Geology Exam 1

tectonic plates move at rates that are approximately

1 to 15 cm/year

the Wadati-Benioff zone extends down within the mantle to a maximum depth of _____

660 km

the image below shows a view of a typical segmented mid-ocean ridge. what letter below marks the location of the active transform fault

B

which one of the pictures does NOT show a rock

D

the image below shows a cross-sectional view of a typical subduction zone, with earthquakes locations shown with small dots. the band of earthquakes that follow the shape of the downing plate is termed the

Wadati- Benioff zone

the internal ordering of mineral crystals can be detected using

X-ray diffraction

in the scope of plate tectonics, an active margin is defined as

a continental coastline that coincides with a plate boundary

minerals are all naturally occurring solid substances with a definable chemical composition. they also must possesses

a fixed crystalline structure (spatial arrangement of atoms and ions)

which of the following is NOT true concerning the color of minerals

a mineral's color reflects the wavelengths of light that are absorbed by the mineral

which of the following would NOT be considered a rock?

a natural pile of unconsolidated sand

cleavage in minerals refers to

a tendency to break along planes of weakness

the rate of the motion of a lithospheric plate with respect to a stationary location inside the Earth is termed ____. while the motion of a plate with respect to another is termed _____

absolute plate velocity; relative plate velocity

earthquakes occur most frequently near ________ margins

active

which of the following is NOT true about minerals

all mineral compounds of more than one element

the oceanic lithosphere is typically coated in a layer of sediment, which of the following is not true about this sediment

all of the sediment is eventually subjected along with the lithosphere into the mantle

in a hot-spot volcanic island chain, such as the Hawaiian Islands, which of the following in NOT true?

all volcanos in the chain can be simultaneously active

the youngest sea floor is typically found _______

along mid-ocean ridges

a guyot is

an extinct ocean hot-spot that has subsided below sea level

Si04, S2-, and CO32- are all examples of ____

anions

of the ~4000 known minerals, the vast majority _____

are rare

most of the pushing force driving plate motion is produced

at mid-ocean ridges

most of the pulling force driving plate motion is produced

at subduction zones

which of the following statements is true concerning rock produced at mid-ocean ridges

basalt is produced at shallow depths and gabbros at deeper depths

why is the rock cycle important

because it explains how rocks are constantly changing from one type to another

why do geologist classify rocks

because rocks are the key to determine how the Earth is formed

what does uplifting metamorphic rocks during mountain building lead to the formation of sedimentary rock

because the rocks become exposed to the elements and erode

with regard to minerals, hardness refers to the ability to resist

being scratched

which of the following is NOT a way for minerals to crystalize

bonding carbon to oxygen atoms to form organic compounds

identify which of the following paths could eventually transform a metamorphic rock into a sedimentary rock

burial -- meting -- erosion and deposition

the image below shows a mineral with hydrochloric acid applied to it. what mineral is this

calcite

diamond and graphite are both polymorphs of

carbon

calcite (CaCO3) is in which mineral class

carbonates

composition describes the

chemical makeup of a rock

minerals are grouped into mineral classes primarily on a basis of

chemistry, specifically the anions within the chemical formula

how is chloride different from chlorine

chloride has more electrons than chlorine

imagine if you are holding a rock composed of small sand grains cemented together. what sub classification of sedimentary rock is this

clastic

when two plates composed of continental lithosphere are pulled together at a convergent boundary, the result is

collision and mountain formation

trace amounts of impurity in a mineral can commonly produce significant differences in ____ amount individual crystals of this mineral

color

synthetically made glass and natural quartz crystals both exhibit a fracture pattern termed

conchoidal fracture

the image below shows a mineral specimen of quartz. what is the term for the smoothly curving clamshell-shaped surface on the sample below

conchoidal fracture

large, thick-crusted, nonvolcanic mountain belts, like the Himalayas, are associated with

continent-continent collisions

deep-oceanic trenches are features of _____ plate boundary type

convergent

subduction zones are found at which basic plate boundary type

convergent

the lithosphere of the Earth is generally thickest at and near _____ plate boundaries

convergent

which basic type of plate boundary is shown in the image below? (towards)

convergent

the volcanoes of the Cascade Mountains in the Northwest United States are related to melting of rock associated with a _____

convergent plate boundary

slab pull occurs because subjecting slabs are

cooler, and therefore more dense, than surrounding asthenosphere

what is the term used for the arrangement of the minerals in this picture

crystalline

what type of texture is shown int he photo micro graph

crystalline

which of the following is NOT one of the three major rock groups

crystalline

where would you expect to find metamorphic rocks forming

deep inside a mountain range

using the Mohs hardness scale below, which of the following statements is NOT true

diamonds are twice as hard as apatite

Under the theory of plate tectonics, the plates themselves are

discrete pieces of lithosphere at the surface of the solid Earth that moves with respect to one another

Iceland is on the of the few places in the world that is both above sea level and situated atop a ___ plate boundrary

divergent

the lithosphere of the earth is generally thinnest at ______ plate boundaries

divergent

which basic type of plate boundary is shown in the image below? (going away)

divergent

mid-ocean ridges are segmented and contain which two basic types of plate boundaries linked together

divergent and transform

natural glass is NOT considered a mineral because it

does not have a fixed crystalline structure

the distribution of _____ across the globe provides the primary indicator of boundaries between all tectonic plates

earthquakes

at transform plate boundaries

earthquakes are common but volcanos are absent

which of the following choices has particles ordered from smaller to largest in size

electron, proton, nucleus, atom

summed over the entire surface of Earth, the rate of spreading at divergent boundaries is lithospheric consumption at subduction zones

equal to

granite is a type of rock that forms deep underground from magma that cools very slowly. what type of rock is granite

equant

in order to form a sedimentary rock, what process must happen

erosion

what process must occur for an igneous rock to turn into a sedimentary rock

erosion

gemstones are commonly found in pegmatites, which are igneous rocks that are

exceptionally coarse grained

the diamonds we typically see today in engagement rings do not display their natural crystal faces but rather _____, which are made by grinding the gem on a spinning lap

facets

minerals that do not possess cleavage are said to process

fracture

in which type of silicate are the greatest portion oxygen atoms shared by pairs pf adjacent tetrahedra

framework silicates

compared to typical oceanic lithosphere, the thickness of the continental lithosphere is _______

greater

which of the following minerals is more commonly known as table salt

halite

according to the model proposed by geophysicist J. Tuzo Wilson, hot spots are caused by _____

hot plumes of mantle material that rise up through cooler, dense surrounding rock

consult the figure below, Hawaii is an example of ______

hot-spot volcanism

which of the following is a mineral

ice, which is water in the solid state

if a rock is buried and subjected to high heat and pressure, then uplifted, exposed, eroded away, and deposited, which type was NOT involved into the sequence

igneous

if a rock is buried, then exposed and eroded, and the sediment is then lithified, after which the rock is melted and cooled, what type of rock is the end result

igneous

what type of rock is being formed in this picture

igneous

what type of rock is formed during a volcanic eruption

igneous

what is the progression of rock types if the steps of a process are are followed: melting and cooling -- erosion and deposition -- burial

igneous -- sedimentary -- metamorphic

if a rock is melted, then erupted a the surface and cooled, then eroded and deposited, what two rock types are involved in the sequence

igneous and sedimentary

the theory of plate tectonics...

incorporates and explains both sea floor spreading and continental drift

unlike the lithosphere, the asthenosphere _______

is able to flow over long periods of time

at a subduction zone, the down going (subducting) plate ______

is always composed of oceanic lithosphere

continental lithosphere

is thicker than oceanic lithosphere

the lithosphere of Earth will not flow because it _______

is too cool

how would you tell if a rock is a crystalline

it contains interlocking crystals

what is the purpose of the cement surrounding the grains in this photo

it creates a coherent, intact rock

diamonds are usually founding pipes 50 to 200 m across made of

kimberlite

ore minerals, such as galena and hematite, tend to be different from typical minerals in that they have a

large specific gravity

the thickness of oceanic lithosphere is _______

last near the mid-ocean ridges and thickens away from the ridges

the way of a mineral scattered light is useful diagnostic property termed

luster

at a subduction zone, the overriding plate ______

may be composed of either oceanic or continental lithosphere

identify the correct steps to transform an igneous rock into a metamorphic rock then into an igneous rock

melted and cooled -- buried deep -- melted and ocoled

what must occur in order to create an igneous rock

melting

what process transforms a metamorphic rock into an igneous rock

melting

what process transforms a sedimentary rock into an igneous rock

melting

if a rock is subjected to high heat and pressure, a _____ rock will form

metamorphic

what type of rock is formed from deep burial

metamorphic

what type of rock is shown in this picture

metamorphic

what is the progression of rock types if the steps of a process are as followed: burial -- uplift, erosion, and deposition -- burial -- melting

metamorphic -- sedimentary -- metamorphic -- igneous

what do geologists call the layering seen in this picture

metamorphic foliation

igneous rock form from

molten rock cooling and forming crystals

what must happen in order to transform a metamorphic rock into a sedimentary rock

mountain building

the single property that can be used to identify any mineral is

multiple properties must be used to identify a mineral

in silicate minerals, silica tetrahedra may be chemically ponded to form all of the following EXCEPT

nearly perfect pyramid-shaped crystals

the atomic number of an element corresponds to the _____

number protons

a volcanic island arc forms when ____

oceanic lithosphere subjects beneath another oceanic lithospheric plate

the most recently formed portion of any crystal is always found

on the outer edges

for the majority of minerals, the streak color obtained when the mineral is scratched against a porcelain plate is

only useful if the mineral is softer than porcleain

minerals utilized by humans as a source of metal are termed ____ minerals

ore

the silica tetrahedron that forms the backbone of all the silicate minerals is composed of silicon and what other element

oxygen

continental coastlines that occur within the interior of a plate tectonic plate are called ____ margins

passive

broad, sediment- covered continental shelves are found along _____

passive margins

which common gemstone results from biomineralization

peral

which of the following is NOT a mineral

petroleum

hot-spots track resulting from moving

plates

when two different minerals have the same chemical formula but different crystal structures, they are said to be

polymorphs

when a solution becomes oversaturated, the new solid particles are said to _____

precipitate from the solution

deformed (bent, stretched, or cracked). lithosphere occurs ______

primarily on the margins of tectonic plates

which of the following common minerals is hardest

quartz

the mid-oceanic ridges are elevated above the surrounding sea floor because

ridge rocks are hot and therefore have relatively low density

what is the name of the cycle shown in the picture

rock cycle

identify the correct steps in the transformation of a sedimentary rock into a metamorphic rock

rock eroded away and deposited in ocean basin -- rock bird under many layers of sediment

identify the correct steps in the transformation of an igneous rock to a metamorphic rock

rock melted and cooled -- rock subjected to high heat and pressure

which is a characteristic used to classify a rock

rock texture

which two gems are special versions of the common mineral corundum (Al2O3)

sapphires and rubies

if a rock is uplifted and exposed, what is the likely next type of rock that will form

sedimentary

what type of rock is formed after erosion, deposition, and lithification

sedimentary

what type of rock is shown in this picture

sedimentary

what type of rock would you expect to form from the material along a beach

sedimentary

which type of rock is formed by precipitation of minerals from a solution

sedimentary

what is the progression of rock types if the steps of a process are as followed: erosion and deposition -- melting -- melting -- erosion and deposition

sedimentary -- igneous -- igneous --sedimentary

potassium feldspar (KAIS3O8) is in which mineral class

silicates

the mineral class that makes up >95% of the continental crust is termed the

silicates

on either side of a mid-ocean ridge, the lithosphere begins to

sink because it cools and contracts

which of the following is not true about Earth's tectonic plates

some tectonic plates contain only continental lithosphere

____ is a mineral property defined by the density of the mineral sample divided by the density of water (1.0 g/cm3)

specific gravity

the color of a mineral in powdered form is termed

streak

the image below shows a mineral specimen of pyrite. what is the term for the thin parallel corrugations or stripes shown on the crystal faces below

striations

how does a metamorphic rock form

subject to a rock to high heat and pressure

pyrite (FeS2) is in which mineral class

sulfides

which of the following common minerals is softest

talc

the primary difference between lithospheric and asthenospheric mantle that gives rise to numerous different patterns of physical behavior is _______

temperature: the lithosphere is cooler than the asthenosphere

_____ is an example of a continental rift and the _____ is/are the result of collusion

the Basin and Range Province; Himalayan Mountains

oceanic lithosphere thickens away from the mid-ocean ridge primarily due to

the addition of new lithospheric mantle as a result of cooling

a triple junction, like the one shown below, is a place on Earth's surface where _____

the boundaries of all three lithospheric plates meet at a single point

geologists sometimes use analytical equipment to help identify rocks. one commonly used machine is the electron micropore, which focuses a beam of electrons on a sample to determine

the chemical composition

minerals in geodes from spectacular euhedral crystals because

the crystals have abundant room to grow in their hollow surroundings

according to Achimedes' principle of buoyancy, an iceberg sinks until ______

the total mass of the water displaced equals the total mass of the whole iceberg

what is the rock cycle

the transformation of one rock type to another

why have many Precambrian rocks remained unchanged for billions of years

they are not protected within the interiors of the contents

the picture below shoes a ____ of rock that geologists use to determine the minerals in a rock

thin section

why do geologists use thin sections of rock

to identify the minerals

the San Andreas fault zone in California is an example of a _____ plate boundary

transform

which type of plate boundary is shown in the image below

transform

segments of mid-ocean ridge systems are offset. between the offset segments we observe _____

transform faults

hot spots can occur

within either continental or oceanic plates