Virtual samples for this lab are online at: http://www.nvcc.edu/home/cbentley/
magic/meta105.html
QUESTION 1
Samples A, B, and C are all examples of schist: different kinds of schist,
each with distinctive porphyroblasts.
Which schist sample is dominated by the mineral muscovite?
Sample A
Sample B
Sample C
All three schists are dominated by muscovite mica.
1 points
QUESTION 2
Samples A, B, and C are all examples of schist: different kinds of schist,
each with distinctive porphyroblasts.
Which schist sample has porphyroblasts of the mineral garnet?
Sample A
Sample B
Sample C
All three display garnet.
1 points
QUESTION 3
Samples A, B, and C are all examples of schist: different kinds of schist,
each with distinctive porphyroblasts.
Which schist sample has porphyroblasts of the mineral magnetite?
Sample A
Sample B
Sample C
All three display magnetite.
1 points
QUESTION 4
Samples A, B, and C are all examples of schist: different kinds of schist,
each with distinctive porphyroblasts.
Which schist sample has porphyroblasts of the mineral glaucophane?
Sample A
Sample B
Sample C
All three display glaucophane.
1 points
QUESTION 5
The graphs below compare various combinations of metamorphic
temperature / pressure conditions. Different metamorphic rocks form
under different conditions.
The second graph shows the tectonic interpretation of these different
metamorphic "facies."
Consider the minerals found in schist samples A, B, and C.
Which of the three is an example of blueschist, a rock that forms in
subduction zones, where the temperature is relatively low compared to
the high pressure?
Sample A
Sample B
Sample C
1 points
QUESTION 6
Compare samples D and E.
"D" is a small sample of rock, about 4 cm across. "E" is an outcrop of
rock; a yellow pencil on the outcrop provides a sense of scale.
Both "D" and "E" exhibit a distinctive metamorphic texture. What is it?
Foliation: slaty cleavage
Foliation: schistocity
Foliation: gneissic banding
Nonfoliation: "fused" texture
1 points
QUESTION 7
Compare samples D and E again.
You identified an important metamorphic texture in the previous question.
What is the other feature to be seen in these rocks?
gneissic banding
porphyroblasts
brecciation
original sedimentary bedding
1 points
QUESTION 8
Compare samples D and E again.
You identified an important metamorphic texture and a primary feature of
the protolith in the previous questions. What do these features imply
about the tectonic history of these two samples?
(More than one answer is correct; select ALL that apply.)
The rocks experienced low grades of metamorphism.
The rocks experienced high grades of metamorphism.
The rocks experienced confining pressure only.
The rocks experienced differential stress.
1 points
QUESTION 9
Refer once again to samples D and E.
Which of the following is the best interpretation for these rocks?
These rocks were subducted, as evidenced by the blueschist mineral
glaucophane. They were likely on some oceanic crust that was
metamorphosed under high pressure but low temperature conditions.
These rocks were subjected to differential stress during mountain building,
causing them to develop metamorphic foliation in the form of slaty
cleavage. However, they were not too throughly recrystallized, which is
why we can still see primary sedimentary bedding. Hence, these rocks
were probably on the fringes of a mountain belt.
These rocks were subjected to confining pressure during an episode of
rifting. Magma intrustions baked them into contact metamorphic rocks.
The rocks were throughly recrystallized.
These rocks were subjected to intense differential stress during mountain
building, causing them to develop metamorphic foliation in the form of
gneissic banding .They were throughly recrystallized at temperature /
pressure conditions near the solidus, which is why we can see evidence of
partial melting. Hence, these rocks were probably in the heart of a
mountain belt.
1 points
QUESTION 10
Compare samples "F" and "G."
There is a scale bar (in centimeters) at the top of the "F" image. The scale
of "G" is indicated by the red pen.
Both samples show dark and light stripes, but this striping has different
causes. In one, it's original sedimentary bedding viewed in cross-section
on the surface of a slate cleavage plane. In the other, the striping is
gneissic banding, viewed in cross-section.
Which sample, F or G, is the result of higher-grade metamorphism?
"F" is higher grade, since it is fine-grained.
"G" is higher grade, since it is coarse-grained.
1 points
QUESTION 11
Compare samples "F" and "G" again. There is another line of evidence
that suggests the one is much more metamorphosed than the other. What
is it?
Folding
Garnet porphyroblasts
Metamorphic aureole
1 points
QUESTION 12
Examine sample H. This sample is 20 cm across.
Is it foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 13
Describe the shape of the large grains of quartz (light colored) in sample
H.
Angular
Moderately rounded
Well rounded
1 points
QUESTION 14
Consider sample I. This sample's scale is indicated by the centimeter
markings on the scale card.
Is the rock sample foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 15
Describe the shape of the large grains of quartz (light colored) in sample I.
Angular
Moderately rounded
Well rounded
1 points
QUESTION 16
Compare samples H and I. One is a metaconglomerate. The other is a
metabreccia (fault breccia). Which is which? Match the sample letter to
the correct identification below:
A.
B.
Sample H
A.
B.
Sample I
A.
Metabreccia (fault breccia)
B.
Metaconglomerate
1 points
QUESTION 17
Interpret sample H.
There was once a deposit of limestone which was later metamorphosed
under differential stress, resulting in this foliated marble. It indicates
passive margin sedimentation on a carbonate bank followed by orogeny
(mountain-building).
There was once a deposit of limestone which was later metamorphosed
under confining pressure, resulting in this nonfoliated marble. It indicates
passive margin sedimentation on a carbonate bank followed by either
burial metamorphism in a sedimentary basin or contact metamorphism by
an intruding magma body.
There was once a deposit of conglomerate which was later
metamorphosed under differential stress, resulting in this foliated
metaconglomerate. It indicates depostion of gravel in a high-energy river
current followed by orogeny (mountain-building).
There was once a deposit of conglomerate which was later
metamorphosed under confining pressure, resulting in this nonfoliated
metaconglomerate. It indicates depostion of gravel in a high-energy river
current followed by either burial metamorphism in a sedimentary basin or
contact metamorphism by an intruding magma body.
There was once a breccia that formed in a fault zone and was later
metamorphosed under differential stress, resulting in this foliated
metabreccia. It indicates faulting (brittle behavior at shallow depths in the
crust) followed by orogeny (mountain-building).
There was once a breccia that formed in a fault zone and was later
metamorphosed under confining pressure, resulting in this nonfoliated
metabreccia. It indicates faulting (brittle behavior at shallow depths in the
crust) followed by either burial metamorphism in a sedimentary basin or
contact metamorphism by an intruding magma body.
There was once a deposit of muddy sandstone which was later
metamorphosed under differential stress, resulting in this foliated schist. It
indicates passive margin sedimentation on a beach followed by orogeny
(mountain-building).
There was once a deposit of muddy sandstone which was later
metamorphosed under confining pressure, resulting in this nonfoliated
quartzite. It indicates passive margin sedimentation on a beach followed
by either burial metamorphism in a sedimentary basin or contact
metamorphism by an intruding magma body.
1 points
QUESTION 18
Interpret sample I.
There was once a deposit of limestone which was later metamorphosed
under differential stress, resulting in this foliated marble. It indicates
passive margin sedimentation on a carbonate bank followed by orogeny
(mountain-building).
There was once a deposit of limestone which was later metamorphosed
under confining pressure, resulting in this nonfoliated marble. It indicates
passive margin sedimentation on a carbonate bank followed by either
burial metamorphism in a sedimentary basin or contact metamorphism by
an intruding magma body.
There was once a deposit of conglomerate which was later
metamorphosed under differential stress, resulting in this foliated
metaconglomerate. It indicates depostion of gravel in a high-energy river
current followed by orogeny (mountain-building).
There was once a deposit of conglomerate which was later
metamorphosed under confining pressure, resulting in this nonfoliated
metaconglomerate. It indicates depostion of gravel in a high-energy river
current followed by either burial metamorphism in a sedimentary basin or
contact metamorphism by an intruding magma body.
There was once a breccia that formed in a fault zone and was later
metamorphosed under differential stress, resulting in this foliated
metabreccia. It indicates faulting (brittle behavior at shallow depths in the
crust) followed by orogeny (mountain-building).
There was once a breccia that formed in a fault zone and was later
metamorphosed under confining pressure, resulting in this nonfoliated
metabreccia. It indicates faulting (brittle behavior at shallow depths in the
crust) followed by either burial metamorphism in a sedimentary basin or
contact metamorphism by an intruding magma body.
There was once a deposit of muddy sandstone which was later
metamorphosed under differential stress, resulting in this foliated schist. It
indicates passive margin sedimentation on a beach followed by orogeny
(mountain-building).
There was once a deposit of muddy sandstone which was later
metamorphosed under confining pressure, resulting in this nonfoliated
quartzite. It indicates passive margin sedimentation on a beach followed
by either burial metamorphism in a sedimentary basin or contact
metamorphism by an intruding magma body.
1 points
QUESTION 19
Compare the outcrop in Sample "J" to the previous two samples, "H" and
"I."
A sense of the scale of the image is provided by the yellow pencil and the
scale card.
Does sample J more closely resemble H or I? Why?
Sample J seems more like H: both have well-rounded grains of lightcolored quartz.
Sample J seems more like I: both have angular grains of light-colored
quartz.
1 points
QUESTION 20
What is the principle difference between the rock making up samples I
and J?
Different clast composition
Different matrix (cement) composition
Different clast shape
One is foliated; the other is nonfoliated.
1 points
QUESTION 21
Compare samples K and L. Note that for each rock sample, two GigaPan
views are provided.
One of these samples is a fault breccia; the other is a mylonite. Review the
characteristics of fault breccia and mylonite with this SmartFigure video.
Which of these two samples, K or L, is the mylonite? Why?
K is the mylonite. It has chunks of garnet in it.
K is the mylonite. It has angular clasts and slickensides on the lower
surface of the sample.
L is the mylonite. It has chunks of garnet in it.
L is the mylonite. It displays "augen" of several minerals, with "tails" that
stretch out parallel to the foliation.
1 points
QUESTION 22
Which of these samples, K or L, formed under brittle conditions?
K; the rocky chunks in it are crushed up and angular
L; the rocky chunks in it are smeared out - evidence of ductile flow
1 points
QUESTION 23
Click on the zone where sample K formed:
Selected Coordinates Clear
1 points
QUESTION 24
Click on the zone where sample L formed:
Selected Coordinates Clear
1 points
QUESTION 25
Review what your textbook has to say about serpentinite, a metamorphic
rock dominated by the mineral serpentine (p 287-288).
Sample M is serpentintite. What is the mineral habit of the serpentine you
can see in sample M?
cubic
hexagonal prisms
asbestiform
sheets
1 points
QUESTION 26
Click on the zone (metamorphic environment) where Sample M would
have formed.
Selected Coordinates Clear
1 points
QUESTION 27
Examine sample N. Is it foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 28
Examine sample N. This rock would NOT effervesce (fizz) if you put
hydrochloric acid (HCl) on it.
Identify the rock.
metaconglomerate
quartzite
marble
hornfels
1 points
QUESTION 29
What is the protolith of sample N?
conglomerate
quartz sandstone
limestone
shale
1 points
QUESTION 30
Examine sample O. Is it foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 31
Examine sample O. This rock would effervesce (fizz) if you put
hydrochloric acid (HCl) on it.
Identify the rock.
metaconglomerate
quartzite
marble
hornfels
1 points
QUESTION 32
What is the protolith of sample O?
conglomerate
quartz sandstone
limestone
shale
1 points
QUESTION 33
Compare samples N and O again.
You identified rock mineralogy as well as an important metamorphic
texture in the previous questions. What does this imply about the tectonic
history of these two samples?
(More than one answer is correct; select ALL that apply.)
Original sedimentary deposits included quartz sand only.
Original sedimentary deposits included both quartz sand and lime mud.
The rocks experienced confining pressure only.
The rocks experienced differential stress.
1 points
QUESTION 34
Examine samples P1 and P2. Are they foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 35
Identify sample P1, noting its dull luster.
slate
phyllite
schist
gneiss
migmatite
1 points
QUESTION 36
Identify sample P2, noting its shiny luster and wavy foliation.
slate
phyllite
schist
gneiss
migmatite
1 points
QUESTION 37
What is the protolith of samples P1 and P2?
conglomerate
quartz sandstone
limestone
shale
1 points
QUESTION 38
If samples P1 and P2 were subjected to further progressive regional
metamorphism, what rock be formed next?
schist
metaconglomerate
migmatite
mylonite
anthracite
marble
1 points
QUESTION 39
Consider sample Q. Is it foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 40
Consider sample Q. Is it fine-grained or coarse-grained?
fine
coarse
1 points
QUESTION 41
Identify sample Q, noting the textural features you identified in previous
questions.
slate
phyllite
schist
gneiss
migmatite
1 points
QUESTION 42
You identified important aspects of sample Q's metamorphic texture in the
previous questions. What do these features imply about the tectonic
history of this sample?
(More than one answer is correct; select ALL that apply.)
The rocks experienced low grades of metamorphism.
The rocks experienced high grades of metamorphism.
The rocks experienced confining pressure only.
The rocks experienced differential stress.
1 points
QUESTION 43
Which of the following is the best interpretation for sample Q?
This rock was subducted, as evidenced by the blueschist mineral
glaucophane. It was likely some oceanic crust that was metamorphosed
under high pressure but low temperature conditions.
This rock was subjected to differential stress during mountain building,
causing it to develop metamorphic foliation in the form of slaty cleavage.
However, it was snot too throughly recrystallized, which is why we can still
see primary sedimentary bedding. Hence, this rock was probably on the
fringes of a mountain belt.
This rock was subjected to confining pressure during an episode of rifting.
Magma intrustions baked it into contact metamorphic rocks. The rock was
throughly recrystallized.
This rock was subjected to intense differential stress during mountain
building, causing it to develop metamorphic foliation in the form of
gneissic banding. It was throughly recrystallized at high temperature /
pressure conditions. Hence, this rock probably formed in the heart of a
mountain belt.
1 points
QUESTION 44
Consider sample R. Is it foliated or nonfoliated?
Foliated
Nonfoliated
1 points
QUESTION 45
Consider sample R. With this GigaPan, we have included four "snapshots"
(see the buttons at the lower left of the GigaPan window) that will zoom
you in on key features of the sample. Notice that each of these
"snapshots" focuses on an area of light-colored, coarse-grained material.
What is this material?
garnet
granite
glaucophane
grenache
1 points
QUESTION 46
Regarding yoru answer above (sample R), so what? In other words: what
process has this rock undergone?
Hydrothermal alteration
Faulting
Partial melting (mafic material melts to form magma; felsic material
remains solid)
Partial melting (felsic material melts to form magma; mafic material
remains solid)
1 points
QUESTION 47
Identify sample R, noting the textural features you identified in previous
questions.
slate
phyllite
schist
gneiss
migmatite
1 points
QUESTION 48
Examine the four specimens in sample set S. These are metamorphic
index minerals. Are minerals the same thing as rocks?
Yep. And "elements" is yet another synonym for Earthy stuff.
No. Minerals are the building blocks of rocks.
1 points
QUESTION 49
The GigaPan of sample set S shows a collection of four different mineral
samples. These are common metamorphic index minerals: minerals
found in metamorphic rocks that indicate a particular set of metamorphic
conditions.
From left to right, let's call them S1, S2, S3, and S4. Use the following
metamorphic index mineral classification
Hardness
Streak
Cleavage
Color
Distinctive
features
Name
Metamorphic
Grade
~ 2.5
White?
1 excellent
Dark green
1 excellent cleavage, green color
Chlorite
Low
6-7
White to grey
1 good
Light ‘pistachio’ green
Dull luster, often occurs in “pods”
Epidote
Low + hydrous (watery) conditions
> 6.5
None
None
Reddish-brown; may show rust
Forms 12-sided crystals
Garnet
Medium
~ 4.0
White
1 excellent
Light blue to grey, often with a rusty surface
Breaks into thin, bladed crystals
Kyanite
Medium-high
> 6.5
None
Poor
Dull brown
Hexagonal prisms, forms crosses
Staurolite
High
A.
B.
C.
D.
S1
A.
B.
C.
D.
S2
A.
B.
C.
D.
S3
A.
B.
C.
D.
S4
A.
staurolite
B.
garnet
C.
kyanite
D.
chlorite
1 points
QUESTION 50
Sample set T was originally one sample, but it was then cut in half and
polished. Note the three snapshots in the lower left of the GigaPan
window. These highlight three minerals in this rock. First, examine the
white / tan mineral shown in the right-most snapshot. This is the main
mineral in this rock. It would effervesce (fizz) if you put hydrochloric acid
on it. What mineral is it?
calcite
quartz
garnet
chlorite
staurolite
kyanite
1 points
QUESTION 51
Continue examining the minerals highlighted in the three snapshots in the
lower left of the GigaPan window for sample T. Now examine the green
mineral shown in the middle snapshot. This is the second most common
mineral in this rock, imparting the prominent green stripes to the rock. It is
a metamorphic index mineral (one of the ones you saw in the previous
sample set, "S"). What mineral is it?
calcite
quartz
garnet
chlorite
staurolite
kyanite
1 points
QUESTION 52
Continue examining the minerals in sample T that are highlighted by the
three snapshots in the lower left of the GigaPan window. Now it is time to
examine the dark red mineral shown in the left-most snapshot. This is the
least common mineral in this rock. It is a metamorphic index mineral
(another one of the minerals that you saw in the previous sample set, "S").
What mineral is it?
calcite
quartz
garnet
chlorite
staurolite
kyanite
1 points
QUESTION 53
Given the presence of these two metamorphic index minerals in sample T,
pick the number on the chart below that best corresponds to the rock's
position and metamorphic grade:
(Note the blue numbers running along the bottom: pick the one of these
numbers that best matches the mineralogy of this sample.)
1.
Parent Rock
2.
Low grade
3.
Low grade
4.
Low grade
5.
Low grade
6.
Intermediate grade
7.
Intermediate grade
8.
Intermediate grade
9.
Intermediate grade
10.
Intermediate grade
11.
Intermediate grade / high grade
12.
High grade
13.
High grade
14.
High grade
15.
High grade
1 points
QUESTION 54
What is the protolith of sample T?
conglomerate
quartz sandstone
limestone layers interbedded with layers of shale
granite
Go to this online site to view the virtual samples for this lab: http://
www.nvcc.edu/home/cbentley/magic/sed105.html (Open this link in a separate
tab before you initiate the lab exercise.)
QUESTION 1
Examine sample A.
What is the sorting of sample A?
Figure 6.3 on page 159 of the lab manual may be useful.
well sorted
moderately sorted
poorly sorted
1 points
QUESTION 2
Examine sample A.
What is the grain roundness of sample A?
Figure 6.3 on page 159 of the lab manual may be useful.
very angular
subangular
subround
well-rounded
1 points
QUESTION 3
Examine sample A.
What is the composition of sample A? (What minerals is it made of?)
Figure 6.2 on page 158 of the lab manual may be useful.
rock fragments
quartz grains
feldspar grains
clay
1 points
QUESTION 4
Examine sample A.
Name sample A.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 5
Think about the characteristics of sample A, and offer an interpretation for
the depositional setting (sedimentary environment; see Figure 6.10 on
page 165) where it would have formed. Your interpretation should be
consistent with the physical characteristics that you have noted for the
sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 6
Examine sample B.
What is the sorting of sample B?
Figure 6.3 on page 159 of the lab manual may be useful.
well sorted
moderately sorted
poorly sorted
1 points
QUESTION 7
Examine sample B.
What is the grain roundness of sample B?
Figure 6.3 on page 159 of the lab manual may be useful.
very angular
subangular
subround
well-rounded
1 points
QUESTION 8
Examine sample B.
What is the composition of sample B? (What minerals is it made of?)
Figure 6.2 on page 158 of the lab manual may be useful.
rock fragments (with hematite cement)
quartz grains (with hematite cement)
feldspar grains (with hematite cement)
clay (with hematite cement)
1 points
QUESTION 9
Examine sample B.
Name sample B.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 10
Think about the characteristics of sample B, and offer an interpretation for
the depositional setting (sedimentary environment; see Figure 6.10 on
page 165) where it would have formed. Your interpretation should be
consistent with the physical characteristics that you have noted for the
sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 11
Copy of Think about the characteristics of sample B, and offer an
interpretation for the depositional setting (sedimentary environment; see
Figure 6.10 on page 165) where it would have formed. Your interpretation
should be consistent with the physical characteristics that you have noted
for the sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 12
Examine sample C.
Sample C is a quartz sandstone with red claystone "rip-up" clasts. The
red color in the mudstone is due to oxidation of iron in the mud. This
implies a depositional setting (sedimentary environment) that was rich in
free oxygen.
Given that sand is deposited under moderately-energetic current
conditions and clay is deposited in low-energy water (i.e., still water), then
what does the presence of the claystone "rip-up" clasts surrounded by
sandstone tell you about how water energy must have changed at this
location when these sediments were deposited (i.e., before they were
lithified to make sedimentary rock)?
It indicates that the energy / strength of the water currents must have
stayed the same over time.
It indicates that the energy / strength of the water currents must have
decreased over time.
It indicates that the energy / strength of the water currents must have
increased over time.
1 points
QUESTION 13
Examine sample C.
There is a prominent sedimentary structure to be seen in this sample.
Consult Figure 6.12 in your lab manual (page 169-170) and identify the
structure.
raindrop impressions
graded bed(s)
current ripple marks (also called "asymmetrical ripple marks")
cross-bedding
bimodal cross-bedding
wave ripple marks (also called "symmetrical ripple marks" or "oscillation
ripple marks")
mudcrack(s) (also called dessication cracks)
salt cast(s) (preserved cubic shapes of halite crystals, now formed from
sedimentary rock)
flute(s)
flute cast(s)
fossil plant roots (trace fossils)
animal burrows (trace fossils)
animal tracks, trackways, and trails (trace fossils)
body fossils (once-living tissue or skeletal material)
1 points
QUESTION 14
Interpret sample C.
Based on the sedimentary structure you identified in the previous
question, what interpretive statement can you make about the conditions
under which this sediment was deposited?
It must have been on the land.
It must have been exposed to the air.
It must have had flowing currents of water.
It must have been deposited in a swampy environment with stagnant
water.
It must have been in a shallow water environment where waves could
reach the bottom.
It must have been in the deep ocean, deposited by turbidity currents.
1 points
QUESTION 15
Take another look at the sedimentary structure in sample C.
Which way was the water moving when this sedimentary structure
formed? [Consult Figure 6.12 in your lab manual (page 169-170).]
from left to right
from right to left
1 points
QUESTION 16
Take another look at the sedimentary structure in sample C.
Based on the way we understand this sedimentary structure to form, is
this sample right-side-up or up-side-down? [Consult Figure 6.12 in your
lab manual (page 169-170).]
right-side-up
up-side-down
1 points
QUESTION 17
Examine sample D.
Sample D is a graywacke sandstone. Two views are provided: On the left,
an original view. On the right, the sample has been flipped and cut into
four pieces. Each of the pieces has been rotated around a vertical axis
(like looking at the face of a slice of bread). The dark gray color
(particularly of the finer-grained portion) is indicative of high levels of
organic carbon and dark clay (with reduced iron).
What does this implies a depositional setting (sedimentary environment) in
terms of its oxygen levels?
It indicates that the depositional setting was relatively low in free oxygen.
It indicates that the depositional setting was relatively high in free oxygen.
1 points
QUESTION 18
Examine sample D.
There is a prominent sedimentary structure to be seen in this sample.
Consult Figure 6.12 in your lab manual (page 169-170) and identify the
structure.
raindrop impressions
graded bed(s)
current ripple marks (also called "asymmetrical ripple marks")
cross-bedding
bimodal cross-bedding
wave ripple marks (also called "symmetrical ripple marks" or "oscillation
ripple marks")
mudcrack(s) (also called dessication cracks)
salt cast(s) (preserved cubic shapes of halite crystals, now formed from
sedimentary rock)
flute(s)
flute cast(s)
fossil plant roots (trace fossils)
animal burrows (trace fossils)
animal tracks, trackways, and trails (trace fossils)
body fossils (once-living tissue or skeletal material)
1 points
QUESTION 19
Interpret sample D.
Based on the sedimentary structure you identified in the previous
question, what interpretive statement can you make about the conditions
under which this sediment was deposited?
It must have been on the land.
It must have been exposed to the air.
It must have had flowing currents of water.
It must have been deposited in a swampy environment with stagnant
water.
It must have been in a shallow water environment where waves could
reach the bottom.
It must have been in the deep ocean, deposited by turbidity currents.
1 points
QUESTION 20
Take another look at the sedimentary structure in sample D.
Based on the way we understand this sedimentary structure to form, is
the original sample (i.e., the one at the left side of the screen) right-side-up
or up-side-down? [Consult Figure 6.12 in your lab manual (page
169-170).]
Hint: The cut-up sample (i.e., the one at the right side of the screen) has
the opposite orientation.
right-side-up
up-side-down
1 points
QUESTION 21
Examine the loose sand samples E, F, G, H, I, and J. Each is displayed in
a petri dish 9 cm in diameter.
Which of the 6 sand samples is dominated by ooids?
E
F
G
H
I
J
1 points
QUESTION 22
Examine the loose sand samples E, F, G, H, I, and J. Each is displayed in
a petri dish 9 cm in diameter.
Which of the 6 sand samples is dominated by olivine?
E
F
G
H
I
J
1 points
QUESTION 23
Examine the loose sand samples E, F, G, H, I, and J. Each is displayed in
a petri dish 9 cm in diameter.
Which of the 6 sand samples is dominated by coarse quartz sand?
E
F
G
H
I
J
1 points
QUESTION 24
Examine the loose sand samples E, F, G, H, I, and J. Each is displayed in
a petri dish 9 cm in diameter.
Which of the 6 sand samples is dominated by fine quartz sand stained
with iron oxide?
E
F
G
H
I
J
1 points
QUESTION 25
Compare the loose sand samples G and H.
Which of the 2 sand samples is is derived from rocks with a significant
quartz content?
G
H
1 points
QUESTION 26
Compare the loose sand samples E, F, G, H, I, and J.
Which of the 6 sand samples is most likely from Hawaii?
E
F
G
H
I
J
1 points
QUESTION 27
Compare the loose sand samples E, F, G, H, I, and J.
Which of the 6 sand samples is most likely from Virginia Beach, Virginia?
E
F
G
H
I
J
1 points
QUESTION 28
Compare the loose sand samples E, F, G, H, I, and J.
Which of the 6 sand samples is most likely from the Bahamas?
E
F
G
H
I
J
1 points
QUESTION 29
Compare the loose sand samples E, F, G, H, I, and J.
Windblown sand is typically finer-grained, better-sorted, and more wellrounded than water-transported sand.
Bearing this in mind, which of the 6 sand samples is most likely from sand
dunes in Dubai?
E
F
G
H
I
J
1 points
QUESTION 30
Compare samples K and L.
Both would fizz if you applied acid to them. Both contain fossils. However,
there are some key differences to be noted.
Based on color, which specimen was deposited under higher-oxygen
conditions?
K
L
1 points
QUESTION 31
Compare samples K and L.
Both show aquatic organisms. However, one shows organisms that live in
freshwater (lakes, rivers), while the other shows organisms that live in the
ocean (marine water).
Which sample was deposited in marine (oceanic) conditions?
K
L
1 points
QUESTION 32
Examine sample K. Bear in mind that it would fizz if you applied
hydrochloric acid to it.
Name sample K.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 33
Copy of Examine sample K. Bear in mind that it would fizz if you applied
hydrochloric acid to it.
Name sample K.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 34
Examine sample L. Bear in mind that it would fizz if you applied
hydrochloric acid to it.
Name sample L.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 35
You have now identified both samples K and L.
Both are fossil-bearing, but only one was "fossiliferous limestone." What
appears to be the critical variable that distinguishes "fossiliferous
limestone" from a massive limestone like micrite that happens to have a
fossil or two in it?
Fossiliferous limestones must be dark-colored.
Fossiliferous limestones must be dominated by fossils: the fossils must
make up a significant volume of the rock itself. In other words, the rock is
defined by it's prodigous fossil content.
1 points
QUESTION 36
Compare samples M and N.
Both show fossils. However, one shows organisms that live on land, while
the other shows organisms that live in the ocean (marine water).
Which sample was deposited in marine (oceanic) conditions?
M
N
1 points
QUESTION 37
Examine samples M and N again.
Both show fossils. However, one shows relatively recent organisms, while
the other shows relatively ancient organisms. Consult Figure 8.10, page
213, in your lab manual. Find the closest match in the diagram for the
fossils you see in the sedimentary rock samples.
How old is sample M?
Quaternary
Neogene
Paleogene
Cretaceous
Jurassic
Triassic
Permian
Pennsylvanian
Mississippian
Devonian
Silurian
Ordovician
Cambrian
1 points
QUESTION 38
Examine samples M and N again.
Both show fossils. However, one shows relatively recent organisms, while
the other shows relatively ancient organisms. Consult Figure 8.10, page
213, in your lab manual. Find the closest match in the diagram for the
fossils you see in the sedimentary rock samples.
How old is sample N?
Quaternary
Neogene
Paleogene
Cretaceous
Jurassic
Triassic
Permian
Pennsylvanian
Mississippian
Devonian
Silurian
Ordovician
Cambrian
1 points
QUESTION 39
Examine sample O. It would fizz if you applied hydrochloric acid to it.
Name sample O.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 40
Sample O was photographed in west Texas. It is Cretaceous in age
(145-65 million years old). What does this imply about the past?
During the Cretaceous, west Texas was below sea level.
During the Cretaceous, west Texas was a rift valley.
During the Cretaceous, west Texas was experiencing an orogeny.
During the Cretaceous, west Texas was a spot where rivers were flowing
strongly through their main channels, and occasionally flooding their
floodplains with mud.
1 points
QUESTION 41
Think about the characteristics of sample O, and offer an interpretation for
the depositional setting (sedimentary environment; see Figure 6.10 on
page 165) where it would have formed. Your interpretation should be
consistent with the physical characteristics that you have noted for the
sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 42
Examine samples P and Q.
P shows a quartet of small rock samples, each a few centimeters long.
Originally, they were collected in West Virginia.
Q is an outcrop in West Virginia, a few miles from where the samples of P
were collected.
Both are the same geologic formation (or geologic unit). Both would fizz if
you first crushed them up to powder, and added hydrochloric acid to that
powder.
Name the sedimentary rock that makes up both samples P and Q.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 43
Examine sample P.
There is a prominent sedimentary structure to be seen in this sample.
Consult Figure 6.12 in your lab manual (page 169-170) and identify the
structure.
(Hint: the lab manual may not be enough for this one!)
raindrop impressions
graded bed(s)
current ripple marks (also called "asymmetrical ripple marks")
cross-bedding
bimodal cross-bedding
wave ripple marks (also called "symmetrical ripple marks" or "oscillation
ripple marks")
mudcrack(s) (also called dessication cracks)
salt cast(s) (preserved cubic shapes of halite crystals, now formed from
sedimentary rock)
flute(s)
flute cast(s)
fossil plant roots (trace fossils)
animal burrows (trace fossils)
animal tracks, trackways, and trails (trace fossils)
body fossils (once-living tissue or skeletal material)
1 points
QUESTION 44
Examine sample Q.
There is a prominent sedimentary structure to be seen in this sample.
Consult Figure 6.12 in your lab manual (page 169-170) and identify the
structure.
raindrop impressions
graded bed(s)
current ripple marks (also called "asymmetrical ripple marks")
cross-bedding
bimodal cross-bedding
wave ripple marks (also called "symmetrical ripple marks" or "oscillation
ripple marks")
mudcrack(s) (also called dessication cracks)
salt cast(s) (preserved cubic shapes of halite crystals, now formed from
sedimentary rock)
flute(s)
flute cast(s)
fossil plant roots (trace fossils)
animal burrows (trace fossils)
animal tracks, trackways, and trails (trace fossils)
body fossils (once-living tissue or skeletal material)
1 points
QUESTION 45
Think about the characteristics of samples P and Q, and offer an
interpretation for the depositional setting (sedimentary environment; see
Figure 6.10 on page 165) where they would have formed. Your
interpretation should be consistent with the physical characteristics that
you have noted for the sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 46
If your interpretation of the depositional setting of samples P and Q is
correct (evaporating, supersaturated water), then what other rock type
may also be associated with this same formation?
breccia
quartz sandstone
arkose
shale
peat
bituminous coal
coquina
chalk
micrite
rock salt
ironstone
chert
1 points
QUESTION 47
Examine sample R. It would not fizz if you applied hydrochloric acid to it.
Name sample R.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 48
Think about the characteristics of sample R, and offer an interpretation for
the depositional setting (sedimentary environment; see Figure 6.10 on
page 165) where it would have formed. Your interpretation should be
consistent with the physical characteristics that you have noted for the
sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 49
Copy of Think about the characteristics of sample R, and offer an
interpretation for the depositional setting (sedimentary environment; see
Figure 6.10 on page 165) where it would have formed. Your interpretation
should be consistent with the physical characteristics that you have noted
for the sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 50
Examine sample S. Note (a) that it would not fizz if you applied
hydrochloric acid to it, and (b) it would break with a conchoidal fracture,
and (c) it can scratch glass.
Name sample S.
Figure 6.9 on page 164 of the lab manual may be useful.
breccia
conglomerate
quartz sandstone
arkose
lithic sandstone
graywacke
siltstone
shale
claystone
peat
lignite
bituminous coal
coquina
fossiliferous limestone
chalk
micrite
oolitic limestone
travertine
dolostone
rock salt
rock gypsum
ironstone
chert
1 points
QUESTION 51
Think about the characteristics of sample S, and offer an interpretation for
the depositional setting (sedimentary environment; see Figure 6.10 on
page 165) where it would have formed. Your interpretation should be
consistent with the physical characteristics that you have noted for the
sample.
evaporating playa lake
hot springs
bog or swamp
glacier
debris at base of cliff / alluvial fan
river channel
river floodplain
lake
delta (where a river flows into a standing body of water like a lake or the
ocean)
sand dunes
beach
shallow sea (clastic sediment)
shallow sea (carbonate bank)
carbonate reef
turbidity current (deep sea fan) on the continental slope
deep sea (abyssal plain)
1 points
QUESTION 52
Describe the energy of the water which deposited sample S, and offer a
justification why you made that choice.
Calm water, since it is so coarse-grained.
Calm water, since it is red.
Calm water, since it is fine-grained and very thinly laminated.
High-energy currents, since it is so coarse-grained.
High-energy currents, since it is red.
High-energy currents, since it is so fine-grained and thinly-laminated.
1 points
QUESTION 53
Examine the coarse-grained samples T, U, V, and W.
Which of the 4 samples features clasts of vesicular basalt?
T
U
V
W
1 points
QUESTION 54
Examine the coarse-grained samples T, U, V, and W.
Which of the 4 samples features clasts of granite?
T
U
V
W
1 points
QUESTION 55
Examine the coarse-grained samples T, U, V, and W.
Which of the 4 samples features well-rounded clasts of green mudrock?
T
U
V
W
1 points
QUESTION 56
Examine the coarse-grained samples T, U, V, and W.
Which of the 4 samples is unlithified?
T
U
V
W
1 points
QUESTION 57
Examine the coarse-grained samples T, U, V, and W.
Which of the 4 samples features clasts that are the most angular of the
group?
T
U
V
W
1 points
QUESTION 58
Examine sample X.
There is a prominent sedimentary structure to be seen in this sample.
Consult Figure 6.12 in your lab manual (page 169-170) and identify the
structure.
raindrop impressions
graded bed(s)
current ripple marks (also called "asymmetrical ripple marks")
cross-bedding
bimodal cross-bedding
wave ripple marks (also called "symmetrical ripple marks" or "oscillation
ripple marks")
mudcrack(s) (also called dessication cracks)
salt cast(s) (preserved cubic shapes of halite crystals, now formed from
sedimentary rock)
flute(s)
flute cast(s)
fossil plant roots (trace fossils)
animal burrows (trace fossils)
animal tracks, trackways, and trails (trace fossils)
body fossils (once-living tissue or skeletal material)
1 points
QUESTION 59
Interpret sample X.
Based on the sedimentary structure you identified in the previous
question, what interpretive statement can you make about the conditions
under which this sediment was deposited?
It must have been on the land.
It must have been exposed to the air.
It must have had flowing currents of water.
It must have been deposited in a swampy environment with stagnant
water.
It must have been in a shallow water environment where waves could
reach the bottom.
It must have been in the deep ocean, deposited by turbidity currents.
1 points
QUESTION 60
Examine sample Y.
Sample Y is a sandstone. Note its color.
What does this implies a depositional setting (sedimentary environment) in
terms of its oxygen levels?
It indicates that the depositional setting was relatively low in free oxygen.
It indicates that the depositional setting was relatively high in free oxygen.
1 points
QUESTION 61
Examine sample Z.
There are two prominent sedimentary structures to be seen in these
samples. One are the empty cylindrical tubes. These are ancient animal
burrows. Identify the other primary sedimentary structure, using Figure
6.12 in your lab manual (page 169-170).
raindrop impressions
graded bed(s)
current ripple marks (also called "asymmetrical ripple marks")
cross-bedding
bimodal cross-bedding
wave ripple marks (also called "symmetrical ripple marks" or "oscillation
ripple marks")
mudcrack(s) (also called dessication cracks)
salt cast(s) (preserved cubic shapes of halite crystals, now formed from
sedimentary rock)
flute(s)
flute cast(s)
fossil plant roots (trace fossils)
animal burrows (trace fossils)
animal tracks, trackways, and trails (trace fossils)
body fossils (once-living tissue or skeletal material)
1 points
QUESTION 62
Interpret sample Z.
Based on the sedimentary structure you identified in the previous
question, what interpretive statement can you make about the conditions
under which this sediment was deposited?
It must have been on the land.
It must have been exposed to the air.
It must have had flowing currents of water and these currents switched
direction periodically.
It must have been deposited in a swampy environment with stagnant
water.
It must have been in a shallow water environment where waves could
reach the bottom.
It must have been in the deep ocean, deposited by turbidity currents.
This portion can be completed by viewing the two referenced topographic maps
and answering and submitting the multiple choice questions on the Topographic
Maps Lab Assignment. The two maps you will examine are the "Ritter Ridge
Quadrangle" and the "Washington West Quadrangle" maps. Both maps are
available in GigaPan format at this link.
QUESTION 1
What is the contour interval on the Ritter Ridge Quadrangle map?
a.
20 ft.
b.
30 ft.
c.
40 ft.
d.
50 ft.
4 points
QUESTION 2
What is the scale of the Ritter Ridge Quadrangle map?
a.
1:12,000
b.
1:24,000
c.
1:48,000
d.
1:10,000
4 points
QUESTION 3
Which of the following are true regrading the scale of the Ritter Ridge
Quadrangle map?
a.
One inch on the map equals 24,000 inches in the actual world.
b.
One centimeter on the map equals 24,000 centimeters in the actual world.
c.
One foot on the map equals 24,000 feet in the actual world.
d.
all of the above
e.
none of the above
4 points
QUESTION 4
What is the elevation of the Hauser Microwave Station on the Ritter Ridge
Quadrangle map?
a.
5000 ft.
b.
5184 ft.
c.
5200 ft.
d.
5217 ft.
4 points
QUESTION 5
What is the latitude (to the nearest minute) of the Hauser Microwave
Station on the Ritter Ridge Quadrangle map?
a.
34° 33' N
b.
34° 33' S
c.
34° 35' N
d.
34° 35' S
e.
34° 32' N
f.
34° 32' S
g.
34° 33' E
h.
34° 32' W
4 points
QUESTION 6
What is the longitude of the Hauser Microwave Station on the Ritter Ridge
Quadrangle map?
a.
118° 12' N
b.
118° 12' S
c.
118° 12' E
d.
118° 12' W
e.
118° 13' N
f.
118° 13' S
g.
118° 13' E
h.
118° 13' W
4 points
QUESTION 7
What does the symbol "BM" refer to on these maps?
a.
Bit Map
b.
Binary Meter
c.
Bench Mark
d.
Below Mean
4 points
QUESTION 8
What is the approximate horizontal distance (in feet) from Lake Palmdale
to the small reservoir directly west of the lake on the Ritter Ridge
Quadrangle map?
a.
1000 ft.
b.
9000 ft.
c.
5000 ft.
d.
3000 ft.
4 points
QUESTION 9
Approximatley how much would you rise in elevation (in feet) when going
from Lake Palmdale to the reservoir?
a.
40 ft.
b.
120 ft.
c.
220 ft.
d.
320 ft.
4 points
QUESTION 10
What is the declination on the Ritter Ridge Quadrangle map?
a.
15°
b.
0°40'
c.
12 MILS
d.
1958
4 points
QUESTION 11
What is the elevation of the base of the Washington Monument on the
Washington West Quadrangle map? (located northeast of the Tidal Basin)
a.
10 ft.
b.
20 ft.
c.
30 ft.
d.
40 ft.
4 points
QUESTION 12
What is the length (in feet) of the Reflecting Pool from one side to the
other? (located due west of the Washington Monument)
a.
1000 ft.
b.
2000 ft.
c.
4000 ft.
d.
8000 ft.
4 points
QUESTION 13
What is the straight line distance (in miles) between the White House and
the U. S. Capitol?
a.
1 mile
b.
1.2 miles
c.
1.4 miles
d.
1.6 miles
4 points
QUESTION 14
Referring to the declination symbols on the bottom of the Washington
West Quadrangle map, what does the "star" represent?
a.
grid north
b.
point of interest
c.
geographic north
d.
magnetic north
4 points
QUESTION 15
What is the approximate distance (in feet) along Rock Creek (following the
course of the creek) between the Taft Bridge and the point that it empties
into the Potomac River?
a.
12,000 ft.
b.
15,000 ft.
c.
18,000 ft.
d.
20,000 ft.
4 points
QUESTION 16
What is the same distance (determined in the previous question 15) along
Rock Creek in kilometers?
a.
1.5 km
b.
2.5 km
c.
3.5 km
d.
4.5 km
4 points
QUESTION 17
Given that the elevation of Rock Creek at the Taft Bridge is 20 ft. above
sea level, and its elevation at the point where it enters the Potomac River
is at sea level, what is the gradient of Rock Creek between the Taft Bridge
and the Potomac River?
a.
.0017%%
b.
0.017%
c.
0.17%
d.
1.7%
e.
17%
4 points
QUESTION 18
Which of the four landmarks (Lincoln Memorial, Jefferson Memorial,
Washington Monument, U.S. Capitol) is at the lowest elevation and will be
the first to be impacted by rising sea levels in the future (the Potomac
River is tidal at this location and thus highly influenced by sea level)
a.
Lincoln Memorial
b.
Jefferson Memorial
c.
Washington Monument
d.
U.S. Capitol
4 points
QUESTION 19
How long of a walk is it (in miles) from the U.S. Capitol to the Lincoln
Memorial and back to the U.S. Capitol?
a.
1.1 miles
b.
2.2 miles
c.
4.4 miles
d.
8.8 miles
4 points
QUESTION 20
How many degrees latitude (range) are presented on the entire
Washington West Quadrangle map?
a.
7° 30'
b.
38° 52' 30"
c.
77° 00'
d.
39° 00'
The lab assignment contains references to topographic maps. We have also
compiled a Google Map of the sites, which may be useful in evaluating the
various landscapes. All the topographic maps used in the exercise are also
gathered together in this GigaPan image. We recommend opening both of these
links in separate tabs to help you answer the lab questions.
QUESTION 1
Map of East Brownsville, TX: What
stage of fluvial landscape
development is shown on this map?
youth
maturity
old age
rejuvenation
2 points
QUESTION 2
Map of East Brownsville, TX: Why does the USA-Mexico
boundary (i.e., the Rio Grande river) frequently change
position?
(see lab manual Figure 11.8 for a view of the larger area,
and changes over time)
Because the river meanders from side to side.
Because politicians redraw the border frequently.
Because the river avulses (changes its position) from one braided channel
to another.
Because the oxbow lakes migrate closer and closer to the main river
channel over time.
2 points
QUESTION 3
Map of East Brownsville, TX: Would this international
boundary be more, or less stable (in terms of its physical
position on the landscape), if base level was to drop?
Less stable. Base level drop would lead to increased meandering.
Less stable. Base level drop would flood the entire region.
More stable. Base level drop would lead to an increase in oxbow lakes in
the region.
More stable. Base level drop would cause the river to incise, locking it in
place on the landscape.
2 points
QUESTION 4
Map of Paw Paw, WV (+MD): What channel type is shown
here? (Figure 11.1, lab manual pg. 285)
straight
meandering
sinuous
braided
2 points
QUESTION 5
Map of Paw Paw, WV (+MD): What
stage of fluvial landscape
development is shown on this map?
youth
maturity
old age
rejuvenation
2 points
QUESTION 6
Map of Paw Paw, WV (+MD): Why
are there no oxbow lakes
associated with the meanders developed here? (Hint: note
the magnitude of the elevation contours)
Weird; an old age river system it should have oxbows... I don't get it.
The rejuvenation has incised the river, "entrenching" the meanders into
bedrock. They are no longer moving side to side over time.
This river is too young to have yet developed any oxbows.
This isn't a natural river pattern, but a human-constructed river channel
shape.
2 points
QUESTION 7
Map of Waldron, AR: The rings of bedrock in this region are
composed of alternating layers of mudstone and quartz-rich
sandstone. Which one makes up the ridges (not the
valleys)?
mudstone
quartz-rich sandstone
granite
schist
2 points
QUESTION 8
Map of Waldron, AR: The rings of bedrock in this region are
composed of alternating layers of mudstone and quartz-rich
sandstone. Which one makes up the valleys (not the
ridges)?
mudstone
quartz-rich sandstone
granite
schist
2 points
QUESTION 9
Map of Waldron, AR: What type of regional stream drainage
pattern is shown here? (Hint: note the “bulls-eye” shape; see
lab manual Fig. 11.2, pg. 287)
Dendritic
Rectangular
Radial
Centripetal
Annular
Trellis
Deranged
2 points
QUESTION 10
Map of Red Leaf, AR: What is the specific name given to
lakes such as Lake Chicot? (p. 531 textbook)
2 points
QUESTION 11
Map of Red Leaf, AR: The Mississippi River is flowing north
to south in this map’s area. In what lateral direction is the
position of the Mississippi River presently tending to migrate
(meander) in the vicinity of this map (choose east, or west,
not “downstream”)?
east
west
downstream
2 points
QUESTION 12
Map of Lake Scott, KS: What type of regional stream
drainage pattern is shown here?
Dendritic
Rectangular
Radial
Centripetal
Annular
Trellis
Deranged
2 points
QUESTION 13
Map of Lake Scott, KS: What stage of fluvial landscape
development is shown on this map?
youth
maturity
old age
rejuvenation
2 points
QUESTION 14
Map of Lake Scott, KS: If you were to hang glide from the
edge of the cliffs at Suicide Bluffs down to Lake Scott, how
many feet of elevation would you drop before you got wet?
100
130
140
150
180
1030
15 miles
2 points
QUESTION 15
This map is contoured in feet. The contour interval is __________ feet.
0
5
10
20
25
100
2 points
QUESTION 16
The elevation of point X is __________ feet.
100
140
180
220
240
260
280
300
2 points
QUESTION 17
The elevation of point B is __________ feet.
100
140
180
220
240
260
280
300
2 points
QUESTION 18
The elevation of point A is __________ feet.
100
140
180
220
240
260
280
300
2 points
QUESTION 19
The distance from point A to point B is __________ mile(s).
0.5
1
1.5
2
2.5
10
2 points
QUESTION 20
The gradient from point A to point B is __________ feet per mile.
40
60
80
100
120
140
2 points
QUESTION 21
Trout Run flows (drains downhill) in what direction?
north
east
south
west
2 points
QUESTION 22
Which of the following shows the correct outline of the Trout Run
watershed (drainage basin), with the black line tracing out the divide that
separates Trout Run from other drainage basins?
This one:
This one:
This one:
This one:
This one:
This one:
2 points
QUESTION 23
Imagine that drums of oil were emptied (illegally) at location “X”. Is it likely
that the oil would wash downhill into Trout Run? Explain your reasoning.
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4 points
QUESTION 24
Map of Cedar Creek Alluvial Fan, Montana: Cedar
Creek alluvial fan
is made of alluvium, sediment that has been transported by
running water. What is the source for sediments on Cedar
Creek Alluvial Fan? (Where did that sediment ultimately
come from?)
Sediment fairies who wave their magic wands to make sediment.
The mountains to the east of Cedar Creek alluvial fan (green "Beaverhead
National Forest" area)
The river generates its own sediment from river water.
The mantle.
2 points
QUESTION 25
Map of Cedar Creek Alluvial Fan, Montana: Calculate the gradient of main
stream in forested mountainous area (points K to L on page 302; these are
also "snapshotted" on the GigaPan map):
Remember to follow the river’s particular path in stream gradient
calculations!
1545 feet per mile
645 feet per mile
145 feet per mile
45 feet per mile
2 points
QUESTION 26
Map of Cedar Creek Alluvial Fan, Montana: Calculate the gradient of one
of the distributaries on the alluvial fan itself (points L to J on page 302;
these are also "snapshotted" on the GigaPan map):
Remember to follow the river’s particular path in stream gradient
calculations!
1324 feet per mile
624 feet per mile
324 feet per mile
24 feet per mile
2 points
QUESTION 27
Map of Cedar Creek Alluvial Fan, Montana: Calculate the gradient of the
Madison River (points H to G on the GigaPan map - use the snapshots):
Remember to follow the river’s particular path in stream gradient
calculations!
1322 feet per mile
622 feet per mile
322 feet per mile
22 feet per mile
2 points
QUESTION 28
Map of Cedar Creek Alluvial Fan, Montana: Relate these three numbers
(your answers to the previous three questions) to the landscape you
observe in the maps.
In other words, tell a story of how a river’s gradient changes from its
headwaters, going downstream
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