WorksheetsEarth History Unit Review
Total questions: 70
Worksheet time: 35mins
Which is an example of absolute age?
"This trilobite is older than that dinosaur."
"That stromatolite is the absolute oldest fossil I've ever seen."
"Velociraptors lived 71-75 million years ago."
"The oldest sedimentary layer is on the bottom."
The half-life of a radioactive substance depends on the
pressure acting on the material.
amount of the material.
temperature of the material.
composition of the material.
A whale bone that originally contained 200 grams of radioactive carbon-14 now contains 25 grams of carbon-14. How many half-lives have passed since this whale was alive?
1
2
3
4
If carbon-14 is heated, the length of its half-life period would
increase
decrease
remain the same
Carbon-14 can only be used to determine the age of
recently living things (thousands of years old).
recent rocks (thousands of years old).
very old fossils (millions of years old).
very old rocks (millions of years old).
Figure A and B represent the same radioactive substance. Compared to the half-life of the material in figure A, the half-life of the material in each small cube in figure B is
1/8 as long
8 times longer
1/64 as long
the same
How much of the Earth's original U-238 still exists today?
100%
75%
50%
25%
What is the approximate age of an igneous rock that contains only one-fourth of its original potassium-40 content due to radioactive decay?
1.3 x 109 years
3,9 x 109 years
2.6 x 109 years
5.2 x 109 years
Compared to the length of time for the first half-life of a sample of a radioactive isotope, the length of time for the second half-life is
less
greater
the same
What happens to a carbon-14 atom that has gone through radioactive decay?
It disappears.
It turns into nitrogen-14
It becomes soil.
It flips over so the radioactive side is face-down.
This diagram represents a sample of 87Rb. Which diagram represents the correct proportion of 87Rb to its decay product, 87Sr, after two half-lives?
Which radioactive substance would probably be used in dating the recent remains of a plant found in sedimentary deposits?
carbon-14
rubidium-87
potassium-40
uranium-238
This graph shows the relationship between mass and time for a radioactive element during radioactive decay. What is the half-life of the element?
50 billion years
60 billion years
350 billion years
100 billion years
Why is radioactive decay useful for determining absolute age?
Radioactive substances decay at a predictable rate.
All Earth materials contain the same radioactive substances.
The mass of radioactive isotopes in a material is equal to the age of the material.
The half-life of a radioactive substance decreases by half after a certain amount of time.
What is the half-life of Rubidium-87
49 billion years
4.9 billion years
490 billion years
490 million years
What is the half-life of Potassium-40?
1.3 billion years
13 billion years
130 million years
13 million years
What is the disintegration product of Rubidium-87?
87Sr
14N
86Rb
87Pb
How old is a rock that contains 6.25% of its original Potassium-40?
6.5 x1010 years
2.6 x1010 years
3.9 x1010 years
5.2 x1010 years
What fraction of U-238 remains in a rock that is 18 billion years old?
1/8
1/16
1/32
1/64
Which isotope is best for determining the age of a Pleistocene epoch fossil?
Uranium-238
Potassium-40
Rubidium-87
Carbon-14
Which sequence of geologic events occurred after the formation of the Cambrian limestone and before the formation of the Silurian limestone?
uplift → weathering → erosion → subsidence
uplift → subsidence → erosion → weathering
subsidence → weathering → erosion → uplift
subsidence → erosion → uplift → weathering
Which rock layer is the youngest?
A
B
C
D
The photograph below shows an outcrop with two basaltic intrusions, labeled A and B, in a rock unit, labeled C. What is the relative age of these three rock units from oldest to youngest?
B → A → C
B → C → A
C → A → B
C → B → A
Letters W, X, Y, and Z represent fossils found in the rock layers. Which fossil could best be used as an index fossil?
W
X
Y
Z
Which principle states that these sedimentary rock layers were originally deposited as horizontal sediment layers?
Superposition
Original Horizontality
Cross-cutting
Contact Metamorphism
Which principle states that the oldest sedimentary layers are deposited first, and should be found closest to the bottom?
Superposition
Original Horizontality
Cross-cutting
Contact Metamorphism
When did faulting along line XY occur?
after the intrusion of rock unit A
after the deposition of rock units B, C, and D
after the formation of rock units E and F
before the formation of rock units G and H
When did intrusion A occur?
after the formation of fault X-Y
after the deposition of rock units B, C, and D
before the formation of rock units E and F
before the formation of rock units G and H
If the granite intrusion occurred 56 million years ago, what are the most probable ages of the schist and shale, in millions of years?
schist – 57; shale – 55
schist – 57; shale – 58
schist – 55; shale – 57
schist – 55; shale – 52
The rock that formed in the contact metamorphic zone between rock unit E and rock unit F is
quartzite
marble
slate
schist
Which sequence best describes the geologic history, from oldest to youngest, that occurred at this site?
deposition of F, D, C, B → intrusion of E → uplift and erosion → deposition of A
intrusion of E → deposition of F, D, C, B → uplift and erosion → deposition of A
deposition of F, D, C, B, A → uplift and erosion → intrusion of E
deposition of F, D, C, B, A → intrusion of E → uplift and erosion
Which layer is the youngest?
gray limestone
red conglomerate
brown siltstone
brown sandstone
Based on evidence shown in the diagram, which rock layer is older than fault XY?
tan conglomerate
black shale
brown siltstone
white limestone
Which is the approximate age of something, in years?
Absolute Age
Relative Age
Uniformitarianism
Original Horizontality
Which is the age of rock layers based on the order in which they formed?
Absolute Age
Relative Age
Uniformitarianism
Original Horizontality
What are the 2 characteristics of a good index fossil?
CHOOSE 2 CORRECT ANSWERS!
Lived for a short time
Lived for a long time
Lived over a large area
Lived over a small area
A fault or igneous intrusion are always ________ the rocks they go through.
younger than
older than
the same age as
What is an unconformity?
A buried erosional surface.
A zone of contact metamorphism.
A sequence of consecutive rock layers.
A type of index fossil.
Which is the best technique for correlating rocks around the world?
matching similar rock types
volcanic ash deposits
index fossils
What is the name of the rock that will form in the zone of contact metamorphism between rocks A and E?
Limestone
Quartzite
Sandstone
Marble
Which processes formed most of the layers in this outcrop?
Compaction & Cementation
Weathering & Erosion
Melting & Solidification
Extreme Heat & Pressure
The phrase "The present is the key to the past" refers to the idea that
your Christmas present is a key that works like a time machine to take you to the past.
processes occurring today have worked the same way throughout most of Earth's history.
older layers are deposited first at the bottom, and younger layers are at the top.
Sedimentary layers are usually deposited...
under water
on land
Most erosion occurs...
under water
on land
What is the name of the process that deformed the shape of layers H, G, F, E & D?
Tilting
Folding
Uplift
Erosion
Compared to the age of the Earth, humans have existed for _______ of this time.
less than 0.1%
5%
10%
30%
Which of the following is an EPOCH in the Cenozoic Era?
Miocene
Neogene
Cretaceous
Phanerozoic
Which of the following are Periods in the Mesozoic Era?
Choose all correct answers.
Jurassic
Triassic
Cretaceous
Permian
During which geologic period did Eurypterids go extinct?
Permian
Triassic
Cretaceous
Ordovician
During which geologic period did the Catskill Delta form?
Devonian
Silurian
Cambrian
Paleogene
Surface bedrock is not found in New York State from any time in the _________ Period
Permian
Devonian
Cretaceous
Cambrian
Which index fossil could be found in the same layer as the trilobite fossil Phacops?
Stylonurus
Coelophysis
Lichenaria
Ctenocrinus
Life on Earth has gradually evolved from _____________.
simple to complex
complex to simple
Which gas did not exist in significant amounts in Earth's early atmosphere?
oxygen
carbon dioxide
hydrogen
water vapor
The release of gases from volcanoes to make Earth's early atmosphere is called
outgassing
superposition
respiration
igneous intrusion
The earliest insect fossils are approximately _____ million years old.
420
410
365
440
Which is responsible for producing oxygen 3 billion years ago?
bacteria carrying out photosynthesis in the ocean
volcanic eruptions
cosmic background radiation
trees and other plants
Which of the following group existed on Earth for the longest time?
Trilobites
Graptolites
Dinosaurs
Birds
During which time period were most continents furthest from the North Pole?
Ordovician
Paleogene
Triassic
Cretaceous
Which index fossil is most likely to be found in Watertown, NY?
Cryptolithus
Hexameroceras
Manticoceras
Mastodont
Which index fossil is most likely to be found in the Allegheny Plateau landscape region of New York?
Cryptolithus
Hexameroceras
Manticoceras
Mastodont
Slide Mountain in New York is primarily composed of bedrock from the ____________ period.
Devonian
Silurian
Ordovician
Triassic
Which group of organisms still exists today?
Brachiopods
Graptolites
Ammonoids
Placoderm Fish
During which period were large amounts of salt and gypsum deposited in evaporite basins in New York State?
Silurian
Jurassic
Devonian
Ordovician
The New York State index fossil Platyceras is a type of ________.
Gastropod
Brachiopod
Coral
Graptolite
When did the earliest stromatolites exist?
3300 million years ago
2600 million years ago
1300 million years ago
365 million years ago
The Earth is...
approximately the same age as the universe.
older than the universe.
younger than the universe.
Which is the largest unit of time?
Eon
Era
Period
Epoch
Which part of an organism is LEAST likely to become preserved in a fossil?
Shell
Bone
Tooth
Skin
Approximately what percentage of species that have existed on Earth have gone extinct?
99.9%
90%
50%
0.1%
