WorksheetsUnit 3 Geologic Time and Fossils Review
Total questions: 48
Worksheet time: 27mins
Which phrase describes the relative age of a rock?
uses the law of superposition to determine which rock is older or younger
can determine the age based on location of a rock within the same layer
requires only one rock to determine the age
can provide the exact age of a rock
The image shows flat sedimentary rock layers in the foreground and angled sedimentary rock layers in the background. According to the principle of original horizontality, what most likely happened to the rock layers in the background?
They cracked at an angle.
They were deposited at an angle.
They were deposited vertically and then shifted by a geologic event.
They were deposited horizontally and then shifted by a geologic event.
Which feature causes a gap in the geologic record?
extrusion
fault
intrusion
unconformity
The image shows cross-cutting relationships. B, W, E, and K represent rock layers, and Q represents a fault. Which statement describes the geologic features?
Layer K is the oldest.
Layer W is the youngest.
Fault Q occurred before layer K was deposited.
Layers B, W, and E were deposited after fault Q occurred.
The images show sedimentary layers before and after they were shifted by a geologic event. After the geologic event, which layer is the oldest?
Layer A
Layer B
Layer C
Layer D
Which characteristic is shared by extrusions, intrusions, and faults?
All are cracks.
All are igneous rocks.
All cause gaps in the geologic record.
All are younger than the surrounding rocks.
How do index fossils help scientists?
They aid in the study of ranges of different organisms.
They advance understanding of the origin of life on Earth.
They aid in comparison of rock layers at distant locations.
They advance understanding of rock type at the time the organism lived.
A scientist finds a fossil that she thinks might make a good index fossil. Which characteristic does this fossil most likely have?
It is the remains of an organism still found alive today.
It is the remains of an organism that is found in abundance nearby.
It is the only fossil for this type of organism that has ever been found.
It is the remains of an organism that lived in a narrow geographic area.
Which information can be determined using half-life?
age of material
type of particle released
percentage of rock that has aged
number of radioactive particles left
After two half-lives, how much of the original material has decayed?
25 percent
50 percent
75 percent
100 percent
For which object would a geologist use carbon-14 dating to determine age?
The bones of animals
Rocks older than 50,000 years
Types of sedimentary rocks
parts of volcanic rock
Which measurement do geologists use to find the absolute age of once-living things?
amount of decayed daughter elements
total number of half-lives for the element potassium
age of ancient rocks located near the remains
amount of carbon-14 and nitrogen-14 in the remains
The graph shows calculations for potassium-argon dating. Which statement explains what geologists can learn from the graph?
They can estimate that all the potassium will have decayed within 6.5 billion years.
They can tell that 1/8 of the argon gas will be left after 3.9 billion years.
They can determine that a rock is 1.3 billion years old if 1/2 of the potassium has decayed.
They can see that potassium’s half-life varies from every 1.3 billion years to every 5.2 billion years.
Which values do scientists compare when using potassium-argon dating?
the number of stable and unstable parent atoms
the number of non-decayed elements left in the rock
the amount of parent and daughter material trapped in the rock
the amount of gas from the decayed material that has escaped from rock
Which phrase describes carbon-14 dating?
uses the rate at which nitrogen-14 decays into carbon-14
dates the remains of organisms to determine when they died
measures the number of unstable elements in ancient volcanic rocks
determines the age of ancient fossils older than 50,000 years old
Which statement accurately describes a half-life?
A rock’s size is determined by half-life.
All stable and unstable elements have a half-life.
An atom of an element becomes half its original size in a half-life.
A half-life is the time required for half of a radioactive element to decay.
Which characteristic of potassium makes it useful for dating rocks?
It has a long half-life.
It decays at an unknown rate.
It produces lead as it breaks down.
It can be used to date all types of rock.
Which statement accurately describes radioactive dating?
Geologists use only one type of radioactive dating.
Geologists compare parent and daughter elements to determine rock type.
Geologists will measure how stable multiple parent elements can decay into multiple daughter elements.
Geologists compare the observed abundance of naturally occurring radioactive isotopes and their decay products using decay rates.
Which best describes eras and periods?
Eras have a smaller time span than periods.
Eras and periods are independent of each other.
Eras and periods both appear at the start of the Cambrian period.
Eras were more recently established on the time scale than periods.
Which best describes the geologic time scale?
It explains why events happen throughout Earth’s history.
It presents the correct sequence of events in Earth’s history.
It is used to determine the absolute dates in years for different periods.
It was created by scientists who studied index fossils and climate change.
What information does the geologic time scale provide?
explanation of how Earth formed
places where dinosaurs roamed on Earth
reasons why organisms evolve into different species
information about when plants first appeared
Study the image. Which describes the geological time of the first land plants?
Conifers appeared after the first flowering plants.
Conifers first appeared around 182 million years ago.
The first flowering plants appeared around 240 million years ago.
The first flowering plants were introduced toward the end of the Mesozoic era.
Why is radioactive dating important when approximating the age of Earth?
Scientists can identify different life forms using index fossil records.
Scientists can examine how temperature changes within Earth’s interior.
Scientists can determine the order of when rocks formed on Earth.
Scientists can analyze changes in chemical concentration of atmospheric gases.
What determines the length of a geologic time period?
fossil record
material density
meteors and rocks
radioactive materials
A volcanic eruption releasing rock, ash, and dust particles into the air is an example of which interaction?
the biosphere interacting with the geosphere
the geosphere interacting with the atmosphere
the geosphere interacting with the hydrosphere
the hydrosphere interacting with the atmosphere
Which spheres of Earth are directly influenced when human-caused air pollution leads to acid rain that dissolves limestone rocks?
atmosphere, cryosphere, geosphere
cryosphere, hydrosphere, biosphere
geosphere, atmosphere, hydrosphere
biosphere, atmosphere, cryosphere
Cars are powered by fossil fuels, which come from the remains of ancient living things that were buried and exposed to high temperature and pressure from Earth’s interior. Which spheres are represented when fossil fuels form?
atmosphere and biosphere
biosphere and geosphere
cryosphere and atmosphere
geosphere and hydrosphere
Which example best explains the interaction of Earth’s spheres when acid rain affects trees?
The geosphere is interacting with the hydrosphere.
The atmosphere is interacting with the hydrosphere.
The biosphere is interacting with the hydrosphere and the cryosphere.
The atmosphere is interacting with the hydrosphere and the biosphere.
Some consumers, like lions, do not eat plants or any other producers. They only eat other animals. How do lions obtain the carbon they need?
by eating animals that have carbon-based molecules stored in their bodies
by breathing it in from the atmosphere in the form of carbon dioxide
by absorbing carbon-based molecules through their skin from the soil
by drinking water that contains carbon dioxide
The diagram illustrates the water cycle. Which best describes the process occurring at locations U and X?
Water cycles from a nonliving to a living part of the environment.
Water changes from a liquid to a gas.
Water changes from a gas to a liquid.
Water cycles from a living to a nonliving part of the environment.
Which process does NOT result in the release of carbon?
Animals break down food molecules to obtain energy.
The remains of producers are broken down by decomposers.
The remains of consumers are broken down by soil decomposers.
Producers take in carbon dioxide.
How is the nitrogen cycle important to humans?
It produces free nitrogen that humans can breathe.
It converts nitrogen into a form that humans can obtain by eating other organisms.
It produces nitrogen compounds that humans can breathe.
It converts nitrogen into a form that humans can obtain by absorbing it through their skin.
The image shows sedimentary rock layers. According to the law of superposition, which layer is the oldest?
1
2
3
4
Which phrase describes faults?
cause gaps in the geologic record
cause rocks to break and move
are older than surrounding rocks
are igneous rocks that form beneath Earth’s surface
Which event is most likely if an index fossil is found in a layer at location 1, but the layer and index fossil are not found at location 2 nearby, which is known to be the same relative age?
The layer at location 2 is too old to contain fossils.
The locations were too close together.
The organism did not exist at location 2.
The layers at location 2 formed much earlier than those at location 1.
In rock layers, jellyfish fossils are found lower than trilobite fossils, and trilobite fossils are found lower than ammonite fossils. What can be determined from this information?
Trilobites existed before jellyfish and ammonites.
Jellyfish existed before trilobites and ammonites.
Ammonites existed before trilobites and jellyfish.
Jellyfish, trilobites, and ammonites lived together.
The image shows sedimentary rock layers with index fossils and a fault. Which statement accurately describes the rock layers?
Layer 8 is older than layer 1.
Layer 3 is younger than layer 6.
Layer 4 and layer 10 are the same relative age.
Layer 2 and layer 9 are the same relative age.
The diagram shows cross-cutting relationships among rocks. Which statement accurately describes the geologic features?
D occurred after B.
D occurred before A.
A formed after the horizontal layer above was deposited.
F formed before the horizontal layer above was deposited.
Which phrase describes the absolute age of a rock?
does not provide an exact age
is the number of years since it formed
is the age compared to other rocks around it
indicates whether it is younger or older than the rocks above it
A geologist finds four layers of sedimentary rock. She determines that no geologic events have shifted the layers. She labels the layers A, B, C, and D from the top to the bottom. Which statement about these layers is accurate?
A is older than B.
B is older than C.
C is younger than A.
B is younger than D.
Which feature forms at Earth’s surface from the cooling of lava?
extrusion
fault
intrusion
unconformity
Which statement explains one reason why unconformities occur?
Rocks along a fault break and move.
Igneous rock forms at Earth’s surface.
No sediment is deposited over a long time.
Igneous rock forms between sedimentary layers.
Which correctly lists three different geologic features that help scientists determine the relative ages of rocks by their positions?
magma, erosion, and intrusions
erosion, magma, and cross-cutting relationships
intrusions, index fossils, and magma
index fossils, intrusions, and cross-cutting relationships
Which phrase describes organisms that formed index fossils?
are extinct
had soft parts
were generally large
lived in a narrow geographic area
Which is the first step that geologists must do to compare rock layers at distant locations?
find the absolute age of rocks at both locations
compare a layer at one location to layers at other locations
identify index fossils in one or more layers at one location
collect fossils from different locations to study the organisms’ lifestyles
Which statement describes the law of superposition?
Sedimentary rocks were originally in horizontal layers.
In horizontal rock layers, each layer is younger than the one below it.
Rock layers must be in existence before something can happen to them.
Rocks that are not in horizontal layers were shifted by some geologic event.
Which statement describes what is gained or lost during radioactive decay?
Atoms gain other atoms.
Elements take in energy.
Atoms lose smaller particles.
Elements gain smaller particles.
Which statement explains why carbon-14 dating cannot be used to date ancient rocks?
Carbon-14 decays at a varying rate.
Carbon-14 decays relatively quickly.
Carbon-14 can be used only to date the remains of organisms.
Carbon-14 has a half-life that is much longer than potassium.
