Geology Test 3
Sedimentary rocks account for about what percentage of the Earth's outermost 10 kilometers of rock (first percentage). Also, what percentage of the Earth's continental area is covered by sedimentary rocks (second percentage)?
5% and 75%
What is the stream gradient of the Arkansas River between the two placemarks in the Stream Gradient folder?
7.22 meters/kilometer
What percentage of the continental areas of Earth's surface is covered by sediments and sedimentary rocks.
75%
Mechanical weathering would predominate.
A cold wet environment at high elevation, in which freezing and thawing is common. A cold dry environment experiencing uplift, in which material is being removed by erosion form an underlying pluton/intrusive igneous rock.
Chemical weathering would predominate.
A hot environment with many short but intense rainstorm. A hot humid climate with heavy precipitation that occurs all year. A warm wet environment with above average yearly rainfall and serial stormy seasons each year.
Which of the following descriptions best matches a "greywacke"?
A sandstone with sand grains embedded in a clay-rich matrix
Which of the following scenarios best describes how sheeting will develop in an igneous rock?
A subterranean platoon is exposed at the surface, releasing confining pressure.
Which one of the following statements correctly describes how stream terraces can form?
A temporary base level is eliminated; the stream downcuts upstream from the old temporary base level, and the former floodplain is left well above the present elevation of the stream.
In which situation does the cone of depression need to be taken into account?
A well for industrial purposes is drilled proximal to a smaller, domestic well.
Suspended load
Affected by both flow velocity and styling velocity of stream
Which of the following applies to the basic constituents of halite, gypsum, and sylvite?
All are transported as dissolved ions and then deposited by evaporation.
What type of sandstone contains abundant feldspar?
Arkose
Which of the following is not a type of limestone?
Arkose
Which of the following is a reason the Gros Ventre rockslide took place?
Because the river eroded material at the valley base, there was no support of the material upslope.
What is probably the single most important, original, depositional feature in sedimentary rocks?
Bedding or stratification
What do freeze-thaw and salt weathering have in common?
Both freeze-thaw and salt weathering require rain and force rocks apart physically.
What is the main difference between a conglomerate and a sedimentary breccia?
Breccia class are angular; conglomerate class are rounded.
What is the main difference between a conglomerate and a sedimentary breccia?
Breccia clasts are angular; conglomerate clasts are rounded.
About how long have wastewater treatment plants been in existence?
120 years
What is the chemical formula for dolomite, the major mineral in dolostone?
CaMa(CO3)2
___________ weathering alters the internal structure of rock materials.
Chemical
Which of the following best describes bedded gypsum and halite?
Chemically derived sedimentary rocks
Which of the following sedimentary rocks would you expect to have originally been deposited by fast-moving streams?
Conglomerate
When water is pumped from a well, drawdown occurs. Which of the following is a true statement regarding drawdown?
Drawdown decreases with increasing distance from the well.
Which of the following statements regarding weathering and erosion is NOT true?
Erosion and weathering have the same definition and can be used interchangeably.
Which of the following statements about deposition and erosion around meander loops is true?
Erosion occurs where water is moving the fastest along the outside of the loop. Deposition occurs where water is moving the slowest along the inside of the loop.
Which of the following describes the correct order for relative solubility of minerals in sedimentary rocks?
Evaporate minerals are more soluble than calcite and quartz.
Drag the appropriate labels to their respective targets.
Feldspar > Clay Quartz > No chemical change Olivine > Limonite
Hydrolysis
Feldspar in granite rocks weathering to clay.
Which of the following minerals in not a common cementing agent for sandstones?
Fluorite
What characteristic is used to classify detrital sedimentary rocks?
Grain sizes of the detrital particles
Which of the following rocks would most likely experience sheeting?
Granite
Rank the rocks in order of the rate of chemical weathering they would experience, assuming they are all located in the same warm wet climate.
Granite, with very few or no cracks. Granite, with abundant cracks. Basalt, with very few to no cracks. Basalt, with abundant vesicles (holes).
________ are characteristics found in all good aquifers.
High porosity and high permeability
Bed load
Highly affected by the velocity of stream
Of the following list, which common mineral found in igneous rock is the most abundant mineral in detrital sedimentary rocks?
Quartz
________, a common mineral found in igneous rocks, is the most abundant mineral in detrital sedimentary rocks.
Quartz
What mineral is the building clock of microcrystalline flint, chert, and jasper?
Quartz (SiO2)
Which one of the following statements is correct?
Sea level drops when water is stored in expanding ice sheets and continental glaciers.
Which one of the following is not a chemical sedimentary rock or evaporate?
Shale
Rank from best to worst.
Shallow aquifer, Deep aquifer, Area with karst topography
In what type of depositional environment is oolitic limestone most likely to form?
Shallow, clear marine waters with vigorous current activity and lots of corals
A cherty limestone would most likely contain which major constituents?
Silica and calcite
At Mouth
Slope is lower discharge is higher flow velocity is more
Which of the following was a major factor leading to the Gros Ventre, Wyoming, slide?
Soils and shallow bedrock were very wet and locally saturated
Are stream terraces depositional or erosional landforms?
Stream terraces can be either depositional or erosional.
________ generally constitutes the highest percentage of the annual sediment load moved by a stream.
Suspended load
If conditions remain the same, which of the following locations will deplete its groundwater first?
Texas
Which of the following can logically be concluded by speleothems/dripstone hanging from a cave roof?
The cave roof was above the water table when the speleothems formed.
Under similar warm, moist climatic conditions, why would basalt and gabbro generally have higher chemical weathering rates than rhyolite and granite?
The ferromagnesian minerals in the gabbro and basalt are subject to oxidation and chemical breakdown.
Oxidation
Yellow-stained rocks that used to contain pyrite before it is weathered. Red color of rocks in Arches National Park
Which of the following is an example of chemical weathering?
a car fender getting rusty
Which of the following best describes the cone of depression?
a dimple in the water table surface due to water pumped faster than an aquifer can be replenished
What is a stream terrace?
a remnant of an older floodplain that sits above the stream valley
The Gros Ventre slide is evident today by __________.
a scar, runout area, and landslide debris filling the valley
All of the following are possible indicators that creep is occurring EXCEPT for ________.
an extremely thick soil profile
You accidentally flush your cell phone. Where will it most likely be found at a wastewater treatment facility?
bar screen
Which of the following products of a wastewater treatment facility is often put on farm fields as a fertilizer?
biosolids
Which common, rock-forming mineral or mineral group is most readily dissolved by groundwater?
calcite
A greenhouse gas called _________________ influences the rate of chem weathering.
carbon dioxide
Potassium feldspar weathers in the presence of water containing ____________
carbonic acid
At Headwaters
channel roughness is high channel size is smaller
What does the Kanapaha Wastewater Treatment Facility use to disinfect the treated water?
chlorine
Which of the following diseases has been all but eliminated from the United States because of wastewater treatment plants?
cholera
Where does settling of solids occur at a wastewater treatment facility?
clarifier
A __________ acted as a sliding surface across which material moved downhill during the Gros Ventre Slide.
clay layer
Which of the following climates would have the greatest degree of ice wedging?
cold in the winter, warm in the summer, and with moderate precipitation.
A hoodoo with a cap rock of sandstone and shale below is an example of __________.
differential weathering
Examine the words and/or phrases below and determine the relationship among the majority of words/phrases. Choose the option that does not fit the pattern.
elevation
All of the following are factors affecting mass movement EXCEPT for ________.
geologic age
Which one of the following is not a speleothem?
geyserite
When sheeting develops in an igneous platoon, fracture all develop in an orientation ______________ to the direction of expansion.
perpendicular
What force pushes groundwater from pore to pore below the water table?
pressure gradient or hydraulic gradient
Which one of the following is NOT an example of a mechanical weathering process?
reactions that occur when rain mixes with carbon dioxide to form carbonic acid
Which of the following sedimentary features can each be used to determine paleocurrent directions?
ripple marks and cross stratification
Heavy rainfall caused the clay to lubricate and the sandstone to become __________.
saturated and heavy
When do streams erode laterally?
when downcutting is occurring in easy-to-erode sediment or rock
When do stream terraces form?
when streams exist under alternating erosional and depositional conditions
In the __________, groundwater fills the pore space.
zone of saturation
To ensure a continuous supply of water, a well must do what?
penetrate well below the regional water table surface
A stream begins at an elevation of 200 meters and flows a distance of 400 kilometers to the ocean? What is the average gradient?
0.5m/km
Where do coal beds originate?
In freshwater coastal swamps and bogs
Which one of the following best describes how urbanization affects small-stream watersheds?
Infiltration decreases; lag time between storms and peak runoff is shortened.
What cement produced bright-red and yellow colors in come sandstone?
Iron oxide
________ cement produces bright-red and yellow colors in some sandstone.
Iron oxide
Consider a weathered rock or soil particle lying on a slope. How will the gravitational force pulling the particle downward along the land surface vary with the inclination of the slope?
It will decrease as the slope angle is lessened.
The water level has dropped the least at the placemark for:
Kansas
What is the most common type of chemical sedimentary rock?
Limestone
In with of the following sedimentary rocks are nonelastic textures common?
Limestones
What is the definition of physical weathering?
Mechanical processes break substances into smaller pieces.
For which of the following sediments does compaction play an important role?
Mud
Which of the following sedimentary features would typically e found in sales but not in sandstones?
Mud cracks
How many stream terraces can exist along a single valley?
No limit exists. Stream terraces will keep forming as long as lateral erosion and downcutting continue.
In the Rocky Mountain region of the United States, north-facing slopes (downhill direction is toward the north) are typically more moist and heavily forested than south-facing slopes. Why?
North-facing slopes receive about the same amount of precipitation as south-facing slopes; less moisture evaporates from north-facing slopes.
Rank the rocks from fastest weathering to slowest weathering.
Peridotite, Gabbro, Diorite, Granite
How can plats physically weather a rock?
Plants roots exert outward pressures as they grow.
The finely divided, red, brown, and yellow soil-coloring minerals originate by what process?
Precipitation of iron oxides during the chemical weathering process
Which of the following statements about water balance in the High Plains Aquifer is correct?
The portion of the aquifer that lies in Texas has the greatest water level change at more than 100ft deficit.
Which of the following statements provides the best description of the chemical gathering seen int he Newspaper Rock photo?
The rock face has desert varnish.
Which of the following statements is true regarding the aftermath of the Gros Ventre rockslide?
The rockslide debris dammed up the river and formed a lake.
Dissolution
The salty taste of ocean water. Caves formed in limestone.
Which of the following is the best example of biological weathering evident in the Lassen NP image?
The trees that are wedging their roots into joints in the rocks.
Which of the following is not an example of biological weathering evident in the Snake River image?
The water interacting with the minerals in the rock.
During the late Cretaceous, the Bisti Badlands were home to numerous animals including turtles, crocodiles, and even dinosaurs. What type of environment were they living in?
They were living along rivers and deltas on the edge of an inland sea.
Which of the following is a form of calcium carbonate?
Travertine
Dissolved load
Unaffected by the velocity of stream
What changes are occurring int the igneous platoon that would result in sheeting?
Volume increase
How can the creation of ice result in physical weathering?
Water expands in volume when freezing, erecting pressure on a container.
Why does water frozen in the cracks of a rock help to break down the rock?
Water expands when frozen and physically forces the rock apart.
Which of the following is a true statement about groundwater
Water in a groundwater system is stored in subsurface pore spaces and fractures.
How did weathering destroy New Hampshire's Old Man in the Mountain?
Water migrated along fractures in the rock, where it froze and wedged the rock apart.
How does physical weathering causes chemical weathering to be more effective?
When a rock is physically broken into smaller pieces, there is a more surface area on which chemical weathering can occur.
Check the box for the SATURATED THICKNESS folder. The saturated thickness of the High Plains Aquifer:
has a maximum of 400-1200 ft in Wyoming.
Which of the following represent the largest volume of freshwater found on Earth?
ice sheets and glaciers
In which area would weathering by frost wedging probably be most effective?
in moist, temperate climates
The cone of depression __________ near a well.
increases the hydraulic gradient
The unsaturated zone ________.
is a well-oxygenated, shallow aquifer
Which of the following geologic materials would have the highest groundwater velocities and be least effective in removing unwanted pollutants from the water?
limestone; numerous solution channels and fractures widened by dissolution
While observing a sedimentary rock outcrop, you note that majority of the material cemented in the stratigraphic unit is gravel-cobble in size, but poorly sorted and angular. From these basic observations, what can you infer about the depositional environment represented by the sedimentary characteristics?
located near the headwaters of a mountain reach of a stream
Where is erosion concentrated along a meandering stream?
on the outer parts of the meander loops or bends
A __________ is separated from the groundwater system by the unsaturated zone.
osing stream (disconnected)
Iron weathers through the process of _____________
oxidation
Which of the following processes would best explain the green patina seen on the Statue of Liberty?
oxidation
Which of the following best describes sets of fractures in relatively fresh bedrock, such as granite, which are roughly parallel to the land surface?
sheeting fractures
A cherty limestone would contain which major constituents?
silica, calcite
The change in water level in:
southwestern Nebraska has been between a 50 ft increase and a 100 ft drop.
The water table __________.
surface is a subdued version of the surface topography
A stream is said to be a losing stream when ________.
the channel bottom is above the local water table
What is salt weathering?
the formation of minerals in rock cracks during the evaporation of salty water, forcing rock apart
Imagine a valley containing four stream terraces. Where would the youngest stream terrace be found?
the lowest terrace
An artesian well is one in which ________.
water rises above the top of the aquifer without any pumping