the choices below: ____ are minerals typically found in igneous rocks that have a high silica content, whereas ____ are minerals that are typically found in igneous rocks with a low silica content. A. Pyroxene and olivine; plagioclase feldspar and quartz B. Pyroxene and amphibole; plagioclase feldspar and potassium feldspar C. Olivine and pyroxene; muscovite and quartz D. Amphibole and pyroxene; potassium feldspar and quartz E. Plagioclase feldspar and quartz; pyroxene and olivine

E. Plagioclase feldspar and quartz; pyroxene and olivine

Define viscosity. A. Resistant to flow. Magma has a higher viscosity if it has a lower temperature, is poor in silica, and contains very few dissolved gases. B. The ease of flow. Magma has a higher viscosity if it has a higher temperature, is poor in silica and contains a high amount of dissolved gases. C. Resistant to flow. Magma has a higher viscosity if it has a higher temperature, is rich in silica, and contains very few dissolved gases. D. Resistant to flow. Magma has a higher viscosity if it has a lower temperature, is rich in silica, and contains a high abundance of dissolved gases. E. Resistance to flow. Magma has a higher viscosity if it has a lower temperature, is rich in silica, and contains very few dissolved gases.

E. Resistance to flow. Magma has a higher viscosity if it has a lower temperature, is rich in silica, and contains very few dissolved gases.

What is the geothermal gradient, and how does it relate to the melting curve of peridotite? A. The geothermal gradient is the increase in temperature with depth under the Earth's surface. The melting curve of peridotite is consistently lower than the geothermal gradient. B. The geothermal gradient is the increase in temperature with depth under the Earth's surface. The melting curve of peridotite is at first higher than the geothermal gradient, but cross to lower than the gradient at about 300km below the Earth's surface. C. The geothermal gradient is the decrease in temperature with depth under the Earth's surface. The melting curve of peridotite is consistently higher than the geothermal gradient. D. The geothermal gradient is the decrease in temperature with depth under the Earth's surface. The melting curve of peridotite is consistently lower than the geothermal gradient. E. The geothermal gradient is the increase in temperature with depth under the Earth's surface. The melting curve of peridotite is consistently higher than the geothermal gradient.

E. The geothermal gradient is the increase in temperature with depth under the Earth's surface. The melting curve of peridotite is consistently higher than the geothermal gradient.

How does the crystallization of igneous material occur? A. The liquid igneous material heats up, the ions within slow in their movement, and they pack more closely together. When sufficiently cooled, ions become confined to a crystalline arrangement. B. The liquid igneous material cools, the ions within slow in their movement, and they move farther away from each other. When sufficiently cooled, ions become confined to a crystalline arrangement. C. The liquid igneous material heats up, the ions within quicken in their movement, and they move farther away from each other. When sufficiently heated, ions become confined to a crystalline arrangement. D. The liquid igneous material heats up, the ions within quicken in their movement, and they pack more closely together. When sufficiently cooled, ions become confined to a crystalline arrangement. E. The liquid igneous material cools, the ions within slow in their movement, and they pack more closely together. When sufficiently cooled, ions become confined to a crystalline arrangement.

E. The liquid igneous material cools, the ions within slow in their movement, and they pack more closely together. When sufficiently cooled, ions become confined to a crystalline arrangement.

Volcanism at divergent plate boundaries is most often associated with which rock type, and what causes rocks to melt in these settings? A. Volcanism at divergent boundaries is most often associated with felsic rock, which is created by water lowering the melting temperature of mantle rock. B. Volcanism at divergent boundaries is most often associated with basaltic rock, which is created by heating of the crust. C. Volcanism at divergent boundaries is most often associated with basaltic rock, which is created by water lowering the melting temperature of mantle rock. D. Volcanism at divergent boundaries is most often associated with felsic rock, which is created by decompression melting. E. Volcanism at divergent boundaries is most often associated with basaltic rock, which is created by decompression melting.

E. Volcanism at divergent boundaries is most often associated with basaltic rock, which is created by decompression melting.

LaGarita, in the San Juan Mountains, is an example of a _____. A. basalt plateau B. Crater Lake-type caldera C. Hawaiian-type caldera D. crater E. Yellowstone-type caldera

E. Yellowstone-type caldera

What is a lahar? A. nuee ardentes B. lavas of an intermediate composition C. a settling of ash and cinders after they have been ejected into the atmosphere D. a mudflow resulting from volcanic debris saturated with lava E. a mudflow of volcanic debris saturated with water

E. a mudflow of volcanic debris saturated with water

Of the five basic controls of soil formation, which factor is the most influential in soil formation? A. time B. plants and animals C. parent material D. topography E. climate

E. climate

What are the two basic categories of weathering? A. disintegrating and decomposing B. water and wind C. mechanical and biological D. chemical and biological E. mechanical and chemical

E. mechanical and chemical

The partial melting of ____ will yield mafic (basaltic) magma. A. granite B. diorite C. andesite D. rhyolite E. peridotite

E. peridotite

Which of the following is an aphanitic igneous rock? A. granite B. diorite C. pumice D. gabbro E. rhyolite

E. rhyolite

What are the three components of magma? A. the liquid portion, which is mostly water, the solid portion which consists of silicate mineral crystals, and the gaseous portion called volatiles B. the liquid portion called volatiles, the solid portion which consists of silicate mineral crystals, and the gaseous portion called melt C. the liquid portion (mobile ions of the eight most common minerals found in the Earth's crust) called melt, the solid portion which consists of silicate mineral crystals, and the gaseous portion called steam D. the liquid portion (mobile ions of the eight most common minerals found in the Earth's crust) called melt, the solid portion which consists of fragments of formed igneous rock, and the gaseous portion called volatiles E. the liquid portion (mobile ions of the eight most common minerals found in the Earth's crust) called melt, the solid portion which consists of silicate mineral crystals, and the gaseous portion called volatiles

E. the liquid portion (mobile ions of the eight most common minerals found in the Earth's crust) called melt, the solid portion which consists of silicate mineral crystals, and the gaseous portion called volatiles