Practice Quiz 2 ANSWERS!! NOTE: practice quizzes are always in “rough” form
and may contain poorly worded questions or errors! feel free to email any questions
raised. If you find an error in the answer key, please email the instructor.
The instructor is not responsible for errors.
How does mechanical weathering aid chemical weathering?
A Chemical weathering cannot occur until mechanical weathering has begun.
B Chemical weathering proceeds only with the aid of mechanical weathering
C Mechanical weathering promotes the physical breakdown of rocks, producing the
weathering chemicals.
D Mechanical weathering increases surface area for chemical attack.
What is by far the most important agent of chemical weathering and why?
A water – it is a good solvent and carrier of acids.
B the Sun – it causes uneven heating of earth’s materials
C clay materials – they are very unstable in surface soils and rocks.
D exfoliation – new cracks gives chemical reactions the chance to operate
Which of the following rock-forming minerals is most resistant to weathering?
A feldspars
B quartz
C hematite
D olivine
In which climate is chemical weathering most effective
A snowy areas with warm temperatures
B wet areas with low temperatures
C moist areas with warm temperatures
D dry areas with low temperatures
Which of the following lists the correct sequence in the formation of a
sedimentary rock?
A
B
C
D
erosion, weathering, lithification, deposition
weathering, lithification, erosion, deposition
weathering, erosion, deposition, lithification
erosion, lithification, weathering, deposition
Use letters A, B, C and D to describe where the following terms (below) would best
describe the conditions for mineral crystallization or weathering beneath and on
earth’s surface.
Choose A, B, C or D
__D___ Very weather resistant on Earth's surface
__B___ low temperature of crystallization
__A___ high temperature of crystallization
__C___ easily weathered on Earth's surface
Calcite, feldspar, and iron oxide are the most common cements.
A true
B false
For the photograph below, which of the following statements is true?
A
Rock layer A resists erosion and rock layer B erodes more easily.
B.
Rock layer A erodes more easily and rock layer B resists erosion.
C.
Both rock layers A and B erode very easily.
D.
Both rock layers A and B resist erosion.
What is the difference between “chemical” and “biochemical” types of chemical
sedimentary rocks?.
A Chemical sediment is formed by processes driven by water-dwelling living organisms,
whereas biochemical sediment is formed by processes such as evaporation and
precipitation.
B Chemical sediment is formed by processes such as evaporation and precipitation,
whereas biochemical sediment is formed by processes driven by water-dwelling living
organisms
C Chemical sediment is formed by the reworking of animal shells, whereas biochemical
sediment is formed in caves by water dripping from the walls and ceiling.
D Chemical sediment is always made of clastic debris and biochemical sediment is a
result of human impact.
The minerals gypsum and halite are found deposited in old lake environments. Which kind
of chemical sedimentary rock do they form?
A limestone
B evaporites
C coal
D chert
How is coal different from other biochemical sedimentary rocks?
A Coal is formed from the fossilized remains of plant material, whereas limestone is formed with
calcium carbonate.
B Coal is formed from marine animals, whereas limestone is formed from the fossilized remains
of plant material
C Coal is more dense than other biochemical sedimentary rocks, and tends to be lighter in color
and without fossils.
D Coal is made of hematite (iron oxide) and clay.
Choose the statement(s) that are generally true:
A Mechanical weathering is one of Earth’s external processes while chemical weathering is an
internal process.
B Heat from the Earth’s interior provides the energy for weathering.
C All weathering processes are external and driven by energy from the sun.
D A and C are generally true
Smaller particles chemically weather faster than larger particles of the same rock because:
A
B
B
C
Smaller particles have smaller density than larger particles
Smaller particles have greater density than larger particles
Smaller particles have more surface area per volume than larger rocks
Smaller particles have less surface area per volume than larger rocks
What is the proper part of the coal-formation process for
each label on the diagram?
Put the letter next to the correct term below.
__B___lignite
stage
__D___anthracite
coal stage
__C___bituminous
coal stage
__A___peat stage
Identify each of the indicated sedimentary environments by selecting the correct
response. .
Top to bottom: D or E, B, F, E, A, C
desert sand
stream
alpine
glacier
alluvial fans
beach
deep sea
fans
Match the agent of erosion with the sedimentary environment in the photos.
Choices:
1. running water 2. wind
3. waves
4. ice
A___2_____
B____3____
C___4_____
D____1____
Match the environment with the usual components within it.
C
transitional environments
A. shallow vs. deep types, coral reefs, continental slope, graded beds
A
marine environments
B. streams, lakes, glaciers, floodplains, alluvial fans, eolian dunes
B
continental environments
C. beaches, tidal flats, spits, barrier islands, deltas
Match the sedimentary structure with its description:
E
crossbedding
A. a secondary feature where fine wet sediment dries in contact with air, and shrinks
B
graded
bedding
B. a single sedimentary layer that shows a gradual change in grain size from bottom to
top, associated with turbidity flows
C ripple
C. small waves of sand on the surface of a sediment layer resulting from moving water
over that surface
A
mud cracks [
D. flat surfaces along which rocks tend to separate or break, representing a single
deposition event
D
bedding
planes
E. non-horizontal deposition of sedimentary layers, characteristic of sand dunes
Match each sediment type with its approximate environment of formation in an ocean. (Marine environments
diagram, Copyright © Tasa Graphic Arts, Inc.)
Top to bottom answers: B C A
B
fine-grained silt and mud from erosion of continental rocks
C
shells of marine organisms
A
coarse-grained sand from erosion of continental rocks
How is “confining pressure” different from “differential stress”?
A Confining pressure holds rocks in place, whereas differential stress is confining
pressure applied equally in all directions.
B Confining pressure is forces applied equally in all directions, whereas differential
stress is forces applied unequally.
C Confining pressure is forces applied unequally in different directions, whereas
differential stress is forces applied equally.
The most important agent of metamorphism provides the energy to drive chemical
reactions. This is:
A Heat
B Pressure
C Hydrothermal Fluids
D Biochemical
Metamorphic textures include:
A Faneritic and non-faneritic
B Differential and static
C Foliated and non-foliated
D Vesicular and linear
Regional metamorphism affects surrounding country rocks on a small scale.
a.
b.
true
false
A rock that exhibits slaty cleavage is likely to have experienced only confining pressure
(stress).
a.
true
b.
false
How does a conglomerate differ from a sedimentary breccia?
a.
b.
c.
d.
breccia is well stratified; conglomerate is poorly stratified
breccia clasts are baseball size; conglomerate clasts are larger
breccia clasts are angular; conglomerate clasts are rounded
breccia has no cement matrix; conglomerate has cement matrix
A coral reef that has been lithified would produce limestone
a.
b.
true
false
_____ In an alluvial fan formed at the base of a steep slope, where would the largest
particles be found?
a.
b.
c.
d.
in the center of the fan
at the outermost edges of the fan, away from the slope
at the part of the fan nearest the slope
the largest particles would wash out beyond the fan
_____ Which is not a common cementing agent for detrital sedimentary rocks?
a. Quartz
b. Calcite
c. Fluorite
d. Iron oxides
The “Ring of Fire” commonly refers to
a..
the Yellowstone caldera
b.
the volcanic ring formed by Iceland, Greenland and the Canary
c.
the active volcanoes of the Pacific Rim
d.
the ruins of Pompeii
Islands