Geology Final

Atoms that are heavier than iron are generally produced by

explosions of supernovas

The energy that is released during an earthquake travels through the Earth an vibrations termed ___

seismic waves

A _____ is a scientific instrument used to sense the ground motions produced by an earthquake

seismometer

The transformation of protoliths into metamorphic rocks solely through transfer of heat is termed____ metamorphism

thermal

Many desert streams are ephemeral, meaning

they only carry water after rainfall events, and most of the time they are dry streambeds

Compared to oceanic crust, continental crust is

thicker and less dense

At a minimum, how many seismic stations are necessary to locate the epicenter of an earthquake?

three

Igneous rocks are formed

through the cooling and crystallization of a melt

If a beach is in an east-west orientation and the waves are approaching the shore from the southeast, as shown in the figure below, which direction will the longshore current be moving? (HINT: the sand is moving from the west to the east)

to the east

The image below shows ancient dunces exposed in Zion National Park in Utah. Using the interpreted portion of the image on the left, what was the dominant wind direction that formed these sedimentary structures?

toward the right

Sea level rises locally, and marine sediments are deposited on top of terrestrial sediments during events termed ____________.

transgression

Grains become rounded primarily during

transportation

Chemically precipitated limestone that forms in caves or around hot springs is termed

travertine

What kind of drainage network is likely to form in a landscape characterized by a parallel series of ridges and valleys

trellis

According to the moment magnitude scale (Mw)—a magnitude 8 earthquake would be 1,000 times greater than a magnitude ____________ earthquake.

5

______ proposed the continental-drift hypothesis, suggesting that the arrangement of continents on the planet has changed over geologic time.

Alfred Wegener

Which of the following best describes how the Earth's Moon formed?

Capture: Planetoid collided with early Earth and debris coalesced to form the Moon

Which of the following is true of continental lithosphere compared to oceanic lithosphere?

Continental lithosphere is thicker than oceanic lithosphere

The term and concept of seafloor spreading were developed by

Harry Hess

Which of the following is true of the lithosphere?

It is composed of the crust and the uppermost rigid part of the mantle

Based on the image below, what is the age of Layer 7 relative to Layer 3?

Layer 7 is younger than Layer 3

______ commonly serves as a protolith in the formation of marble

Limestone

Which type of seismic wave has the fastest velocity?

P-wave

____ can occur where undercutting by waves or rivers removes support from beneath the cliff overhangs

Rock falls

______ commonly serves as a protolith in the formation of phyllite

Shale

Why do submarine slumps pose a hazard to people living in coastal areas?

Submarine slumps can trigger tsunamis

In a hot-spot volcanic island chain, such as the Hawaiian Islands, which of the following is true?

The ages and distance between volcanoes can be used to calculate plate velocities

Why is radiocarbon dating only rarely applied in geological work?

The half-life of carbon-14 is so short that it can only be used to date materials that are less than 70,000 years old.

Valleys carved by glaciers tend to be shaped like the letter _____, whereas valleys carved by water tend to shaped like the letter _____.

U; V

What type of mass wasting event is beginning to form on the hillside shown in the image below?

a slump

Vesicles in an igneous rock are evidence for which of the following?

abundant volatiles that formed gas bubbles

The image below of Delta Valley, CA shows a road that curves around a

alluvial fan

Seafloor spreading is driven by volcanic activity

along mid-ocean ridges

What is ventifact?

an exposed rock with facets carved by wind

Which of the following magma compositions are most commonly erupted in continental arc settings?

andesite and rhyolite

Look at the figure below. The contact between the Unkar Group and the Tapeats Sandstone is a(n)

angular unconformity

Structures- like jetties, groins, and breakwaters- that are designed to prevent beach erosion _____

are temporary solutions that decrease beach erosion in some places and increase it in others.

The _____ can flow while the ______ is a rigid solid.

asthenosphere; lithosphere

The majority of new oceanic crust is created

at mid-ocean ridges

A(n) _____ is a type of offshore sand bar that forms due to abundant sediment supply and sits above the mean high water level

barrier island

A vast, composite intrusive igneous body that covers hundreds of square kilometers (in a map view) is called a

batholith

If glaciers carry a mixture of different clast sizes, why are glacial outwash deposits layered?

because a glacier does not deposit outwash sediments; a river does

Why are salt lakes salty?

because evaporation from the lakes remove water but not salt

Why do deltas form?

because when streams reach base level, the sediments they carry settles out and is deposited

The ____ in the sequence of sedimentary rocks shown below may become a failure surface.

bedding planes

Body waves include

both S-and P-waves

Marble and quartzite are nonfoliated rocks because ____________.

both are dominated by minerals that produce equant grains

Faulting and earthquakes are examples of what type of deformation?

brittle

Glacial ice exhibits ________ behavior near the top but ________ behavior beneath a depth of more than 60 m.

brittle; plastic

the image below shows a mineral with hydrochloric acid applied to it. Based on the reaction and presence of gas bubbles which of the following minerals is the most likely to be ____

calcite

Explosive or voluminous eruptions may cause the volcano to collapse on the floor of the (now empty) magma chamber, producing a broad depression termed a ___________.

caldera

Limestone reefs and salt deposits are important rocks in the reconstruction of Earth history because they ____________.

can be used to infer the ancient climate of the Earth; they are deposited in environments that are restricted to warm climates

The majority of large cave and karst systems have resulted from _____ etching into _____

carbonic acid; limestone

Broadly, metamorphism involves

changes in mineralogy and texture in response to heat and stress

What type of sediment is typically found in lake bottoms?

clay/mud

The tendency for minerals to break along distinct planar surfaces that have a specific orientation in relation to the crystal structure is called

cleavage

Surface currents flow _____ in the Northern Hemisphere and _____ in the Southern Hemisphere

clockwise; counterclockwise

A desert may form along a coastline because a

cold current coals and dries the air

The image below shows an outcrop of coarse-grained sedimentary rock. Note the rock hammer for scale. What type of rock is smooth and rounded?

conglomerate

Large, thick-crusted, nonvolcanic mountain belts, like the Himalayas, are associated with ________.

continent-continent collisions

Subduction zones are found at ______ plate boundaries

convergent

Most medium- and deep-focus earthquakes occur at

convergent-plate boundaries

A volcanic arc results from ____ tectonic movements and its associated with a

convergent; subduction zone

As compared to coarse-grained igneous rocks, fine-grained igeneous rocks

cool and solidify more quickly

Slab pull occurs because subducting slabs are ___, and therefore are ____ dense than the surrounding asthenosphere

cooler; more

Which of the following types of mass movement takes place most gradually?

creep

The process of lowering the land surface by wind erosion is know as

deflation

The metal alloy that makes up the core of the Earth is _____ compared to the rocky mantle.

denser

The application of ____ during metamorphism causes elongated crystals to align parallel with each other. When this happens, the rock develops____

differentail stress; foliation

Which basic type of plate boundary is shown in the image below? (image is plates moving away from the mid-ocean ridge)

divergent

The study of which process has proven very useful in determining the structure and layering of the Earth's interior?

earthquakes

At transform plate boundaries

earthquakes are common but volcanoes are absent

Before an earthquake, rocks can respond to applied stress to a small degree by bending and warping without breaking. This is termed ___

elastic behavior

The point on the Earth's surface directly above the point where an earthquake occurs is termed the

epicenter

The intersection between a fault plane and the ground surface is called the

fault trace

That flat-lying area surrounding a river channel is termed the

floodplain

The speed at which ice in a glacier moves is slowest along the sides and bottom due to

friction

The idea that the continents had once fit together as a single supercontinent called Pangaea was rejected when first proposed because

geologists did not know of a force great enough to move continents

We distinguish between a mineral and a naturally formed glass (such as obsidian) because

glass does not have a fixed crystal structure

Mass movements are driven by

gravity

As compared to mafic igneous rocks, felsic igneous rocks

have a higher Si content

Basaltic lavas

have loe viscosity and low silica content

Over time, a stream tends to increase in length by eroding and extending to channel upstream, in a process called

headward erosion

An aquifer has ____ porosity and _____ permeability

high; high

Hot spots are caused by

hot plumes of mantle material that rises up through cooler, denser surrounding rock

The Hawaiian island chain is an example of a(n)

hot-spot island chain

When the Universe was very young, almost all matter consisted of the elements _______ and __________

hydrogen, helium

Hot water reacting with crust is the basis for what type of metamorphism?

hydrothermal

The point within the Earth where an earthquake originates is termed the

hypocenter (focus)

Thermal (contact) metamorphism occurs ____________.

in areas surrounding igneous intrusions.

If we mentally align the continents to fit Wegener's concept of Pangaea, evidence of Late Paleozoic glacial deposits ____________.

in much more readily explained than if continents are in their modern configuration

A coral reef would MOST likely be found

in the shallow waters surrounding a tropical volcanic island

If a body of magma becomes more felsic, its viscosity will

increase

With increasing distance from a mid-ocean ridge, the age of oceanic crust

increases

When magma solidifies below the surface of the Earth ___ are formed

intrusive igneous rocks

In the figure below, there are springs located along the surface trace of the fault. Given that the recharge area for these springs is located in the rocks on the left of the figure, what can be said about rock unit A on the right side of the fault?

it has low permeability

Which of the following describes sediment deposition in alluvial fans?

it is where the slope of the stream decreases and the water slows

A fast-moving wet slurry consisting of a mixture of water and volcaniclastic debris is termed a

lahar

The fault (moves down on the left side and up on the right side) is

left lateral strike-slip

Wet and unconsolidated substrates are uniquely susceptible to ________ during an earthquake.

liquefaction

Compaction and cementation of grains occurs during

lithification

What magma properties would most likely lead to the formation of a shield volcano?

low viscosity and mafic composition

Land subsidence is likely when ________.

lowering the water table causes sediment pores to collapse

Pumping vast quantities of water locally

lowers the local water table, forming a cone-shaped depression

The difference between magma and lava is that

magma is melt underground, whereas lava is melt that has emerged from the surface

Marine magnetic anomalies in oceanic crust result from seafloor spreading in conjunction with

magnetic polarity reversals

Flood basalts such as those found in the Columbia Plateau and the Deccan region are associated with

mantle plumes

What types of moraines are shown as the dark strips in the figure below? (long, curvy, and goes downwards)

medial moraines

Foliated metamorphic rocks possess

mineral grains in preferred orientations or patterns of association.

During an earthquake, if a hanging wall slides downward relative to a footwall, that fault is ____ (it pushes outwards away from each other)

normal

How much of a radioactive parent isotope will remain after three half-lives have passed?

one-eighth

Which of the following human-activities will lead to destruction?

overgrazing by livestock in an area

A meander that is cut off to become completely isolated from the main channel but which retains water is called a(n)

oxbow lake

Volcanism is least likely to occur in which of the following geologic setting?

passive margin

According to the theory of plate tectonics, plates are

pieces of lithosphere that move over the surface of the Earth with respect to one another.

When a solution becomes oversaturated new solid particles

precipitate from the solution

Surface waves

produces most of the damage to buildings during earthquakes

The preexisting rock that is subsequently altered to form a metamorphic rock is termed a

protolith

A fragmental, extrusive igneous rock is referred to as which of the following?

pyroclastic

Sediments deposited in a beach environment are typically

rounded and well sorted

In the picture below, fragments of bed load bounce along the bed and knock other grains up into the flow to move downstream for short distances in a process called

saltation

Which of the following features is characteristic of a rocky coast?

sea stacks

Which of the following describes the progression of rock types through increasing metamorphic grade from left to right?

shale-> slate-> phyllite-> schist

Limestone is most likely formed in which of the following environments?

shallow-marine carbonate

The vertical features preserved in the basalt flow in the image below formed because the lava

shrank as it cooled, forming tall polygonal-shaped fractures

The mineral class that makes up more than 95% of the continental crust is termed as

silicates

What type of igneous intrusion is the horizontal rock unit (in the between the sandstone layers)

sill

On either side of a mid-ocean ridge, oceanic lithosphere slowly ___

sinks into the asthenosphere because it cools and thickens, increasing in density

A hanging valley is formed when a _____

smaller glacially carved valley intersects a larger glacially carved valley

The Milankovitch cycles describe the change in ____ cannot by cyclical changes in the Earth's orbit around the Sun

solar insolation

Tropical storms and cyclones can cause significant coastal flooding called _____ when winds push water onto shore and low pressure causes the sea surface to rise.

storm surge

Of the three primary forms of subaerial volcanoes ____ are large cone-shaped mountains that consist of alternatives of tephra and solidified lava

stratovolcanoes

Generally, which of the following types of earthquakes waves travel with the slowest velocity?

surface waves

In the heliocentric model,

the Earth orbits around the sun

Which earthquake severity scale varies from locality to locality for a single earthquake?

the Mercalli scale

Porosity is best described by which of the following?

the amount of open space in a rock or sediment

What kind of information does a roche mountonee reveal?

the direction a glacier was moving

If a basalt body cuts across a fault, what are the relative ages of the basalt and the fault?

the fault must to be older, according to the principle of crosscutting relationships

Which of the following statements is true regarding the clasts inside the granite pluton?

the inclusions are older than the pluton

Which geological setting is likely to experience the least amount of seismic activity?

the interior of a tectonic plate

A long delay between the arrival of P-waves and S-waves at a seismometer means that

the seismometer is located far from the earthquake

the pillow basalts in the image are

underwater at a mid-ocean ridge

Which of the following scenarios is most likely to result in an emergent coast?

uplift associated with active margin tectonics

In what direction does water flows in the unsaturated zone?

vertically downward

Differentiation of the core from the mantle early in the Earth's history was possible because the planet was ______ at the time

very hot

Deep-sea trenches are likely to be located near

volcanic arcs

Common volcanic gases include the following

water vapor, carbon dioxide, and sulfur dioxide

The breakdown of exposed rock into small fragments and dissolved ions is termed

weathering

Slope failures are most likely to occur in _____ conditions

wet, high-relief

The Great Basin deserts found in the western United States are primarily the result of being located

within the rain shadow of one or more mountain ranges