UNIT #6 EXAM
EARTH HISTORY
NAME:_________________________
BLOCK_____ DATE______________
1. Unless a series of sedimentary rock layers has been
overturned, the bottom rock layer usually
A)
B)
C)
D)
4. The diagram below represents a cross section of a
portion of the Earth's crust.
contains fossils
is the oldest
contains the greatest variety of minerals
has the finest texture
2. Which is the youngest rock shown in the diagram
below?
Which graph best indicates the relative age of the rock
units along line AF?
A) 1
B) 2
C) 3
A)
B)
C)
D)
D) 4
3. The diagram below represents a geologic cross
section.
5. Base your answer on the geologic cross section below.
Which geologic event occurred most recently?
A)
B)
C)
D)
In the cross section, the basalt is known to be younger
than the sandstone because
A) in places, the sandstone is above the basalt
B) rocks are older than the igneous intrusions
that cut through them
C) the sandstone is made of weathered basalt
D) igneous rocks are usually younger than
sedimentary rocks
folding at A
the intrusion at B
faulting at C
the unconformity at D
6. A fossil is not likely to be found in
A) limestone
C) basalt
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B) sandstone
D) shale
7. The geologic cross section below represents a cliff
outcrop. Some bedrock layers are labeled as millions
of years old (myo). Letters A through E represent
different rock types.
10. Which characteristics of a fossil would make it
useful as an index fossil in determining the relative
age of widely separated rock layers?
What is a possible age of igneous rock E?
A)
B)
C)
D)
1.5 million years old
12 million years old
28 million years old
40 million years old
8. What is the relative age of a fault that cuts across
many rock layers?
A) The fault is younger than all the layers it cuts
across.
B) The fault is older than all the layers it cuts
across.
C) The fault is the same age as the top layer it cuts
across.
D) The fault is the same age as the bottom layer it
cuts across.
9. Which is the best method of determining the relative
ages of a layer of sandstone in western North Carolina
and a layer of sandstone in eastern North Carolina?
A) Compare the thickness of the two layers.
B) Compare the colors of the two layers.
C) Compare the size of sand particles of the two
layers.
D) Compare the index fossils in the two layers.
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A) a wide time range and a narrow geographic
range
B) a wide time range and a wide geographic range
C) a narrow time range and a wide geographic
range
D) a narrow time range and a narrow geographic
range
Base your answers to questions 11 and 12 on the diagram below which shows three geologic columns
representing widely separated rock outcrops. Letters A through E represent fossils found in the
outcrops. Line XY represents a fault in column I. The layers have not been overturned.
11. Which rock would most likely be produced by the metamorphism of the grey limestone?
A) quartzite
B) slate
C) marble
D) gneiss
12. What is the oldest layer shown?
A) glacial soil
C) tan limestone
B) brown sandstone
D) grey limestone
13. In which way are index fossils and volcanic ash
deposits similar?
A)
B)
C)
D)
15. Which life-form appeared first?
Both can usually be dated with radiocarbon.
Both normally occur in nonsedimentary rocks.
Both strongly resist chemical weathering.
Both often serve as geologic time markers.
14. For which segment of the Earth's geologic history
are fossils rarely found?
A) Cenozoic
C) Paleozoic
B) Mesozoic
D) Precambrian
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A) trilobite
C) coelophysis
B) human
D) stromatolite
16. Base your answer to the following question on the geologic cross section below. Overturning has not
occurred. The dike and sills shown in the cross section are igneous intrusions.
Which feature is represented by symbol A along the edges of the dike and sills?
A) contact metamorphic rock
C) a glacial moraine
B) an unconformity
D) index fossils
17. The diagram below represents two geologic rock
columns. The color and environment of deposition of
each sedimentary rock are indicated beside the rock
layers. Which rock layer in the West geologic
column is most likely the same as rock layer X in the
East column?
A) A
B) B
C) C
D) D
18. At which location in New York State would one
least expect to find fossils in the surface bedrock?
A) 42º N. 79º W.
C) 44º N. 74º W.
B) 43º N. 76º W.
D) 42º N. 75º W.
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19. Base your answer to the following question on the geologic cross section below. The large
cone-shaped mountain on Earth’s surface is a volcano. Letters A, B, and C represent certain rocks.
Which statement correctly describes the relative ages of rocks A and C and gives the best supporting
evidence from the cross section?
A)
B)
C)
D)
A is younger than C, because A is a lower sedimentary rock layer.
A is younger than C, because the intrusion of A metamorphosed part of rock layer C.
A is older than C, because A has older index fossils.
A is older than C, because the intrusion of A cuts across rock layer C.
20. Trilobite fossils may be found in Cambrian rocks.
Which statement best explains why trilobite fossils
are missing in Triassic rocks?
21. What great orogeny (mountain-building episode)
occurred in New York State during the Devonian
time period?
A) Trilobites became extinct before Triassic
time.
B) Sedimentary rock did not form during Triassic
time.
C) Widespread volcanic activity during Triassic
time melted Triassic trilobite fossils.
D) Uplift and erosion destroyed Triassic trilobite
fossils.
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A)
B)
C)
D)
Taconian Orogeny
Grenvillian Orogeny
Alleghenyan Orogeny
Acadian Orogeny
22. Base your answer to the following question on the geologic cross section below in which overturning
has not occurred. Letters A through H represent rock layers.
The folding of rock layers G through C was most likely caused by
A) erosion of overlying sediments
C) the collision of lithospheric plates
B) contact metamorphism
D) the extrusion of igneous rock
23. Which column best represents the relative duration
of the major intervals of geologic history?
A)
C)
B)
24. The geologic columns A, B, and C in the diagrams
below represent widely spaced outcrops of
sedimentary rocks. Symbols are used to indicate
fossils found within each rock layer. Each rock layer
represents the fossil record of a different geologic
time period.
D)
According to the diagrams for all three columns,
which would be the best index fossil?
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A)
B)
C)
D)
25. The diagram below represents a cross section of rock
layers. Along which line is a former interface
between erosion and deposition most likely to be
found?
A) A
B) B
C) C
D) D
26. When did armored fishes become extinct?
A)
B)
C)
D)
before the appearance of dinosaurs
before the appearance of terrestrial plants
after the appearance of reptiles
after the appearance of birds
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27. Base your answer to the following question on the diagrams of fossil trilobites shown below. The
geologic period in which each trilobite form existed is given.
The diagrams below show different geologic cross sections of rock layers in the Earth's crust. Which
cross section best shows the relative location of these four types of trilobites if overturning of the rock
layers has not occurred?
A)
B)
C)
D)
28. An unconformity between two sedimentary layers is
most likely produced by
A) the deposition of gravel followed by the
deposition of sand and silt
B) continuous sedimentation in a deep basin over a
long period
C) uplift followed by extensive erosion,
submergence, and deposition
D) a period of extrusive vulcanism followed by
another period of extrusive vulcanism
29. The changes observed in the fossil record from the
Precambrian Era to the Cenozoic Era best provide
evidence of
A) sublimation
C) evolution
B) radioactive decay
D) planetary motion
30. How many million years ago did the surface bedrock
under Watertown, New York, form?
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A) 345 to 395
C) 435 to 500
B) 395 to 435
D) 500 to 570
31. Base your answer to the following question on the
map below. The map represents the movement of
tectonic plates that resulted in the collision of India
with Asia. Scientists believe that 71 million years
ago, India was at position A.
Which life-forms were living on Earth when India
was at position A?
A) humans
C) trilobites
B) dinosaurs
D) armored fishes
32. Why are radioactive materials useful for measuring
geologic time?
A) The disintegration of radioactive materials
occurs at a predictable rate.
B) The half-lives of most radioactive materials are
less than five minutes.
C) The ratio of decay products to undecayed
material remains constant in sedimentary rocks.
D) Measurable samples of radioactive materials
are easily collected from most rock types.
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33. Base your answer to the following question on the block diagram and the cross section below. The
block diagram shows the present position of Niagara Falls in relation to the Niagara Escarpment. The
cross section shows the general bedrock structure of present-day Niagara Falls.
What is the approximate age of the Queenston shale?
A) 97 million years
C) 331 million years
B) 220 million years
D) 452 million years
34. Which radioactive element would a scientist most
likely have used to date the age of a fossil that is
10,000 years old?
A) potassium-40
C) uranium-238
B) carbon-14
D) rubidium-87
35. Which radioactive substance has the longest
half-life?
A) carbon-14
C) rubidium-87
B) potassium-40
D) uranium-238
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36. The diagram below shows a geologic cross section of 38. The element K 40 radioactively decays to Ar 40. The
a region where no faulting has occurred.
diagram below shows a model of the relative
amounts of K 40 and Ar40 remaining after one
half-life. Which diagram best illustrates the relative
amounts of K 40 and Ar40 remaining after two
half-lives?
A)
B)
C)
D)
Which statement about the geologic history of the
area is best supported by the evidence in the
diagram?
A) The rocks at A formed before those at B.
B) The rocks at D folded after the deposition of
rock layer B.
C) A long period of erosion took place before
the deposition of rock layer B.
D) The major agent of erosion acting on the
present surface is ice.
37. In the geologic cross section shown below, between
which two layers is part of the rock record most
likely missing?
A) A and B
C) C and D
39. Which graph best represents the relationship
between the remaining mass of a radioactive element
and time?
B) B and C
D) D and E
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A)
B)
C)
D)
40. Base your answer to the following question on the
graph below which shows the rate of radioactive
decay of element A and the rate at which decay
product B is formed.
According to the graph, what is the total percentage
of radioactive element A present after 3 half-lives?
A) 12.5%
C) 75.0 %
B) 25.0%
D) 87.5%
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Base your answers to questions 41 and 42 on the table below, which shows the results of a student's
demonstration modeling radioactive decay. To begin, the student put 50 pennies heads up in a
container. Each penny represented one radioactive atom. The student placed a top on the box and
shook the box. Each penny that had flipped over to the tails up side was replaced with a bean that
represented the stable decay product. The student continued the process until all of the pennies had
been replaced by beans.
41. On the grid provided on your answer paper, graph the data shown on the table by following the steps
below.
a Mark with a dot each number of radioactive atoms (pennies) after each shake. Surround each dot
with a small circle. The zero shake has been plotted for you.
b Connect all the dots with a solid line.
c Mark with an X the number of stable decay atoms (beans) after each shake. The zero shake has
been plotted for you.
d Connect all the X's with a dashed line.
42. Assume that each shake number represents an additional 100 years. State the half-life of the
radioactive material in this model.
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Base your answers to questions 43 and 44 on the newspaper article below.
New Fossils Indicate Arctic Climate Used To Be Floridian
The frigid Arctic regions were as warm as present-day Florida some 90 million years ago,
according to researchers who found fossils of a crocodile-like animal in northern Canada.
Six hundred miles from the North Pole, researchers from the University of Rochester found the
fossilized remains of the champosaur, a toothy, 8-foot-long extinct crocodile.
"We found a whole collection of fossils, from both young and adults," said scientist John H.
Tarduno.
"The champosaur is a cold-blooded animal that could not have survived in the current climate
of the Canadian Arctic where the fossils were found," Tarduno said.
Temperatures at the fossil site now routinely drop to minus 60 degrees Fahrenheit in the winter.
When the champosaur lived there 86 million to 92 million years ago, winter temperatures rarely
dropped to freezing and summer readings of 80 degrees were common.
The cold-blooded champosaur depended on the environment for warmth and probably became
immobile if the temperature was too cold. Most likely, the champosaur was too small to have
migrated seasonally.
A field team from the University of Rochester found the fossils in a layer of sandstone located
above a layer of basaltic lava.
43. State the geologic time period in which the champosaur lived.
44. Explain why no champosaur fossils were found within the layer of basaltic lava.
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Base your answers to questions 45 and 46 on the geologic cross section and graph provided below,
which represents an outcrop of various types of bedrock and bedrock features in Colorado.
45. The shale and sandstone layers both contain fossilized leaves from the Fagopsis tree, an index fossil
for the Oligocene Epoch. State a possible age for these rock layers, in million years.
46. Place the geologic events listed in order by numbering them from oldest (1) to youngest (4).
__________The fault was formed.
__________The shale was deposited.
__________The vesicular basalt was formed.
__________The sandstone was deposited.
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Base your answers to questions 47 through 49 on the cross section provided in your answer booklet.
The cross section represents a portion of Earth’s crust. Letters A, B, C, and D are rock units.
47. Igneous rock B was formed after rock layer D was deposited but before rock layer A was deposited.
Using the contact metamorphism symbol shown in the key, draw that symbol in the proper locations
on the cross section provided above to indicate those rocks that underwent contact metamorphism
when igneous rock B was molten.
48. In relation to rock units A and B in the cross section, when was igneous rock C formed?
49. Describe one observable characteristic of rock A that indicates that rock A is sedimentary.
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50. Base your answer to the following question on the information and diagram below. The diagram
represents a cliff of exposed bedrock that was investigated by an Earth science class.
After the students examined the cliff, they made three correct inferences about the geologic history of
the bedrock.
Inference 1: The shale layer is older than the basaltic intrusion.
Inference 2: The shale layer is older than the sandstone layer.
Inference 3: An unconformity exists directly under the shale layer.
Explain how each inference is supported by evidence shown in the diagram.
Page 17
Answer Key
Earth History Unit Exam 2011
1.
B
36.
C
50.
2.
C
37.
A
3.
B
38.
D
4.
A
39.
A
5.
C
40.
A
6.
C
41.
7.
B
8.
A
9.
D
10.
C
42.
100 years
11.
C
43.
12.
D
The Cretaceous
Period
13.
D
44.
14.
D
15.
D
16.
A
17.
B
Examples: The
basalt is older than
92 million years.
Fossils are not
normally found in
igneous rock.
18.
C
45.
33.7 to 24 million
years
19.
B
46.
20.
A
21.
D
22.
C
23.
A
24.
D
4-The fault was
formed. 2-The shale
was deposited.
3-The vesicular
basalt was formed.
1-The sandstone was
deposited.
25.
B
26.
A
27.
D
28.
C
29.
C
30.
C
31.
B
32.
A
33.
D
34.
B
35.
C
47.
48.
examples: – C was
formed before both
B and A. – C is
older than both B
and A.
49.
– Rock A is a
mixture of rounded
rock fragments of
different sizes
connected together.
– Rock A is a
horizontal layer.
Page 18
(essay)
Answer Key
Earth History Unit Exam 2011
50.
Inference 1 examples: – An igneous intrusion is younger than the bedrock it intrudes. – The basalt
metamorphosed the shale.
Inference 2 examples: – The shale layer is below the sandstone layer. – Younger sedimentary bedrock is
normally found on top of older sedimentary bedrock.
Inference 3 examples: – The limestone layers are folded and tilted but the shale layer is not folded and is
horizontal. – The shale layer is not metamorphosed by the granite. – There is an irregular (erosional)
surface between the shale and the limestone.