Earth’s History Test Prep
Base your answers to the following three questions on the diagram below of a cross section of a portion of
Earth’s crust. Letters A through D represent landscape features, and numbers 1 through 7 represent rock
layers. The detail shows a fossil found in layer 3.
1.What is the correct sequence of events from oldest to most recent in the geologic history of this area?
1 deposition of layers from 1 to 7 intrusion of basalt faulting
2 deposition of layers from 1 to 7 faulting intrusion of basalt
3 deposition of layers from 7 to 1 intrusion of basalt faulting
4 deposition of layers from 7 to 1 faulting intrusion of basalt
2.The fossil found in layer 3 indicates that the age of this shale layer is approximately
(1) 70 million years
(2) 220 million years
(3) 430 million years
(4) 520 million years
3.Which landscape features provide evidence that weathering and erosion were likely to have occurred?
(1) A and D, only
(2) B and C, only
(3) A, C, and D, only
(4) A, B, C, and D
4.A bone sample contains only of its original radioactive C14 content. How old is the bone sample?
(1) 1 C14 half-life
(2) 2 C14 half-lives
(3) 9 C14 half-lives
(4) 4 C14 half-lives
The shaded portion of the map below of North America shows areas believed to have been below sea level
during the Pennsylvanian Period. Point A is a location in the inland sea.
5.Present-day evidence of the existence of the inland sea during the Pennsylvanian Period is best provided by
1 marine fossils at point A
2 seawater at point A
3 metamorphic rock at point A
4 terrestrial rock at point A
6.Which type of rock is most likely to contain fossils?
1 granite
2 gneiss
3 shale
4 metaconglomerate
7.Why are radioactive substances useful for measuring geologic time?
1 The ratio of decay products to radioactive substances remains constant in rocks.
2 The half-lives of radioactive substances are short.
3 Samples of radioactive substances are easy to collect from rocks.
4 Radioactive substances undergo decay at a predictable rate.
Base your answers to the following 5 questions using the Earth Science Reference Tables, the block diagram
and the cross section below, and your knowledge of Earth science. 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.
8.What is the approximate age of the Queenston shale?
(1) 97 million years
(2) 220 million years
(3) 331 million years
(4) 452 million years
9.Which evidence in the cross section of Niagara Falls most clearly shows that erosion is occurring today?
1 upper rock units of early Silurian age
2 layering of the rock units of the face of the falls
3 sand grains within the Grimsby and Whirlpool sandstones
4 piles of rock fragments at the base of the falls
10.During the last 12,000 years, the waterfall gradually shifted upstream 11 kilometers. The average rate of
headward erosion from the original waterfall location at the escarpment (cliff) near Lewiston to the presentday waterfall location was approximately 1 kilometer every
(1) year
(2) 100 years
(3) 1,000 years
(4) 10,000 years
11.At the end of the glacial period, the Niagara River began flowing over the Niagara Escarpment. At the
end of which epoch of geologic time did this situation occur?
1 Pleistocene
2 Pliocene
3 Miocene
4 Oligocene
12.There are no major faults in the vicinity of the Niagara Escarpment that would explain its formation by
crustal movement. What is the most logical explanation of how the escarpment formed?
1 Erosion removed the rock layers north of the escarpment.
2 The rock layers north of the escarpment were folded upward.
3 The Lockport dolomite was deposited south of the escarpment only.
4 The unconformity provided a layer that was resistant to the erosion of the river.
13.Scientists have inferred that Earth’s original atmosphere was formed by the
(1) outgassing from Earth’s interior
(2) erosion of Earth’s surface
(3) decay of microorganisms in Earth’s oceans
(4) radioactive decay of elements in Earth’s core
14.A fossil shell contains 25% of the original amount of its carbon-14. Approximately how many years ago
was this shell part of a living organism?
(1) 5,700 years ago
(2) 11,400 years ago
(3) 17,100 years ago
(4) 22,800 years ago
15.Which sequence shows the correct order of Earth’s geologic time intervals from oldest to youngest?
(1) Archean Mesozoic Cenozoic Paleozoic Proterozoic
(2) Archean Proterozoic Paleozoic Mesozoic Cenozoic
(3) Cenozoic Mesozoic Paleozoic Proterozoic Archean
(4) Cenozoic Paleozoic Archean Mesozoic Proterozoic
Base your answers to the following 2 questions on the calendar model shown below of the inferred history of
the universe and on your knowledge of Earth science. The 12-month time line begins with the Big Bang on
January 1 and continues to the present time, which is represented by midnight on December 31. Several
inferred events and the relative times of their occurrence have been placed in the appropriate locations on the
time line.
16.State one piece of evidence used by scientists to support the theory that the Big Bang event occurred.
______________________________________________________________________________________
______________________________________________________________________________________
17.How many million years of Earth’s geologic history elapsed between the event that occurred on
September 10 and the event that occurred on September 25 in this model?
______________________________________________________________________________________
Base your answers to the following 3 questions on the table of index fossils shown below and on your
knowledge of Earth science.
18.During what geologic time period did the oldest index fossil shown in this table exist?
______________________________________________________________________________________
19.State one characteristic of a good index fossil.
______________________________________________________________________________________
20.Complete the following classification table by filling in the general fossil group name for each index
fossil.
Fossil Classification
Index Fossil
Eospirifer
Manticoceras
Phacops
General Fossil Group
Base your answers to the following 3 questions on the cross sections below, which show widely separated
outcrops at locations W, X, Y, and Z. The rock layers have not been overturned. Line AB in the cross section
at location W represents an unconformity. Fossils are shown in some of the layers.
21.Determine the relative geologic age of the four fossils by correlating the rock layers between these
outcrops. Below, number the fossils from 1 to 4 in order of relative age, with 1 as the oldest and 4 as the
youngest.
22.What evidence shown in the outcrop at location W suggests that the igneous intrusion occurred after both
fossils were deposited at location W?
_____________________________________________________________________________________
_____________________________________________________________________________________
23.Identify two of the processes involved in the formation of the unconformity represented by line AB in the
cross section at location W.
_______________________________________________________________________________________
24.Which group of organisms is inferred to have existed for the least amount of time in geologic history?
(1) trilobites
(2) dinosaurs
(3) eurypterids
(4) placoderm fish
The geologic cross section below shows an unconformity in New York State bedrock layers that have not
been overturned. Index fossils found throughout some rock layers are shown.
25.Which New York State index fossil may have been present in a rock layer that is missing due to the
unconformity?
The models below represent the decay of radioactive atoms to stable atoms after their first and second halflives.
26.Which model best represents the number of undecayed and decayed atoms after three half-lives?
Base your answers to the following question on the map below. The map shows some regions where
metamorphic bedrock of the Grenville Province in northeastern North America is exposed at Earth’s surface.
27.The bedrock of the Grenville Province is generally thought to have formed approximately
(1) 250 million years ago
(2) 400 million years ago
(3) 560 million years ago
(4) 1100 million years ago
28.An archeologist found an ancient skeleton estimated to be 10,000 to 25,000 years old. Which radioactive
isotope would be most useful for finding the age of the skeleton?
1 carbon-14
2 potassium-40
3 uranium-238
4 rubidium-87
Base your answers to the following 2 questions 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.
29.Which present-day geologic feature in Nepal resulted from this collision?
1 a rift valley
2 a mountain range
3 an oceanic ridge
4 an oceanic trench
30.Which life-forms were living on Earth when India was at position A?
1 humans
2 dinosaurs
3 trilobites
4 armored fishes
31.What is the estimated age of Earth?
(1) 4.6 x 106 years
(2) 4.6 x 107 years
(3) 4.6 x 108 years
(4) 4.6 x 109 years
Base your answers to the following 2 questions on the geologic cross section below of the Grand Canyon.
The numbers 1 through 10 represent Paleozoic sedimentary rock layers.
32.The unconformity between the Paleozoic sedimentary rocks and the Precambrian sedimentary rocks
represents
1 a gap in the geologic time record
2 an intrusion of igneous rock
3 an abundance of fossils
4 a region of metamorphic rock
33.Which Paleozoic rock layer is the oldest?
(1) 1
(2) 10
(3) 5
(4) 4
The primitive lobe-finned fish shown below is thought to be an ancestor of early amphibians.
34.This evolutionary development from fish to amphibian is believed to have occurred during the
1 Triassic Period
2 Devonian Period
3 Tertiary Period
4 Permian Period
Base your answers to the following 5 questions on the Earth Science Reference Tables, the index fossil
diagram below, and your knowledge of Earth science. This index fossil was found in surface bedrock in
New York State.
35.This index fossil is representative of a group of invertebrate animals known as
1 trilobites
2 stromatolites
3 brachiopods
4 eurypterids
36.During which geologic time period was this particular species alive and most abundant?
1 Cambrian
2 Jurassic
3 Silurian
4 Tertiary
37.Index fossils, such as the one in the diagram, are useful to geologists for correlating rocks because each
species
1 was narrowly distributed and became extinct after a long geologic existence
2 was widely distributed and became extinct after a short geologic existence
3 is easily found and is living today
4 is rarely found and is no longer living
38.Which information could scientists most easily infer about the location where this index fossil was found?
1 environmental conditions that existed when the animal lived
2 change in the seafloor-spreading rates from the time this animal lived to the present
3 length of time necessary to form the igneous rock in which this fossil was found
4 amount of radioactive carbon-14 in Earth’s atmosphere when this animal lived
39.The surface bedrock in which this index fossil was found is most likely composed of
1 basalt
2 granite
3 limestone
4 anthracite coal
40.The large coal fields found in Pennsylvania provide evidence that the climate of the northeastern United
States was much warmer during the Carboniferous Period. This change in climate over time is best explained
by the
(1) movements of tectonic plates
(2) effects of seasons
(3) changes in the environment caused by humans
(4) evolution of life
41.Which graph best shows the radioactive decay of carbon-14?
42.Approximately what percentage of the estimated age of Earth does the Cenozoic Era represent?
(1) 1.4%
(2) 5.0%
(3) 11.9%
(4) 65.0%
The geologic cross section below shows the geologic age of two rock layers separated by an unconformity.
43.The unconformity at the bottom of the Silurian rock layer indicates a gap in the geologic time record.
What is the minimum time, in millions of years, shown by the gap?
(1) 13
(2) 47
(3) 101
(4) 126
Base your answers to the following 3 questions on the newspaper article shown below and on your
knowledge of Earth science.
Fossilized Jellyfish Found in Wisconsin
Fossil hunters have unearthed the largest collection of fossilized jellyfish ever discovered, including
the largest fossilized jellyfish ever found.
The remains of soft-bodied animals such as jellyfish are relatively rare because they don’t have
bones, fossil dealer Dan Damrow, James W. Hagadorn of the California Institute of Technology and Robert
H. Dott Jr. of the University of Wisconsin at Madison noted in describing the find in the journal Geology.
About a half-billion years ago, during the Cambrian period, the quarry in Mosinee,
Wis., where the deposits were found was a small lagoon. The jellyfish apparently died when they were
washed up by a freak tide or storm, the researchers said. The jellyfish remains were probably preserved
because of a lack of erosion from sea water and wind, and a lack of scavengers, the researchers concluded.
“It is very rare to discover a deposit which contains an entire stranding event of jellyfish,” Hagadorn
said. “These jellyfish are not just large for the Cambrian, but are the largest jellyfish in the entire fossil
record.”
Washington Post, January 2002
44.These fossilized jellyfish were most likely discovered in which type of rock?
(1) sandstone
(2) granite
(3) pumice
(4) slate
45.Which two marine organisms most likely lived at the same time as these jellyfish?
(1) crinoids and dinosaurs
(2) ammonoids and placoderm fish
(3) brachiopods and gastropods
(4) amphibians and eurypterids
46.Which evidence would lead scientists to suspect that a tide or storm had washed up these jellyfish on a
beach?
(1) Primitive life existed on land 500 million years ago.
(2) The rock containing the jellyfish fossils has distorted crystal structure.
(3) Treeroot fossils appear to have been pitted and folded.
(4) Large ripple marks were found in the fossil-containing rock layers.
Base your answers to the following 3 questions on the cross section of the bedrock outcrop shown below and
on your knowledge of Earth science. Index fossils found in some of the rock units are shown. The rock units
are labeled I through IX.
47.In the space provided below, number the relative age of rock units VII, VIII, and IX from 1 to 3, with
number 1 indicating the oldest rock and number 3 indicating the youngest rock.
48.The fossil shown in rock unit VIII is a member of an extinct group of fossils. State two other index fossils
that are also members of the same group of extinct fossils.
49.Based on the fossils shown in the limestone and shale layers, state the type of environment in which these
sedimentary rocks were deposited.
_______________________________________________________________________________________
50.Which characteristic is most useful in correlating Devonian-age sedimentary bedrock in New York State
with Devonian-age sedimentary bedrock in other parts of the world?
(1) color
(2) index fossils
(3) rock types
(4) particle size
51.According to fossil evidence, which sequence shows the order in which these four life-forms first
appeared on Earth?
(1) reptiles amphibians insects fish
(2) insects fish reptiles amphibians
(3) amphibians reptiles fish insects
(4) fish insects amphibians reptiles
The fossil below was found in surface bedrock in the eastern United States.
52.Which statement best describes the formation of the rock containing this fossil?
(1) The rock was formed by the metamorphism of sedimentary rock deposited in a terrestrial environment
during the Cretaceous Period.
(2) The rock was formed by the compaction and cementation of sediments deposited in a terrestrial
environment during the Triassic Period.
(3) The rock was formed by the compaction and cementation of sediments deposited in a marine
environment during the Cambrian Period.
(4) The rock was formed from the solidification of magma in a marine environment during the Triassic
Period.
Base your answers to the following two questions on the diagram below, which represents a model of a
radioactive sample with a half-life of 5000 years. The white boxes represent undecayed radioactive material
and the shaded boxes represent the decayed material after the first half-life.
53.How many more boxes should be shaded to represent the additional decayed material formed during the
second half-life?
(1) 12
(2) 6
(3) 3
(4) 0
54. radioactive isotope has a half-life closest in duration to this radioactive sample?
(1) carbon-14
(2) potassium-40
(3) uranium-238
(4) rubidium-87
The diagrams below represent four series of events over the passage of time.
55.Which series of events took the least amount of time to complete?
(1) A
(2) B
(3) C
(4) D
Base your answers to the following 2 questions on the diagrams below. Diagram I shows part of a geologic
map. Diagram II shows a geologic cross section taken along line CD. The rock layers shown have not been
overturned. Numbers 1 through 5 represent locations on the surface bedrock.
56.Which graph best represents the age of the surface bedrock along line CD?
57.Which type of surface bedrock would most likely be found at location 5?
1 shale
2 sandstone
3 chemical limestone
4 siltstone
58.Which column best represents the relative duration of the major intervals of geologic history?
The diagrams below represent the rock layers and fossils found at four widely separated rock outcrops.
59.Which fossil appears to be the best index fossil?
Base your answers to the following 5 questions on the Earth Science Reference Tables, the core section
below, and your knowledge of Earth science. The core section shows the subsurface bedrock geology for a
location north of Buffalo, New York.
60.Which rock type is found at a depth of 1,800 feet at this location?
1 Oswego sandstone
2 “Basement” gneiss
3 Trenton limestone
4 Theresa sandstone
61.What do the unconformities shown near the base of the drill core indicate?
1 The continental plates were separated for a long period of time.
2 Part of the geologic rock record has been destroyed.
3 This area was covered by a warm, shallow sea.
4 Extinction of many kinds of living things was widespread.
62.Which “Important Fossils of New York” are most likely to be found in the Utica black shale or the Black
River limestone?
63.Which statement best explains why more fossils are found in outcrops of Black River rocks than in
outcrops of Utica shales?
1 Life-forms lacked hard parts at the time of Black River deposition.
2 Many fossils of the Utica shales were destroyed by metamorphism.
3 The Black River group was deposited in an environment that supported more life-forms.
4 The Utica shales were deposited over a wider geographic area.
64.Based on studies of fossils found in the Trenton group, scientists have estimated that the climate of New
York State during this part of the Ordovician Period was much warmer than the present climate. Which
statement best explains this change in climate?
1 The North American Continent was nearer to the Equator during the Ordovician Period.
2 The Sun emitted less sunlight during the Ordovician Period.
3 Earth was farther from the Sun during the Ordovician Period.
4 Many huge volcanic eruptions occurred during the Ordovician Period.
65.What is the approximate age of an igneous rock that contains only one-fourth of its original potassium-40
content due to radioactive decay?
(1) 1.3 x 109 years
(2) 2.6 x 109 years
(3) 3.9 x 109 years
(4) 5.2 x 109 years
The cross section below represents bedrock that has been changed by several geologic events.
66.Which geologic event happened most recently?
1 tilting of rock A
2 intrusion of rock B
3 formation of the unconformity at D
4 erosion of rocks B and C
The dots on the map below show the present locations of living coral reefs. Site X indicates an area of fossil
coral reefs preserved in rocks formed during the Jurassic Period.
67.Which inference is best supported by this map?
1 The climate at site X during the Jurassic Period was colder than the present climate at site X.
2 The coral at site X evolved from ocean-dwelling animals into land-dwelling animals after the Jurassic
Period.
3 Site X has drifted southward since the Jurassic Period.
4 Site X was covered by warm ocean water during the Jurassic Period.
68.Trilobite fossils were recently discovered in Himalayan Mountain bedrock. During which geologic period
could this bedrock have been formed?
1 Tertiary
2 Cretaceous
3 Triassic
4 Cambrian
Base your answers to the following two questions on the table below. The table shows the characteristics and
geological range of the four general fossil types of one kind of echinoderm called crinoids.
69.Which type of crinoid is shown below?
1 Camerata
2 Flexibilia
3 Inadunata
4 Articulata
70.Evidence shown on the chart suggest that most crinoid types
1 are extinct
2 lacked a mouth
3 had a rigid calyx
4 lived during the Cambrian
71.Evidence found in igneous rocks suggest that, through geologic time, Earth’s magnetic poles have
1 maintained their present positions
2 corresponded exactly with Earth’s geographic poles
3 maintained constant strength
4 reversed their magnetic polarities
A graph of the radioactive decay of carbon-14 is shown below.
72.Which graph correctly shows the accumulation of nitrogen-14, the decay product of carbon-14, over the
same period?
The diagram below represents a sedimentary rock composed of pebbles and sand.
73.Which statement most accurately compares the ages of the cracks and pebbles to the age of the
sedimentary rock in which they are found?
1 The cracks and pebbles are both younger than the sedimentary rock.
2 The cracks and pebbles are both older than the sedimentary rock.
3 The cracks are younger and the pebbles are older than the sedimentary rock.
4 The cracks are older and the pebbles are younger than the sedimentary rock.
Base your answers to the following three questions on the diagram below, which represents a cross section of
rock layers that have not been overturned.
74.Within which rock type would a fossil most likely be found?
75.The breccia layer is composed mostly of
1 cemented, rounded rock fragments
2 cemented, angular rock fragments
3 intergrown, fine-textured crystals
4 microscopic shells
76.If the breccia layer formed during the Carboniferous Period, the shale layer below it could have formed
during which geologic time period?
1 Cretaceous
2 Triassic
3 Permian
4 Carboniferous
77.Which bedrock feature is most useful in correlating sedimentary bedrock in one area with sedimentary
bedrock in another area?
1 index fossils
2 cementing agent
3 texture
4 color
Base your answers to the following five questions on the Earth Science Reference Tables, the diagram
below, and your knowledge of Earth science. The diagram 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.
78.What is the oldest layer shown?
1 glacial soil
2 brown sandstone
3 tan limestone
4 grey limestone
79.When did fault XY, located in column I, most likely occur?
1 before the formation of the grey limestone
2 during the formation of the grey siltstone
3 during the formation of the black shale
4 after the formation of the red sandstone
80.Which rock would most likely be produced by the metamorphism of the grey limestone?
1 quartzite
2 slate
3 marble
4 gneiss
81.The wavy line located between the green shale and the tan limestone layers in columns I and II most
likely represents
1 contact metamorphism
2 a volcanic ash layer
3 a buried erosional surface
4 an igneous intrusion
82.Fossil A, in the tan limestone layer, is a fossil of the first known coral. This tan limestone layer was most
likely deposited during which geologic time interval?
1 Precambrian
2 Paleozoic
3 Mesozoic
4 Cenozoic
Base your answers to the following five questions on the Earth Science Reference Tables, the graph below,
and your knowledge of Earth science. The graph represents the decay of radioactive material X into a stable
decay product.
83.What is the approximate half-life of radioactive material X?
(1) 5,000 yr
(2) 10,000 yr
(3) 50,000 yr
(4) 100,000 yr
84.Radioactive material X can only be used to date young geologic material because radioactive material X
1 has only recently become radioactive
2 has a relatively short half-life
3 never existed in older rocks
4 has only recently been discovered
85.Which graph best represents the relative percentages of radioactive material X and its stable decay product
after 15,000 years?
86.Each of the objects below has different amounts remaining of the original radioactive material X. Which
object is most likely the oldest?
87.If radioactive material X were heated, the length of its half-life period would
1 decrease
2 increase
3 remain the same
88.Trilobite fossil remains are most likely to be found in bedrock of
1 Precambrian age near Mt. Marcy
2 Cretaceous age on Long Island
3 Triassic age northwest of New York City
4 Ordovician age near Plattsburgh
89.Approximately how long ago did the first dinosaurs appear on Earth?
(1) 66 million years ago
(2) 187 million years ago
(3) 230 million years ago
(4) 374 million years ago
90.Which statement can best be supported by the fossil record?
(1) Humans have lived on Earth throughout geologic history.
(2) The organisms on Earth have not changed.
(3) Most life-forms that existed on Earth have become extinct.
(4) Dinosaurs existed on Earth for more than 544 million years.
The diagram below shows a geologic cross section. Letters A through D represent different rock units.
91.Which sequence correctly shows the age of the lettered rock units, from oldest to youngest?
(1) A B C D
(2) C D A B
(3) D B A C
(4) D C B A
The three cross sections of sedimentary bedrock shown below represent widely separated surface exposures
of layers that contain fossils. Letters A, B, C, and D represent four different marine fossils found in these
rock layers.
92.Which letter best represents an index fossil?
(1) A
(2) B
(3) C
(4) D
Base your answers to the following four questions on the geologic time line shown below. Letters a through
g on the time line indicate specific reference points in geologic time.
93.Place an X on the geologic time line above, so that the center of the X shows the time that the coral index
fossil Lichenaria shown below existed on Earth.
94.Letter a indicates a specific time during which geologic period?
95.Identify the mountain building event (orogeny) that was occurring in eastern North America at the time
represented by letter g.
96.Identify one letter that indicates a time for which there is no rock record in New York State.
_______________________________
Base your answers to the following two questions on the diagram and information below about fossil snails
and on your knowledge of Earth science.
Snails have lived in most of the world’s oceans over a period of hundreds of millions of years.
Paleontologists discovered that in warm, tropical waters more snails have shells that, when viewed from the
top, spiral outward in a clockwise direction. In cool or cold waters, more snails have shells that spiral
outward in a counterclockwise direction. Both clockwise- and counterclockwise-spiraled snail fossils have
been found in New York State bedrock.
97.In a slab of rock that contains many fossil snails, what evidence would lead geologists to conclude that the
slab was formed in a tropical climate?
______________________________________________________________________________________
______________________________________________________________________________________
98.State one reason bedrock that formed in tropical regions is found in New York State.
______________________________________________________________________________________
Base your answers to the following two questions on the passage below and on your knowledge of Earth
science.
Radiocarbon Dating
Radioactive carbon-14 (C14), because of its short half-life, is used for the absolute dating of organic
remains that are less than 70,000 years old.
Carbon-14 is an isotope of carbon that is produced in Earth’s upper atmosphere. High-energy cosmic
rays from the Sun hit nitrogen-14 (N14), producing radioactive C14. This C14 is unstable and will eventually
change back into N14 through the process of radioactive decay. The proportions of C14 and ordinary C12 in
Earth’s atmosphere remain approximately constant.
Radioactive C14, just like ordinary C12, can combine with oxygen to make carbon dioxide. Plants use
CO2 during photosynthesis. The proportion of C14 to C12 in the cells and tissues of living plants is the same as
the proportion of C14 to C12 in the atmosphere. After plants die, no new C14 is taken in because there is no
more photosynthesis. Meanwhile, the C14 in the dead plant keeps changing back to N14, so there is less and
less C14. The longer the plant has been dead, the less C14 is found in the plant. The age of organic remains
can be found by comparing how much C14 is still in the organic remains to how much C14 is in a living
organism.
99.Radioactive C14 was used to determine the geologic age of old wood preserved in a glacier. The amount
of C14 in the old wood is half the normal amount of C14 currently found in the wood of living trees. What is
the geologic age of the old wood?
100.State one difference between dating with the radioactive isotope C14 and dating with the radioactive
isotope uranium-238 (U238).
_______________________________________________________________________________________
_______________________________________________________________________________________
101..Fossils of trilobites, graptolites, and eurypterids are found in the same bedrock layer in New York State.
During which geologic time interval could this bedrock layer have formed?
(1) Late Ordovician to Early Devonian
(2) Late Silurian to Early Cretaceous
(3) Early Permian to Late Jurassic
(4) Early Cambrian to Middle Ordovician
The block diagram below of a portion of Earth’s crust shows four zones labeled A, B, C, and D outlined with
dashed lines.
102.In which zone is a younger rock unit on top of an older rock unit?
(1) A
(2) B
(3) C
(4) D
The graph below shows the rate of decay of the radioactive isotope K-40 into the decay products Ar-40 and
Ca-40.
103.Analysis of a basalt rock sample shows that 25% of its radioactive K-40 remained undecayed. How old
is the basalt?
(1) 1.3 billion years
(2) 2.6 billion years
(3) 3.9 billion years
(4) 4.6 billion years
Base your answers to the following five questions on the geologic cross section below and on your
knowledge of Earth science. The cross section shows New York State index fossils in rock layers that have
not been overturned. Rock unit A is an igneous intrusion and line XY represents an unconformity.
104.Based on fossil evidence, determine the geologic period during which the unconformity formed.
_______________________________________________________________________________________
105.Identify the coral index fossil that would most likely be found in the same layer as the index fossil
Ctenocrinus.
_______________________________________________________________________________________
106.Each index fossil existed for a relatively short geologic time interval. State one other characteristic that
each fossil must have to be considered an index fossil.
______________________________________________________________________________________
______________________________________________________________________________________
107.Describe the type of depositional environment in which the fossilized organisms lived.
_____________________________________________________________________________________
_____________________________________________________________________________________
108.Identify one piece of evidence shown in this cross section that indicates that the igneous intrusion, A, is
older than the sandstone layer.
_______________________________________________________________________________________
_______________________________________________________________________________________
109.The presence of brachiopod, nautiloid, and coral fossils in the surface bedrock of a certain area indicates
the area was once covered by
(1) tropical vegetation
(2) glacial deposits
(3) volcanic ash
(4) ocean water
The time line below represents the entire geologic history of Earth.
110.Which letter best represents the first appearance of humans on Earth?
(1) A
(2) B
(3) C
(4) D
Three extinct organisms are shown in the diagrams below.
111.Which other life-form reached its peak development during the same period in geologic history that
these three life-forms first appeared on Earth?
(1) dinosaurs
(2) stromatolites
(3) mastodonts
(4) eurypterids
The graph below shows the radioactive decay of a 50-gram sample of a radioactive isotope.
112.According to the graph, what is the half-life of this isotope?
(1) 100 years
(2) 150 years
(3) 200 years
(4) 300 years
Base your answers to the following four questions on the cross sections of three rock outcrops, A, B, and C.
Line XY represents a fault. Overturning has not occurred in the rock outcrops.
113.The volcanic ash layer is considered a good time marker for correlating rocks because the volcanic ash
layer
(1) has a dark color
(2) can be dated using carbon-14
(3) lacks fossils
(4) was rapidly deposited over a wide area
114.Which sedimentary rock shown in the outcrops is the youngest?
(1) black shale
(2) conglomerate
(3) tan siltstone
(4) brown sandstone
115.What is the youngest geologic feature in the three bottom layers of outcrop C?
(1) fault
(2) igneous intrusion
(3) unconformity
(4) zone of contact metamorphism
116.Which processes were primarily responsible for the formation of most of the rock in outcrop A?
(1) melting and solidification
(2) heating and compression
(3) compaction and cementation
(4) weathering and erosion
Base your answers to the following five questions on the passage and the cross section below. The passage
describes the geologic history of the Pine Bush region near Albany, New York. The cross section shows the
bedrock and overlying sediment along a southwest to northeast diagonal line through a portion of this area.
Location A shows an ancient buried stream channel and location B shows a large sand dune.
The Pine Bush Region
The Pine Bush region, just northwest of Albany, New York, is a 40-square mile area of sand dunes
and wetlands covered by pitch pine trees and scrub oak bushes. During the Ordovician Period, this area was
covered by a large sea. Layers of mud and sand deposited in this sea were compressed into shale and
sandstone bedrock.
During most of the Cenozoic Era, running water eroded stream channels into the bedrock. One of
these buried channels is shown at location A in the cross section. Over the last one million years of the
Cenozoic Era, this area was affected by glaciation. During the last major advance of glacial ice, soil and
bedrock were eroded and later deposited as till (a mixture of boulders, pebbles, sand, and clay).
About 20,000 years ago, the last glacier in New York State began to melt. The meltwater deposited
pebbles and sand, forming the stratified drift. During the 5000 years it took to melt this glacier, the entire
Pine Bush area became submerged under a large 350-foot-deep glacial lake called Lake Albany. Delta
deposits of cobbles, pebbles, and sand formed along the lake shorelines, and beds of silt and clay were
deposited farther into the lake.
Lake Albany drained about 12,000 years ago, exposing the lake bottom. Wind erosion created the
sand dunes that cover much of the Pine Bush area today.
117.According to the passage, how old is the bedrock shown in the cross section?
118.What evidence shown at location A suggests that the channel in the bedrock was eroded by running
water?
______________________________________________________________________________________
119.List, from oldest to youngest, the four types of sediment shown above the bedrock in the cross section.
120.Explain why the till layer is composed of unsorted sediment.
_______________________________________________________________________________________
_______________________________________________________________________________________
121.How does the shape of the sand dune at location B provide evidence that the prevailing winds that
formed this dune were blowing from the southwest?
_______________________________________________________________________________________
_______________________________________________________________________________________
122.Layers of volcanic ash often serve as useful geologic time markers because ash layers usually
1 deposit quickly over a wide area
2 are older than the surrounding rock
3 can be sampled easily
4 darken with age
123.According to available fossil evidence, which set of events is listed in the correct order from earliest to
most recent?
1 extinction of trilobites, extinction of armored fishes, extinction of dinosaurs
2 appearance of first corals, appearance of earliest insects, appearance of earliest reptiles
3 decline of brachiopods, appearance of earliest amphibians, appearance of earliest grasses
4 peak development of eurypterids, appearance of earliest birds, appearance of earliest chordates
124.Which statement about the species of animals and plants that lived on Earth in the past is best supported
by the fossil record?
1 Most became extinct.
2 Most lived on the land.
3 Most were preserved in metamorphic rock.
4 Most appeared during the Cambrian period.
Base your answers to the following two questions on the Earth Science Reference Tables and on the diagram
below. The diagram shows the evolutionary development of the horse, as supported by the fossil record.
125.The earliest geologic epoch in which Mesohippus existed was the
1 Paleocene
2 Eocene
3 Miocene
4 Pliocene
126.Which statement best explains the changing appearance of the horse, as supported by the fossil record?
1 The horse evolved due to the influence of humans.
2 The horse evolved from a complex life-form to a simpler life-form.
3 The horse evolved into a life-form better able to survive.
4 The horse evolved from larger ancestors without forelimbs.
127.Which statement best explains why geologic materials from the Quarternary Period must be dated by
using radioactive isotopes different from the isotopes used to date materials from the Cambrian Period?
1 All rocks contain radioactive substances.
2 Some isotopes decay faster than others.
3 Not all isotopes form stable decay products.
4 The decay of atoms occurs as a random event.
The geologic cross section below shows sedimentary rock layers A, B, C, and D, which have not been
overturned. E is an igneous intrusion. Line XY represents a fault.
128.Which geologic event occurred most recently?
1 deposition of sediments for rock layer A
2 formation of the fault
3 intrusion of the igneous material E
4 cementation of sediments for rock layer D
129.Chemical evaporite bedrock is found approximately 20 kilometers south of Rochester, New York. This
bedrock most likely formed during which geologic time interval?
1 Silurian Period
2 Devonian Period
3 Pleistocene Epoch
4 Pennsylvanian Epoch
Base your answers to the following five questions on the Earth Science Reference Tables, the geologic cross
section of bedrock shown below, and your knowledge of Earth science. The cross section shows bedrock
exposed along part of the Genesee River in New York State. The rock has not been overturned.
130.Which rock group contains the oldest layers?
1 West Falls
2 Hamilton
3 Lockport
4 Clinton
131.A buried erosional surface indicating a time gap in the rock record is shown between which two groups?
1 Clinton and Lockport
2 Lockport and Salina
3 Salina and Onondaga
4 Onondaga and Hamilton
132.A fossil of which animal is most likely to be found in the bedrock of the Hamilton Group?
1 early reptile
2 early dinosaur
3 brachiopod
4 human
133.The bedrock shown in the cross section was formed during which geologic era?
1 Proterozoic
2 Paleozoic
3 Mesozoic
4 Cenozoic
134.Which rock layers in this formation appear to be the most resistant to weathering?
1 shales
2 gypsum
3 dolostones
4 salt
135.Which animals do scientists believe could have been hunted by humans, based on evidence such as stone
spearpoints found embedded in the animals’ bones?
1 dinosaurs
2 mammoths
3 armored fishes
4 trilobites
A geologic cross section for a portion of Earth’s crust is shown below. Letter A is a location in a rock layer,
and line XY represents a fault.
136.Which of these events occurred most recently at this location?
1 deposition of the layer at A
2 igneous intrusion
3 contact metamorphism
4 faulting along line XY
The diagram below shows how scientists think some of Earth’s continents were joined together in the
geologic past.
137.When do scientists think these continents were joined together?
1 during the Tertiary period, only
2 from the Cretaceous Period through the Tertiary Period
3 from the Devonian Period through the Triassic Period
4 during the Cambrian Period, only
138.Fossils would most likely be found in a sample of
1 limestone
2 granite
3 quartzite
4 metaconglomerate
Base your answers to the following two questions on the chart below. The thickness of the shaded areas
shows the relative abundance of some animals and plants through geologic time.
139.Which life-forms appear to be extinct?
1 sponges, insects, and flowering plants
2 bony fishes, dinosaurs, and mammals
3 sponges, insects, and reptiles
4 trilobites, ammonites, and dinosaurs
140.Which life-form was most abundant 250 million years ago?
1 dinosaurs
2 reptiles
3 bony fishes
4 trilobites
141.Which two elements are most useful for the radioactive dating of recent organic remains?
(1) C14 and N14
(2) K40 and Ca40
(3) U238 and Pb206
(4) Rb87 and Sr87
142.The largest meteorite impact crater in North America formed approximately 1,850 million years ago,
which was during the
1 Middle Archean Era
2 Early Proterozoic Era
3 Early Jurassic Period
4 Late Cretaceous Period
143.Based on fossil evidence, most scientists infer that
(1) life has not changed significantly throughout Earth’s history
(2) life has evolved from complex to simple forms
(3) many organisms that lived on Earth have become extinct
(4) mammals developed early in the Precambrian time period
144.The presence of which index fossil in the surface bedrock most likely indicates that a forest environment
once existed in the region?
(1) Aneurophyton
(2) Cystiphyllum
(3) Centroceras
(4) Bothriolepis
145.Which pie graph best represents the percentage of total time for the four major divisions of geologic
time?
Base your answers to the following two questions on the map below, which shows Earth’s Southern
Hemisphere and the inferred tectonic movement of the continent of Australia over geologic time. The arrows
between the dots show the relative movement of the center of the continent of Australia. The parallels of
latitude from 0° to 90° south are labeled.
146.The geographic position of Australia on Earth’s surface has been changing mainly because
(1) the gravitational force of the Moon has been pulling on Earth’s landmasses
(2) heat energy has been creating convection currents in Earth’s interior
(3) Earth’s rotation has spun Australia into different locations
(4) the tilt of Earth’s axis has changed several times
147.During which geologic time interval did Australia most likely have a warm, tropical climate because of
its location?
(1) Cambrian
(2) Carboniferous
(3) Late Permian
(4) Eocene
Base your answers to the following four questions on the diagrams below, which represent two bedrock
outcrops, I and II, found several kilometers apart in New York State. Rock layers are lettered A through F.
Drawings represent specific index fossils.
148.During which geologic time period was rock layer C deposited?
149.Identify two processes that produced the unconformity in outcrop I.
150.Describe one characteristic a fossil must have in order to be considered a good index fossil.
_______________________________________________________________________________________
_______________________________________________________________________________________
151.Explain why carbon-14 cannot be used to find the geologic age of these index fossils.
_______________________________________________________________________________________
_______________________________________________________________________________________
152.It is inferred that during the early Archean Era the atmosphere of Earth contained water vapor, carbon
dioxide, nitrogen, and other gases in small amounts. These gases probably came from
(1) precipitation of groundwater
(2) volcanic eruptions
(3) evaporation of Paleozoic oceans
(4) convection currents in the mantle
153.There is evidence that an asteroid or a comet crashed into the Gulf of Mexico at the end of the Mesozoic
Era. Consequences of this impact event may explain the
(1) extinction of many kinds of marine animals, including trilobites
(2) extinction of ammonoids and dinosaurs
(3) appearance of the earliest birds and mammals
(4) appearance of great coal-forming forests and insects
154.Which type of rock most likely contains fossils?
(1) scoria
(2) gabbro
(3) schist
(4) shale
Base your answers to the following three questions on the reading passage and the drawing below and on
your knowledge of Earth science.
Fossil With Signs of Feathers Is Cited as Bird-Dinosaur Link
Paleontologists have discovered in China a fossil dinosaur with what are reported to be
clear traces of feathers from head to tail, the most persuasive evidence so far, scientists say,
that feathers predated the origin of birds and that modern birds are descendants of
dinosaurs.
Entombed in fine-grained rock, the unusually well-preserved skeleton resembles that
of a duck with a reptilian tail, altogether about three feet in length. Its head and tail are
edged with the imprint of downy fibers. The rest of the body, except for bare lower legs,
shows distinct traces of tufts and filaments that appear to have been primitive feathers. On
the backs of its short forelimbs are patterns of what look like modern bird feathers.
Other dinosaur remains with what appear to be featherlike traces have been unearthed
in recent years, but nothing as complete as this specimen, paleontologists said. Etched in
the rock like a filigree decoration surrounding the skeleton are imprints of where the down
and feathers appear to have been.
The 130-million-year-old fossils were found a year ago by farmers in Liaoning Province
in northeastern China. After an analysis by Chinese and American researchers, the fossil
animal was identified as a dromaeosaur, a small fast-running dinosaur related to velociraptor.
The dinosaurs belonged to a group of two-legged predators known as advanced theropods . . .
excerpted from “Fossil With Signs of
Feathers Is Cited as Bird-Dinosaur Link”
John Noble Wilford
New York Times, April 26, 2001
The drawing below shows an artist’s view of the dinosaur, based on the fossilized remains.
155.During which period of geologic time have paleontologists inferred that the feathered dinosaur
mentioned in the passage existed?
(1) Cambrian
(2) Cretaceous
(3) Paleocene
(4) Permian
156.This feathered dinosaur is not considered an index fossil because it
(1) existed too long ago
(2) was preserved in ash
(3) was a land-dwelling animal
(4) was found in only one area
157.The reference to the bird-dinosaur link is most likely referring to the concept of
(1) plate tectonics
(2) evolution
(3) dynamic equilibrium
(4) recycling
Base your answers to the following two questions on the diagram below, which represents a model of the
radioactive decay of a particular element. The diagram shows the decay of a radioactive element (
into the stable decay element (
)
) after one half-life period.
158.On the diagram provided below, shade in the amount of stable decay element present after the second
half-life period.
159.If the radioactive element in this model is carbon-14, how much time will have passed after one halflife?
Base your answers to the following three questions on the cross section below, which shows several rock
formations found in New York State. The rock layers have not been overturned.
160.How does this cross section indicate that the Stockton sandstone is the oldest rock layer?
_______________________________________________________________________________________
_______________________________________________________________________________________
161.State one piece of evidence that supports the fact that the Palisade Sill is younger than the Brunswick
sandstone.
_______________________________________________________________________________________
_______________________________________________________________________________________
162.State one tectonic event affecting North America that occurred at the same time as the Palisade Sill
intrusion.
_______________________________________________________________________________________
Base your answers to the following three questions on the cross section below and on your knowledge of
Earth science. The cross section shows a portion of Earth’s crust. The age, in millions of years, of each
boundary between the different sedimentary rock layers is shown. The age of boundary X between the
sedimentary rock and the metamorphic rock is not shown. Assume no overturning has occurred.
163.Identify the geologic feature represented by boundary X.
_________________________________________
164.Describe how the rock type below boundary X was formed.
_______________________________________________________________________________________
_______________________________________________________________________________________
165.Identify by name one index fossil that existed when the limestone rock shown in the cross section was
being formed.
_______________________________________________________________________________________
166.Earth’s fossil record shows evidence that
(1) very few life-forms have become extinct
(2) life-forms existed on land before life-forms existed in water
(3) more complex life-forms probably have evolved from less complex life-forms
(4) older bedrock contains a great variety of life-forms, while younger bedrock contains less variety of lifeforms
Bedrock outcrops A and B are located at two different locations along the Genesee River in western New
York State. Rock layers 1, 2, and 4 are the same in both outcrops.
167.Which statement best explains why rock layer 3 is missing from outcrop B?
(1) A fault exists between outcrops A and B.
(2) Erosion created an unconformity between rock layers 2 and 4 in outcrop B.
(3) A volcanic eruption destroyed rock layer 3 in outcrop B.
(4) Metamorphism of outcrop A created rock layer 3.
168.Fossilized footprints of Coelophysis dinosaurs have been found in bedrock closest to which New York
State location?
(1) New York City
(2) Old Forge
(3) Watertown
(4) Niagara Falls
169.A sample of wood that originally contained 100 grams of carbon-14 now contains only 25 grams of
carbon-14. Approximately how many years ago was this sample part of a living tree?
(1) 2,850 years
(2) 5,700 years
(3) 11,400 years
(4) 17,100 years
Base your answers to the following four questions on the geologic cross section below. Radioactive dating
indicates that the granite intrusion is 279 million years old and the vesicular basalt is 260 million years old.
The rock layers have not been overturned.
170List the six rock units in the order from the oldest to the youngest.
171.During which geologic time period did the shale layer form?
172.The granite intrusion caused part of the limestone layer to undergo metamorphism.
What metamorphic rock would most likely be found in this zone of contact metamorphism?
___________________________________________
173.Describe the rate of cooling that must occur for magma to form vesicular basalt.
_______________________________________________________________________________________
The geologic drill core below shows bedrock layers A, B, and C that have not been overturned.
The geological ages of layers A and C are shown.
174.What is the geologic age of layer B?
(1) Cambrian
(2) Ordovician
(3) Devonian
(4) Permian
The sequence of diagrams below represents the gradual geologic changes in layer X, located just below
Earth’s surface.
175.Which type of sedimentary rock was formed at layer X?
(1) conglomerate
(2) shale
(3) rock salt
(4) coal
The graph below shows the average change in the elevation of a mountain range over time.
176.According to the graph, the rate of uplifting was greater than the rate of erosion during which geologic
time period?
(1) Silurian
(2) Devonian
(3) Carboniferous
(4) Permian
.At which latitude and longitude in New York State would a salt mine in Silurian-age bedrock most likely be
located?
(1) 41° N 72° W
(3) 44° N 74° W
(2) 43° N 77° W
(4) 44° N 76° W
Base your answers to the following two questions on the diagram below, which shows a cross section of
Earth’s crust.
177.Which statement gives an accurate age relationship for the bedrock in the cross section?
(1) Intrusion A is younger than intrusion C.
(2) Intrusion C is younger than intrusion B.
(3) Intrusion B is older than intrusion A.
(4) Intrusion C is older than layer E.
178.The most apparent buried erosional surface is found between rock units
(1) A and B
(2) C and D
(3) D and F
(4) E and H
179.Which inference is best supported by the rock and fossil record in New York State?
(1) Eurypterids lived in shallow seas near present day Syracuse.
(2) Coelophysis wandered through jungles near present-day Albany.
(3) The first coral reefs formed off the shoreline of present-day Long Island.
(4) The condor nested on the peaks of the ancestral Adirondack Mountains during the Grenville Orogeny.
The geologic block diagram below shows surface features and subsurface structures of a section of Montana.
180.The faulting shown in the diagram could have occurred
(1) 2,100 million years ago
(2) 520 million years ago
(3) 250 million years ago
(4) 50 million years ago
The diagram below shows a cross section of New York State bedrock that has not been overturned. Line X
represents an unconformity.
181.The index fossil Eurypterus is found in the limestone layer. What trilobite index fossil could be found in
the shale layer?
______________________________________________
Base your answers to the following two questions on your knowledge of Earth science and on the newspaper
article shown below, written by Paul Recer and printed in the Times Union on October 9, 1998.
Astronomers peer closer to big bang
WASHINGTON — The faintest and most distant objects ever sighted — galaxies of
stars more than 12 billion light years away — have been detected by an infrared camera on
the Hubble Space Telescope.
The sighting penetrates for the first time to within about one billion light years of the very
beginning of the universe, astronomers said, and shows that even at that very early time there already
were galaxies with huge families of stars.
“We are seeing farther than ever before,” said Rodger I. Thompson, a University of
Arizona astronomer and the principal researcher in the study.
Thompson and his team focused an infrared instrument on the Hubble on a narrow patch of
the sky that had been previously photographed in visible light. The instrument detected about
100 galaxies that were not seen in the visible light and 10 of these were at extreme distance.
He said the galaxies are seen as they were when the universe was only about 5 percent
of its present age. Astronomers generally believe the universe began with a massive explosion,
called the “big bang,” that occurred about 13 billion years ago.
Since the big bang, astronomers believe that galaxies are moving rapidly away from each
other, spreading out and becoming more distant.
182.The big-bang theory is widely believed by astronomers to explain the beginning of the universe. Why
does the light from distant galaxies support the big-bang theory?
_______________________________________________________________________________________
_______________________________________________________________________________________
183.Compare the age of Earth and our solar system to the age of these distant galaxies of stars.
_______________________________________________________________________________________
_______________________________________________________________________________________
184.During which geologic time period did the earliest reptiles and great coal-forming forests exist?
(1) Devonian
(2) Quaternary
(3) Mississippian
(4) Pennsylvanian
Base your answers to the following two questions in part on the newspaper article below.
Ancient human footprints found
PARIS — In the darkness of an underground cave lined with prehistoric paintings,
French scientists believe they have discovered the oldest footprints of humans in Europe.
Embedded in damp clay, the imprints, slightly more than 8 inches long, appear to be
those of a boy, 8 or 10 years old, who was walking barefoot between 25,000 and 30,000 years
ago, prehistorians said Wednesday.
They said the dates are only hypothetical because there is no precise way to determine
when the markings were made. But Michel-Andre Garcia, one prehistorian who has studied
the site, said that the carbon datings in the cave and the context make this “a very strong
hypothesis.” The four footprints were found in the Ardeche region of southern France,
deep inside the Chauvet cave.
— Times Union, June 10, 1999
185.Scientists have inferred that these “oldest” European human footprints were made during which
geologic epoch?
186.Which characteristic of the radioactive isotope carbon-14 explains why carbon-14, rather than the
radioactive isotope uranium-238, was used by archeologists in dating the age of their findings?
_______________________________________________________________________________________
The table below gives information about the radioactive decay of carbon-14. Part of the table has been
deliberately left blank for student use.
187.After how many years will
(1) 22,800 yr
(2) 28,500 yr
(3) 34,200 yr
(4) 39,900 yr
gram of the original carbon-14 remain?
188.Which event occurred earliest in geologic history?
(1) appearance of the earliest grasses
(2) appearance of the earliest birds
(3) the Grenville Orogeny
(4) the intrusion of the Palisades Sill
189.A very large, circular, impact crater under the coast of Mexico is believed to be approximately 65
million years old. This impact event is inferred to be related to the
(1) appearance of the earliest trilobites
(2) advance and retreat of the last continental ice sheet
(3) extinction of the dinosaurs
(4) formation of Pangea
190.The characteristic of the radioactive isotope uranium-238 that makes this isotope useful for accurately
dating the age of a rock is the isotope’s
(1) organic origin
(2) constant half-life
(3) common occurrence in sediments
(4) resistance to weathering and erosion
Base your answers to the following five questions on the geologic cross section of bedrock shown below.
A through G identify rock layers and Q represents a fault. Lines W, X, Y, and Z are locations of
unconformities. The rocks have not been overturned.
191.Which rock or feature is oldest?
(1) rock A
(2) rock G
(3) fault Q
(4) unconformity Z
192.The unconformities shown in the cross section represent
(1) buried erosional surfaces
(2) locations of index fossils
(3) volcanic ash deposits
(4) boundaries between oceanic and continental crust
193.The movement of bedrock along fault Q most probably produced
(1) gaps in the rock record
(2) an earthquake
(3) a volcanic lava flow
(4) zones of contact metamorphism
194.Which rock most likely formed in the zone of contact between rock E and rock F?
(1) obsidian
(2) slate
(3) metaconglomerate
(4) sandstone
195.Rock layers B, C, and D formed during the Devonian Period. Which fossil might be found in these rock
layers?
The diagram below shows a fossil found in the surface bedrock of New York State.
196.Which other fossil is most likely to be found in the same age bedrock?
(1) Phacops
(2) condor
(3) Coelophysis
(4) Tetragraptus
197.Which group of organisms, some of which were preserved as fossils in early Paleozoic rocks, are still in
existence today?
(1) brachiopods
(2) eurypterids
(3) graptolites
(4) trilobites
198.Which graph shows the relative duration of geologic time for the Precambrian, Paleozoic, Mesozoic, and
Cenozoic time intervals?
199.According to the Geologic History of New York State in the Earth Science Reference Tables, the
inferred latitude of New York State 362 million years ago was closest to
(1) where it is now
(2) the North Pole
(3) the Equator
(4) 45° south
Base your answers to the following two questions on the maps below, which show changes in the
distribution of land and water in the Mediterranean Sea region that scientists believe took place over a period
of 6 million years.
200.Which type of rock was precipitated from seawater as the Mediterranean Sea evaporated between 8
million years ago and 5.5 million years ago?
(1) rock salt
(2) basalt
(3) sandstone
(4) metaconglomerate
201.During which geologic time period did the changes shown in the maps take place?
(1) Cambrian
(2) Cretaceous
(3) Permian
(4) Neogene
Base your answers to the following five questions on the geologic cross section provided below, which
represents an outcrop of various types of bedrock and bedrock features in Colorado.
202.On the cross section provided above, indicate with arrows the direction of movement on both sides of
the fault.
203.According to this cross section, what is the amount of vertical movement of the shale along the fault?
Express your answer to the nearest tenth of a meter.
204.Place the geologic events listed below in order by numbering them from oldest (1) to youngest (4).
205.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.
206.The vesicular basalt includes zircon crystals containing the radioactive isotope U-235, which
disintegrates to the stable isotope Pb-207. The zircon crystals have 98.44% of the original U-235 remaining,
and 1.56% has decayed to Pb-207. Based on the table below, how many half-lives have elapsed since the
formation of these
crystals?
Base your answers to the following two questions on the table and graph below. The table labeled “Animal
Key” shows symbols to represent various animal groups that exist on Earth. The graph shows inferred
changes in Earth’s average temperatures over the last 500 million years.
207.On the graph provided below, indicate when each of the life-forms in the table is believed to have first
appeared on Earth by placing the letter for each animal group in the correct box. The correct location for
earliest fish, letter B, has already been plotted above the graph.
208.The two factors listed below could have caused the temperature variations shown on the graph. For each
factor, state the effect that the increase described would have had on Earth’s temperature, and explain why
that temperature change would have taken place.
Factors
A Increase in carbon dioxide (CO2) and water vapor (H2O gas) content of Earth’s atmosphere
B Increase in volcanic ash in Earth’s atmosphere
209.During which era did the initial opening of the present-day Atlantic Ocean most likely occur?
(1) Cenozoic
(2) Mesozoic
(3) Paleozoic
(4) Late Proterozoic
210.The absolute age of a rock is the approximate number of years ago that the rock formed.
The absolute age of an igneous rock can best be determined by
(1) comparing the amounts of decayed and undecayed radioactive isotopes in the rock
(2) comparing the sizes of the crystals found in the upper and lower parts of the rock
(3) examining the rock’s relative position in a rock outcrop
(4) examining the environment in which the rock is found
The diagram below is a portion of a geologic time line. Letters A through D represent the time intervals
between the labeled events, as estimated by some scientists.
211.Fossil evidence indicates that the earliest birds developed during which time interval?
(1) A
(2) B
(3) C
(4) D
Base your answers to the following four questions on the geologic cross section below, which shows a view
of rock layers at Earth’s surface. The dashed lines connect points of the same age. Major fossils contained
within each rock layer are shown. The valleys are labeled X, Y, and Z.
212.In which type of environment were the sediments that formed these sedimentary rock layers most likely
deposited?
(1) glacial
(2) mountainous
(3) marine
(4) terrestrial plateau
213.Which fossil would most likely be found in the same siltstone layer as the Cryptolithus fossil?
214.The sedimentary rock layers at the three locations can be most accurately correlated by comparing the
(1) thickness of the sedimentary rock layers
(2) foliation bands in the metamorphic basement rocks
(3) fossils in the sedimentary rocks
(4) minerals in the igneous rocks
215.In this region, valley X is more deeply eroded than either valley Y or valley Z. The most likely
explanation for this occurrence is that the metamorphic rock near X has been
(1) weakened by faulting
(2) folded by pressure
(3) intruded by melted rock
(4) covered by sedimentary rocks
Base your answers to the following two questions on the geologic cross section below. Overturning has not
occurred. The dike and sills shown in the cross section are igneous intrusions.
216.Which rock type is the oldest?
217.Which feature is represented by the symbol
(1) contact metamorphic rock
(2) an unconformity
(3) a glacial moraine
(4) index fossils
along the edges of the dike and sills?
218.Which radioactive isotope is most useful for determining the age of mastodont bones found in late
Pleistocene sediments?
(1) uranium-238
(2) carbon-14
(3) potassium-40
(4) rubidium-87
The Devonian-aged siltstone shown in the photograph below occurs as surface bedrock near Hamilton,
New York.
219.What does the presence of the fossils suggest about the Hamilton area during the Devonian?
(1) It had a terrestrial environment sometime between 443 and 418 million years ago.
(2) It had a terrestrial environment sometime between 418 and 362 million years ago.
(3) It had a marine environment sometime between 443 and 418 million years ago.
(4) It had a marine environment sometime between 418 and 362 million years ago.
Base your answers to the following three questions on the map below, which shows most of New York State.
Isolines indicate the depth of the Precambrian bedrock surface below present-day sea level. Depths are in
feet.
220.According to the map, in which two present-day New York State landscape regions is the most
Precambrian bedrock likely to be exposed on the land surface?
(1) Erie-Ontario Lowlands and Tug Hill Plateau
(2) Allegheny Plateau and Catskills
(3) Adirondack Mountains and Hudson Highlands
(4) Hudson-Mohawk Lowlands and Champlain Lowlands
221.What is the geologic age of most of the bedrock covering the Precambrian rock in present-day New
York State?
(1) Paleozoic
(2) Cenozoic
(3) Mesozoic
(4) Archean
222.Which map best shows the location of the –4,000-foot isoline?
Base your answers to the following three questions on the paragraph below, which provides background
information regarding recent fossil discoveries in Canada.
Scientific evidence indicates that the earliest mammals may have evolved approximately
225 million years ago from an ancient reptile group called the therapsids. For millions of
years afterward, early mammals and therapsids coexisted until the therapsids apparently
became extinct 165 million years ago. However, geologists have recently found a fossil they
believe to be a therapsid that is only 60 million years old. They found the fossil, which they
have named Chronoperates paradoxus (paradoxical time-wanderer), near Calgary in
Canada. This find suggests that for 105 million years after the apparent extinction of the
therapsids, a few of the reptiles continued to live in a narrow geographic range in Canada.
223.According to fossil evidence, during which geologic period did the earliest mammals appear on Earth?
224.Explain briefly why Chronoperates paradoxus would not be a good index fossil.
_______________________________________________________________________________________
_______________________________________________________________________________________
225.State one method geologists could have used to determine that Chronoperates paradoxus lived 60
million years ago.
_______________________________________________________________________________________
_______________________________________________________________________________________
Base your answers to the following two questions 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.
226.Explain how each inference is supported by evidence shown in the diagram.
227.Students compared samples of the granite and basalt. State one observable characteristic other than
crystal size that makes granite different from basalt.
_______________________________________________________________________________________
228.Fossil pollen has been recovered from sediments deposited in late-Pleistocene lakes. The pollen’s
geologic age can most accurately be measured by using
(1) rubidium-87
(2) potassium-40
(3) oxygen-18
(4) carbon-14
229.According to plate tectonic theory, during which geologic time interval did the continents of North
America and Africa separate, resulting in the initial opening of the Atlantic Ocean?
(1) Mesozoic Era
(2) Paleozoic Era
(3) Proterozoic Eon
(4) Archean Eon
230.Near which location in New York State would a geologist have the greatest chance of finding dinosaur
footprints in the surface bedrock?
(1) 41° 10' N latitude, 74º W longitude
(2) 42º 10' N latitude, 74º 30' W longitude
(3) 43º 30' N latitude, 76º W longitude
(4) 44º 30' N latitude, 75º 30' W longitude
Geologic cross sections A through F shown below represent different stages in the development of one part
of Earth’s crust over a long period of geologic time.
231.What is the correct order of development from the original (oldest) stage to the most recent (youngest)
stage?
(1) B D C F A E
(2) B F C D E A
(3) E A D F C B
(4) E A F C D B
232.Uranium-238 that crystallized at the same time Earth formed has undergone approximately how many
half-lives of radioactive decay?
(1) one half-life
(2) two half-lives
(3) three half-lives
(4) four half-lives
The diagram below represents bedrock layers found in an outcrop. Three index fossils are found within the
bedrock layers.
233.Which evidence best suggests that this outcrop has undergone crustal movement?
(1) The same rock layers appear twice within the outcrop.
(2) The trilobite fossil is not found in all five layers.
(3) The sedimentary layers have the same thickness.
(4) The eurypterid fossil is absent in the middle layer.
Base your answers to the following four questions on the reading passage below and on your knowledge of
Earth science. The reading passage provides some background information about a recent fossil discovery.
The map of Canada shows the fossil site. The scale drawing shows the new trilobite fossil compared to other
trilobite fossils.
The World’s Biggest Trilobite
A team of Canadian paleontologists examining rock units along the shore of Hudson
Bay in northern Manitoba has discovered the world’s largest recorded complete fossil of a
trilobite, a many-legged, sea-dwelling animal inferred to have lived during the late
Ordovician Period. The giant creature, measuring 70 centimeters in length, is a new species
of the genus Isotelus. This remarkable discovery adds to our knowledge of the diversity of
life following one of the greatest increases in the number and types of life-forms in history.
The new Isotelus species existed just before the end of the Ordovician Period.
234.In what type of rock was the new Isotelus fossil most probably found?
___________________________________
235.At the time the new Isotelus fossil lived and died, during the Ordovician Period, what was the
approximate latitude of the fossil site according to plate tectonic theory?
___________________________________
236.What New York State nautiloid index fossil would most likely be found in the bedrock just below the
new Isotelus fossil?
___________________________________
237.The actual new Isotelus fossil is approximately how many times larger than scale drawing A?
___________________________________
238.Carbon-14, an isotope used to date recent organic remains, would most likely be useful in determining
the age of a fossil
(1) trilobite
(2) Coelophysis
(3) armored fish
(4) Beluga whale
The cartoon below illustrates possible interaction between humans and mammoths.
239.
During which geologic timespan could this “game” have occurred?
(1) Pleistocene Epoch
(2) Pennsylvanian Epoch
(3) Precambrian Era
(4) Paleozoic Era
The diagram below shows the abundance of organisms called crinoids, blastoids, and echinoids throughout
different geologic periods. The number of species living at any given time is represented by the width of
the blackened areas.
240.Which statement about crinoids, blastoids, and echinoids is best supported by the diagram?
(1) They are now extinct.
(2) They came into existence during the same geologic period.
(3) They existed during the Devonian Period.
(4) They have steadily increased in number since they first appeared.
The diagram below shows trends in the temperature of North America during the last 200,000 years, as
estimated by scientists.
241.What is the total number of major glacial periods that have occurred in North America in the last
200,000 years?
(1) 5
(2) 2
(3) 3
(4) 4
242.The Himalayan Mountains are located along a portion of the southern boundary of the Eurasian Plate. At
the top of Mt. Everest (29,028 feet) in the Himalayan Mountains, climbers have found fossilized marine
shells in the surface bedrock. From this observation, which statement is the best inference about the origin of
the Himalayan Mountains?
(1) The Himalayan Mountains were formed by volcanic activity.
(2) Sea level has been lowered more than 29,000 feet since the shells were fossilized.
(3) The bedrock containing the fossil shells is part of an uplifted seafloor.
(4) The Himalayan Mountains formed at a divergent plate boundary.
The diagram below represents the present number of decayed and undecayed atoms in a sample that was
originally 100% radioactive material.
243.If the half-life of the radioactive material is 1,000 years, what is the age of the sample represented by the
diagram?
(1) 1,000 yr
(2) 2,000 yr
(3) 3,000 yr
(4) 4,000 yr
Base your answers to the following five questions on the cross sections below, which show widely separated
outcrops at locations X, Y, and Z.
244.Which rock layer is oldest?
(1) gray siltstone
(2) green shale
(3) tan limestone
(4) brown siltstone
245.At location Y, the boundary between the red sandstone and the black shale marks the
(1) beginning of the Cenozoic Era
(2) beginning of the Mesozoic Era
(3) end of the Cenozoic Era
(4) end of the Mesozoic Era
246.An unconformity can be observed at location Z. Which rock layer was most probably removed by
erosion during the time represented by the unconformity?
(1) conglomerate
(2) gray siltstone
(3) black shale
(4) brown siltstone
247.The fossils in the rock formations at location X indicate that this area was often covered by
(1) tropical rain forests
(2) glacial ice
(3) desert sand
(4) seawater
248.Which rock layer was formed by the compaction and cementation of particles that were all less than
0.0004 centimeter in diameter?
(1) red sandstone
(2) green shale
(3) brown siltstone
(4) conglomerate
Some marine organisms swim or float in the ocean, and others live on or in the sediment of the ocean floor.
A group of floating organisms called graptolites were common in some ancient seas that covered New York
State and are found in some New York State bedrock.
249.State one reason why certain species of graptolites are used as an index fossil.
_______________________________________________________________________________________
_______________________________________________________________________________________
Base your answers to the following three questions in part on the newspaper article shown below, taken and
adapted from the Los Angeles Times.
Volcanic Blast Shaped Earth
Study finds eruption split an ancient continent,
creating Atlantic Ocean
The largest volcanic eruption in Earth’s history — so powerful it split an ancient
supercontinent and created the Atlantic Ocean — spewed millions of square miles of searing lava
that extinguished much of life on ancient Earth.
From hundreds of basalt outcrops that rim the Atlantic coasts, scientists have pieced
together evidence of the titanic eruption 200 million years ago. Researchers said that the
eruption set the fractured landmasses adrift and, by wedging them apart, gradually opened
the gulf that created the Atlantic — giving the map of the world the form it has today.
“This is one of the biggest things that has ever happened in Earth’s history. This is a gigantic,
igneous event and it all seems to have occurred in an amazingly brief amount of time.”
To reconstruct the ancient catastrophe, a team of scientists analyzed basalt dikes, sills,
and lavas from the New Jersey Palisades, the Brazilian Amazon, Spain, and West Africa.
By studying the chemical composition and dating the residual radioisotopes in the
basaltic rocks, the researchers determined that the rocks all originated from the same eruption.
Once they realized the outcrops were linked, they were able to determine that, in the
distant past, the rocks all had been located together at the center of an immense continent
called Pangea that once stretched, unbroken, from pole to pole.
250.Name the geologic time period when this major volcanic eruption initially opened the Atlantic Ocean.
251.Scientists stated that rocks from the volcanic eruption that separated the continents are basalt. List two
observable characteristics that are normally used to identify basaltic rock.
252.Basaltic outcrops are not the only evidence of this ancient continental splitting. Describe another piece
of evidence that supports the idea that the present-day continents were once part of the large ancient
continent, Pangea, that split apart.
_______________________________________________________________________________________
_______________________________________________________________________________________
Base your answers to the following two questions on the chart below, which shows the geologic ages of
some well-known fossils.
253.The Spirifer, Crinoid stem, and Neospirifer fossils might be found in some of the surface bedrock of
which New York State landscape region?
(1) the Allegheny Plateau southeast of Jamestown
(2) the Catskills near Slide Mountain
(3) the Adirondack Mountains near Mt. Marcy
(4) the Erie-Ontario Lowlands northeast of Niagara Falls
254.Which New York State fossil is found in rocks of the same period of geologic history as Meekoceras?
(1) Condor
(2) Placoderm fish
(3) Eurypterus
(4) Coelophysis
255.A sample of wood found in an ancient tomb contains 25% of its original carbon-14. The age of this
wood sample is approximately
(1) 2,800 years
(2) 5,700 years
(3) 11,400 years
(4) 17,100 years
256.Specific mass extinction of living organisms and global climatic changes in geologic history are inferred
by most scientists to have been caused by
(1) the impact of asteroids or large meteors on Earth’s surface
(2) the gravitational pull of the Sun on Earth’s surface
(3) large energy surges from the surface of the Sun
(4) earthquakes occurring along crustal plate boundaries
Earth’s History Test Prep
Teacher Answer Key – Guide
1.What is the correct sequence of events from oldest to most recent in the geologic history of this area?
2 deposition of layers from 1 to 7 faulting intrusion of basalt
2.The fossil found in layer 3 indicates that the age of this shale layer is approximately
(3) 430 million years
3.Which landscape features provide evidence that weathering and erosion were likely to have occurred?
(4) A, B, C, and D
4.A bone sample contains only of its original radioactive C14 content. How old is the bone sample?
(2) 2 C14 half-lives
5.The shaded portion of the map below of North America shows areas believed to have been below sea level
during the Pennsylvanian Period. Point A is a location in the inland sea. Present-day evidence of the
existence of the inland sea during the Pennsylvanian Period is best provided by
1 marine fossils at point A
6.Which type of rock is most likely to contain fossils?
3 shale
7.Why are radioactive substances useful for measuring geologic time?
4 Radioactive substances undergo decay at a predictable rate.
8.What is the approximate age of the Queenston shale?
(4) 452 million years
9.Which evidence in the cross section of Niagara Falls most clearly shows that erosion is occurring today?
4 piles of rock fragments at the base of the falls
10.During the last 12,000 years, the waterfall gradually shifted upstream 11 kilometers. The average rate of
headward erosion from the original waterfall location at the escarpment (cliff) near Lewiston to the presentday waterfall location was approximately 1 kilometer every
(3) 1,000 years
11.At the end of the glacial period, the Niagara River began flowing over the Niagara Escarpment. At the
end of which epoch of geologic time did this situation occur?
1 Pleistocene
12.There are no major faults in the vicinity of the Niagara Escarpment that would explain its formation by
crustal movement. What is the most logical explanation of how the escarpment formed?
1 Erosion removed the rock layers north of the escarpment.
13.Scientists have inferred that Earth’s original atmosphere was formed by the
(1) outgassing from Earth’s interior
14.A fossil shell contains 25% of the original amount of its carbon-14. Approximately how many years ago
was this shell part of a living organism?
(2) 11,400 years ago
15.Which sequence shows the correct order of Earth’s geologic time intervals from oldest to youngest?
(2) Archean Proterozoic Paleozoic Mesozoic Cenozoic
16.State one piece of evidence used by scientists to support the theory that the Big Bang event occurred.
Acceptable responses include, but are not limited to:
— Cosmic background radiation remains.
— There is a redshift in the light from stars in distant galaxies.
— the apparent expansion of the universe
— More-distant stars are moving away from Earth at a greater rate than nearby stars.
17.How many million years of Earth’s geologic history elapsed between the event that occurred on
September 10 and the event that occurred on September 25 in this model?
1300 (±200) million years
18.During what geologic time period did the oldest index fossil shown in this table exist?
Silurian Period
19.State one characteristic of a good index fossil.
Acceptable responses include, but are not limited to:
— existed for a short geologic time
— widespread geographically
20.Complete the following classification table by filling in the general fossil group name for each index
fossil.
Fossil Classification
Index Fossil
Eospirifer
Manticoceras
Phacops
General Fossil Group
Brachiopod
Ammonoid
Trilobite
21.Determine the relative geologic age of the four fossils by correlating the rock layers between these
outcrops. Below, number the fossils from 1 to 4 in order of relative age, with 1 as the oldest and 4 as the
youngest.
22.What evidence shown in the outcrop at location W suggests that the igneous intrusion occurred after both
fossils were deposited at location W?
Acceptable responses include, but are not limited to:
— contact metamorphism
— Contact metamorphism is shown in both the sandstone and shale layers.
— An igneous intrusion is younger than the bedrock it intrudes.
23.Identify two of the processes involved in the formation of the unconformity represented by line AB in the
cross section at location W.
Acceptable responses include, but are not limited to:
— uplift
— weathering
— erosion
— submergence
— deposition
— burial
24. Which group of organisms is inferred to have existed for the least amount of time in geologic history?
(4) placoderm fish
25.The geologic cross section below shows an unconformity in New York State bedrock layers that have not
been overturned. Index fossils found throughout some rock layers are shown. Which New York State index
fossil may have been present in a rock layer that is missing due to the unconformity?
26.The models below represent the decay of radioactive atoms to stable atoms after their first and second
half-lives. Which model best represents the number of undecayed and decayed atoms after three half-lives?
27.The bedrock of the Grenville Province is generally thought to have formed approximately
(4) 1100 million years ago
28.An archeologist found an ancient skeleton estimated to be 10,000 to 25,000 years old. Which radioactive
isotope would be most useful for finding the age of the skeleton?
1 carbon-14
29.Which present-day geologic feature in Nepal resulted from this collision?
2 a mountain range
30.Which life-forms were living on Earth when India was at position A?
2 dinosaurs
31.What is the estimated age of Earth?
(4) 4.6 x 109 years
32.The unconformity between the Paleozoic sedimentary rocks and the Precambrian sedimentary rocks
represents
1 a gap in the geologic time record
33.Which Paleozoic rock layer is the oldest?
(1) 1
34.The primitive lobe-finned fish shown below is thought to be an ancestor of early amphibians.
This evolutionary development from fish to amphibian is believed to have occurred during the
2 Devonian Period
35.This index fossil is representative of a group of invertebrate animals known as
4 eurypterids
36.During which geologic time period was this particular species alive and most abundant?
3 Silurian
37.Index fossils, such as the one in the diagram, are useful to geologists for correlating rocks because each
species
2 was widely distributed and became extinct after a short geologic existence
38.Which information could scientists most easily infer about the location where this index fossil was found?
1 environmental conditions that existed when the animal lived
39.The surface bedrock in which this index fossil was found is most likely composed of
3 limestone
40.The large coal fields found in Pennsylvania provide evidence that the climate of the northeastern United
States was much warmer during the Carboniferous Period. This change in climate over time is best explained
by the
(1) movements of tectonic plates
41.Which graph best shows the radioactive decay of carbon-14?
42.Approximately what percentage of the estimated age of Earth does the Cenozoic Era represent?
(1) 1.4%
43.The geologic cross section below shows the geologic age of two rock layers separated by an
unconformity.
The unconformity at the bottom of the Silurian rock layer indicates a gap in the geologic time record. What is
the minimum time, in millions of years, shown by the gap?
(2) 47
44.These fossilized jellyfish were most likely discovered in which type of rock?
(1) sandstone
45. Which two marine organisms most likely lived at the same time as these jellyfish?
(3) brachiopods and gastropods
46.Which evidence would lead scientists to suspect that a tide or storm had washed up these jellyfish on a
beach?
(4) Large ripple marks were found in the fossil-containing rock layers.
47.In the space provided below, number the relative age of rock units VII, VIII, and IX from 1 to 3, with
number 1 indicating the oldest rock and number 3 indicating the youngest rock.
48.The fossil shown in rock unit VIII is a member of an extinct group of fossils. State two other index fossils
that are also members of the same group of extinct fossils.
Cryptolithus and Phacops
49.Based on the fossils shown in the limestone and shale layers, state the type of environment in which these
sedimentary rocks were deposited.
Acceptable responses include, but are not limited to:
marine
ocean
water
50.Which characteristic is most useful in correlating Devonian-age sedimentary bedrock in New York State
with Devonian-age sedimentary bedrock in other parts of the world?
(2) index fossils
51.According to fossil evidence, which sequence shows the order in which these four life-forms first
appeared on Earth?
(4) fish insects amphibians reptiles
52.The fossil below was found in surface bedrock in the eastern United States. Which statement best
describes the formation of the rock containing this fossil?
(3) The rock was formed by the compaction and cementation of sediments deposited in a marine
environment during the Cambrian Period.
53.How many more boxes should be shaded to represent the additional decayed material formed during the
second half-life?
(2) 6
54.Which radioactive isotope has a half-life closest in duration to this radioactive sample?
(1) carbon-14
55. Which series of events took the least amount of time to complete?
(3) C
56.Which graph best represents the age of the surface bedrock along line CD?
57.Which type of surface bedrock would most likely be found at location 5?
2 sandstone
58.Which column best represents the relative duration of the major intervals of geologic history?
59.Which fossil appears to be the best index fossil?
60.Which rock type is found at a depth of 1,800 feet at this location?
3 Trenton limestone
61.What do the unconformities shown near the base of the drill core indicate?
2 Part of the geologic rock record has been destroyed.
62.Which “Important Fossils of New York” are most likely to be found in the Utica black shale or the Black
River limestone?
63.Which statement best explains why more fossils are found in outcrops of Black River rocks than in
outcrops of Utica shales?
3 The Black River group was deposited in an environment that supported more life-forms.
64.Based on studies of fossils found in the Trenton group, scientists have estimated that the climate of New
York State during this part of the Ordovician Period was much warmer than the present climate. Which
statement best explains this change in climate?
1 The North American Continent was nearer to the Equator during the Ordovician Period.
65.What is the approximate age of an igneous rock that contains only one-fourth of its original potassium-40
content due to radioactive decay?
(2) 2.6 x 109 years
66.Which geologic event happened most recently?
4 erosion of rocks B and C
67.Which inference is best supported by this map?
4 Site X was covered by warm ocean water during the Jurassic Period.
68.Trilobite fossils were recently discovered in Himalayan Mountain bedrock. During which geologic period
could this bedrock have been formed?
4 Cambrian
69.Which type of crinoid is shown below?
3 Inadunata
70.Evidence shown on the chart suggest that most crinoid types
1 are extinct
71.Evidence found in igneous rocks suggest that, through geologic time, Earth’s magnetic poles have
4 reversed their magnetic polarities
72.Which graph correctly shows the accumulation of nitrogen-14, the decay product of carbon-14, over the
same period?
73.Which statement most accurately compares the ages of the cracks and pebbles to the age of the
sedimentary rock in which they are found?
3 The cracks are younger and the pebbles are older than the sedimentary rock.
74.Within which rock type would a fossil most likely be found?
75.The breccia layer is composed mostly of
2 cemented, angular rock fragments
76.If the breccia layer formed during the Carboniferous Period, the shale layer below it could have formed
during which geologic time period?
4 Carboniferous
77.Which bedrock feature is most useful in correlating sedimentary bedrock in one area with sedimentary
bedrock in another area?
1 index fossils
78.What is the oldest layer shown?
4 grey limestone
79.When did fault XY, located in column I, most likely occur?
4 after the formation of the red sandstone
80.Which rock would most likely be produced by the metamorphism of the grey limestone?
3 marble
81.The wavy line located between the green shale and the tan limestone layers in columns I and II most
likely represents
3 a buried erosional surface
82.Fossil A, in the tan limestone layer, is a fossil of the first known coral. This tan limestone layer was most
likely deposited during which geologic time interval?
2 Paleozoic
83.What is the approximate half-life of radioactive material X?
(1) 5,000 yr
84.Radioactive material X can only be used to date young geologic material because radioactive material X
2 has a relatively short half-life
85.Which graph best represents the relative percentages of radioactive material X and its stable decay product
after 15,000 years?
86.Each of the objects below has different amounts remaining of the original radioactive material X. Which
object is most likely the oldest?
87.If radioactive material X were heated, the length of its half-life period would
3 remain the same
88.Trilobite fossil remains are most likely to be found in bedrock of
4 Ordovician age near Plattsburgh
89.Approximately how long ago did the first dinosaurs appear on Earth?
(3) 230 million years ago
90.Which statement can best be supported by the fossil record?
(3) Most life-forms that existed on Earth have become extinct.
91.Which sequence correctly shows the age of the lettered rock units, from oldest to youngest?
(4) D C B A
92.Which letter best represents an index fossil?
(3) C
93.Place an X on the geologic time line above, so that the center of the X shows the time that the coral index
fossil Lichenaria shown below existed on Earth.
The center of the X in the student response should fall within the circle shown on the time line below:
94.Letter a indicates a specific time during which geologic period?
Cambrian Period
95.Identify the mountain building event (orogeny) that was occurring in eastern North America at the time
represented by letter g.
Appalachian Orogeny or Alleghanian Orogeny
96.Identify one letter that indicates a time for which there is no rock record in New York State.
f or g
97.In a slab of rock that contains many fossil snails, what evidence would lead geologists to conclude that the
slab was formed in a tropical climate?
Acceptable responses include, but are not limited to:
— Clockwise spiral snail shells are found in greater numbers.
— more clockwise fossil shells than counterclockwise
98.State one reason bedrock that formed in tropical regions is found in New York State.
Acceptable responses include, but are not limited to:
— New York State experienced a warmer climate when it was located closer to the Equator.
— The North American Plate has drifted northward from the equator region over time.
— New York State used to be in the tropics.
99.Radioactive C14 was used to determine the geologic age of old wood preserved in a glacier. The amount
of C14 in the old wood is half the normal amount of C14 currently found in the wood of living trees. What is
the geologic age of the old wood?
Acceptable responses include, but are not limited to:
— 5,700 years
— 5.7 × 103 years
100.State one difference between dating with the radioactive isotope C14 and dating with the radioactive
isotope uranium-238 (U238).
Acceptable responses include, but are not limited to:
— U238 has a longer half-life.
— U238 can be used to date older geologic events.
— C14 is used to date organic remains while U238 is not.
101.Fossils of trilobites, graptolites, and eurypterids are found in the same bedrock layer in New York State.
During which geologic time interval could this bedrock layer have formed?
(1) Late Ordovician to Early Devonian
102.In which zone is a younger rock unit on top of an older rock unit?
(1) A
103.Analysis of a basalt rock sample shows that 25% of its radioactive K-40 remained undecayed. How old
is the basalt?
(2) 2.6 billion years
104.Based on fossil evidence, determine the geologic period during which the unconformity formed.
Devonian Period
105.Identify the coral index fossil that would most likely be found in the same layer as the index fossil
Ctenocrinus.
Pleurodictyum
106.Each index fossil existed for a relatively short geologic time interval. State one other characteristic that
each fossil must have to be considered an index fossil.
Acceptable responses include, but are not limited to:
— widespread geographic distribution
107.Describe the type of depositional environment in which the fossilized organisms lived.
Acceptable responses include, but are not limited to:
— The organisms lived in a shallow sea.
— They lived in a marine environment.
108.Identify one piece of evidence shown in this cross section that indicates that the igneous intrusion, A, is
older than the sandstone layer.
Acceptable responses include, but are not limited to:
— There is no contact metamorphism between rock unit A and the sandstone.
— An unconformity exists between the igneous intrusion and sandstone layer.
109.The presence of brachiopod, nautiloid, and coral fossils in the surface bedrock of a certain area indicates
the area was once covered by
(4) ocean water
110.Which letter best represents the first appearance of humans on Earth?
(4) D
111.Which other life-form reached its peak development during the same period in geologic history that
these three life-forms first appeared on Earth?
(4) eurypterids
112.According to the graph, what is the half-life of this isotope?
(3) 200 years
113.The volcanic ash layer is considered a good time marker for correlating rocks because the volcanic ash
layer
(4) was rapidly deposited over a wide area
114.Which sedimentary rock shown in the outcrops is the youngest?
(3) tan siltstone
115.What is the youngest geologic feature in the three bottom layers of outcrop C?
(1) fault
116.Which processes were primarily responsible for the formation of most of the rock in outcrop A?
(3) compaction and cementation
117.According to the passage, how old is the bedrock shown in the cross section?
Any response from 490 to 443 million years
118.What evidence shown at location A suggests that the channel in the bedrock was eroded by running
water?
Acceptable responses include, but are not limited to:
— The channel at A has a V-shape.
— Running water produces V-shaped channels.
119.List, from oldest to youngest, the four types of sediment shown above the bedrock in the cross section.
1. till
2. stratified drift
3. clay and silt
4. wind-blown sand
120.Explain why the till layer is composed of unsorted sediment.
Acceptable responses include, but are not limited to:
— Glacial deposits are unsorted.
— Till is a direct ice deposit.
121.How does the shape of the sand dune at location B provide evidence that the prevailing winds that
formed this dune were blowing from the southwest?
Acceptable responses include, but are not limited to:
— The gentle slope of the dune is on the southwest side.
— The windward side has a less steep slope.
— The steeper side is leeward.
122.Layers of volcanic ash often serve as useful geologic time markers because ash layers usually
1 deposit quickly over a wide area
123.According to available fossil evidence, which set of events is listed in the correct order from earliest to
most recent?
2 appearance of first corals, appearance of earliest insects, appearance of earliest reptiles
124.Which statement about the species of animals and plants that lived on Earth in the past is best supported
by the fossil record?
1 Most became extinct.
125.The earliest geologic epoch in which Mesohippus existed was the
2 Eocene
126.Which statement best explains the changing appearance of the horse, as supported by the fossil record?
3 The horse evolved into a life-form better able to survive.
127.Which statement best explains why geologic materials from the Quarternary Period must be dated by
using radioactive isotopes different from the isotopes used to date materials from the Cambrian Period?
2 Some isotopes decay faster than others.
128.Which geologic event occurred most recently?
3 intrusion of the igneous material E
129.Chemical evaporite bedrock is found approximately 20 kilometers south of Rochester, New York. This
bedrock most likely formed during which geologic time interval?
1 Silurian Period
130.Which rock group contains the oldest layers?
4 Clinton
131.A buried erosional surface indicating a time gap in the rock record is shown between which two groups?
3 Salina and Onondaga
132.A fossil of which animal is most likely to be found in the bedrock of the Hamilton Group?
3 brachiopod
133.The bedrock shown in the cross section was formed during which geologic era?
2 Paleozoic
134.Which rock layers in this formation appear to be the most resistant to weathering?
3 dolostones
135.Which animals do scientists believe could have been hunted by humans, based on evidence such as stone
spearpoints found embedded in the animals’ bones?
2 mammoths
136.Which of these events occurred most recently at this location?
4 faulting along line XY
137.When do scientists think these continents were joined together?
3 from the Devonian Period through the Triassic Period
138.Fossils would most likely be found in a sample of
1 limestone
139.Which life-forms appear to be extinct?
4 trilobites, ammonites, and dinosaurs
140.Which life-form was most abundant 250 million years ago?
2 reptiles
141.Which two elements are most useful for the radioactive dating of recent organic remains?
(1) C14 and N14
142.The largest meteorite impact crater in North America formed approximately 1,850 million years ago,
which was during the
2 Early Proterozoic Era
143.Based on fossil evidence, most scientists infer that
(3) many organisms that lived on Earth have become extinct
144.The presence of which index fossil in the surface bedrock most likely indicates that a forest environment
once existed in the region?
(1) Aneurophyton
145.Which pie graph best represents the percentage of total time for the four major divisions of geologic
time?
146.The geographic position of Australia on Earth’s surface has been changing mainly because
(2) heat energy has been creating convection currents in Earth’s interior
147.During which geologic time interval did Australia most likely have a warm, tropical climate because of
its location?
(1) Cambrian
148.During which geologic time period was rock layer C deposited?
Cambrian Period
149.Identify two processes that produced the unconformity in outcrop I.
Allow credit if both processes are correct. Acceptable responses include, but are not limited to:
— uplift
— erosion
— weathering
— subsidence
— deposition
— burial
150.Describe one characteristic a fossil must have in order to be considered a good index fossil.
Acceptable responses include, but are not limited to:
— widespread geographic distribution
— short existence in geologic time
151.Explain why carbon-14 cannot be used to find the geologic age of these index fossils.
Acceptable responses include, but are not limited to:
— Carbon-14’s half-life is too short.
— Not enough carbon-14 is left to measure.
— The fossils are too old.
152.It is inferred that during the early Archean Era the atmosphere of Earth contained water vapor, carbon
dioxide, nitrogen, and other gases in small amounts. These gases probably came from
(2) volcanic eruptions
153.There is evidence that an asteroid or a comet crashed into the Gulf of Mexico at the end of the Mesozoic
Era. Consequences of this impact event may explain the
(2) extinction of ammonoids and dinosaurs
154.Which type of rock most likely contains fossils?
(4) shale
155.During which period of geologic time have paleontologists inferred that the feathered dinosaur
mentioned in the passage existed?
(2) Cretaceous
156.This feathered dinosaur is not considered an index fossil because it
(4) was found in only one area
157.The reference to the bird-dinosaur link is most likely referring to the concept of
(2) evolution
158.On the diagram provided below, shade in the amount of stable decay element present after the second
half-life period.
Allow credit for the correct response shown below.
159.If the radioactive element in this model is carbon-14, how much time will have passed after one halflife?
Allow credit for 5.7 103 years or 5,700 years.
160.How does this cross section indicate that the Stockton sandstone is the oldest rock layer?
Acceptable responses include, but are not limited to, these examples:
Stockton sandstone is on the bottom.
Law of Superposition
161.State one piece of evidence that supports the fact that the Palisade Sill is younger than the Brunswick
sandstone.
Acceptable responses include, but are not limited to, these examples:
Contact metamorphism can be found on both sides of the Palisade Sill within the Brunswick
sandstone.
An intrusion is younger than the rock it intrudes.
162.State one tectonic event affecting North America that occurred at the same time as the Palisade Sill
intrusion.
Acceptable responses include, but are not limited to, these examples:
earthquakes
volcanic eruptions
The rifting of North America occurred.
Pangea began to break up.
North America and Africa began to separate.
163.Identify the geologic feature represented by boundary X.
Acceptable responses include, but are not limited to, these examples:
unconformity
nonconformity
time gap in the rock record
buried erosional surface
164.Describe how the rock type below boundary X was formed.
Acceptable responses include, but are not limited to, these examples:
heat and pressure
recrystallizing of preexisting rock
metamorphism
165.Identify by name one index fossil that existed when the limestone rock shown in the cross section was
being formed.
Acceptable responses include, but are not limited to, these examples:
Hexameroceras
Eucalyptocrinus
Eurypterus
Cooksonia
Cystiphyllum
Eospirifer
166.Earth’s fossil record shows evidence that
(3) more complex life-forms probably have evolved from less complex life-forms
167.Which statement best explains why rock layer 3 is missing from outcrop B?
(2) Erosion created an unconformity between rock layers 2 and 4 in outcrop B.
168.Fossilized footprints of Coelophysis dinosaurs have been found in bedrock closest to which New York
State location?
(1) New York City
169.A sample of wood that originally contained 100 grams of carbon-14 now contains only 25 grams of
carbon-14. Approximately how many years ago was this sample part of a living tree?
(3) 11,400 years
170.List the six rock units in the order from the oldest to the youngest.
Allow credit for the correct response shown below.
171.During which geologic time period did the shale layer form?
Permian Period
172.The granite intrusion caused part of the limestone layer to undergo metamorphism.
What metamorphic rock would most likely be found in this zone of contact metamorphism?
marble or hornfels
173.Describe the rate of cooling that must occur for magma to form vesicular basalt.
Acceptable responses include, but are not limited to, these examples:
fast rate
rapid cooling
174.What is the geologic age of layer B?
(3) Devonian
175.Which type of sedimentary rock was formed at layer X?
(4) coal
176.According to the graph, the rate of uplifting was greater than the rate of erosion during which geologic
time period?
(3) Carboniferous
177.Which statement gives an accurate age relationship for the bedrock in the cross section?
(2) Intrusion C is younger than intrusion B.
178.The most apparent buried erosional surface is found between rock units
(3) D and F
179.Which inference is best supported by the rock and fossil record in New York State?
(1) Eurypterids lived in shallow seas near present day Syracuse.
180.The faulting shown in the diagram could have occurred
(4) 50 million years ago
181.The index fossil Eurypterus is found in the limestone layer. What trilobite index fossil could be found in
the shale layer?
Allow credit for the trilobites Elliptocephala or Cryptolithus. Do not allow credit for the trilobite
Phacops or any fossil that is not a trilobite.
181.The big-bang theory is widely believed by astronomers to explain the beginning of the universe. Why
does the light from distant galaxies support the big-bang theory?
Acceptable responses include, but are not limited to, these examples:
A shift of light from distant galaxies toward the red end of the spectrum shows galaxies are
moving away from Earth.
The red shift shows that the universe is expanding.
183.Compare the age of Earth and our solar system to the age of these distant galaxies of stars.
Allow credit for any answer that shows the correct relative-age relationship even if the actual ages are
incorrect. Acceptable responses include, but are not limited to, these examples:
Earth and our solar system are younger than the Milky Way galaxy.
The estimated age of Earth and our solar system is 4.6 billion years and these distant galaxies
are 12 billion years old.
Our solar system is about 5 billion years old, much younger than these 12-billion-year-old
galaxies.
184.During which geologic time period did the earliest reptiles and great coal-forming forests exist?
(4) Pennsylvanian
185.Scientists have inferred that these “oldest” European human footprints were made during which
geologic epoch?
Pleistocene epoch
186.Which characteristic of the radioactive isotope carbon-14 explains why carbon-14, rather than the
radioactive isotope uranium-238, was used by archeologists in dating the age of their findings?
Acceptable responses include, but are not limited to, these examples:
The half-life of radioactive carbon is shorter.
Radioactive carbon-14 is found in recent organic remains.
187.After how many years will
(4) 39,900 yr
gram of the original carbon-14 remain?
188.Which event occurred earliest in geologic history?
(3) the Grenville Orogeny
189.A very large, circular, impact crater under the coast of Mexico is believed to be approximately 65
million years old. This impact event is inferred to be related to the
(3) extinction of the dinosaurs
190.The characteristic of the radioactive isotope uranium-238 that makes this isotope useful for accurately
dating the age of a rock is the isotope’s
(2) constant half-life
191.Which rock or feature is oldest?
(2) rock G
192.The unconformities shown in the cross section represent
(1) buried erosional surfaces
193.The movement of bedrock along fault Q most probably produced
(2) an earthquake
194.Which rock most likely formed in the zone of contact between rock E and rock F?
(3) metaconglomerate
195.Rock layers B, C, and D formed during the Devonian Period. Which fossil might be found in these rock
layers?
196.Which other fossil is most likely to be found in the same age bedrock?
(1) Phacops
197.Which group of organisms, some of which were preserved as fossils in early Paleozoic rocks, are still in
existence today?
(1) brachiopods
198.Which graph shows the relative duration of geologic time for the Precambrian, Paleozoic, Mesozoic, and
Cenozoic time intervals?
199.According to the Geologic History of New York State in the Earth Science Reference Tables, the
inferred latitude of New York State 362 million years ago was closest to
(3) the Equator
200.Which type of rock was precipitated from seawater as the Mediterranean Sea evaporated between 8
million years ago and 5.5 million years ago?
(1) rock salt
201. During which geologic time period did the changes shown in the maps take place?
(4) Neogene
202.On the cross section provided above, indicate with arrows the direction of movement on both sides of
the fault.
Allow credit if both arrows are correct, as shown in the diagram below, or if the student draws only
one arrow and it points in the correct direction for that side of the fault.
203.According to this cross section, what is the amount of vertical movement of the shale along the fault?
Express your answer to the nearest tenth of a meter.
1.7 (±0.2) meters
204.Place the geologic events listed below in order by numbering them from oldest (1) to youngest (4).
Allow credit for the correct response shown below.
205.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.
Allow credit for any response from 33.7 to 24 million years.
206.The vesicular basalt includes zircon crystals containing the radioactive isotope U-235, which
disintegrates to the stable isotope Pb-207. The zircon crystals have 98.44% of the original U-235 remaining,
and 1.56% has decayed to Pb-207. Based on the table below, how many half-lives have elapsed since the
formation of these
crystals?
Allow credit for
or 0.03125 half-lives.
207.On the graph provided below, indicate when each of the life-forms in the table is believed to have first
appeared on Earth by placing the letter for each animal group in the correct box. The correct location for
earliest fish, letter B, has already been plotted above the graph.
The correct responses are shown below.
208.The two factors listed below could have caused the temperature variations shown on the graph. For each
factor, state the effect that the increase described would have had on Earth’s temperature, and explain why
that temperature change would have taken place.
Factors
A Increase in carbon dioxide (CO2) and water vapor (H2O gas) content of Earth’s atmosphere
B Increase in volcanic ash in Earth’s atmosphere
Allow credit for a correct response for factor A. Acceptable responses include, but are not limited
to, this example:
Effect on Earth’s temperature: increase
Why temperature changes: More outgoing infrared radiation is trapped by Earth’s
atmosphere.
and
Allow credit for a correct response for factor B. Acceptable responses include, but are not limited to,
this example:
Effect on Earth’s temperature: decrease
Why temperature changes: More sunlight is reflected away from Earth.
209.During which era did the initial opening of the present-day Atlantic Ocean most likely occur?
(2) Mesozoic
210.The absolute age of a rock is the approximate number of years ago that the rock formed.
.The absolute age of an igneous rock can best be determined by
(1) comparing the amounts of decayed and undecayed radioactive isotopes in the rock
211.Fossil evidence indicates that the earliest birds developed during which time interval?
(3) C
212.In which type of environment were the sediments that formed these sedimentary rock layers most likely
deposited?
(3) marine
213.Which fossil would most likely be found in the same siltstone layer as the Cryptolithus fossil?
214.The sedimentary rock layers at the three locations can be most accurately correlated by comparing the
(3) fossils in the sedimentary rocks
215.In this region, valley X is more deeply eroded than either valley Y or valley Z. The most likely
explanation for this occurrence is that the metamorphic rock near X has been
(1) weakened by faulting
216.Which rock type is the oldest?
217.Which feature is represented by the symbol
(1) contact metamorphic rock
along the edges of the dike and sills?
218.Which radioactive isotope is most useful for determining the age of mastodont bones found in late
Pleistocene sediments?
(2) carbon-14
219.What does the presence of the fossils suggest about the Hamilton area during the Devonian?
(4) It had a marine environment sometime between 418 and 362 million years ago.
220.According to the map, in which two present-day New York State landscape regions is the most
Precambrian bedrock likely to be exposed on the land surface?
(3) Adirondack Mountains and Hudson Highlands
221.What is the geologic age of most of the bedrock covering the Precambrian rock in present-day New
York State?
(1) Paleozoic
222.Which map best shows the location of the –4,000-foot isoline?
223.According to fossil evidence, during which geologic period did the earliest mammals appear on Earth?
Triassic Period
224.Explain briefly why Chronoperates paradoxus would not be a good index fossil.
Acceptable responses include, but are not limited to, this example:
They have only been found in a narrow geographic range.
225.State one method geologists could have used to determine that Chronoperates paradoxus lived 60
million years ago.
Acceptable responses include, but are not limited to, these examples:
Use the law of superposition to compare the age with the age of other nearby fossils and/or rock
layers.
radioactive age dating (not C-14)
226.Explain how each inference is supported by evidence shown in the diagram.
Acceptable responses include, but are not limited to, these examples:
Inference 1: An igneous intrusion is younger than the bedrock it intrudes.
The basalt metamorphosed the shale.
Inference 2: The shale layer is below the sandstone layer.
Younger sedimentary bedrock is normally found on top of older sedimentary
bedrock.
Inference 3: 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.
227.Students compared samples of the granite and basalt. State one observable characteristic other than
crystal size that makes granite different from basalt.
differences in mineral composition, density, or color
228.Fossil pollen has been recovered from sediments deposited in late-Pleistocene lakes. The pollen’s
geologic age can most accurately be measured by using
(4) carbon-14
229.According to plate tectonic theory, during which geologic time interval did the continents of North
America and Africa separate, resulting in the initial opening of the Atlantic Ocean?
(1) Mesozoic Era
230.Near which location in New York State would a geologist have the greatest chance of finding dinosaur
footprints in the surface bedrock?
(1) 41° 10' N latitude, 74º W longitude
231What is the correct order of development from the original (oldest) stage to the most recent (youngest)
stage?
(2) B F C D E A
232.Uranium-238 that crystallized at the same time Earth formed has undergone approximately how many
half-lives of radioactive decay?
(1) one half-life
233.Which evidence best suggests that this outcrop has undergone crustal movement?
(1) The same rock layers appear twice within the outcrop.
234.In what type of rock was the new Isotelus fossil most probably found?
sedimentary rock or any specific type of sedimentary rock
235.At the time the new Isotelus fossil lived and died, during the Ordovician Period, what was the
approximate latitude of the fossil site according to plate tectonic theory?
Acceptable responses include, but are not limited to, these examples:
0º (±10º) latitude
Equator
236.What New York State nautiloid index fossil would most likely be found in the bedrock just below the
new Isotelus fossil?
Valcouroceras
237.The actual new Isotelus fossil is approximately how many times larger than scale drawing A?
11 (±1)
238.Carbon-14, an isotope used to date recent organic remains, would most likely be useful in determining
the age of a fossil
(4) Beluga whale
239.During which geologic timespan could this “game” have occurred?
(1) Pleistocene Epoch
240.Which statement about crinoids, blastoids, and echinoids is best supported by the diagram?
(3) They existed during the Devonian Period.
241What is the total number of major glacial periods that have occurred in North America in the last
200,000 years?
(2) 2
.242The Himalayan Mountains are located along a portion of the southern boundary of the Eurasian Plate. At
the top of Mt. Everest (29,028 feet) in the Himalayan Mountains, climbers have found fossilized marine
shells in the surface bedrock. From this observation, which statement is the best inference about the origin of
the Himalayan Mountains?
(3) The bedrock containing the fossil shells is part of an uplifted seafloor.
243.If the half-life of the radioactive material is 1,000 years, what is the age of the sample represented by the
diagram?
(2) 2,000 yr
244.Which rock layer is oldest?
(1) gray siltstone
245.At location Y, the boundary between the red sandstone and the black shale marks the
(2) beginning of the Mesozoic Era
246.An unconformity can be observed at location Z. Which rock layer was most probably removed by
erosion during the time represented by the unconformity?
(1) conglomerate
247.The fossils in the rock formations at location X indicate that this area was often covered by
(4) seawater
248.Which rock layer was formed by the compaction and cementation of particles that were all less than
0.0004 centimeter in diameter?
(2) green shale
249.State one reason why certain species of graptolites are used as an index fossil.
Acceptable responses include, but are not limited to, these examples:
Graptolites floated freely in the ocean and could distribute themselves easily over a wide
geographic area.
Certain species of graptolite existed for a limited geologic time.
Certain species of graptolite are unique and easily identified.
250.Name the geologic time period when this major volcanic eruption initially opened the Atlantic Ocean.
Jurassic Period
251.Scientists stated that rocks from the volcanic eruption that separated the continents are basalt. List two
observable characteristics that are normally used to identify basaltic rock.
Acceptable responses include, but are not limited to, these examples:
fine grained (crystals less than 1 mm)
glassy texture
vesicular texture
dark colored
mafic (high Fe and Mg content)
high density (3.0 g/cm3)
mineral composition:
plagioclase feldspar
pyroxene
olivine
amphibole
252.Basaltic outcrops are not the only evidence of this ancient continental splitting. Describe another piece
of evidence that supports the idea that the present-day continents were once part of the large ancient
continent, Pangea, that split apart.
Acceptable responses include, but are not limited to, these examples:
Continents fit together like puzzle pieces.
Continents have matching bedrock types along coastlines.
Continents have correlating fossils.
strips of magnetic reversals found in ocean bedrock
253.The Spirifer, Crinoid stem, and Neospirifer fossils might be found in some of the surface bedrock of
which New York State landscape region?
(1) the Allegheny Plateau southeast of Jamestown
254.Which New York State fossil is found in rocks of the same period of geologic history as Meekoceras?
(4) Coelophysis
255.A sample of wood found in an ancient tomb contains 25% of its original carbon-14. The age of this
wood sample is approximately
(3) 11,400 years
256.Specific mass extinction of living organisms and global climatic changes in geologic history are inferred
by most scientists to have been caused by
(1) the impact of asteroids or large meteors on Earth’s surface