Chapter 6,7,13
Review the statements below. Two of these statements are true of conglomerate sedimentary rock similar to the one shown in the Gigapan image. Select the two correct statements
-Many of the clasts in this rock have rounded edges -Many of the clasts within this rock are larger than sand
A stream begins at an elevation of 200 meters and flows a distance of 400 kilometers to the ocean. What is the average gradient?
0.5 m/km
Many large rivers in the Colorado Plateau region meander in deep, narrow canyons and have no floodplains. How could this have happened
Original old-age streams downcut as the land gradually rose
Which of the following processes would best explain the green patina seen on the Statue of Liberty
Oxidation
What process creates finely divided red, brown, and yellow minerals in soils?
Precipitation of iron oxides during the chemical weathering process
Of the following list, which common mineral found in igneous rocks is the most abundant mineral in detrital sedimentary rocks?
Quartz
What mineral is the building block of microcrystalline flint, chert, and jasper?
Quartz (SiO2)
What type of stream pattern develops only on growing mountains like volcanoes or where the land surface is tectonically doming upward?
Radial
Which term describes a soil formed by weathering of the underlying bedrock?
Residual
Choose the most likely scenario for how this rock formed. You can infer the environmental conditions where the rock formed from the characteristics of the clasts. For example, in places where sediments are affected by high-energy waves or wind, clasts will be weathered to a similar size and thus will be well sorted. In places with quiet, calm water, small clasts like mud are most likely to accumulate in thin layers
Rocks eroded from mountains were deposited over a short time in a dry environment, where they were buried by other sediments and cemented into rock
What term describes the particle transport mode that is intermediate between suspension and rolling along the bottom of streams? This process also moves sand grains in a sand dune
Saltation
Which one of the following statements is correct?
Sea level drops when water is stored in expanding ice sheets and continental glaciers.
Which of the following must result in a lower base level for rivers and streams
Sea level falls or land rises.
How does gypsum form
Gypsum forms from evaporation of shallow seas by a chemical process
A sweeping bend of a stream which is migrating laterally in a wide, flat valley is called a(n) __________
meander
A stream with a low to moderate gradient, carrying most of its load in suspension, should be characterized by many curves and bends called
meanders
Take a moment to think about how the Colorado River has evolved through time. Focus on how changing base level and stream incision created landforms, such as incised meanders and rincons, and arrange these events accordingly. Rank from oldest to youngest.
1. A stream migrates laterally across its floodplain developing meanders. This stream terminates at a lake, which is its base level. 2. The base level of the stream is lowered by crustal uplift and the river begins to incise downward. 3.Incised meanders form. 4.A rincon forms by the cutoff of an incised meander, which shortens the river.
How many kilometers wide was the main channel of the river before the flood (1991)?
1.2 km
Part B Part complete How many kilometers wide was the floodplain that was submerged in the 1993 imagery? Include the pink regions, since they were recently under water when the image was captured.
6.7 km
What percentage of the continental areas of Earth's surface is covered by sediments and sedimentary rocks?
75%
Which of the placemarks in the Exfoliation Dome folder is the best example of an exfoliation dome
A
Which of the following is a characteristic of a conglomerate
A conglomerate is made up of course grains that are poorly sorted
Which of the following descriptions best matches a "greywacke"?
A sandstone with sand grains embedded in a clay-rich matrix
The Google Earth image and photo below, which depict the same location from different angles, show two features, labeled A and B, that were created by downcutting of the San Juan River. Choose the correct pair of terms from the choices below.
A) incised meanders, B) terraces
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
How much of Earth's surface water exists in the oceans
Almost all of Earth's surface water exists in the ocean.
Making sure that the Mississippi River Map is deselected, evaluate the city elevations directly under the dot for each city location and the river height 0.25 km south of the north end of the transect line. (The elevation of the ground under your cursor is shown at the bottom of your screen.) Which of the following statements about the elevations of Alton, West Alton, and the Mississippi River is correct?
Alton is 18 m higher than West Alton.
Which one of the following rivers has the largest water discharge of any in the world?
Amazon
What fills an abandoned cutoff or meander loop?
An oxbow lake
What type of sandstone contains abundant feldspar
Arkose
Which of the following is not a type of limestone?
Arkose
How did the Mississippi River delta form?
As the Mississippi River enters the Gulf of Mexico, its velocity decreases and it begins to drop its sediment load.
What is probably the single most important, original, depositional feature in sedimentary rocks?
Bedding or stratification
What is the main difference between a conglomerate and a sedimentary breccia?
Breccia clasts are angular; conglomerate clasts are rounded.
The processes of chemical weathering results in the decomposition of minerals within rocks over time. Fill in the sentences below to explore the different chemical weathering processes
CHEMICAl weathering alters the internal structure of rock materials Potassium feldspar weathers in the presence of water containing CARBONIC ACID Iron weathers through the process of OXIDATION A greenhouse gas called CARBON DIOXIDE influences the rate of chemical weathering.
What is the chemical formula for dolomite, the major mineral in dolostones?
CaMg(CO3)2
Which of the following materials is/are most susceptible to chemical weathering by dissolution?
Calcite
Which of the following is not part of the hydrologic cycle
Calcium carbonate dissolving in soil water and groundwater
correct What term describes the total sediment load transported by a stream?
Capacity
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
A dam and a reservoir are constructed on a graded river. What will happen?
Deposition upstream from the dam; channel downcutting below
At the head of a delta, the major channel splits into smaller channels that follow different paths to the sea. What is the name applied to these smaller channels
Distributaries
Which one of the following statements best describes erosion?
Erosion is the process by which weathered rock and mineral particles are removed from one area and transported elsewhere.
Which of the following pairs of words are components of the hydrologic cycle that release water vapor directly into the atmosphere?
Evaporation and transpiration
Which of the following processes of mechanical weathering is most likely responsible for the appearance of Half Dome?
Exfoliation
With the addition of water, the minerals in granite rocks chemically weather into other minerals, known as products. Test your knowledge of the by-product of each mineral as a result of chemical weathering by labeling the minerals below with their respective products
Feldspar-clay Quartz- No chemical change Olivine- Limonite
What has caused the hypoxic "dead zone" to form off the coast of the Gulf states?
Fertilizers promote the growth of algae. When they die and decompose, oxygen is depleted in the Gulf of Mexico.
Which of the following minerals is not a common cementing agent for sandstones?
Fluorite
Which of the following processes is most likely responsible for the broken rocks found in the Cathedral Lake, Colorado image
Frost Wedging
Which one of the following is an important mechanical weathering process for enlarging fractures and extending them deeper into large boulders and bedrock in temperate and arctic environments?
Frost wedging
What characteristic is used to classify detrital sedimentary rocks?
Grain sizes of the detrital particles
Which of the following statements concerning humus is not true?
Humus is readily leached from the B horizon in weakly acidic soil solutions.
What term describes the movement of water through Earth's hydrosphere?
Hydrologic cycle
Three types of chemical weathering processes are particularly important for transforming minerals within rocks into weathered products. These are hydrolysis, oxidation, and dissolution. Through hydrolysis reactions, minerals are weathered in the presence of water. Hydrolysis takes place when acid rain reacts with rock-forming minerals such as feldspar to produce soluble minerals that are removed in solution. Through oxidation reactions, iron-rich materials transform in the presence of oxygen in the air. Oxidation is responsible for why an apple may turn brown after your cut it open and place it in an open space. And through dissolution, minerals dissolve in water, making their chemical products ions within water. Example: Halite (NaCl) usually forms where ocean water evaporates. On the otherhand, it undergoes dissolution when placed in water. You will sort each example into its category of chemical weathering process.
Hydrolysis -Feldspar in granite rocks weathering to clay Oxidation- red color of rocks in Arches National Park -yellow-stained rocks that use to contain pyrite before it is weathered Dissolution -the salty taste of ocean water -caves formed in limestone
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 shortens
How does urbanization (paving, etc.) affect runoff and infiltration in a small, previously forested drainage basin
Infiltration decreases; runoff increases.
What cement produces bright-red and yellow colors in some sandstones?
Iron oxide
Which of the following surface openings are best represented by the parallel features seen at the Openings for Weathering placemark
Joints
Why is the humus layer typically thicker in a cool, temperate forest soil than in a tropical rainforest soil?
Less humus is produced in the cool, temperate forest but the rate of decay and oxidation is slower than in a tropical rainforest.
What is the most common type of chemical sedimentary rock?
Limestone
In which of the following sedimentary rocks are nonclastic textures common?
Limestones
Which term best describes all the processes that move weathered rock materials and soils downslope?
Mass wasting
Which one of the following statements concerning mechanical weathering is not true?
Mechanical weathering involves a major change in the mineral composition of the weathered material.
Which of the following best describes the process of mineral subtraction or eluviation?
Mineral subtraction or eluviation is the removal of very fine-sized silt and clay particles from the A and E soil horizons.
A delta forms at the ______ of a river, where the velocity of the water flow decreases and deposition is highest
Mouth
For which of the following sediments does compaction play an important role?
Mud
Which of the following sedimentary features would typically be found in shales but not in sandstones?
Mud cracks
Which of the following features characterize wide streams and valleys?
Natural levees; broad floodplains
Where are the headwaters of the Mississippi River?
Northern Minnesota
From the land surface downward to the unweathered bedrock, which of the following is the correct order of the different soil horizons in temperate environments?
O, A, E, B, C, bedrock
How does water get from the oceans onto land?
Ocean water evaporates to form gaseous water and moves into the atmosphere, where it condenses into liquid water and falls out of the atmosphere to land as rain.
Where is erosion concentrated along a meandering stream?
On the outer parts of the meander loops or bends
Sort the following everyday examples of sedimentary processes into the bins labeled with the sedimentary processes they most closely represent
Sediment Erosion/transport -The dirt going down the drain after you give your dog a bath and drain the tub -Dirt being blown off a patio Deposition of sediment -Dust collecting on furniture Weathering of rock -Tree roots extending into a rock layer and breaking it down -Ice expanding in a crack in the road creating a pothole Compaction/lithification -A dump truck dumps a load of gravel on your lawn. The dirt below it becomes more consolidated
Which one of the following is not a chemical sedimentary rock or evaporite?
Shale
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
Which one of the following statements concerning soil erosion is not true?
Sheet erosion, rills, and arroyos or gullies develop mainly during prolonged droughts
Which of the following best describes sets of fractures in relatively fresh bedrock, such as granite, that are roughly parallel to the land surface?
Sheeting fractures
A cherty limestone would most likely contain which major constituents?
Silica and calcite
correct What are the primary sizes of grains that make up the suspended loads of most rivers and streams
Silt and clay-sized detrital grains
Sort the statements describing the clasts shown
Statement describes the rock shown in this Gigapan -The clasts of this rock are well cemented. -The clasts within this rock show signs of abrasion. -The clasts within this rock are older than the rock itself. Statement does NOT describe the rock shown in this Gigapan -The clasts within this rock are all from the same rock type. -The clasts within this rock are younger than the rock itself.
What is the term for the drop in water surface elevation divided by the distance the water flows?
Stream gradient
What term generally refers to the highest percentage of the annual sediment load moved by a stream
Suspended load
Which regolith material results from frost wedging?
Talus slopes
During the 1930s, the United States suffered its greatest natural catastrophe. What great natural disaster affected both the farmers and the urbanites and led to the creation of the Soil Conservation Service?
The Dust Bowl
Why are the sedimentary layers at Capitol Reef tilted
The Laramide Orogeny is responsible for tipping the strata on their sides
What portion of an angular, fracture-bounded granitic block shows the highest rate of weathering?
The corners
Which of the following is the correct definition of stream gradient
The drop in elevation of a stream divided by the distance the water travels
What does the hydrologic cycle describe?
The hydrologic cycle describes how liquid and gaseous water move between the ocean, atmosphere, and land.
What would happen to the oceans if surface runoff and groundwater flow did NOT occur?
The oceans would become smaller.
Which of the following statements provides the best description of the chemical weathering seen in the Newspaper Rock photo
The rock has desert varnish
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 was the cause of the extraordinarily severe flooding on the Mississippi River and its tributaries in 1993?
The upper basin of the Mississippi sustained very heavy rainfall in the late spring and early summer.
Which of the following is a form of calcium carbonate?
Travertine
What type of drainage pattern generally develops in areas underlain by tilted or folded strata, where tributary streams flow along outcrop areas of soft strata
Trellis
Using the following photos, classify the observations according to whether they are "true," or " false."
True At least two episodes of downcutting have occurred. Rounded gravels provide evidence that these flat-topped features are terraces. False The local base level for this stream is sea level. Only one terrace is present at La Cañada Alamosa.
What two factors speed up rates of chemical reaction and weathering in rocks and soils?
Warm temperatures; abundant moisture
Assume that water filling a crack in a rock undergoes cycles of freezing and melting. Which of the following statements is true?
Water expands as it freezes, causing the crack walls to be pushed apart.
Double-click the Drainage Pattern E placemark. Use the visibility slider to adjust the transparency of the map overlay from opaque to transparent and back so that you can view the terrain as well as the stream channels. Which type of drainage pattern is this?
annular drainage
Where is most of Earth's freshwater found?
as ice at Earth's surface
The lowest level to which a stream can erode is called _______
base level
What are the three types of loads carried by streams?
bed load, suspended load, dissolved load
Complete this analogy: Bouncing is to sand as suspension is to_____________
clay
Water erodes the outside of a river bend to form a __________.
cut bank
Double-click the Drainage Pattern F placemark. Which type of drainage pattern is this?
dendritic drainage
Double-click the Drainage Pattern D placemark. Which type of drainage pattern is this?
deranged drainage
The volume of water flowing past a certain point in a given amount of time is a river's _________
discharge
The geographical area where all surface water converges to one location is called its_______
drainage basin
Incised meanders and terraces are __________.
erosional features
A river with a well-developed _______ has a flat low-lying channel and experiences flooding during periods of high discharge
floodplain
The flat, broad area surrounding a stream is referred to as a(n) ___________
floodplain
Which environment of deposition is NOT represented by the rocks in Capitol Reef National Park
glacial
Which of the following are part of the bed load?
gravel and sand
The ________ of a river have a steep gradient, high channel roughness, and low water volume
headwaters
A(n) ________ is a bend in a steep narrow bedrock valley.
incised meander
Complete this analogy: Sliding is to gravel as dissolution is to
ions
Examples of local base level include a stream or a(n) ______
lake
Double-click the Drainage Pattern B placemark. Which type of drainage pattern is this?
parallel drainage
Double-click the Drainage Pattern A placemark. Which type of drainage pattern is this?
radial drainage
Double-click the Drainage Pattern G placemark. Which type of drainage pattern is this?
rectangular drainage
How can pieces of rock in contact with a stream bed move?
rolling, sliding, bouncing
A(n) _______ is the remnant of a former floodplain.
terrace
Which ocean is Earth's largest?
the Pacific Ocean
What is discharge a measurement of?
the amount of water flowing in a river
What would happen to atmospheric water if Earth were mostly covered with land?
the atmosphere would contain less water
What is suspended load?
the fine-grained particles that travel in the water column above the stream bed
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
Double-click the Drainage Pattern C placemark. Which type of drainage pattern is this?
trellis drainage
What does the term aeolian mean
wind-borne origin
