Geog Ch.12, Geog Ch.12
How does mineral wedging occur?
Minerals precipitate in joints and exert an outward force on rocks as they grow into crystals.
Select the areas in the United States where karst topography is common. (Select all that apply.)
Along belts of folded rocks in and near the Appalachian Mountains, Florida
Identify the examples of biotic weathering listed below. (Select all that apply.)
A bear digs into the soil and loosens rock, A species of lichen living on a rock secretes a chemical that slowly dissolves the rock.
True or false: An area with steep slopes and highly weathered bedrock is a good place to build and is not likely to have future slope failure.
False
True or false: How a mineral weathers depends only on the climate in which it is located.
False
What process occurs when a mineral reacts and combines with water to form a new mineral?
Hydrolysis
Choose the ways in which rocks are chemically weathered.
Hydrolysis Oxidation Dissolution
Why is hydrolysis an important process in affecting the salinity of oceans?
Hydrolysis reactions produce the sodium and potassium ions that form common salts.
Match the soil horizon letter (O, A, E...) with the description of what type of soil is in the layer.
O: Surface litter: Organic litter A: Topsoil: Humus, organisms, inorganic E: Zone of leaching: Chemically weathered B: Subsoil: Accumulated material from above C: Regolith: Weathered bedrock or unconsolidated sediment R: Bedrock
In which of the following settings would you expect to find a thick exposure of soil?
One in which conditions favor extensive weathering
What is the general term used for the rocks and minerals acted upon by physical and chemical weathering?
Parent material
Which of the following types of information did geologists use to study the Slumgullion landslide in Colorado?
Physical properties of landslide materials Soil horizon thicknesses Aerial photographs Weather records
___ breaks rocks into smaller pieces without changing their composition.
Physical weathering
Weathering is the change in the physical and chemical character of rock exposed at Earth's surface. Identify the ways in which physical (mechanical) and chemical weathering can be differentiated from one another. (Select all that apply.)
Physical weathering involves breaking rock apart, whereas chemical weathering involves the breakdown of minerals in a rock; Rocks subjected to physical weathering do not change in composition, whereas rocks undergoing chemical weathering do not change in composition
Which of the following are surface features that may indicate caves at depth?
Presence of limestone Sinkholes Disappearing streams
Match the rock type with the correct descriptions of its solubility and how it most commonly weathers.
Quartzite: Very low solubility, Weathers physically Limestone: Very soluble, Prone to chemical weathering
Weak acids formed in water can cause changes in the rocks and minerals with which they interact. Identify those changes. (Select all that apply.)
Result in the formation of clay minerals, Loosen mineral grains, Dissolve rocks and minerals
Which of the following human modifications might cause slope failure?
Road construction
What type of slope failure would most likely occur in this outcrop?
Rock slides
Which of the following describes the process of unloading?
Rocks fracture as overlying rock is removed
A weathered landscape would likely have which of the following features?
Rounded sediments Thick soils in areas with extensive weathering
A weathered landscape would likely have which of the following features? (Select all that apply.)
Rounded sediments, Thick soils in areas with extensive weathering
Which of the following would decrease the angle of repose for a given sediment deposit?
Rounding the grains
What key factor is Florida lacking that results in a low overall risk for landslides?
Steep slopes
True or false: A pile of rocks at the base of a hill suggests that slope failure has occurred.
True
True or false: As it moves downhill, a debris slide may change and transition into a flow.
True
True or false: Plants can be agents of physical weathering, breaking rocks apart.
True
True or false: A rock outcrop may form alternating ledges and slopes because some sections are more susceptible to weathering than others.
True, Small differences in rock properties or setting may cause this differential weathering.
True or false: Sand created through weathering commonly is deposited along rivers, in dunes, and on beaches.
True. Sands accumulate in a variety of environments.
Match each of the types of physical weathering with its description.
Unloading - Formation of joints due to the removal of overlying rock and subsequent expansion Frost wedging - Widening of cracks in rock by water expanding as it freezes to ice Thermal expansion - Heating and cooling that causes minerals to expand and contract differently Plant growth - Widening of cracks by expanding tree roots
In 2002, the Black Rapid Glacier in Alaska was covered in the material from numerous slope failures that were all triggered by ______.
an earthquake
The occurrence of wildfires in many areas of the western United States removes the vegetation that often gives strength to slopes ______ that are already ripe for debris flows.
and worsens conditions
The steepest angle at which a pile of unconsolidated grains remains stable is called the ______.
angle of repose
The steepest angle at which a pile of unconsolidated grains remains stable is called the ___.
angle of response
Secondary minerals that form the chemical weathering of other minerals ___.
are more stable than the original minerals
Slope ___ and altitude affect the degree and type of weathering a rock undergoes.
aspect
How a mineral weathers depends on time of exposure, the surrounding climate, and the mineral's ______.
atomic structure chemical composition
Although debris and rock ___ vary in the size and types of materials that compose each, both can move very quickly and are extremely hazardous.
avalanches
A site in an earthquake-prone area that is located on a steep slope composed of weak materials should be ______.
avoided, as its slope failure potential is high
Chemical weathering occurs ______ in warm, humid areas than it does in cold, dry settings.
faster
The depth of weathering in the mid-latitudes is ______ than in deserts because ______ in the mid-latitudes.
greater; there is more precipitation
Rock slides commonly occur in rock outcrops that ___.
have discrete layers that are oriented parallel to the direction of downhill movement
Rock slides commonly occur in rock outcrops that ______.
have discrete layers that are oriented parallel to the direction of downhill movement
The upper end, or ___, of a rock slide marks where the slide pulled away from the rest of the hill.
head
The upper end, or ___________ , of a rock slide marks where the slide pulled away from the rest of the hill.
head
Minerals that crystalize at ___ temperatures inside Earth are unstable at Earth's surface and weather easily
high
The thickness of a weathering rind may be used to suggest ______.
how long a rock has been exposed to weathering
Limestone is composed of calcite, a mineral that dissolves easily in ___ climates.
humid
Limestone is composed of calcite, a mineral that dissolves easily in ______ climates.
humid
What are the three types of soil water?
hygroscopic water, capillary water, gravitational water
Excessive water increases the susceptibility of a slope to failure by adding weight and by ______.
increasing pore pressure and pushing the grains farther apart
Excessive water increases the susceptibility of a slope to failure by adding weight and by ___.
increasing pore pressure and pushing the grains further apart
A ______ is a fracture in a rock along which movement has not occurred.
joint
The type of fracture, which is small and has no significant offset, promotes weathering by allowing water and plant roots to penetrate the rock.
joint
This type of fracture, which is small and has no significant offset, promotes weathering by allowing water and plant roots to penetrate the rock.
joint
Sinkholes, disappearing streams, and limestone pillars are characteristics of __ topography.
karst
Sinkholes, disappearing streams, and limestone pillars are characteristics of __________topography.
karst
The Slumgullion landslide, as well as other geologic hazards, are best studied with the use of detailed ___. These then can be used to share information. (Use just one word for your answer.)
maps
Oxidation of minerals usually occur ___.
near Earth's surface
Oxidation of minerals usually occurs ___.
near Earth's surface
The _______ is the component of gravity that is perpendicular to the slope and tends to cause a block to ______.
normal component; stay in place
Gravity (shown by the thickest arrow) can be broken into two component forces: the ___ component, which is perpendicular to the slope, and the ___ component, which is parallel to the slope.
normal; shear
Rock broken into ___ pieces increases the amount of surface area on which chemical weathering can occur.
numerous and small
The process of ___ occurs when minerals react with oxygen at or near Earth's surface.
oxidation
The process of ______ occurs when minerals react with oxygen at or near Earth's surface.
oxidation
Geologists assess the ___ slope failure by studying slope steepness, rock condition, and possible triggers.
potential for
Geologists assess the ______ slope failure by studying slope steepness, rock conditions, and possible triggers.
potential for
Slope failures can be triggered by different types of specific events, including ____. (Select all that apply.)
precipitation, slope modification, earthquakes
Expansion joints are formed from either cooling or the release of ___ as rocks are uplifted to the surface.
pressure
Managing the number of animals grazing, using "no till" agriculture practices, and strip cropping are ___ techniques for soil erosion management.
preventative
The work geologists do in studying recent and prehistoric slope failures help to mitigate the loss of life and ___ from future slope failures.
property
The work geologists do in studying recent and prehistoric slope failures helps to mitigate the loss of life and___________ from future slope failures.
property
In a sequence of rocks that is susceptible to rock slide failure, detachment commonly occurs along the base of a(n) ___ rock, such as shale or salt.
weak
In a sequence of rocks that is susceptible to rock slide failure, detachment commonly occurs along the base of a(n) ______ rock, such as shale or salt.
weak
Most of the salt in the oceans is derived from ___.
weathering of rocks on land
Most of the salt in the oceans is derived from ______.
weathering of rocks on land
Chemical and physical ___ causes the breakdown of surface materials. This process increases slope instability, thus increasing the likelihood of gravity causing mass ___.
weathering; wasting
What is the annual economic cost of slope failures in the U.S.?
$3,000,000,000
Order the materials below based on their likely angle of repose relative to each other. (Place the material with the highest angle of repose at the top.)
1. Coarse, angular sand that is slightly wet 2. Dry, partially round, fine sand 3. Clay flakes that are saturated with water
Order the materials below based on their likely angle of repose relative to each other. (Place material with the highest angle of response at the top.)
1. Coarse, angular sand that is slightly wet 2. Dry, partially round, fine sand 3. Clay flakes that are saturated with water
How did Carlsbad Caverns in New Mexico form?
A large reed in a warm sea formed a limestone deposit, which later dissolved as acids leaked into it from underlying petroleum accumulations.
Select the scenario that most likely explains how the cave pictured here formed.
A less resistant rock weathered and eroded more quickly to form the cave and a more resistant rock remains to form the roof.
Which of the following locations would be expected to have the highest degree of chemical weathering?
A shady, flat slope with abundant vegetation
What occurs in the creation of a rock avalanche from an initial rockslide?
A solid piece of rock breaks apart as it is moving rapidly.
Which location described below would you expect to have the highest degree of physical weathering?
A steep, windy, high-elevation mountaintop
Which of the following factors would tend to increase the depth of weathering (and thickness of soils) in an area?
An increase in rainfall An increase in plant growth Higher temperatures
Which of the following factors would tend to increase the depth of weathering (and thickness of soils) in an area? (Select all that apply.)
An increase in rainfall, Higher temperatures, An increase in plant growth
You are studying a large rock outcrop in the U.S. that has both a southern and a northern exposure. Why might the weathering of this rock be different on the two sides?
Because the southern side is likely sunnier and drier, physical weathering may dominate in this location.
A________ hangs from the ceiling of a cave, and a(n) ______________ grows upward from the floor.
Blank 1: stalactite Blank 2: stalagmite
What type of material dominates the downslope movement of a debris flow?
Boulders and gravel in mud
Why is carbonic acid the most important agent of chemical weathering despite being a weak acid?
Carbon dioxide and water are abundant in the atmosphere, so carbonic acid is present in all rainfall.
Which of the following are characteristics of karst topography?
Caves Disappearing streams Limestone pillars Sinkholes
What features are indicators of rock dissolution? (Select all that apply.)
Cavities, Pits
The Slumgullion landslide is located in the San Juan Mountains of ___: it originates in high elevation, steep peaks dominated by ___ rocks.
Colorado; igneous
The Slumgullion landslide is located in the San Juan Mountains of ______; it originates in high-elevation, steep peaks dominated by ______ rocks.
Colorado; igneous
Geologists who studied the 1999 debris flow disaster in Caraballada, Venezuela, found that destroyed buildings has been built upon older debris flows. How can this information be used for the future? (Select all that apply.)
Data suggests that debris flows are normal events for this area, Future development in this area should either be minimized or done with very careful planning.
Which of the following are hazards associated with living on an active alluvial fan? (Select all that apply.)
Debris flow, Flash flooding
Choose the rock properties that directly influence weathering.
Discontinuities Mineral composition
Which of the following are possible causes for submarine slope failure? (Select all that apply.)
Earthquakes, Volcanic eruptions, Sediment overloading
___ is the movement of weathered materials. If this movement of weathered materials happens in a downslope direction due to the force of gravity, we call it ___.
Erosion; mass wasting
Since time is variable in the rates of both physical and chemical weathering, time can be canceled out as a factor in weathering.
False. Time cannot be canceled out as a factor and is, in fact, a crucial factor in weathering.
How a mineral weathers depends only on the climate in which it is located.
False: here are many factors that affect mineral weathering.
What mineral found in granite commonly weathers to produce both dissolved ions and clay minerals?
Feldspar
What type of material typically is involved in the downslope fluid motion of an earth flow?
Fine-grained soils
Significant deposits of clay minerals typically accumulates in what types of environments? (Select all that apply.)
Floodplains, Deltas, Lake bottoms
Select the areas in the United States where karst topography is most common. (Select all that apply.)
Florida, Along belts of folded rocks in and near the Appalachian mountains
Select geologic features that can be formed when groundwater interacts with limestone. (Select all that apply.)
Flowstone, Sinkholes, Caves
What factor is most important in designating the Appalachian Mountains as having a high risk for landslides?
Folded, faulted, and weathered rocks
Numerous factors control mass wasting; choose all of the primary factors from below.
Geology Slope angle Vegetation Climate
Which of the factors listed below make the Pacific Northwest particularly vulnerable to damage from debris flow? (Select all that apply.)
Heavy annual precipitation, High elevations steep slopes, volcanic activity
What event triggered the Vaiont Dam rock slide disaster?
Heavy rainfall
Which of the factors listed below make the Pacific Northwest particularly vulnerable to damage from debris flows?
High elevation, steep slopes Heavy annual precipitation Volcanic activity
___ are soils formed from wetlands without permafrost. They are susceptible to being compacted but are very fertile.
Histosols
Geologists used GPS to determine what information regarding the Slumgullion landslide?
How fast it was moving
Geologists used carbon-14 to determine what information regarding the Slumgullion landslide?
How long ago the failure began
What types of evidence are geologists looking for when trying to locate prehistoric slope failures?
Hummocky topography Bedding and structures that are at a different tilt or orientation than surrounding outcrops Debris pile rocks that are different in type from the immediate landscape
What type of slope failure would most likely occur in the upper section of this outcrop?
Infrequent rock falls
Which of the factors listed below likely played an important role in the failure of this slope in California? (Select all that apply.)
Intense rainfall, Highway construction, Costal erosion
What will eventually happen to material on a steep slope if it is internally weak and poorly attached to the hillside?
It will fall and move downslope.
What is the global distribution of karst topography?
Karst is very widespread globally and occurs on populated continents
Significant deposits of clay minerals typically accumulate in what types of environments? (Select all that apply.)
Lake bottoms, Deltas, Floodplains
What is the general term commonly applied to the slow to very rapid movement of rock or soil downslope?
Landslide
Which of the following is a common, nonscientific term used to describe mass movements of varying nature and speed?
Landslides
___ cause 25 to 50 annual fatalities in the United States. (Use just one word.)
Landslides
Which of the following outcrops has the greatest potential for rock slide failure?
Layers of shale and sandstone with a moderate dip
What sedimentary rock is composed primarily of calcium carbonate?
Limestone
Which of the following are characteristics of karst topography? (Select all that apply.)
Limestone pillars, Sinkholes, Caves, Dessappearing streams
Which of the following indicates an area might have a high potential for slope failure? (Choose all that apply.)
Loose material that is relatively weak; Evidence of past slope failures in an area with known problems; Steep slopes or recent changes in slopes; Potential triggers in the area such as possible earthquakes and volcanic eruptions
Weak acids formed in water can cause changes in the rocks and minerals with which they interact. Identify those changes below. (Select all that apply.)
Loosen mineral grains, Dissolve rocks and minerals, Result in the formation of clay minerals
Select geologic features that can be formed when groundwater interacts with limestone.
Sinkholes Caves Flowstone
Which of the following best describes the relationship between rate of movement in the Slumgullion landslide and precipitation?
The failure moves more slowly in drier periods.
How does time affect weathering?
The more time, the more weathering occurs.
What process forms the shape displayed in exfoliation domes?
The occurrence of exfoliation joints that run parallel to the rock's surface
Slope failure classification is based upon which of the three following characteristics?
The type of material involved, The rate of movement, How the material is moving
Match the sections of the Slumgullion landslide to their descriptions.
The upper part: Scarps are present where the land is pulling away from the adjacent rocks. The sides and middle: Linear to gently curved zones of shearing are present at boundaries behind sections moving with different velocities. The toe (lower part): Parts of the slide are overriding material that has not slipped or slipped as much.
How are weathering and mass wasting related?
The weathering of earth materials loosens them, increasing the likelihood of downslope movements by mass wasting.
How do joints influence the development of a landscape? (Select all that apply.)
They affect the strength of the rocks, They decrease a rock's resistance to weathering, They decrease a rock's resistance to erosion
How do joints influence the development of a landscape?
They affect the strength of the rocks. They decrease a rock's resistance to erosion. They decrease a rock's resistance to weathering.
Why are geomorphologists often some of the first people to arrive at the location of a recent, large slope failure? (Select all that apply.)
They are involved in assessing the potential for future danger from the same type of event, They want to collect data in order to understand how the event happened
How are evaporite rocks associated with karst topography?
They are soluble in water and so can dissolve to form karst topography.
How do joints influence the development of a landscape? (Select all that apply.)
They decrease a rock's resistance to weathering, They affect the strength of the rocks, They decrease a rock's resistance to erosion
How do lava tubes (pictured here) form?
They form as the lava that flowed in the tunnel drained out of it.
Select the accurate summary below of time's influence on weathering.
Time is a critical factor in that it allows for more weathering to occur.
What evidence is shown on this photograph that suggests the Slumgullion landslide has not or is not moving rapidly?
Trees are growing on the landslide material.
Which of the following is indicative of a slow slope failure?
Trees on top of the slope are alive yet tilted
Match each of the types of physical weathering with its description. Unloading Frost Wedging Thermal Expansion Plant growth
Unloading: Formation of joints due to the removal of overlying rock and subsequent expansion. Frost wedging: Widening of cracks in rock by water expanding as it freezes to ice. Thermal expansion: Heating and cooling that causes minerals to expand and contract differently. Plant growth: Widening of cracks by expanding tree roots.
The natural, erosive action of ______________often removes the toe of a slope and causes failure because of oversteepening.
WATER
Which of the following types of information do geologists use to study the Slumgullion landslide in Colorado?
Weather records, Soil horizon thicknesses, Aerial photographs, Physical properties of landslide materials
What is biotic weathering?
Weathering causes by biological activity
Rocks with ___ may weather rapidly because fractures and bedding planes provide a pathway for water into the rocks.
abundant discontinuties
Rainwater is slightly ___ because it contains dissolved carbon dioxide and sulfur dioxide and will dissolve limestone if the two are in contact.
acidic
In general and over time, weathering will tend to cause rock features to ___.
become more rounded
In general and over time, weathering will tend to cause rock features to ______.
become more rounded
What types of evidence are geologists looking for when trying to locate prehistoric slope failures? (Select all that apply.)
bedding and structures that are at a different tilt or orientation than surrounding outcrops, debris pile that are different in type from the immediate landscapes, hummocky topography
Given the forces shown here, the block will most likely ___.
begin to slide downslope
Weathering that is caused by the activity of living organisms is ______ weathering.
biotic
The tombstone in the image has a white streak that extends down its face from a metal plate. The most likely cause of the darker areas around this white streak is ___.
biotic weathering
The tombstone in the image has a white streak that extends down its face from a metal plate. The most likely cause of the darker areas around this white streak is ______.
biotic weathering
Limestone is easily dissolved by weak acids because it is composed primarily of the
calcite
Limestone is easily dissolved by weak acids because it is composed primarily of the mineral ___.
calcite
Limestone is primarily composed of ___.
calcium carbonate
Limestone is primarily composed of ______.
calcium carbonate
Rainwater is slightly acidic because of the dissolved ______ and sulfur dioxide.
carbon dioxide
H2CO3, better known as ______, is a weak and common compound that readily dissolves limestone.
carbonic acid
The presence of limestone on a surface, sinkholes, and other features of karst topography may indicate that there are ___ at depth.
caves
The presence of limestone on the surface, sinkholes, and other features of karst topography may indicate that there are________ at depth.
caves
The hydrosphere is essential for ___ weathering because oxygen dissolved in water oxidizes iron in rocks, and carbon dioxide mixed with water forms carbonic acid, which breaks down minerals in rocks.
chemical
How a mineral weathers depends on time of exposure, the surrounding climate, and the mineral's ___.
chemical composition, atomic structure
Hydrolysis, dissolution, oxidation, and biological reactions all are agents of
chemical weathering
The decomposition of rock resulting from exposure to water and atmospheric gases is referred to as ______.
chemical weathering
The material in the Slumgullion landslide is rich in ______ minerals, which were created through the weathering of volcanic rocks found in the San Juan Mountains.
clay
The weathering of feldspar found in granite can create both dissolved ions and ___ minerals.
clay
Through the process of hydrolysis, K-feldspar combines with slightly acidic water and converts into ___.
clay minerals
The weathering of feldspar found in granite can create both dissolved ions and
clay or secondary materials
The very slow yet continuous movement of earths materials downslope is classified as ___. (Use just one word.)
creep
A ______ fall occurs when a mix of unconsolidated materials falls from a cliff.
debris
A very rapidly moving, turbulent mass of debris, air, and water is known as a ___.
debris avalanche
A very rapidly moving, turbulent mass of debris, air, and water is known as a ______.
debris avalanche
A flow involving soil where much of the material is coarse grained (boulders and gravel) is known as a(n) ______.
debris flow
The alternating ledges and slopes shown in this photograph are the result of ___ weathering, as some of the rock layers are more susceptible to weathering than others.
differential
The alternating ledges and slopes shown in this photograph are the result of ___ weathering, as some of the rock layers are susceptible to weathering than others.
differential
The alternating ledges and slopes shown in this photograph are the result of ______ weathering, as some of the rock layers are more susceptible to weathering than others.
differential
Slope failure, or mass wasting, is movement in which bedrock, rock debris, or soil moves ___ in response to the pull of ___.
downhill; gravity
Feldspar in granite may become sand in conditions where chemical weathering is minimal, such as in ___ climates.
dry
The Slumgullion slope failure is typically called a landslide, but it could be categorized as a(n) ___ flow because it is composed mostly of fine-grained materials.
earth
A(n) ______ is the downslope movement of earth as a viscous fluid.
earth flow
Geologists help to mitigate damage from slope failures by ___. (Select all that apply.)
examining evidence of past slope failures, identifying areas that have a high potential for future failure
As rocks are uplifted to the surface, ___ may form as the rock cools and pressure is released.
expansion joints
The classification of slope ________ is based upon what type of material is moving, the way the material is moving, and the rate of movement.
failures
A debris slide moves downhill more coherently than a debris _____, which contains more water and usually is a more disordered movement.
flow
___ form(s) in some limestone caves as water flows down the walls and forms travertine in thin layers that can become thicker over time.
flowstone
Geologists identify prehistoric slope failures by studying topography, rock distribution, and the ______ of geologic structures.
geometry
_______________cause 25 to 50 annual fatalities in the United States. (Use just one word.)
landslide
La Conchita, California, is unsuitable for permanent housing because ___.
landslides have occurred there in the past and will occur there in the future
Caves, travertine, and karst topography are formed when groundwater interacts with ___.
limestone
Caves, travertine, and karst topography are formed when groundwater interacts with ______.
limestone
Travertine is a sedimentary rock that is formed when ___ that was dissolved in groundwater reprecipitates when the groundwater flows onto the surface.
limestone
Travertine is a sedimentary rock that is formed when ______ that was dissolved in groundwater reprecipitates when the groundwater flows onto the surface.
limestone
Thermal expansion, pressure release, and mineral, frost, and root wedging all are
mechanical weathering process
Specific rock properties that influence weathering include the grain size and ___ composition, as well as the types and numbers of discontinuities, such as fractures and bedding planes.
mineral
Specific rock properties that influence weathering include the grain size and _____composition, as well as the types and number of discontinuities, such as fractures and bedding planes.
mineral or chemical
The work geologists do in studying prehistoric and recent slope failures helps to ______ damage from future landslides when the data are used and distributed to the people living in dangerous areas.
minimize
Data collected from the Slumgullion landslide were used to create a computer ___ to better understand the movement of the materials.
model
In general, limestone located in a wet climate will weather ___ limestone in a dry climate.
more rapidly than
In general, limestone located in a wet climate will weather ______ limestone in a dry climate.
more readily than
We use the terms slump and rotational slide to describe slope failures that ___.
move along curved surfaces with some backward rotation of the material
We use the terms slump and rotational slide to describe slope failures that ______.
move along curved surfaces with some backward rotation of the material
As the rate of physical weathering increases, the amount of chemical weathering also increases because ___.
physical weathering increases the amount of surface area on which chemical weathering can occur
Rock properties such as cleavage, fractures, and bedding planes ______ the mechanical strength of rock and may allow for downhill slippage.
reduce
The outer zone of a rock that has been weathered is called the weathering
rind
The outer zone of a rock that has been weathered is called the weathering ___.
rind
What does "parent material" mean in this context of weathering? Parent materials are the ______.
rocks and minerals acted upon by physical and chemical weathering
The salt content of water is referred to as its ___.
salinity
The salinity of the water is simply a measure of the water's ______.
salt content
A debris slide occurs as unconsolidated materials move downhill in a semicoherent mass, leaving behind a low ___ on the hillside.
scarp
The new minerals that form as a result of chemical weathering at Earth's surface are more stable than the original minerals. These minerals are referred to as ___ minerals.
secondary
Soil on slopes resist downslope movement due to the ___ component of gravity.
shear
Soil on slopes resists downslope movement due to the ________________ component of gravity.
shear
Collapse of the roof of a cave can produce a(n) ___.
sinkhole
Which of the following are surface features that may indicate caves at depth? (Select all that apply.)
sinkholes, presence of limestone, disappearing streams
A(n) ___ is a class of slope failure that involves a relatively intact block of material moving along a well defined plane. A(n) ___ involves material free-falling or bouncing down a cliff. (Hint: Put one word in each blank.)
slide; fall
The Gros Ventre slope failure that occurred in Wyoming in 1925 is one of the largest rock ____________ ever in the U.S. A 1.5-km long slab of limestone was involved.
slides
The Gros Ventre slope failure that occurred in Wyoming in 1925 is one of the largest rock__________ever in the U.S. A 1.5-km long slab of limestone was involved.
slides
The Gros Ventre slope failures that occurred in Wyoming in 1925 is one of the largest rock ___ ever in the U.S. A 1.5km long slab of limestone was involved.
slides
The lack of vegetation on this hillside is a scar indicating an area of ______.
slope failure
Slope failures can be triggered by different types of specific events, including ______.
slope modification precipitation earthquakes
Although earth flows and debris flows both are dominated by fine-grained materials such as mud and soil, an earth flow typically moves ______ than a debris flow.
slower
Another name for a rotational slide is a(n) ___.
slump
Another name for a rotational slide is a(n)
slumps
Tilted fence posts, curved tree trunks, and bedrock layers bent downslope are all indicators of ___.
soil creep
Tilted fence posts, curved tree trunks, and bedrock layers bent downslope are all indicators of ______.
soil creep
Chemical weathering is generally more intense on the corners and edges of a block of rock, resulting in the rock becoming rounded. This weathering feature is known as ___ weathering.
spheroidal
A(n) ___ hangs from the ceiling of a cave, and a(n) ___ grows upward from the floor.
stalactite; stalagmite
A(n) ____ hangs from the ceiling of a cave, and a(n) ___ grows upward from the floor.
stalactite; stalagmite
In some limestone caves, ______ hang from the ceiling as they form and ______ grow upward from the floor of the cave.
stalactites; stalagmites
As physical weathering occurs, the amount of ___ area of a rock outcrop increases, and this allows more ___ weathering to occur.
surface; chemical
The angular blocks of rock near the bottom of a hill or mountain are called ___.
talus
When groundwater is carrying dissolved limestone and that groundwater flows onto the surface, ___ is formed.
tavertine
Minerals formed at depth within Earth may be unstable at the surface due to very different ___ conditions. (Select all that apply.)
temperature, moisture, pressure
The primary difference between debris and rock avalanches is ___.
the composition of the material involved
In the image provided, a light-colored dike (labeled with a yellow O) sticks out from the darker rock around it. The most likely reason this light-colored dike sticks out is that ______.
the dike is more resistant to weathering (i.e., differential weathering) than the surrounding rock
When ocean water evaporates, ___.
the dissolved salts remain in the sea
When ocean water evaporates, ______.
the dissolved salts remain in the sea
The flow of material downhill will occur if ______.
the material is internally weak the slope is steep the material is poorly attached to the hillside
The development of joints in rocks changes how a landscape develops because ______.
they increase the rate at which weathering and erosion occur
The leading downhill edge, or front, of a rock slide is called the ______.
toe
Scarps are present on the ______ part of the Slumgullion landslide, and the ______ portion shows moving material being thrust over land that is not moving.
top; bottom
When groundwater is carrying dissolved limestone and that groundwater flows onto the surface, ______ is formed.
travertine
Slope failures are common secondary hazards of ___ eruptions that cause shaking, tilting, and fracturing of the ground.
volcanic
Caves and caverns can be formed by the dissolution of limestone by flowing ___.
water
Even though the steepness of the Slumgullion landslide is reduced significantly from the head to the toe, the failure continues because of the abundant ___ in the materials.
water
Flowstone or debris are formed in caves when travertine precipitates out of ___ that is flowing down cave walls or along the cave floors.
water
Flowstone or draperies are formed in caves when travertine precipitates out of ___ that is flowing down cave walls or along the cave floors.
water
Flowstone or draperies are formed in caves where travertine precipitates out of ___ that is flowing down cave walls or along the cave floors.
water
The natural, erosive action of ___ often removes the toe of a slope and causes failure because of oversteepening.
water
The process of hydrolysis occurs when minerals combine with ___.
water
The fatalities connected with the Vaiont Dam disaster were caused ___.
when a rock slide created large waves that overtopped the dam
The global abundance of limestone and other soluble rocks explains why karst topography is ___.
widespread
The global abundance of limestone and other soluble rocks explains why karst topography is ______.
widespread
Studies show that the rate of movement in the Slumgullion landslide decreases in the ___.
winter
Studies show that the rate of movement in the Slumgullion landslide decreases in the ______.
winter