Unit 1 - Quizzes

Which layer accounts for most of the volume of the Earth? Choose one: A. lithosphere B. mantle C. crust D. inner core

B. mantle

The center of a mid-ocean ridge is where Choose one: A. molten basalt subducts into the mantle. B. new oceanic lithosphere is being created. C. the oldest and densest oceanic crust is found. D. two continental plates converge.

B. new oceanic lithosphere is being created.

The Earth's magnetic field is created primarily by the Choose one: A. flow of liquid iron alloy in the Earth's molten outer core. B. air currents blowing across the Earth's crust. C. convection of iron-rich minerals in the Earth's mantle. D. tilt of the Earth's rotational axis.

A. flow of liquid iron alloy in the Earth's molten outer core.

Why would brick not be considered a rock? Choose one: A. Bricks are composed of different types of minerals instead of just one mineral type. B. Bricks are widely used in building. C. Bricks are not solid. . Bricks are human-made.

. Bricks are human-made.

The global occurrence of earthquakes reveals that Choose one: A. the Earth is splitting apart (rifting) at all plate boundaries. B. they usually occur at the center of plates .C. they usually occur on the boundaries of plates. D. their locations are randomly scattered.

.C. they usually occur on the boundaries of plates.

The Hawaiian Islands, a chain of volcanic islands located in the middle of the Pacific Plate, extend northwest across the Pacific as shown in the figure. The island of Hawaii is the youngest, and the islands get progressively older to the northwest. How are the positions of the islands explained by plate tectonic theory? Choose one: A. A hot spot is currently situated under Hawaii, and the Pacific Plate is moving across it in a northwesterly direction. B. The Pacific Plate is undergoing rifting, starting at the northwest end of the chain and extending southeast to Hawaii. C. A hot spot moves toward the southeast through the mantle and under the Pacific Plate. D. Microplates break loose from the Pacific Plate as it moves, leaving this chain of islands in its wake.

A. A hot spot is currently situated under Hawaii, and the Pacific Plate is moving across it in a northwesterly direction.

Which of the following statements about lithosphere and asthenosphere is TRUE? Choose one: A. Lithosphere consists of the crust and the upper mantle and behaves like a hard layer that breaks and bends. B. Lithospheric mantle has a composition that is different from asthenospheric mantle. C. Lithosphere and asthenosphere are both rigid. D. Asthenosphere consists of the middle and lower mantle and is mantle material that is cooler than 1280°C.

A. Lithosphere consists of the crust and the upper mantle and behaves like a hard layer that breaks and bends.

Which explosive volcano erupted in 1815, resulting in temperatures so cool that the following year was called "the year without a summer"? Choose one: A. Mt. Tambora in Indonesia B. Mt. Pinatubo in the Philippines C. Mt. Vesuvius in Italy D. Mt. Pelée in Martinique

A. Mt. Tambora in Indonesia

Observe the figure, paying attention to the magnetic anomaly pattern. Based on your observation, what can be said about the frequency of magnetic reversals? Choose one: A. There is no pattern with respect to frequency of magnetic reversals. B. Magnetic reversals occur at regular intervals. C. The mid-ocean ridge is currently recording a magnetic reversal. D. On average, magnetic reversals occur every 1-2 million years.

A. There is no pattern with respect to frequency of magnetic reversals.

In 79 AD, Mt. Vesuvius erupted, sending out a pyroclastic flow that buried the cities of Pompeii, Herculaneum, Oplontis, and Stabiae. Pompeii is the most well known of these cities. How would history have been different if the magma chemistry in Mt. Vesuvius had been mafic rather than felsic? Choose one: A. There would not have been a pyroclastic flow. B. The pyroclastic flow would have flowed much further. C. There would have been a huge pyroclastic blast, similar to what Yellowstone is capable of, sending a deadly shockwave in all directions. D. It would have been the same outcome.

A. There would not have been a pyroclastic flow.

The Himalayas are currently growing because at their location Choose one: A. a continental plate is colliding with another continental plate. B. two plates are moving past each other at a transform plate boundary. C. an oceanic plate is converging with a continental plate and subducting. D. two continental plates are diverging.

A. a continental plate is colliding with another continental plate.

Nuclear fission occurs when Choose one: A. atoms break apart B. photons are absorbed. C. helium becomes lithium. D. atoms fuse together.

A. atoms break apart

What type of map is needed to view the depths of the ocean floor? Choose one: A. bathymetric B. geologic C. navigational D. topographic

A. bathymetric

What type of volcanic activity is associated with the mid-ocean ridge tectonic boundary shown? Choose one: A. black smokers B. cinder cones C. pyroclastic debris D. stratovolcanoes

A. black smokers

The rate of plate motion Choose one: A. can range from 1 to 15 cm per year. B. can range from 1 to 15 m per year. C. cannot be measured directly. D. can range from 1 to 15 km per year.

A. can range from 1 to 15 cm per year.

Which of the following would be considered sediment? hoose one: A. clam shells on a beach B. quartz crystals in basalt C. silicate minerals in a metamorphic rock D. mica crystals in granite

A. clam shells on a beach

The quartz in this figure shows a very specific type of breakage. What is this type of break called? Choose one: A. conchoidal fracture B. internal fracture C. irregular fracture D. concave fracture

A. conchoidal fracture

East Africa and the Basin and Range Province of the United States are examples of a Choose one: A. continental rift. B. transform plate boundary. C. subduction zone. D. passive continental margin.

A. continental rift.

The Moho is the boundary between the Earth's Choose one: A. crust and mantle. B. inner and outer core. C. continental crust and oceanic crust. D. mantle and outer core.

A. crust and mantle.

Natural, smaller-scale cracks in a rock that form as deeply buried crust is exposed to the Earth's surface are called Choose one: A. clasts. B. joints. C. grains. D. faults.

B. joints.

From earliest to latest, which of the following is the correct order of events in the formation of the Earth? Choose one: A. formation of accretionary disk, formation of planetesimals, differentiation, formation of Moon B. formation of planetesimals, formation of accretionary disk, differentiation, formation of Moon C. formation of accretionary disk, formation of Moon, formation of planetesimals, differentiation D. formation of accretionary disk, differentiation, formation of Moon, formation of planetesimals

A. formation of accretionary disk, formation of planetesimals, differentiation, formation of Moon

The Earth's core Choose one: A. generates the Earth's magnetic field. B. is composed mainly of silicon. C. is divided into two parts: the lithosphere and the asthenosphere. D. is the thinnest layer of the Earth's interior.

A. generates the Earth's magnetic field.

Obsidian is classified as having a __________ texture. Choose one: A. glassy B. vesicular C. crystalline D. fragmental

A. glassy

According to the Mohs hardness scale, Choose one: A. gypsum is softer than fluorite. B. quartz is softer than talc. C. diamond is about 6 in hardness. D. calcite is softer than talc.

A. gypsum is softer than fluorite.

Glass is not considered a mineral because Choose one: A. it does not have a crystal structure. B. it does not have a definable chemical composition. C. it is not solid. D. it is organic.

A. it does not have a crystal structure.

The dramatic scenery of the Sierra Nevada in California, shown here, Choose one: A. owes its existence to erosion of a batholith. B. is primarily formed from dark-colored basaltic rock. C. is composed of fine-grained volcanic rock. D. is the result of a continental hot spot.

A. owes its existence to erosion of a batholith.

The geothermal gradient Choose one: A. refers to the rate of increase in temperature with increasing depth in the Earth. B. states that the average ground-surface temperature is approximately 50°C. C. states that temperatures at the center of the Earth are about 1,000 to 2,000°C. D. refers to the rate of decrease in temperature with increasing depth in the Earth.

A. refers to the rate of increase in temperature with increasing depth in the Earth.

Rocks that form at or near the Earth's surface by the cementing of grains or precipitation from water are Choose one: A. sedimentary. B. igneous. C. metamorphic. D. bedrock.

A. sedimentary.

The most abundant mineral group on the Earth is the Choose one: A. silicates. B. sulfides .C. carbonates. D. oxides.

A. silicates.

When a mineral specimen is scraped along a ceramic plate to observe the color of its powder, the physical property being checked is Choose one: A. streak. B. cleavage. C. luster. D. specific gravity.

A. streak.

The leading hypothesis for the formation of our Moon states that it Choose one: A. was formed by the collision of the Earth with a protoplanet. B. spun off the fast-spinning Earth during the early formation of the Solar System. C. coalesced from gas and dust in the asteroid belt. D. was a separate small planet before it was captured by the Earth's gravity.

A. was formed by the collision of the Earth with a protoplanet.

In the figure, the magnetic anomaly pattern is mirrored on either side of the central ridge. What is responsible for this pattern? Choose one: A. Seafloor sections with different magnetic polarities converge at the central ridge. B. Changes in the Earth's magnetic field are recorded in the solidifying magma during seafloor spreading. C. Changing rates of the Earth's rotation can create polarity bands of different widths. D. Different magma compositions create different magnetic polarities.

B. Changes in the Earth's magnetic field are recorded in the solidifying magma during seafloor spreading.

Why was asbestos used in brake pads? Choose one: A. It is fibrous. B. It has a high melting temperature. C. It contains quartz. D. It is very strong.

B. It has a high melting temperature.

Which of these is a terrestrial planet? Choose one: A. Jupiter B. Mars C. Saturn D. Neptune

B. Mars

Which of the following volcanic areas is part of the Ring of Fire? Choose one: A. Hawaiian Islands B. Mt. Pinatubo, Philippines C. Iceland D. Yellowstone

B. Mt. Pinatubo, Philippines

This figure shows the planets of the Solar System and their positions relative to the Sun. Which observation about the planets' arrangement is true? Choose one: A. The asteroid belt marks the boundary between the rocky planets and the ice giants. B. The asteroid belt marks the boundary between the rocky planets and the gas giants. C. The asteroid belt marks the boundary between the gas giants and the ice giants. D. Rocky planets, gas giants, and ice giants are mixed randomly through the Solar System.

B. The asteroid belt marks the boundary between the rocky planets and the gas giants.

Carefully examine the Wadati-Benioff zone illustrated. If the angle of subduction was less steep, how would the diagram be different? Choose one: A. The scenario is not possible because subduction angle is a constant. B. The distance from the trench to the volcanic arc would increase. C. A volcanic arc would not appear. D. Faulting would be less intense.

B. The distance from the trench to the volcanic arc would increase.

Which of the following serves as a trap for cosmic rays and shields life on the Earth from charged particles? Choose one: A. Kuiper belt B. Van Allen belts C. Oort cloud D. asteroid belt

B. Van Allen belts

Asbestos was widely used as a fireproofing insulation. Why is it no longer used? Choose one: A. When touched it can cause severe burns. B. When inhaled it can embed in the lungs and cause cancer. C. Toxic lead can leach out over time, resulting in lead poisoning. D. It can pollute the groundwater.

B. When inhaled it can embed in the lungs and cause cancer.

Based on the behavior of hot spots and the figure shown, in what state did McDermitt Volcanic Field most likely erupt? Choose one: A. Idaho B. Wyoming C. Northern California D. Oregon

B. Wyoming

Referring to the figure, would either of these rock samples be considered crystalline? Choose one: A. No, both are clastic. B. Yes, (b) is crystalline. C. Yes, (a) is crystalline. D. No, they are both fragmentary.

B. Yes, (b) is crystalline.

The presence of pillow basalt is evidence of Choose one: A. high-silica magma. B. a submarine eruption. C. an explosive eruption. D. caldera formation.

B. a submarine eruption.

Calcite that constitutes clamshells is an example of which method of mineral formation? Choose one: A. solid-state diffusion B. biomineralization C. solidification of a melt D. precipitation from a solution

B. biomineralization

Identify the type of plate boundary shown in the image. Choose one: A. transform B. convergent C. divergent D. seafloor spreading

B. convergent

A bathymetric map of the Earth's oceans would reveal that most of the ocean floor is made up of Choose one: A. trenches. B. deep ocean plains. C. continental shelves. D. mid-ocean ridges.

B. deep ocean plains.

The mineral crystals of amethyst growing into the center of the geode in the figure are Choose one: A. cubic. B. euhedral. C. anhedral. D. tetrahedral.

B. euhedral.

The nebular theory explains Choose one: A. why the Universe is expanding. B. how the Solar System formed. C. why Pluto has no moon. D. why larger stars burn out more quickly than medium-sized stars.

B. how the Solar System formed.

The earliest nebulae to form in the Universe were made almost entirely of Choose one: A. carbon and nitrogen. B. hydrogen and helium. C. iron and magnesium. D. chlorine and argon.

B. hydrogen and helium.

During the process of seafloor spreading, Choose one: A. new seafloor is formed at trenches. B. new seafloor is formed at ridges. C. seafloor is neither formed nor destroyed but spreads apart at ridges. D. seafloor is neither formed nor destroyed, and total seafloor volume stays constant.

B. new seafloor is formed at ridges.

The two most common gases of the Earth's atmosphere are Choose one: A. oxygen (O2) and methane (CH4). B. nitrogen (N2) and oxygen (O2). C. carbon dioxide (CO2) and oxygen (O2). D. water (H2O) and oxygen (O2).

B. nitrogen (N2) and oxygen (O2).

According to Bowen's reaction series, as a magma cools in the discontinuous series, minerals will crystallize in which order? Choose one: A. olivine, plagioclase, quartz, muscovite B. olivine, pyroxene, amphibole, biotite C. muscovite, k-feldspar, biotite, amphibole D. plagioclase, k-feldspar, muscovite, quartz

B. olivine, pyroxene, amphibole, biotite

Which layer of the Earth's interior is completely molten? Choose one: A. crust B. outer core C. inner core D. mantle

B. outer core

The contact between lithospheric plates is called a Choose one: A. microplate. B. plate boundary. C. passive margin. D. continental shelf.

B. plate boundary.

Based on the figure provided, which plate is moving the fastest? Choose one: A. the African Plate B. the Pacific Plate C. the Eurasian Plate D. the North American Plate

B. the Pacific Plate

Stars that we observe in the night sky are trillions of kilometers away. Rather than using such large numbers, we use light-years to describe the distances. What is a light-year? Choose one: A. the amount of time it takes light to travel from the Sun to the Earth B. the distance light travels in one year C. the amount of light a star emits in one year D. the distance from the Earth to the Sun

B. the distance light travels in one year

Which of the following was used as evidence by Wegener to develop the theory of continental drift? Choose one: A. the process of subduction B. the presence of matching mountain chains on continents currently separated by oceans C. the presence of earthquakes in seismic belts along trenches, ridges, and fracture zones D. the process of seafloor spreading

B. the presence of matching mountain chains on continents currently separated by oceans

Magmas have a variety of chemical compositions because Choose one: A. the minerals in the rocks that form magma all melt at the same time. B. they can incorporate chemicals from the surrounding rock. C. different magmas formed in different locations are isolated and never mix. D. magmas become more mafic as they cool.

B. they can incorporate chemicals from the surrounding rock.

Which of the following has faulting but no volcanic activity? Choose one: A. continental rift B. transform plate boundary C. hot spot D. subduction zone

B. transform plate boundary

Magma may cool and crystallize to become solid igneous rock Choose one: A. when its volatile content increases. B. very slowly (in centuries to a million years) when it forms a deep pluton. C. when pressure increases as rock sinks into the mantle. D. more slowly in the presence of circulating groundwater.

B. very slowly (in centuries to a million years) when it forms a deep pluton.

Bowen's reaction series Choose one: A. has a continuous series with a progressive change from sodium-rich to calcium-rich amphibole. B. was established by laboratory experiments in the 1920s. C. creates a progressively more mafic melt as the magma cools. D. shows the sequence in which different sulfate minerals form during the progressive cooling of a melt.

B. was established by laboratory experiments in the 1920s.

Diamonds are very hard gemstones that form Choose one: A. by precipitation in a freshwater lake. B. when carbon is subducted to 100 or more kilometers of depth. C. from biomineralization like an oyster pearl. D. when quartz and other silicate minerals are subjected to high pressure.

B. when carbon is subducted to 100 or more kilometers of depth.

A subducting (or downgoing) plate Choose one: A. is always made up of continental lithosphere. B. will have a trench associated with it. C. is not likely to have earthquakes happen in it. D. descends into the mantle at an oceanic ridge.

B. will have a trench associated with it.

How many planes of cleavage does this mineral have? Choose one: A. 2 at 90° intersections B. 3 not at 90° intersections C. 1 D. 0

C. 1

How were thick layers of halite and gypsum deposited beneath the Mediterranean Sea? Choose one: A. Widespread layers of gypsum and halite were deposited in the deep ocean over millions of years. B. Large rivers from the surrounding continents increased their flow into the Mediterranean Sea, bringing in more mineral-rich sediments. C. At times of low global sea level, the Mediterranean Sea was cut off from the Atlantic Ocean, and the trapped seawater evaporated. D. At times of high global sea level, the Mediterranean Sea was cut off from the Atlantic Ocean, and the trapped seawater evaporated.

C. At times of low global sea level, the Mediterranean Sea was cut off from the Atlantic Ocean, and the trapped seawater evaporated.

Why does subduction occur at some convergent boundaries but not others? Choose one: A. When the types of crust are the same (oceanic or continental), subduction does not occur. B. Two continental plates must collide in order for subduction to take place. C. If one of the colliding plates is oceanic, subduction will occur. D. A continental tectonic plate must be present in order for subduction to take place.

C. If one of the colliding plates is oceanic, subduction will occur.

___________ rocks form when existing rocks are subjected to high temperatures and pressures that cause changes in mineralogy and texture but do not melt. Choose one: A. Igneous B. Chemical sedimentary C. Metamorphic D. Clastic sedimentary

C. Metamorphic

How did the Earth become round? Choose one: A. The gravitational pull of the Moon wore down the early Earth's jagged edges. B. Erosion over time wore down the early Earth's jagged edges. C. The early Earth's interior rock became warm enough to flow in response to gravity. D. The solar wind shaped the early Earth.

C. The early Earth's interior rock became warm enough to flow in response to gravity.

Overall, iron is the Earth's most abundant element. However, most of the crustal rocks are silicates, SiO4, with minor amounts of iron. What, then, accounts for the large proportion of iron? Choose one: A. Iron is almost always a component of silicate rocks. B. Mantle rocks are primarily iron. C. The inner and outer core is 94% iron, and the volume of the core is much greater than that of the crust. D. Major amounts of dissolved iron ions in ocean waters.

C. The inner and outer core is 94% iron, and the volume of the core is much greater than that of the crust.

Plate tectonics theory took decades to be accepted because Choose one: A. most of Wegener's ideas turned out to be wrong. B. his research was not well known in the scientific community. C. Wegener couldn't explain how continents moved. D. climate, fossil distributions, and land shape offered conflicting evidence.

C. Wegener couldn't explain how continents moved.

The chain of volcanoes along the west coast of South America (the Andean arc) exists because Choose one: A. basalt is pushing up through the trench that parallels the west coast of South America. B. an oceanic plate is sliding past the western edge of the South American Plate. C. an oceanic plate is subducting under the western edge of the South American Plate. D. an oceanic plate is rifting apart from the western edge of the South American Plate.

C. an oceanic plate is subducting under the western edge of the South American Plate.

The Big Bang Choose one: A. is the explanation for how the planets in the Solar System developed. B. had very little energy after the first instant. C. began with all of the known Universe concentrated in an infinitesimally small point. D. occurred about 2.2 million years ago.

C. began with all of the known Universe concentrated in an infinitesimally small point.

This image shows a classic example of Choose one: A. accretionary lapilli. B. volcanic blocks. C. columnar jointing. D. tephra.

C. columnar jointing.

The process by which the Earth developed its layered interior is called Choose one: A. sublimation. B. condensation. C. differentiation. D. precipitation.

C. differentiation.

The migration of atoms or molecules through a material is called Choose one: A. biomineralization. B. solidification of a melt C. diffusion. D. precipitation from a gas.

C. diffusion.

By using GPS data, scientists have been able to Choose one: A. show that only oceanic plates are moving. B. show that only the continents are moving. C. directly observe plate motions. D. track the movement of mantle plumes.

C. directly observe plate motions.

Which of the following is considered a warning sign of imminent eruption? Choose one: A. decrease in gas emissions B. drying up of hot springs C. earthquake activity D. erosion of volcanic peaks

C. earthquake activity

What physical property of a mineral describes the shape of a cluster of many well-formed crystals that grew together as a group? Choose one: A. fracture B. hardness C. habit D. cleavage

C. habit

A felsic or silicic magma Choose one: A. crystallizes at the highest temperatures. B. is about 44%-50% silica C. is more viscous than mafic magma. D. is formed by melting of oceanic crust.

C. is more viscous than mafic magma.

Igneous material at a depth of 400 kilometers and 1,200°C would be in which state of matter? Choose one: A. partially molten B. liquid C. solid D. plasma

C. solid

The image shows a calcite fragment. The calcite has Choose one: A. two inclined planes of cleavage. B. one plane of cleavage. C. three planes of cleavage. D. two perpendicular planes of cleavage.

C. three planes of cleavage.

Identify the type of plate boundary shown in the image. Choose one: A. seafloor spreading B. divergent C. transform D. convergent

C. transform

At what elevation is air pressure highest? Choose one: A. 10 km B. 36 km C. 8 km D. 0 km

D. 0 km

Using this image, describe the relationship between air pressure and altitude Choose one: A. At the altitude that commercial jets fly (12-15km), air pressure is higher than 1 bar. B. Air pressure increases linearly as altitude increases. C. Air pressure is approximately 0.8 bar at the top of Denali. D. At the top of Mt. Everest, air pressure is less than 0.4 bar..

D. At the top of Mt. Everest, air pressure is less than 0.4 bar..

The Earth behaves similarly to a bar magnet, creating a magnetic field. In which polarity direction does the magnetic field travel? Refer to the magnetic field lines in the figure. Choose one A. east to west B. south to north C. west to east D. north to south

D. North to South

The figure shows a sample of pyrite (FeS2). Which of the following statements can be determined to be true simply by visual inspection of this sample? Choose one: A. Pyrite has nonmetallic luster. B. Pyrite has one plane of cleavage. C. Pyrite has a golden streak. D. Pyrite has metallic luster.

D. Pyrite has metallic luster.

Observe the map of seafloor ages. Why does the Eastern Pacific have a much wider band of red than the Atlantic Ocean? Choose one: A. The spreading rate in the Atlantic is faster than the spreading rate in the Pacific. B. The Pacific Ocean is younger than the Atlantic Ocean. C. The Atlantic Ocean is younger than the Pacific Ocean. D. The spreading rate in the Pacific is faster than the spreading rate in the Atlantic.

D. The spreading rate in the Pacific is faster than the spreading rate in the Atlantic.

Volcanic eruptions vary in size from very small to extremely large events. This image shows the different stages of a cataclysmic eruption. What type of eruption is shown by this sequence of images? Choose one: A. cinder cone eruption B. stratovolcano eruption C. fissure eruption D. caldera eruption

D. caldera erupt

Which of the following is associated with intrusive igneous activity? Choose one: A. lava floods B. explosive volcanic eruptions C. debris avalanches D. crystallization of magma underground

D. crystallization of magma underground

Which describes the melting that takes place when deep, hot rock rises to shallower depths without cooling? Choose one: A. eruptions of lava B. heat-transfer melting C. flux melting D. decompression melting

D. decompression melting

Using the diagram, identify the coarse-grained igneous rock with abundant plagioclase and lesser amounts of quartz, pyroxene, amphibole, and biotite. Choose one: A. granite B. olivine C. gabbro D. diorite

D. diorite

Which of the following describes an elongated crack that may serve as a conduit for lava to erupt on the surface? Choose one: A. vent B. vesicle C. magma chamber D. fissure

D. fissure

The gemstones amethyst (a form of quartz), topaz, diamond, and sapphire (a form of corundum) all have this property in common. Choose one: A. color B. fluorescent under UV light C. cleavage D. harder than glass

D. harder than glass

Lahars, composed of ash, pyroclastic debris, and water, Choose one: A. occur only in Arctic regions because snow supplies the water. B. are also called lava fountains. C. are less dense than a similarly sized stream of pure water. D. have often resulted in damage and death to humans and their property.

D. have often resulted in damage and death to humans and their property.

Edwin Hubble's research was important because Choose one: A. he proposed the Big Bang theory. B. he proposed the nebular theory. C. he determined the differences between terrestrial and Jovian planets. D. his measurements of galaxies showed that the Universe is expanding.

D. his measurements of galaxies showed that the Universe is expanding.

A moving, glowing, descending cloud of hot ash and rock Choose one: A. is associated with shield volcanoes. B. is so rare, none occurred in the last century. C. has a Hawaiian name because this event is common there. D. is called a pyroclastic flow or nuée ardente.

D. is called a pyroclastic flow or nuée ardente.

Which of the following would be best used to study rocks in the field? Choose one: A. petrographic microscope B. mass spectrometer C. electron microprobe D. magnifying glass

D. magnifying glass

The figure shows the Aleutian Islands, a volcanic island arc associated with a trench. What type of plate boundary formed these islands? Choose one: A. continental-oceanic plate boundary B. hot spot C. continental-continental convergent boundary D. oceanic-oceanic plate boundary

D. oceanic-oceanic plate boundary

Which of the following is a mineral? Choose one: A. amber (fossilized tree resin) B. petroleum (crude oil) D. salt (NaCl) D. saltwater

D. salt (NaCl)

Accretionary prisms form as a result of what process? Choose one: A. divergence B. rifting C. transform motion D. subduction

D. subduction

The magma with the highest percentage of iron oxide and magnesium oxide, and lowest percentage of silica, is Choose one: A. intermediate. B. mafic. C. felsic. D. ultramafic.

D. ultramafic.