CH. 2, 3, 4, 5 Copy from web

Which term describes the changing of the composition of magma by incorporating surrounding host rock?

assimilation

The three most common volatiles in magma are:

carbon dioxide, sulfur dioxide, and water vapor

In which type of chemical bonding are electrons shared between adjacent atoms?

covalent

If you find a 500 meter depression atop a volcano, it is likely a:

crater

Magnetic anomalies result from the seafloor spreading in conjunction with:

magnetic polarity reversals

Refer to the following hypothetical plate map below to answer the following questions How many tectonic plates are shown on this map? Which plates A,B, and/or C likely have active volcanoes? In which direction is continent A moving relative to the adjacent subduction zone?

1. 5 2. A & B 3. Southeast

Magmas are classified based on their SiO2 content. Match the following composition terms with the amount of SiO2 contained in a rock of the composition. 1. felsic 2. intermediate 3. mafic 4. ultramafic

1. 66-76% 2. 52-66% 3. 45-52% 4. 38-45%

Considering a mafic melt, define the following magma properties as compared to a felsic melt. 1. silica content 2. viscosity 3. tendency to produce pyroclastic material 4. eruptive temperature

1. lower 2. lower 3. lower 4. higher

Based on what you learned about minerals and igneous rocks, and based on the following mineral compositions, are following mafic or felsic minerals? 1. olivine - Mg2SiO4 2. quartz - SiO2 3. biotite mica - KMg3AlSi3O10(OH)2 4. feldspar - KAlSi3O8

1. mafic 2. felsic 3. mafic 4. felsic

Based on the following definitions, match the correct state of a volcano. 1. ____ volcanoes are those that are currently erupting 2. ____ volcanoes are those that aren't capable of erupting 3. ____ volcanoes are those that have recently erupted 4. ____ volcanoes are those that have not erupted in hundreds of thousands of years

1. active 2. extinct 3. active 4. dormant

Match the following geologic features on Earth with their tectonic boundaries: 1. Appalachian Mountains 2. Andes Mountains 3. The Arabian Peninsula and Madagascar 4. San Andreas Fault

1. continent-continent 2. continent ocean 3. continental rift 4. transform

Match the following description of relative motion at plate boundaries with their boundary type: 1. lithospheric plates move toward each other 2. lithospheric plates slide past each other 3. lithospheric plates move away from each other

1. convergent 2. transform 3. divergent

For each of the tectonic settings listed below, choose the most likely form of melting you would expect to see: 1. mid ocean ridge 2. felsic magma in a continental rift 3. oceanic hot spot 4. subduction zone 5. continent continent collision

1. decompression melting 2. heat transfer melting 3. decompression melting 4. volatile melting 5. no melting

Match the following magma producing processes with their definitions: 1. the melting temperature of hot material is lowered as the surrounding pressure decreases 2. water is added to a region with rocks at a temperature where they will melt if water is added 3. hot material moves into a region with higher temperatures. than its melting temperature 4. hot material moves into a region with water or carbon dioxide, which lowers its melting temperature

1. decompression melting 2. volatile melting 3. heat transfer melting 4. not a form of melting

Match each of the following ocean features with their tectonic setting. 1. seamounts 2. island arcs 3. mid ocean ridge

1. hot spots 2. subduction zone 3. divergent plate boundary

When Earth's magnetic field reverses polarity, it's recorded in ____ formed at that time. Paleomagnetic researchers of the find fairly ____ patterns of alternating magnetism that parallel ___. Such a pattern forms when an older crust is carried away in an opposite directions by ____.

1. oceanic crust 2. symmetric 3. mid-ocean ridges 4. sea-floor spreading

Cooled magma chambers from _____ whereas cooled volcanic feeders form ____, which are both ____ igneous features.

1. plutons 2. dikes 3. intrusive

Are each of the following minerals, yes or no? 1. gold nugget 2. seawater 3. quartz 4. glacial ice 5. calcite 6. sugar 7. table salt

1. yes 2. no 3. yes 4. yes 5. yes 6. no 7. yes

A typical rate of plate motion is:

3 centimeters/year

Movement of plates away from each other at divergent boundaries typically shows which of the following average velocities?

5 cm per year

What is the general temperature range that most silicate magmas exist?

650-1100 degrees Celsius

Non-silicate minerals make up about ____ percent of Earth's crust.

8

Specific gravity is used to describe the density of minerals. The specific gravity of a mineral indicates its weight as compared to water. Water is used as the comparison because it is something we are familiar with. Water is assigned a specific gravity of one, and other materials are compared to that. For example, if a mineral were twice as dense as water, its specific gravity would be two. If you had a gallon of that mineral, it would weigh as much as two gallons of water. (A gallon of water weighs about 8 pounds, so the mineral would weigh 16 pounds.)Gold has a specific gravity of almost 20. A 5-gallon bucket of water weighs 40 pounds. How much would a 5-gallon bucket of gold weigh?

800 pounds

What causes the volcanoes and deep valleys of East Africa?

A continental rift along parts of the African continent beginning to slowly separate

What type of boundary occurs along the Aleutian Islands in the North Pacific?

A convergent boundary on a volcanic arc above the northward-subducting Pacific plate

What type of plate boundary is usually associated with pull-apart rift zones?

A divergent plate boundary

What is required to generate an igneous rock with a fine-grained texture?

A fine-grained texture is the product of rapid cooling and crystallization of lava.

What type of region is the modern-day Red Sea?

A rift zone that may eventually open into a major ocean if Arabia and Africa continue to separate

What causes the same mineral to occur in varieties that are different colors?

A small amount of impurities in the crystal structure.

Which type of basaltic lava flow has its surface covered with sharp-edged, angular blocks and rubble?

A'a

Which scientist argued forcefully for continental drift in the early part of the 20th century?

Alfred Wegener

Crustal rifting is currently occurring in East Africa. Which of the following features would you expect to find there?

All of the above are correct normal faults + long/wide valley + lava flows + only normal faults and long, wide valleys

Which of the following processes can be observed at the margins of lithospheric plates?

All of the responses are correct .faulting + earthquakes + volcanoes + mountain building

Of the following choices, which best describes Mt. St. Helens?

An explosive stratovolcano

Which of the following pairs of igneous rocks exhibit aphanitic texture?

Andesite; rhyolite

What type of magma typically comprises stratovolcanoes?

Andesitic

Why are lava flows typically finer-grained than intrusive igneous rocks?

Because the extrusive magma cools quickly and mineral grains do not have time to grow

Where in the ocean does oceanic lithosphere sink into the mantle?

At subduction zones along convergent plate boundaries

Which of the following is an accurate description of ionic bonding?

Atoms of different elements, having gained or lost electrons, form negative and positive ions that are bonded together by attractive forces between ions with opposite charges.

Atoms attach to one another creating compounds and the chemical structure of minerals. The attachments, called bonds, form when an electron is transferred from one atom to another or shared between atoms. The electrons in the outermost shell of an atom are usually involved in forming bonds. Through chemical bonding, atoms fill their outermost shell until it contains eight electrons. Once the outermost shell is full, it is stable and will not bond. This is known as the octet rule. Atoms on the far right side of the periodic table (the noble gases) contain eight electrons in their outer shell and will not bond with other atoms.

Atoms that have eight electrons in their outer shell—the noble gases—are stable and will not form chemical bonds with other atoms according to the octet rule. Other atoms are likely to either give up an electron to another atom, bonding the two together, or share an electron between atoms.

What type of magma is the most abundant at oceanic-spreading centers?

Basaltic

What type of volcanoes are Kilauea and Mauna Loa in Hawaii?

Basaltic shield volcanoes

Why was Wegener's continental drift hypothesis rejected?

Because Wegener could not identify a mechanism capable of moving continents

When considering evidence of glaciation on the southern continents, why did Wegener reject the explanation that the entire planet had experienced a period of extreme cooling and was covered in glaciers 250 million years ago?

Because geologic evidence supported the existence of tropical swamps in the Northern Hemisphere at the same time as the glaciers existing in the Southern continents

Which one of the following statements concerning volcanic blocks and bombs is true?

Blocks are ejected as solid fragments; bombs are ejected as magma lumps.

What causes a lack of cleavage in some minerals?

Bonds of equal strength in all directions- A mineral will not have cleavage if there are not weaker bonds oriented in a particular direction.

What mineral is not scratched by a fingernail, but is scratched by a copper penny?

Calcite

What volcanic events formed Crater Lake, Oregon? When did they take place?

Caldera collapse followed by major ash and pyroclastic-flow eruptions; 7000 years ago.

Use the map of GPS velocities below and indicate which of the following plates is moving slowest

Caribbean

Which of the following best describes the term cleavage?

Cleavage is the splitting of minerals along natural planes of weakness.

In a collision between two continental plates, can a continental plate subduct? Why or why not?

Continental plates are too buoyant to subduct.

Suppose you found a mineral crystal that looked like topaz. What two minerals could you use in a scratch test to help determine if the mineral is indeed topaz?

Corundum and quartz

Name the hardest and softest mineral on the Moh's scale.

Diamond (hardest) and talc (softest)

In studies of rock obtained from ocean basins all over Earth, the oldest ages obtained are approximately 200 million years before the present. Why have no older oceanic rocks been discovered?

Due to tectonic activity, rocks on the ocean floor are continually recycled.

Which of the following silicate minerals has the most silicon relative to oxygen?

E

In general, why does Earth's crust sit on top of the mantle?

Earth's crust is less dense than the mantle.

Which one of the following is an important fundamental assumption underlying the plate tectonic theory?

Earth's diameter has been essentially constant over time.

Color is a reliable identification technique for minerals.

False

True or False. Landslides can cause volcanic eruptions even in extinct volcanoes

False

You have found a mafic rock with a phaneritic texture. What is a potential rock name?

Gabbro

Which of the following exhibits three sets of cleavage at 90° angles?

Galena

Why is glass is not considered a mineral?

Glass has a disorderly atomic structure.

What do pumice and obsidian have in common?

Glassy texture

Which rock would be most likely to contain visible quartz and potassium feldspar crystals?

Granite

Which of the following fits the definition of a mineral?

Gypsum, because it's crystalline

How are felsic magmas formed?

Heat from the mantle melts part of the lower crust.

Intrusive and extrusive igneous rocks are classified based on what criteria?

How quickly the molten rock cools and crystallizes, and where this occurs with respect to Earth's surface

What is the basic foundation of Moh's hardness scale?

If a mineral scratches an object, then the mineral is harder than the object.

How are igneous rocks formed?

Igneous rocks are formed by the cooling and crystallization of molten rock.

Which of the following best defines a mineral and a rock?

In a mineral, the constituent atoms are bonded in a regular, repetitive, internal structure; a rock is a lithified or consolidated aggregate of different mineral grains.- Geologists define a mineral as any naturally occurring inorganic solid that possesses an orderly crystalline structure and a well-defined chemical composition. In contrast to minerals, rocks are more loosely defined. Minerals are the building blocks of rocks. A rock is defined as any solid mass of mineral or mineral-like matter that occurs naturally on our planet.

What fate befell the "Lost City of Atlantis" mentioned in Plato's writings?

It disappeared as part of caldera collapse following a major, explosive, volcanic eruption.

Why does magma have a tendency to rise after its formation?

It is less dense than the surrounding rock.

What is one way a glassy texture forms?

Lava cools rapidly.

Which ocean basin is rimmed by the most subduction zones?

Pacific

Given the periodic table below, are the following elements more likely to gain or lose electrons when forming an ion?

Lithium (lose)Oxygen (gain)

How is the thickness of the lithosphere going to change as it moves away from a divergent plate boundary?

Lithosphere will thicken as more mantle is added

What do you think will happen to the location of Los Angeles with continued activity along the San Andreas Fault over a long time span?

Los Angeles will slide to the northwest

Since color is not a very useful way to identify a mineral, what other optical property or properties can be used?

Luster and streak

Which of the following is true about mafic igneous rocks?

Mafic igneous rocks are rich in Fe, Mg, and Ca

Which of the following everyday objects do you think contains minerals that need to be mined?

McDonald's milkshake + eye-shadow + hard rubber + cell phone battery

Why would a plume of solid silicate rock rising slowly from deep in the mantle begin melting as it neared the base of the lithosphere?

Melting temperatures drop because the pressure is lowered.

How do rocks differ from minerals?

Minerals aggregate to form rocks, but rocks do not aggregate to form minerals.

A scientist creates diamonds using high-pressure laboratory experiments. These diamonds are not considered minerals because which of the following requirements has been violated?

Minerals must occur naturally.

As the map above shows the oldest seafloor is generally less than 200 million years old. Why?

Most oceanic lithosphere eventually gets subducted beneath the continents by the time it's 200 million years old because the older it gets, the colder and denser it gets

Based on the diagram shown in the video, name two minerals that are unlikely to coexist in the same igneous rock.

Muscovite and pyroxene

Which of the following statements regarding transform plate boundaries is not correct?

New oceanic crust is formed at transform plate boundaries.- Crust is neither created nor consumed at transform plate boundaries.

Do fracture zones near transform boundaries play a role in plate motion?

No, fracture zones play no role in plate motion

__________ destroyed the city of St. Pierre, Martinique in 1902.

Nueé ardente

Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface?

Pahoehoe

What is the largest known volcano in the solar system?

Olympus Mons, Mars

The former late Paleozoic (250 million years) age supercontinent is known as:

Pangaea

The former, late Paleozoic supercontinent is known as __________.

Pangaea

What type of igneous rock consists of very coarse crystals?

Pegmatite

Which of the following textures describes an igneous rock with anomalously large crystals?

Pegmatitic

Which term describes a texture of igneous rocks that crystallized over a single, long period?

Phaneritic

Which texture listed below would be most unlikely to occur in an extrusive igneous rock?

Phaneritic

Plate A has oceanic lithosphere on its leading edge that is 10 million years old. Plate B has oceanic lithosphere on its leading edge that is 200 million years old. Which plate will be subducted if they collide with each other, and why?

Plate B will subduct because it is older—and therefore colder—and more dense.

Which of the following textures indicates two stages of cooling and crystallization?

Porphyritic

How do mafic volcanic rocks get to Earth's surface?

Pressure from overlying crust forces mantle magmas through cracks to Earth's surface. These magmas erupt out of volcanoes, cool, and solidify into rock.

Based on what you learned in this video, what minerals make up rhyolite?

Quartz, K-feldspar, and plagioclase feldspars, with relatively fewer biotite and amphiboles

Which one of the following shows the correct order from left to right of decreasing magmatic viscosity?

Rhyolite, andesite, basalt

Which of the following statements about rock melting is most accurate?

Rock can remain solid, become partially melted, or melt completely at the same depth within Earth, depending on the temperature.

Which fault in Southern California was created by the sliding of the Pacific Plate past the North American Plate?

San Andreas Fault - T

Which volcanoes are sometimes very large, with a gently sloping mound composed mainly of lava flows?

Shield

What are the 8 most concentrated elements in Earth's crust?

Si (silicon), O (oxygen), Na (sodium), K (potassium), Ca (calcium), Mg (magnesium), Fe (iron), Al (aluminum)

What process is evident at oceanic trenches?

Sinking of oceanic lithosphere into the mantle at a subduction zone

Imagine that you are studying seafloor spreading along two different mid oceanic ridges. Using data from a magnetometer, you produced the two following maps. From these maps, what can you determine about the relative rates of seafloor spreading along these two ridges?

Spreading Center A produces new oceanic crust faster than B

Which kind of volcanism is typical of mid-oceanic ridge systems?

Submarine; basaltic lava flows

Which of the following is a mineral?

Table Salt (NaCl)

Why is decompression melting common at mid-ocean ridges but not at subduction zones?

Tectonic plates are moving apart at mid-ocean ridges, resulting in a lowering of pressure beneath the ridge. Tectonic plates are moving together at subduction zones, resulting in an increase of pressure under new mountains.

Which of the following statements best describes the Hawaiian volcanoes?

The Hawaiian volcanoes are situated in the interior of a Pacific plate above a hot spot deep in the mantle.

The western edge of the Juan de Fuca Plate is a divergent boundary with a ragged, zigzag edge. (See the figure.) Which of the following describes the motion of the Juan de Fuca plate on its southern boundary at the Mendocino Fault?

The Juan de Fuca Plate has right-lateral motion with the Pacific Plate along the transform Mendocino Fault.

Why is water a necessary component of the melting process in subduction zones?

The addition of water lowers the melting temperature of rock.

Which of the following is correct for isotopes of the same element?

The atoms have different numbers of neutrons and the same number of protons.

Which region has the greatest concentration of currently active volcanoes?

The circum-Pacific area or "Ring of Fire"

Which of the following best describes the term streak?

The color of a powdered form of a mineral produced by rubbing it across a hard surface.

What are two differences between oceanic crust and continental crust?

The continental crust is thicker and less dense than oceanic crust.

What does it mean if an igneous rock has an aphanitic texture?

The igneous rock exhibits mineral crystals too small to see with the naked eye.

Why are shield volcanoes wider than composite volcanoes?

The lava that flows out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes.

Which of the following is an example of an active continent-continent collision?

The northward movement of India into Eurasia

What atomic particle in an atom is the same for each element?

The number of protons in the nucleus.

At a subduction zone where oceanic lithosphere meets continental lithosphere, which would subduct and why?

The oceanic lithosphere would subduct because it has a higher density at 3.0 grams per cubic centimeter.

What does an igneous rock with a pyroclastic texture tell a geologist?

The rock was likely formed by a violent volcanic eruption.

Which of the following best describes mineral habit?

The shape a mineral grows into, given sufficient space.

Which one of the following best describes volcanism of the Cascade Range in the northwestern United States?

The volcanism is related to plate subduction.

Which of the following properly describes Mount St. Helens and the other Cascade volcanoes?

They are young, active volcanoes built on a continental margin above a sinking slab of oceanic lithosphere.

Most igneous rocks never reach the surface. However, igneous rocks other than those formed in volcanoes are found exposed on many parts of Earth. How do you account for this phenomenon?

They formed at depth and have been exposed by uplift and erosion.

Why is Tuttle and Bowen's experiment useful to geologists?

This experiment allows geologists to interpret where granitic rock solidifies beneath Earth's surface.

Other than space, what two additional factors are significant for a crystal to attain habit?

Time and necessary elements

What role do transform boundaries play?

Transform boundaries connect other segments of plate boundaries.

What is the relationship between transform boundaries and mid-ocean ridges?

Transform boundaries connect segments of mid-ocean ridges.

Refer to the periodic table of the elements to help you answer this question. If the number of protons in an electrically neutral atom is 92 and its mass number is 238, what is the name of that element, its number of electrons, and number of neutrons?

Uranium, 92 electrons and 146 neutrons

Which of the following describes a texture containing bubble-shaped cavities?

Vesicular

What are the two primary factors that determine the manner in which magma erupts?

Viscosity of magma and the amount of gasses in magma. An increasing in either or both of those factors makes eruption more explosive.

What is the most common volatile constituent in both magmas and volcanic gases?

Water

What two gases are the most abundant gases emitted during basaltic volcanism?

Water and carbon dioxide

Where does the water involved in melting at subduction zones come from?

Water contained within minerals in the subducting plate is released during metamorphism.

How does water content of granitic magmas change as the magmas move towards Earth's surface?

Water content decreases.

How does water content of melt change with increasing pressure?

Water content increases with increasing pressure.

Which of the following issues initially prevented the widespread acceptance of Alfred Wegener's continental drift hypothesis?

Wegener's lack of a good mechanism to explain why the continents moved

To what is the geologically recent volcanic activity in Yellowstone National Park usually attributed?

Yellowstone volcanism is usually attributed to intraplate (meaning "within the plate"), hot spot volcanism.

Currently the Juan de Fuca plate is interacting with the North American plate where inland volcanoes and deep focus earthquakes are occurring. What type of plate boundary is this?

a convergent plate boundary

A transform plate boundary is characterized by __________.

a deep, vertical fault along which two plates slide past one another in opposite directions

A mineral, as geologists understand the term, is a naturally occurring solid substance with a definable chemical composition and...

a fixed crystalline structure

Flood basalts typically originate from:

a mantle plume

In the Atlantic Ocean, where does the youngest oceanic crust occur?

adjacent to the mid ocean ridge

What makes CO2 gas hazardous to humans?

all are true about CO2 gas it is colorless and odorless it is denser than air so it will not rise rapidly and can easily be breathed i without one's knowledge of its presence it can deprive the brain of oxygen and cause fainting and or death

Which of the following is true about lahars:

all are true about lahars can occur even if an eruption has not occurred recently can carry away people/buildings/other structures high density + fast flowing floods of water and tephra

In general, when will melted rock in the mantle rise?

almost always

Seafloor spreading is driven by volcanic activity that occurs:

along mid ocean ridges

Where would you expect to find volcanoes in an oceanic--continental convergence zone?

always on the continental plate

In addition to viscosity, which of the following parameters has an influence on whether a volcanic eruption will be effusive or violent?

amount of gas in the magma

What is an ion?

an atom that has gained or lost 1 or more electrons and is charged either positively or negatively

Continued movement of the continental crust on the west side of the San Andreas fault could result in which of the following features?

an island

What is a mantle plume?

an upwelling of hot mantle from the Earth's interior that is cylindrical in shape

Moderately viscous and gas-rich ____ lavas can erupt as lava flows or pyroclastic materials, leading to the steepening slope of composite volcanoes.

andesitic

Based on what we learned about igneous composition and texture, which of the following statements is TRUE?

any composition of magma/lava can cool to form any of the discussed textures, because the two properties are independent from one another

What is the smallest size classification of pyroclastic material?

ash

Pyroclastic debris from a volcanic eruption can include _____.

ash and cinders

Which of the following is a layer of the Earth that is classified NOT by composition, but by physical properties?

asthenosphere- The asthenosphere is a solid, but mobile part of the upper mantle.

Where in the ocean does oceanic lithosphere sink into the mantle?

at ocean trenches

In which of the following lava types would you expect to see the development of pahoehoe?

basalt

What is the dominant lava erupted from volcanoes on Hawaii and Iceland?

basalt

Broad sheets of fluid ____ lava travel long distances and give shield volcanoes their distinctive shape.

basaltic

Which of the following types of lava will most likely lead to a volcanic eruption of an effusive nature?

basaltic

Mt. Vesuvius erupted in a very violent explosion in 79 CE and buried the residents of Pompeii in ash. On the basis on this information, which of the following would you LEAST expect to find at Vesuvius?

basaltic (mafic) lava

The character of a lava flow depends on the viscosity of the lava erupted. _____ lava is less viscous than ____ lava.

basaltic / rhyolitic

Minerals must be solid, have an orderly atomic structure, have a recognized chemical composition, be naturally occurring, and __________.

be generally inorganic in origin

The mineral composed of calcium carbonate that reacts with hydrochloric acid to produce carbon dioxide bubbles and a solution of water and calcium ions is called:

calcite

Which carbonate mineral reacts readily with cool, dilute hydrochloric acid (HCl) to produce visible bubbles of carbon dioxide gas?

calcite

Most marine organisms produce the mineral substance ________, which will later become limestone.

calcite (CaCO3)

Which of the following could cause rock to melt?

change in composition, decrease in pressure, increase in temperature

A very steep-sided volcano built primarily from ejected lava fragments is called a ____

cinder cone

What is the tendency of certain minerals to break along smooth, parallel planes called?

cleavage

Convection works because _____

cold material is denser than the same material when it is hot

A ____ has broad and moderately steep flanks and a steep summit. It results from the eruption of a mixture of both lava flows and pyroclastic deposits that contain less fluid materials and travel shorter distances.

composite volcano

Quartz exhibits __________.

conchoidal fracture

Which of the following are true dark colored silicate minerals?

contain iron and magnesium high density high melting temperaturecommon in Earth's oceanic crust

Which type of tectonic boundary is the result of two tectonic plates colliding with each other?

convergent boundary

volatile rich magmas are generated by melting due to addition of volatiles. At what plate tectonic setting does this occur?

convergent subduction

Which of the following is a factor that does not affect the generation of magma?

crystal size

Continental rifts produce magma that is formed by ____ melting in the mantle with felsic magmas produced by _____

decompression / partial melting of continental crust

Which two processes commonly generate magma?

decompression melting and wet melting (the addition of volatiles)

What main hazard do lava flows pose to humans?

destruction of immovable property

What mineral is the hardest known substance in nature?

diamond

Which tectonic boundary results when two tectonic plates pull apart from each other?

divergent boundaries

A caldera forms by:

draining of a magma chamber beneath a volcano during an eruption

What are the lightest in weight or least massive of the basic atomic particles?

electrons

What discourages minerals from achieving habit?

enclosed spaces

When lava erupts at Earth's surface, what type of rock is produced?

extrusive

The last minerals to crystallize on Bowen's Reaction Series result in igneous rocks with a __________ composition.

felsic

Which of the choices below lists the four basic compositional groups of igneous rocks in order from highest silica content to lowest silica content?

felsic, intermediate, mafic, ultramafic

What type of texture occurs in igneous rocks that cool so rapidly that unordered ions are "frozen" in place?

glassy

Which of the following has the highest specific gravity?

gold

determine the composition of the granite and basalt below

granite = felsic basalt = mafic

Igneous rocks of felsic composition have __________ and __________ relative to mafic igneous rocks.

greater silica; lower melting temperature

What minerals make up table salt?

halite

Why does a higher temperature cause the viscosity of a magma to decrease?

heat breaks bonds between atoms and allows them to move easily past one another

Are the vertical or horizontal lines the transform boundary?

horizontal

A very long-lived magma source located deep in the mantle is called a(n) __________.

hot spot

Which of the following is false about hot spot volcanism?

hot spot volcanoes are always explosive

Which of the following is a mineral?

ice

Based on the map image below, where do you think the spreading rate is greatest?

in the Pacific Ocean

If a body of magma becomes more felsic (richer in Si), its viscosity will:

increase

Which of the following could cause rock to melt?

increase in temperature, change in composition, decrease in pressure

As the silicate structures change from isolated silica tetrahedra to chains and frameworks of silica tetrahedra, the ration of silicon atoms to oxygen atoms _____.

increases

Which of the following minerals is an example of a silicate

olivine (MgFe)2SiO4

Considering a felsic magma, what was the likely composition of the source of that magma, knowing that most magma forms by partial melting of a source rock?

intermediate

A phaneritic texture is characteristic of a(n) __________ igneous rock that cooled __________.

intrusive; below the surface

What is the name given to an atom that gains or loses electrons in a chemical reaction?

ion

The crystallization of salt from evaporating sea water:

is an example of precipitation from a solution

Identify the FALSE statement about volcanic ash hazards

it is not hazardous if breathed in because the size of particles is too small

All of the following criteria define a mineral except:

it is organic- For any substance to be considered a mineral, it must be inorganic.

The external expression of a mineral's orderly internal arrangement of atoms is referred to as:

its crystal form.

What does grain size generally indicate about the cooling of a melt?

larger crystals indicate that the melt cooled very slowly at depth

Which of these volcanic settings produced 70% of the Earth's surface?

lavas erupted at mid-ocean ridges

Magmas are composed of which of the following components:

liquid melt, solid minerals, gasses (either dissolved in the melt or as gas bubbles)

Which of the following are true of light colored silicate minerals?

low density low melting temperaturecommon in Earth's continental crust

The amount or quality of light that is reflected from a mineral surface is known as __________.

luster

Which of the following describes the way light reflects from the surface of a mineral?

luster

________ refers to a mineral's intensity and quality of reflected light.

luster

Effusive volcanoes are those with low viscosity lavas that are likely ____ in composition. A _____ volcano is usually effusive.

mafic / shield

The property of cleavage reflects:

mechanical breakage along planes of weakness within the mineral.

Regardless of their size, most rocks are made up of __________.

minerals

Which of the following statements about divergent boundaries is true?

new ocean crust is created at a divergent boundary

Are rhyolite eruptions always explosive?

no, sometimes they produce lava domes that erupt very slowly over many years

This is a glassy textured igneous rock that is black in color. What rock is this?

obsidian

Why are rocks that formed in an oceanic environment found in the highest parts of the Himalayan Mountains today?

ocean sediments were trapped and deformed during the continent-continent collisions that formed the Himalayan Mountains

What is the main material being subducted at an ocean-continent convergent boundary?

oceanic lithosphere

The major difference between oceanic-oceanic convergence and oceanic-continental convergence is that:

oceanic-oceanic convergence produces A VOLCANIC ISLAND ARC and oceanic continental convergence produces A CONTINENTAL VOLCANIC ARC

Which of the following minerals crystallize early in Bowen's reaction series?

olivine

Which of the following is not part of the definition of a mineral?

organic

Oceanic lithosphere contains oceanic crust and the __________.

outermost part of mantle beneath the oceanic crust

Rigid lithosphere plates move ____

over the more ductile asthenosphere

What element is the most abundant in Earth's crust by weight?

oxygen

Which of the following terms best describes this extrusive igneous feature?

pahoehoe lava

Which of the following is NOT a piece of evidence Alfred Wegener used to describe his hypothesis of Continental Drift?

paleomagnetism

Why are volcanic chains associated with convergent boundaries?

partial melting occurs due to subduction

Which model of the atom most closely represents our understanding of the structure of atoms?

probability model

Which of the following denotes the massive, positively charged, nuclear particles?

protons

Sometimes minerals have nice crystal faces that can make them quite valuable to collectors. Minerals can form in this way:

providing there is open space for them to grow

Which volcanic rock is extremely vesicular and glassy?

pumice

Explosive eruptions of ____ create steep-sided cinder cone volcanoes.

pyroclastic materials

In the field, you find an unidentified mineral that is clear, exhibits conchoidal fracture, and can scratch glass. This mineral is most likely:

quartz

Which mineral is composed of silicon dioxide (SiO2)?

quartz

Which of the following substances is a mineral?

quartz- Quartz is a naturally occurring inorganic compound with an orderly internal structure and a chemical composition of SiO2.

The principal mineral used in making glass is:

quartz- The mineral quartz is a primary ingredient in the production of glass.

Hardness describes a mineral's __________.

resistance to being scratched

Which of the following is a chemical equivalent of granite?

rhyolite

Which of the following types of magma has the highest viscosity?

rhyolitic

Which statement correctly describes rock forming minerals and economic minerals?

rock-forming minerals consist of a few types of minerals that are abundant in Earth's crust, whereas economic minerals are less abundant and are used extensively in the manufacture of products

Which of the following is not a fundamental particle found in atoms?

selectron

A wide volcano that produces mainly basaltic lava flows is called a _____

shield volcano

Most igneous rocks are composed of ____ minerals.

silicate

Transform boundaries are classified under which type of fault?

strike-slip

The main difference between lavas that form pahoehoe texture and lavas that form aa texture is:

temperature

rhyolite lava:

tends to erupt explosively due to pressure buildup from the high viscosity of the lava

What experiments did Tuttle and Bowen perform?

tests of the temperature and pressure conditions required to melt granite and form magma

What term describes the sizes, shapes, and arrangements of mineral grains in an igneous rock?

texture

Which of the following lithospheric plates is not included among the seven largest?

the Philippine plate-

Why does water induce melting in a subduction zone?

the addition of water lowers the melting of rock

What is the significance of the ages of the Hawaiian Islands in terms of plate tectonics?

the ages decrease toward the big island of Hawaii, showing that the Pacific plate is moving NW over a stationary hot spot

Crystal habit is the shape that a mineral develops by the repetition of __________.

the basic unit cell of a mineral

What is the geothermal gradient?

the increases in temperature of the Earth with increased depth

The hotter the magma...

the less viscous it becomes

If you had the ability to travel anywhere on Earth, inside or out, where would be the best place to go find peridotite?

the mantle

As a result of partial melting, magma originates in __________.

the mantle and crust

Which of the following determines the chemical properties of an element?

the number of protons

Earth's lithospheric plates are composed of crust and which of the following layers?

the outermost portion of the mantle

At a divergent boundary, what is the relative motion of the plates on each side of the boundary?

the plates away from each other

In the Mastering Geology assignment this week we learned about Flood Basalts. One example was the Columbia River Flood Basalt Province. Which of the following are true about these flood basalts?

the relatively flat features of solidified flood basalts is indicative of the very low viscosity of the lava when it was erupted and emplaced the flood basalts have fine grained texture that indicates relative fast extrusive cooling thick layers of basalt indicate many repeated eruptions of multiple lava flows with the youngest flows at the top

What does pyroclastic texture in an igneous rock suggest about its formation?

the rock likely formed by a violent volcanic eruption

What is peridotite?

the rock making up the mantle

When moving away from a divergent boundary in either direction, which of the following statements is true?

the rocks increase in age

Many people say that California is going to fall off the face of the Earth, using what we know about plate tectonics, which of the following is most likely?

the western most edge of California and the Baja Peninsula will slowly move north relative to the rest of the North American continent

Why can't scientists retrieve information about the Atlantic Ocean basin that is older than roughly 200 million years?

there was no Atlantic Ocean 200 million years ago

Identify the FALSE statement about pyroclastic flow hazards

they can flow up to 100 km away from a volcano

How do the electrons behave in a mineral with metallic bonding?

they can move relatively easily from atom to atom inside the mineral

Which of the following are used for studying rocks with a polarizing or petrographic microscope?

thin sections

Why does quartz have this pyramid shape?

this shape results from the ordered crystal structure of SiO2

Which one of these processes does NOT contribute to plate motions?

tidal forces

Which type of tectonic boundary is the result of two tectonic plates sliding past each other?

transform boundary

Divergent boundaries are not one, smooth ridge of separation. Instead, they are broken into a series of segments, with different segments of fault offset from others. What features allow for the offset of divergent boundaries?

transform faults

Hornblende has _____ cleavage planes at _____ angles.

two; non-90°

A __________ is an open cavity in a volcanic rock that was filled by a gas bubble when the lava was still mainly liquid.

vesicle

Why are volcanic rocks often exposed at Earth's surface as hills, ridges, and mountains surrounded by areas of lower elevation?

volcanic rocks are often more resistant to erosion than surrounding rock

nonexplosive eruption

volcano fed by magma with low of dissolved gases volcano fed by mafic (basaltic) magma volcano fed by high temperature (100 degree Celsius) magma`

explosive eruption

volcano fed by silica rich magma

cinder cone

volcano known for reddish brown lapilli volcano with a crater at the summit and steep flanks

not related to eruption explosiveness

volcano that has not erupted for a long time volcano at high elevation

composite cone

volcano with a steep summit and broad moderately steep flanks volcano known for erupting lava and pyroclastic material

shield volcano

volcano with very broad slopes and a caldera volcano known for long lava flows and lava tubes

Which of the following geologic processes and/or phenomena is not found at transform plate boundaries?

volcanoes

What material was added to powdered rock during Tuttle and Bowen's experiments?

water

Water induced melting at subduction zones comes from where?

water contained within minerals in the subducting plate is released during metamorphism

Which of the following igneous rocks has a pyroclastic texture, meaning it was formed from a glowing avalanche?

welded tuff

The volcanic islands in the above figure were created as the tectonic plate passed over a hot spot in the mantle. Based on the ages of the volcanic islands, in what direction was the tectonic plate moving toward?

west

When will magma rise to Earth's surface?

when the magma is less dense than adjacent rock