Glossary of Geoscience

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What type of weathering is accomplished by physical forces that break rock into smaller and smaller pieces without changing the rock's mineral composition?
mechanical weathering
When water in cracks and joints freezes and expands the rock is broken into angular fragments. This process is known as _____ ________. (two words)
frost wedging
Stone Mountain, Georgia, and Half Dome in Yosemite National Park are excellent examples of ________ domes.
______ weathering alters the internal structures of minerals by removing and/or adding elements.
The general rounding of the corners and edges of angular blocks of rock is termed _____ _______. (two words)
spheroidal weathering
The downslope movement of rock, regolith, and soil under the direct influence of gravity is called _____ _______. (two words)
mass wasting
Loose particles assume a stable slope called the _____ __ ______ (3 words), the steepest angle at which material remains stable.
angle of repose
________ occurs when material usually saturated with water moves downslope as a viscous fluid.
The most rapid form of mass wasting is termed a ___ _________ (two words).
rock avalanche
The downward slipping of a mass of rock or unconsolidated debris moving as a unit along a curved surface is called _________.
Events along Wyoming's Gros Ventre River (1925) represent an excellent example of _________.
Mudflows that occur on the slopes of some volcanoes are known as ______.
The destructive mudflows at Nevado del Ruiz in 1985 are also known by the Indonesian term _____.
The most important weathering process is what?
What are three facts about sheeting?
-caused by unloading
-can produce exfoliation domes
-commonly associated with large bodies of granite
In what kind of climate would chemical weathering be most effective? (temperature, moisture)
in a warm, humid climate
What are three examples of the products of chemical weathering of the mineral potassium (K) feldspar?
silica, potassiu bicarbonate, and clay
What sedimentary rock is composed of the most abundant product of chemical weathering?
If granite and basalt outcropped in an area with a hot humid climate, what rock would weather faster, or both?
the basalt would weather quicker
Which type of weathering would predominate...(if granite and basalt outcropped a hot and humid area)?
chemical weathering
What is one true fact about mechanical weathering and its effect on metamorphic rocks?
it does not affect them
The incorporation and transportation of material by water, wind, or ice describes the process of...?
When water freezes, does its volume increase or decrease?
An accumulation of angular rock fragments at the base of a steep cliff is called?
talus slope
Which of the locations would frost wedging be most effective?
-Amazon Basin of Brazil
-Chicago, Illinois
-north (Arctic) coast of Alaska
-frost wedging should be equally effective at all of these places
Chicago, Illinois
What factors influence the type and rate of weathering?
-mineral content
-presence of joints
Bauxite has an ore of...
Bauxite formation is associated with what?
rainy, tropical climates
What factors contributed to the Gros Ventre rockslide?
-strata were dipping
-a layer of clay was present
-there were heavy rains and melting snow
What terms describe what happens in a mass wasting event? (3 terms)
fall, slide, flow
What is the controlling force of mass wasting?
Solifluction is common during...?
A rapid form of flowage that is common in dry regions is?
Alternate wetting and drying or freezing and thawing leads to what?
What occurs when a tongue of clay-rich material flows downslope in a humid region?
True/False: Cleopatra's Needle, a granite obelisk moved to New York City from Egypt, illustrates that the rate of chemical weathering in New YOrk is much more rapid than in Egypt.
True/False: Cleopatra's Needle, a granite obelisk moved to New York City from Egypt, illustrates that granite weathers more rapidly in a dry climate.
True/False: Sheeting results from unloading
True/False: Sheeting most commonly affects large igneous masses composed of granite.
True/False: Sheeting is an especially important weathering process affecting thinly-bedded sedimentary rocks such as shale.
True/False: Chemical weathering is ineffective in polar regions.
True/False: Chemical weatheirng does not occur in arid regions.
True/False: Sheeting is a mechanical weathering process.
True/False: Thermal expansion is the most important process in the formation of an exfolation dome.
True/False: Quartz is very resistant to chemical weathering.
True/False: Clay minerals are a product of chemical weathering.
True/False: The order in which the silicate minerals chemically weather is opposite their order of crystallization.
True/False: Water is basic to all mass wasting processes.
True/False: Slump is an imperceptibly slow, downhill flow of soil.
True/False: Solifluction is definitely more common in Alaska than in Florida.
True/False: Mudflows are most common in semiarid mountainous regions.
True/False: Mudflows are equally common in humid and dry regions.
True/False: Gravity plays an important role in all mast wasting events.
True/False: The Gros Ventre slide of 1925 has recently been reclassified as a lahar.
True/False: Slump is the most rapid form of mass wasting.
True/False: Mass wasting has played an important role in forming the Grand Canyon.
True/False: Lahars occur in association with volcanoes.
True/False: Earthflows are most common in arid and semiarid regions.
True/False: The freezing and thawing of soil can produce a gradual downhill movement of material.
True/False: Mudflows that accur when layers of volcanic ash become saturated are termed solifluction lobes.
Another name for the Ice Age is:
the Pleistocene epoch
What are the glacial stages of the Ice Age in order from first to last?
Nebraskan, Kansan, Illinoian, Wisconsinan
How does an alpine glacier modify the valley through which it moves?
it straightens it
What are three characteristics of continental glaciation moraines?
-terminal moraine
-ground moraine
-recessional moraine
What are three true facts about glacial deposits?
-drift refers to any glacial deposit
-stratified drift is deposited by meltwater
-erratics are rocks deposited by a glacier
What is a fiord?
a drowned glacial trough
Give one true fact about drumlins
they are found in clusters (groups)
If the steep side of a drumlin is on the northeast, it indicates that the glacier advanced from what direction?
what feature is created when two lateral moraines join?
medial moraine
During the most recent ice age, what percentage of the earth did glaciers cover?
What are three indirect effects of glaciers?
-extinction of organisms
-changes in river courses
-formation of pluvial lakes
What percent of the earth's land surface is covered by ice sheets?
What are three glacial erosion effects or processes?
-glacial striations
In North America, the greatest concentration of pluvial lakes existed in:
the Basin and Range region of Utah and Nevada
Who proposed the astronomical theory of the Ice Age climatic fluctuations?
What three factors may have contributed to the climatic changes related to the Ice Age?
-plate movement
-wobbling of the earth's axis
-variations in the shape of the earth's orbit
A layer of till deposited as the front of a glacier retreats is called a(n):
ground moraine
What is a streamlined asymmetrical hill composed of till?
A broad accumulation of stratified drift deposited adjacent to the downstream edge of an end moraine is a(n):
outwash plain
A long and narrow sinuous ridge composed of sand and gravel is:
an esker
How does wind transport sand grains?
by saltation as part of the bed load
Desert pavement is a result of:
The slip face of a particular barchan dune is on the southeast side. The prevailing wind in this area is from the:
Which stage of landscape evolution in a mountainous desert is relief greatest?
early stage
Inselbergs are:
erosional remnants on an old age desert landscape
Desert and steppe regions cover what fraction of the earth's land surface?
What percent of the desert's surface is covered by sand dunes?
A wash is:
a desert stream channel
What are three types of wind erosion?
-slip face
Blowouts are most common in the: (it's a place)
Great Plains
What is a place that represents the late stage of the evolution of a mountainous desert landscape?
southern Arizona
How high can the surface can sand be carried during very strong winds?
one meter
Dunes whose tips point into the wind are:
parabolic dunes
Often form along coasts where strong winds create a blowout: (a type of dune)
Solitary dunes whose tips point downwind are:
barchan dunes
Sand ridges oriented at right angles to the wind are:
transverse dunes
Long sand ridges that are pointed more or less parallel to the wind are:
longitudinal dunes
True/False: Even when the front of a glacier is retreating, the ice withing the glacier is advancing.
True/False: crevasses form in the zone of fracture.
True/False: When accumulation exceeds ablation, the front of the glacier advances.
True/False: Till is sediment deposited directly by a glacier.
True/False: Except for their relative positions, terminal and recessional moraines are essentially alike.
True/False: Melting is a form of ablation.
True/False: Glaciers cannot erode below sea level.
True/False: The Hudson Bay region has been gradually subsiding (sinking) since the close of the Ice Age.
True/False: The Pleistocene eopch is the only glacial period for which evidence exists.
True/False: Many scientists believe that the plate tectionics theory offers the best explanation for the alternation glacial and interglacial climates of the Ice Age.
True/False: Greenland's ice sheet is about equal in sizee to Antarctica's.
True/False: A cirque is the primary sone of ablation for alpine glaciers.
True/False: The coasts of Norway, Chile, and Alaska all exhibit fiords.
True/False: Sea level does not act as base level for glaciers.
True/False: Ice Age glaciers covered more lan din North America than in Siberia.
True/False: Louis Agassiz proposed the astronomical theory of Ice Age climatic fluctuations.
True/False: The Matterhorn is an excellent example of an arete.
True/False: Fiords are found exclusively along the coast of Norway.
True/False: All of Wisconsin is characterized by relatively thick glacial deposits.
True/False: Moraines are the only glacial deposits composed of till.
True/False: Running water is the most important erosional agent in arid regions.
True/False: The geological processes (forces) operating in deserts are quite different than those operating in humid regions.
True/False: Loess deposits are more blanket-like whereas deposits of wind-blown sand are more commonly in the form of mounds or ridges.
True/False: Arid and semiarid climates cover nearly one-third of the earht's land surface.
True/False: The Basin and Range region of the western US is an excellent example of a mountainous desert landscape.
True/False: A playa is a dry, flat lake bed on the floor of a desert basin.
True/False: The Colorado River is an example of a large wash.
True/False: Loess deposits usually take the form of dunes.
True/False: Except for some scattered accumulations in Alaska, loess deposits are not present in the US.
True/False: Blowouts are shallow depressions caused by deflation.
True/False: Desert pavement results from deflation.
True/False: Desert pavement protects a surface from deflation.
True/False: The windward slope of a sand dune is known is a slip face.
True/False: The famous Navajo Sandstone exposed in Zion National Park shows excellent cross bedding.
True/False: Longitudinal dunes are oriented at right angles to the prevailing wind whereas transverse dunes are more or less parallel to the prevailing wind.
True/False: THe predominant particle size in loess deposits is silt.
The upper 50 meters or so of a glacier consists of brittle ice that often exhibits cracks called ______.
The upper 50 meters or so of a glacier is britlle and referred to as the zone of ______.
The general term for the wastage of glacial ice is __________.
Glaciers erode on the land and primarily in two ways. List these two processes.
abrasion and plucking
Bridalveil Falls in Yosemite National Park cascades a feature called a ________ _________. (two words)
hanging valley
The bowl-shaped depressions at the head of glaciated valleys are termed _______.
The word ____ is an all-embracing term for sediments of glacial origin.
Glacial deposits are divided into two distinct types: ______ and ___________ _________. (three words, but two terms)
till, stratified drift
An _____ ________ is a ridge of till that forms at the terminus of both alpine and continental glaciers. (two words)
end moraine
A gently rolling layer of till laid down as the front of a glacier retreats is termed _______ _________. (two words)
ground moraine
Smooth, elongate hills composed of till called __________ have a steeper slope that faces the direction of glacial ice advance.
Depressions called ______ are found when a block of stagnant ice becomes buried in drift and then melts.
Most of the recent Ice Age occurred during the __________ epoch.
Desert stream courses, which are usually dry, are known as ________.
The lifting and removal of loose material by wind is called ________.
The main factor that controls the depth of a blowout is ____ _________. (two words)
water table
As deflation lowers the surface by removing sand and silt, eventually a continuous cover of coarse particles known as ________ _________ remains. (two words)
desert pavement
The leeward slope of a dune, called the ________ ________, maintains an angle of about thirty-four degrees.
slip face
The sloping layers within a sand dune are called ____ ____. (two words)
cross bed
What are four basic dune types?
barchan, transverse, longitudinal, and parabolic
Dunes whose tips point into the wind are ________ dunes.
Deposits of windblown silt are known as _____.
What is the source of the energy that radiates in all directions from an earthquake?
An earthquake with a magnitude of 6.5 on the Richter scale releases about ____ times more energy than one with a magnitude of 5.5.
What is the term used to describe what occurs to produce an earthquake?
elastic rebound
The Mercalli scale rates earthquake intensity by determining:
the amount of damage to structures
The amount of destruction caused by earthquake vibrations is affected by:(three factors)
-the design structures
-the intensity and duration of the vibrations
-the nature of the surface
The method of using a seismograph to establish the strength of earthquakes wasd developed by:
Charles Richter
Major earthquakes are often followed by somewhat smaller events known as:
The instrument which records earthquake events is termed a:
Most strong earthquakes occur in a zone known as the:
circum-pacific belt
What is the type of measurement used to describe the quantity of energy released by an earthquake
The position on the earth's surface directly above the earthquake source is called:
The mechanism by which rocks store and eventually release energy in the form of an earthquake is termed:
elastic rebound
The study of seismology dates back to when?
the ancient chinese
The principle of the seismograph is based on:
the inertia of a suspended mass
What seismic wave is the most destructive overall?
surface waves
An increase of one unit of magnitude on the Richter scale equates to about a:
30-fold increase in energy
What seismic wave travels the most rapidly?
P waves (primary)
At 6.5 Richter magnitude earthquake releases _____ times more energy than a 4.5 Richter magnitude earthquake.
Considering its distance from the source of the September 19, 1985 earthquake, Mexico City was damaged more than might be expected because:
the unconsolidated sediments on which the city was built intensified the vibrations
Following the 1964 Alaskan earthquake, much of the destruction was attributed to:
numerous ground failures and landslides
What are two names that are the correct term for the succession of ocean waves set in motion by a submarine earthquake called?
tsunami or seismic sea waves
The distance between a seismological recording station and the earthquake source is determined from what?
the arrival time of P and S waves
The record obtained from seismic instruments of an earthquake is called:
The slow continual movement which occurs along some fault zones is termed:
Most of our knowledge about the earth's interior comes from:
seismic waves
The discovery of the shadow zone provided evidence for what?
the existence of a core.
The dense core of the earth is thought to consist mostly of:
The thinnest layer of the earth is the:
S waves are not transmitted through this layer.
inner core
The densest layer of the earth is the:
inner core
The lithosphere is defined as:
a rigid layer of crustal and mantle material
The Moho is the boundary between the: (two layers it is the boundary between)
mantle and crust
The average composition of the upper mantle is thought ot approximate that of:
The average composition of the oceanic crust is thought to approximate that of:
The average composition of the continental crust most closely approximate that of:
The astenosphere is located:
in the upper mantle
True/False: Since San Francisco has already experienced a very destructive earthquake (1906), it is not likely to experience another.
True/False: During the 1964 Alaskan earhtquake, structures which has been built to conform to the earthquake provisions of the Uniform Housing Code of California went undamaged.
True/False: Seismographs can only detect earthquakes within 500 miles of the instrument.
True/False: During the 1964 Alaskan earthquake, landslides and ground subsidence probably caused more damage to buildings than was caused directly by the vibrations of the earth.
True/False: The adjustments which follow a major earthquake often generate small earthquakes called foreshocks.
True/False: The epicenter is the location on the earth's surface directly above the focus.
True/False: An increase of one on the Richter scale corresponds to a tenfold increase in the amplitude of surface waves.
True/False: An earthquake is the vibration of the earth produced by the rapid release of energy.
True/False: The energy released during an earthquake can be detected for at most a few minutes.
True/False: Most major earthquakes are followed by smaller tremors, some of which can be destructive to already weakened structures.
True/False: When examining a typical seismic record, we expect to find surface waves arriving before body waves.
True/False: S waves can only travel through a solid medium.
True/False: P waves can travel through solids, liquids, and gases.
True/False: Travel-time graphs are used to determine the distances to earthquakes.
True/False: A total of 1,000 earthquakes are estimated to occur worldwide each year.
True/False: All of the major earthquakes in the United States have occurred in coastal regions.
True/False: It is now possible for seismologists to predict an earthquake to withing a few weeks or at most a few months of its occurrence.
True/False: Faults which are not experiencing active creep are considered safe.
True/False: Generally speaking, brick structures are far more resistant to earthquake damage than are wood frame buildings.
True/False: During the 1906 San Francisco earthquake, much of the destruction was caused by fires which ran unchecked because of damaged water lines.
True/False: There are several reliable methods of short-range earthquake prediction.
True/False: The outer core is solid and the inner core behaves as a liquid.
True/False: The continental crust is much thicker than the oceanic crust.
True/False: Most of our knowledge about the earth's interior comes from deep-sea drilling.
True/False: Continental rocks are very similar in composition (mineral make-up) to ocean rocks.
True/False: The Moho is a boundary which seperates the mantle and crust.
True/False: The lithosphere is a plastic layer located in the mantle.
True/False: The composition of the upper mantle is thought to approximate that of the rock peridotite.
True/False: The oceanic crust has a composition similar to the rock basalt.
The mechanism of earthquake generation was discovered by ______ following the 1906 San Francisco earthquake.
Earthquakes frequently are associated with large fractures in the earth called ______.
The source of an earthquake is known as the ______.
The position at the earth's surface directly above the earthquake source is called the ________.
The mechanism by which rocks store and eventually release energy to produce an earthquake is termed _____ ________. (two words)
elastic rebound
The greatest frequency of large earthquakes occur along a relatively narrow zone known as the ______ _________ ______. (three words)
circum-pacific belt
An earthquake is the vibration of the earth produced by the rapid release of ________.
Which type of body wave can be transmitted through solids but not fluids?
S waves
The slow continual movement which occurs along some fault zones is termed _________.
Seismic sea waves are also known by the Japanese name ________.
The method by which seismographs are used to determine the magnitude of an earthquake was developed by _________.
Major earthquakes are preceded by smaller seismic events known as ______.
The instrument used to record the vibrations generated by earthquakes is called a(n) ____________.
The energy released by an earthquake is a measurment referred to as _________.
The principle of a seismograph is based on the ___________ of a suspended mass.
Most of the destruction produced by earthquakes is associated with ______ waves.
An increase of one unit of magnitude on the Richter scale means that the release of energy will be ____ times greater.
In addition to damage caused by vibrations, many buildings in San Francisco were destroyed during the 1906 earthquake by ____.
The most voluminous layer of the earth is the _______.
The rigid layer of the earth which consists of the crust and uppermost mantle is termed the ________.
Which of the major subdivisions of the earht's interior is thought to be liquid?
outer core
List the major subdivisions of the earth's interior.
crust, mantle, outer core and inner core
The thinnest layer of the earth is the _______.
The mobile layer of the earth located directly below the lithosphere is the ____________.
The mineral composition of the oceanic crust is similar to the rock ________.
The dense core of the earth is thought to consist predominantly of _____.
The boundary between the crust and the mantle is called the ________.
The man who pioneered the continental drift hypothesis was:
Alfred Wegener
is the name of a supercontinent
The asthenosphere is the source of what at divergent boundaries?

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