question

The original volcano Mount Mazama erupted to form Crater Lake, Oregon

answer

True

question

A___is a volcanic depression much larger than the original crater, formed when the volcano collapses into a vacated magma chamber.

answer

Caldera

question

__describes the surface of a basalt flow with a smooth ropy surface.

answer

Pahoehoe

question

Major volcanic peaks of the Cascade Mountains, like Mt. Rainier, Mt. Shasta, Mt Hood, and Mt St Helens, have been active volcanos for 30 to 40 million years.

answer

false

question

Shield volcanos have _bases and_ inclined slopes.

answer

broad, gently

question

What are the three factors that influence viscosity of a lava?

answer

temperature, composition, dissolves gasses

question

Most of the gas released by volcanic eruption is sulfur dioxide.

answer

False

question

Occasionally, a volcano will spew large amounts of fine volcanic dust into the high atmosphere. This dust can have the effect of_.

answer

All of the answers are correct

question

_describes the surface of a basalt flow with a jagged, rubble surface.

answer

Aa

question

Silica lavas, which are relatively high in silica, tend to be more fluid than mafic magmas

answer

True

question

Weather volcanic ash and lava produce excellent fertile soils.

answer

True

question

The last volcano to erupt in the continental 48 states was_

answer

Mt. St. Helens

question

Tuff is a rock composed of fine-grained pyroclastic particles.

answer

True

question

The large pyroclasts are_

answer

Bombs/blocks

question

_are tunnel like caves within a lava flow.

answer

Lava tubes

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Pillow structures, pillow-shaped rounded masses, form where lava is extruded under water.

answer

True

question

How do scientist indicate the power of volcanic eruption?

answer

volcanic explosive index

question

The most common mafic volcanic rock is

answer

basalt

question

The more_ the lava, and the greater the amount of gas trying to escape, the more violent the eruption.

answer

viscous

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Volcanic eruptions have no effect on climate.

answer

False

question

Composite volcanoes are also called cinder cones volcanoes.

answer

false

question

The Roman city of_ was destroyed by the eruption of Vesuvius in 79 AD.

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Pompeii

question

The island of the Hawaiian chain are an excellent example of a series of_

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shield volcanoes

question

The most abundant silicic volcanic rock is_

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rhyolite

question

A_ volcano is composed of alternating layers of pyroclastic fragments and solidified lava flows.

answer

composite

question

The island o Hawaii are essentially a series of shield volcanoes built upward from the ocean floor over million years.

answer

True

question

The eruption of_ is related tot he fact that the North American plate is overriding a portion of the Pacific Ocean floor.

answer

Mount St. Helen

question

The term_ is used for molten rock on the Earth surface

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lava

question

Pahoehoe lava is characterized by a ropy or billowy surface.

answer

True

question

Earth is the only major body in the solar system on which there are active volcanoes.

answer

False

question

The single most important agent for the chemical weathering is temperature.

answer

false

question

Chemical weathering generally proceeds_

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along contacts between mineral grains

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Water that has trickled down into a joint in a rock can freeze, expand, and_

answer

widen the crack and hastening the rock's disintegration

question

The_ horizon is the incompletely weathered parent material lying below the B-horizon

answer

C

question

the process of chemical weathering is also called

answer

rock decomposition

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Plants and burrowing organisms contribute to soil development by

answer

all answers are correct

question

At the surface of the earth, ultramafic rocks in kimberlite pipes weather away leaving behind concentration of_

answer

diamonds

question

_is wind transported and deposited sediment

answer

LOESS

question

Sulfuric acid is produced naturally during_

answer

some volcanic eruptions

question

Ordinary rain has a pH of about 5.5 to 6 from the carbon dioxide in the atmosphere and from natural sources of acid sulfur gases

answer

true

question

Plants such as roots growing in cracks, and animals compacting the soil have little influence on mechanical weathering.

answer

false

question

Ferromagnesian minerals such as pyroxene, amphibole, biotite, and ovaline are chemically altered in the presence of_

answer

oxygen

question

Oxygen is abundant in the atmosphere but it does not combine with minerals of the Earth's crust.

answer

fasle

question

_is weathered unconsolidated material on top of solid bedrock

answer

REGOLITH

question

_are commonly left after complete chemical weathering

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Quarts and clay material

question

All rocks chemically weather the same way

answer

false

question

The B-horizon in soil is the zone of accumulation

answer

true

question

The_ horizon is the dark colored soil horizon that is rich in organic materials and forms just below the surface vegetation

answer

A

question

As soils mature, distinct layers called _appear

answer

horizons

question

Frost wedging is most effective_

answer

in areas with many days of freezing and thawing

question

_is a byproduct of rock weathering

answer

soil

question

The most important natural source for the formation of acid rock weathering at the Earth's surface is dissolved_

answer

carbon dioxide

question

The term mechanical weathering refers to changes in a rock that are physical: there is little or no chemical change

answer

true

question

Hydrogen Ions give off by natural acids can disrupt the crystal structure o most minerals, making the structure susceptible to further decomposition

answer

true

question

A_ soil is one that develops from the bedrock directly beneath it

answer

residual

question

_is the mineral least susceptible to chemical attack on the Earth's surface

answer

Quartz

question

_is picking up and physical removal of rock particles by an agent such as wind, flowing liquid water, or glaciers

answer

EROSION

question

The_ horizon is the upper most layer of a soil; it consist of organic material

answer

O

question

_refers to a group of destructive process that change the physical and chemical character of rocks at the Earth's surface

answer

WEATHERING

question

In tropical regions where temperatures are high and rainfall abundant, highly leached soils called_ (oxisols) form

answer

laterite soil

question

Sand grains can be distinguished from silt grains by_

answer

the gritty feelings between the fingers

question

Boulders include all rounded particles coarser than 2 mm in diameter

answer

false

question

_are massive deposits of limestone

answer

Reefs

question

_is a general term for the processes that convert loose sediment into sedimentary rock

answer

lithification

question

_is the process by which sediment grains are selected and separated according to grain size by agent transportation

answer

sorting

question

_is a hard compact, very fine grained sedimentary rock composed entirely of silica

answer

Chert

question

_is an organic rock formed from the compression and alteration of plant remains such as leaves, twigs and tree trunks

answer

Coal

question

_limestones have clastic texture

answer

Chemical

question

Under what conditions is a sediment considered to be well-sorted

answer

when the grains are nearly all the same

question

Under what conditions is a sediment considered to be well-sorted?

answer

when the grains are nearly all the same size

question

A sandstone with more than 25% sand-sized feldspar is an arkose

answer

true

question

_are polygonal patterns that form in very fine sediment as it dries.

answer

Mud cracks

question

Sedimentary rocks can form from the deposition of solid particles eroded from pre-existing rock or from the deposition of the hard parts of organisms

answer

true

question

Silt is mostly composed of_ grains

answer

quartz

question

_are sedimentary rocks deposited by direct precipitation of minerals from water

answer

chemical rocks

question

_forms only in fine grained sediments that are exposed to air

answer

Mudcrcks

question

Peat is a brown lightweight unconsolidated deposit that ultimately can transform into

answer

coal

question

Lithification is the general term for the processes that covert loose sediment into a sedimentary rock

answer

true

question

_is the shift to a tighter packing of sediment grains due to the weight of overburden

answer

compaction

question

A sedimentary rock that consist of sediment grains bound by cement into a rigid framework is called_

answer

calstic

question

The most common cements are_and_

answer

silica, calcite

question

A_ is a body of sediment deposited when a river flows into standing water, like a lake or sea

answer

delta

question

_is a sedimentary rock formed by the cementation of coarse angular fragments of rubble

answer

Breccia

question

Asymmetrical_ are produced by current flowing in a single direction

answer

ripple marks

question

In order of decreasing size(largest listed first), sedimentary grain sizes include_

answer

gravel, sand, silt, clay

question

A_ is a sandstone containing a significant amount of feldspar

answer

arkose

question

Oil and natural gas originate from_ in marine sediments

answer

organic matter

question

_sediments are deposited or precipitated as a result of the action of organisms

answer

biochemical

question

_is a coarse grained sedimentary rock formed by the cementation of rounded gravel

answer

conglomerate

question

A_ is a layer of sedimentary rock with a vertical charge in particle size, usually from coarse at the bottom to fine at the top.

answer

graded bed

question

Hot water (or vapor) is the most important fluid involved in metamorphic processes

answer

true

question

Meteor craters show an unusual type of metamorphism called shock metamorphism

answer

true

question

In some instances a single mineral, a_, suffices for determination of the pressure and temperature under which a metamorphic rock formed

answer

metamorphic index mineral

question

_stress is a type of deferential stress

answer

shearing

question

_ forms when a limestone recrystallizes during metamorphism

answer

Marble

question

Because of the ease with which it can be split into thin flat sheets, this metamorphic rock is used for making chalkboard, pool tables and roofs.

answer

slate

question

Metamorphic rocks forms pre-existing rock when heat and pressure cause solid-state transformation

answer

true

question

If limestone is metamorphosed at relatively low temperatures and pressure it recrystallizes into marble

answer

true

question

_are important economic resources for lead, zink, gold, silver, tungsten, tin and mercury

answer

Hydrothermal veins

question

The major classification of metamorphic rocks divides them into foliated and non-foliated groups

answer

textural

question

_metamorphism takes place at considerable depth underground(generally greater than 5km)

answer

Regional

question

_tends to deform objects into oblong or flattened forms

answer

differential stress

question

The zone of contact metamorphism(the aureole), _

answer

is commonly rather narrow, from 1-100 meters wide

question

Confining pressure is pressure applied equally on all surfaces of a substance as a result of burial or submergence

answer

true

question

Metamorphism may involve all of the following except_

answer

complete melting of the rock

question

Andalusite, kyanite, and sillimanite are among the best known index minerals that provide information about the temperature and pressure of metamorphism.

answer

ture

question

Schist is a metamorphic rock characterized by a ninfoliated texture

answer

false

question

A metamorphic rock is similar both in mineralogy and texture to its parent rock

answer

false

question

Contact metamorphism occurs adjacent to a pluton when a body of magma intrudes relatively cool country rock

answer

true

question

_ is a fine grained metamorphic rock whose parent rock was basalt

answer

hornfels

question

The two most common non-foliated metamorphic rocks are_ and marble

answer

quantize

question

_ metamorphism is a term used for the process in which rocks are altered by hot water

answer

hydrothermal

question

Any new mineral that has crystalized under high pressure conditions tends to occupy less space than did the mineral or minerals from which it formed

answer

true

question

_ is a metamorphic rock with distinct light and dark layers that formed at high temperatures and pressures

answer

Gneiss

question

The deeper a rock is below the earth's surface_

answer

the hotter it will be

question

_ is the lowest grade rock in progressive metamorphism

answer

slate

question

_ metamorphism occurs adjacent to a pluton when a body of magma intrudes a relatively cool country rock

answer

contact

question

_ is pressure applied equally to all surfaces of a substance as a result of burial or submergence

answer

Confining pressure

question

Lines connecting points of equal temperature on maps or cross sections are called_

answer

isotherms

question

The relative dating principal of _ states that fragments include in a host of rock are older than the host rock

answer

inclusion

question

The principle of _ states that fragments include in a host rock must be_ than the host rock

answer

Inclusion, older than

question

By the principal of_ the surface feature known as the Grand canyon is- than the sedimentary formations that are exposed in the side walls of the Grand Canyon

answer

cross cutting relationships; younger

question

Fossils are common in

answer

sedimentary rocks

question

Relative time refers to the time sequence in which events take place rather than the number of years involved

answer

True

question

Under some circumstances, correlation between two regions can be made by assuming that similar rock types in the two regions formed at the same time

answer

true

question

Alvarez and other proposed a hypothesis that dinosaurs occurred because

answer

one or more steroids impacted the earth, resulting in environmental changes

question

In radioactive decay a_ emission is the emission of two neutrons and two protons from a nucleus

answer

alpha

question

An index fossil is a fossil from a very short-lived geographically widespread species known to exist during a specific interval of geological time

answer

T

question

The_ Era is the Age of Mammals

answer

Cenozoic

question

The principal of superposition states that within a sequence of undisturbed sedimentary rocks, the layer get younger going from bottom to top

answer

F

question

Isotope dating has shown that the Precambrian took up_ % of all geological time

answer

87%

question

_ donates the vast amount of time that precedes the Paleozoic Era

answer

Precambrian

question

Our ability to assign an age to geological an archeological materials is based on our ability to measure the relative abundance of radioactive_ and their stable decay products

answer

Isotopes

question

Geologist use fossils in sedimentary rocks to assign their correct place in geological history.

answer

True

question

_ is the spontaneous nuclear change o isotopes with unstable nuclei

answer

Radioactive decay

question

Half life is the time for a given amount of a radioactive isotope to decay to half it's original amount

answer

True

question

the Mesozoic Era precedes (is older than) the Paleozoic Era

answer

False

question

Earth is between 1 and 2 billion years old

answer

false

question

Isotopes date from volcanic ash or lava flows layers between fossiliferous sedimentary rocks have been used to assign numerical ages to the geologic time scale

answer

true

question

In geology,_ usually means determining time equivalency of rock units

answer

correlation

question

The principal of_ states that an original sedimentary layer extends laterally until it tapers or thins at is edges

answer

lateral continuity

question

The_ of a radioactive material is the time it takes for a given amount of radioactive isotopes to be reduced by half.

answer

half life

question

The half life of the carbon 14 isotope is 5730 years. If there were 4 billion atoms of C-14 in a particular organism at the time it died, how many atoms of C-14 would there be in the remains of that organism 11,460 years after it died?

answer

1 billion

question

In the radioactive decay process of_ decay an electron is emitted from the nucleus of the parent isotope.

answer

beta

question

The principal of original horizontal states that beds of sediment are nearly always deposited as nearly horizontal layers

answer

true

question

In the radioactive decay process of electron capture a_ in the nucleus captures an orbiting electron.

answer

proton

question

When the_ came to a close, dinosaurs became extinct

answer

Mesozoic

question

When marine geologist collects a core of unreformed ocean-floor sediment, they know that the youngest layer if on the top of the core and the oldest is at the bottom because of the principal of_

answer

Superposition

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