Read It! Station Instructions
Each member of the group will read the passage and
answer the questions from the task cards on the lab sheet
in the Read It! section.
It is important to remember that the answers will come
directly from the reading passage
INPUT
STATION
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Input:
Read It!
How Old Is It?
How do scientists know the ages of rocks? Geologic age
dating—assigning an age to materials—is an entire
discipline of its own. In a way this field, called
geochronology, is some of the purest detective work earth
scientists do. There are two basic approaches to
discovering the age of rocks: relative age dating, and
absolute age dating.
To determine the relative age of different rocks,
geologists start with the assumption that unless something
has happened, in a sequence of sedimentary rock layers,
the newer rock layers will be on top of older ones. This is
called the Rule of Superposition. You may not know the
exact age, but you can tell if one rock layer is older
relative to another layer.
Absolute age dating gives age in actual years. It’s based
either on fossils which are recognized to represent a
period of time, or on radioactive decay of specific isotopes.
Based on the Rule of Superposition, certain organisms
clearly lived before others, during certain geologic times.
After all, a dinosaur wouldn’t be caught dead next to a
trilobite. The narrower a range of time that an animal
lived, the better it is as an index of a specific time. No
bones about it, fossils are important age markers. But the
most accurate forms of absolute age dating are
radiometric methods.
Absolute age dating method works because some
unstable (radioactive) isotopes of some elements decay at
a known rate into daughter products. This rate of decay is
Geologic Time Scale Station Lab
called a half-life. Half-life simply means the amount of
time it takes for half of a remaining isotope to decay to a
daughter product.
So, geochronologists just measure the ratio of the
remaining parent atom to the amount of daughter, and
they determine how long the molecule has been hanging
out decaying.
Not all rocks have radioactive elements. Sedimentary
rocks are notoriously radioactive-free zones. So, to date
those, geologists look for layers like volcanic ash that
might be sandwiched between the sedimentary layers, and
that tend to have radioactive elements.
Each radioactive isotope works best for different
applications. The half-life of carbon 14, for example, is
5,730 years. On the other hand, the half-life of the isotope
potassium 40 as it decays to argon is 1.26 billion years.
So, carbon 14 is used to date materials that aren’t that old
geologically, say in the tens of thousands of years, while
potassium-argon dating can be used to determine the
ages of much older materials, in the millions and billions
year range.
Geologists tend to mix and match relative and absolute
age dates to piece together a geologic history. If a rock
has been partially melted, or otherwise metamorphosed,
that causes complications for radiometric (absolute) age
dating as well. Like the other kind of dating, geologic
dating isn’t always simple.
© Kesler Science, LLC
Input:
Read It!
How Old Is It?
How do scientists know the ages of rocks? Geologic age
dating—giving an age to materials—is an entire science
field of its own. This field is called geochronology. It takes
pure detective work to find the age of a rock. There are
two basic methods for dating rocks: relative age dating,
and absolute age dating.
To determine the relative age of rocks, geologists start
with the idea that unless something disturbed sedimentary
rock layers, the newer layers will be on top of older ones.
You may not know the exact age, but you can tell if one
rock layer is older relative to another layer.
With absolute age dating, you get a real age in actual
years. The age based either on fossils which are known to
have lived during a specific time. The age can also be
based on radioactive decay of certain types of atoms.
Based on the Rule of Superposition, certain organisms
clearly lived before others. After all, a dinosaur fossil
wouldn’t be caught dead next to an earlier trilobite fossil.
The fewer years a species lived, the more it helps to
determine its age.
Radioactive atoms are called isotopes. Scientists measure
the percent of what’s left of the original isotope to the
percent of new isotope, called daughter isotopes.
Not all rocks have radioactive isotopes. To date
sedimentary rocks, geologists look for layers of volcanic
ash that might be squeezed between the sedimentary
layers. These tend to have radioactive elements.
The half-life of carbon 14, for example, is 5,730 years. On
the other hand, the half-life of the isotope potassium 40 as
it decays to argon is 1.26 billion years. So, carbon 14 is
used to date materials that aren’t that old geologically,
about tens of thousands of years. Potassium-argon dating
can be used to decide the ages of much older materials, in
the millions and billions year range.
Geologists tend to mix and match relative and absolute
age dates to piece together a geologic history. If a rock
has been partly melted, that is a problem for scientists
determining its age. Like the other kind of dating, geologic
dating isn’t always easy.
The most exact forms of absolute age dating are
radiometric methods. This method works because some
unstable (radioactive) atoms decay at a constant rate.
This rate of decay is called a half-life. Half-life simply
means the amount of time it takes for half of the atom to
decay.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Input:
Read
It!
1 of 4
1. What two methods are
used for determining the
age of rocks and fossils?
A. Relative and Absolute Dating
B. Absolute and Resolute Dating
C. Carbon and Water Dating
D. Relative and Absent Dating
Input:
Read
It!
2 of 4
2. Which is true about
relative dating?
A. Relative dating uses the half-life of
isotopes to get the exact age of a rock
or mineral
B. Carbon-14 dating is used on rocks and
minerals that are relatively young
C. Potassium –Argon dating is used on
very old rocks and minerals.
D. The law of superposition is used to
determine a rocks relative age.
Geologic Time Scale Station Lab
Input:
Read
It!
© Kesler Science, LLC
© Kesler Science, LLC
Input:
Read
It!
3. What is half-life?
3 of 4
4 of 4
A. The length an organism lived in
prehistoric times.
B. The time it takes for the radioactivity
of a specific isotope to fall to half its
original value
C. Half the life of an organism
D. The time it takes for a geologist to
determine the age of a rock or
mineral
Geologic Time Scale Station Lab
Geologic Time Scale Station Lab
© Kesler Science, LLC
4. There are vocabulary words
on your answer sheet. Use
the space around them to jot
down notes or drawings to
help you remember their
meanings from the reading.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Watch It! Station Instructions
Each member of the group will go to the website listed on
task card #1
Complete the task cards in order.
Every student will answer the questions from the task
cards on the lab sheet in the Watch It! section of the lab
sheet.
INPUT
STATION
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Input:
Watch
It!
1 of 4
Youtube, “Laws of Relative
Rock Dating”
https://www.youtube.com/w
atch?v=M2Ex5DIjtfU
Input:
Watch
It!
2 of 4
1. What is the law of
superposition?
Click Play on the video.
Answer questions from cards #24 on your lab sheet.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Geologic Time Scale Station Lab
Input:
Watch
It!
Input:
Watch
It!
3 of 4
4 of 4
2. What is the law of
crosscutting?
Geologic Time Scale Station Lab
© Kesler Science, LLC
3. What is the law of
inclusions?
© Kesler Science, LLC
Geologic Time Scale Station Lab
© Kesler Science, LLC
Explore It! Station Instructions
One member of the group will read the task cards in
order. The group will be responsible for completing each
of the tasks that are being read.
Each member of the group will then write their
conclusions down on the lab sheet in the Explore It!
section.
INPUT
STATION
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Input:
Explore
It!
1 of 4
Use the outcrop models for
this station. Each model
represents an outcrop of the
Earth’s crust from a different
part of the world.
1. Which layer is the oldest
layer?
2. Which layer is the youngest or
newest?
Input:
Explore
It!
2 of 4
The Law of Superposition states
that in any undisturbed sequence of
rocks deposited in layers, the
youngest layer is on top and the
oldest on bottom. Each layer is
younger than the one beneath it and
older than the one above it.
3. How do you know?
Geologic Time Scale Station Lab
Input:
Explore
It!
3 of 4
© Kesler Science, LLC
Index fossils are useful for
dating and correlating the
strata in which it is found.
When the same fossils are found in all of
the same strata (layers) across different
regions of the Earth, then the rock layers
and fossils are likely the same age.
Which fossils would make good index
fossils from the models? Hint: You will
have to turn them.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Geologic Time Scale Station Lab
Input:
Explore
It!
4 of 4
© Kesler Science, LLC
4. Which are good index
fossils in the model?
Why?
5. Which fossils are the
oldest?
6. Which fossils are the
youngest?
Geologic Time Scale Station Lab
© Kesler Science, LLC
Index Fossils
Outcrop #1
Geologic Time Scale Station Lab
Index Fossils
Outcrop #2
Geologic Time Scale Station Lab
Index Fossils
Outcrop #3
Geologic Time Scale Station Lab
Index Fossils
Outcrop #4
Geologic Time Scale Station Lab
Index Fossils Setup
Geologic Time Scale Station Lab
Research It! Station Instructions
Each member of the group will go to the website listed on
task card #1
Complete the task cards in order.
Every student will answer the questions from the task
cards on the lab sheet in the Research It! section.
INPUT
STATION
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Input:
Research
It!
Input:
Research
It!
1 of 4
2 of 4
Go to http://deeptime.info/
Answer the questions on
your lab sheet.
Geologic Time Scale Station Lab
© Kesler Science, LLC
1. Click on each of the different
eons and write a one sentence
summary of what was
happening during that eon on
your lab sheet.
Geologic Time Scale Station Lab
Input:
Research
It!
Input:
Research
It!
3 of 4
4 of 4
2. When do scientists believe
the first life form showed up
on Earth? What was it?
Hint: use the categories on the lefthand side.
Geologic Time Scale Station Lab
© Kesler Science, LLC
You are looking at a clock
that represents the entire
history of Earth.
© Kesler Science, LLC
3. About what “time” was it
on Earth’s geologic scale
when dinosaurs showed
up?
4. What is the most surprising
to you when looking at the
geologic time of Earth?
Geologic Time Scale Station Lab
© Kesler Science, LLC
Organize It! Station Instructions
It is recommended that you have completed at least two
of the following stations before working at this station.
-Read It!
-Explore It!
-Watch It!
-Research It!
OUTPUT
STATION
Do at least two
input stations
before this.
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Organize It! Output Instructions
Card #1 of 1
Create 4 columns of cards using the card with the border
as the category.
Once complete, have your teacher sign your lab sheet.
Please mix up the cards again before the next group
arrives at this station.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Relative Dating Law of
Superposition
Analogy – Inserting
a knife into a
layered cake and
removing a piece
Relative Dating Law of
Crosscutting
Rocks found inside
of other rocks are
the older of the two
Relative Dating Law of Inclusions
Analogy – Removing a
scoop of 7-layer dip
and putting it onto
your plate.
Analogy – a loaf of
banana bread that has
pieces of banana
throughout the bread
Analogy – Making a
casserole and
layering it one
ingredient at a time
PotassiumArgon Dating
Carbon-14
Dating
When undisturbed,
the oldest rock layers
are underneath the
newest rock layers
Analogy – an omelet
which includes
ingredients like ham
and green onions
throughout each bite
Geologic Time Scale Station Lab
Absolute
Dating
A process of
determining the rocks
age by using
radioactive material to
find the half-life
Features like faults
and dikes are newer
than the rock they
cut through
Analogy – Students
turning in work into a
large stack where the
first paper turned in is
on the bottom
©
© Kesler
Kesler Science,
Science, LLC
LLC
Illustrate It! Station Instructions
Each member of the group will draw a quick sketch on the
lab sheet that shows they understand the concept that is
being taught.
Use the colored pencils and markers that are provided.
The directions for the sketch are provided on the task card
at the table.
OUTPUT
STATION
Do at least two
input stations
before this.
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Illustrate It! Output Instructions
Card #1 of 1
Draw three images to help explain the laws of relative
rock dating.
The three laws are:
1. The law of superposition
2. The law of crosscutting
3. The law of inclusions
Geologic Time Scale Station Lab
© Kesler Science, LLC
Assess It! Station Instructions
It is recommended that you have completed at least two
of the following stations before working at this station.
-Read It!
-Explore It!
-Watch It!
-Research It!
Each member will answer the questions from the task
cards on the lab sheet in the Assess It! section.
OUTPUT
STATION
Do at least two
input stations
before this.
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Output:
Assess
It!
1 of 4
1. Which fossil would make
the best index fossil?
Outcrop #1
Output:
Assess
It!
2 of 4
Outcrop #2
A. Beetle
B. Flower
2. If a student used the
analogy of her stacking
books in her locker, which
law of relative dating is
she referring to?
A. Law of Superposition
C. Frog
B. Law of Crosscutting
D. Fish
C. Law of Inclusions
D. Law of Inertia
Geologic Time Scale Station Lab
Output:
Assess
It!
3 of 4
© Kesler Science, LLC
3. Which statement is
incorrect about the
Geologic Time Scale?
A. Life was not present when the Earth
was still cooling.
B. Prokaryotes showed up on Earth long
before reptiles and small plants.
C. Modern humans arrived later than
reptiles and small plants
D. Dinosaurs showed up just after the
Earth was created.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Geologic Time Scale Station Lab
Output:
Assess
It!
4 of 4
© Kesler Science, LLC
Use the vocabulary words from
“Read It” to complete the following
sentences.
Geologists use two main ways to find the age of rocks.
When they want an age in actual years, they find the
(4)_____. This involves looking at the radioactive
decay of specific isotopes. The rate of decay is called
the (5)_____ of the isotope, or the time it takes for
half of the isotope to decay to a daughter product.
Sometimes, geologists will also use (6)_____ to
represent a specific period of time to help them find an
age. When geologists use a sequence of layers to find
an age they are finding the (7)_____ of the layer. This
is done by the (8)_____, where it is assumed the
topmost layer is the youngest and the bottom-most
layer is the oldest.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Write It! Station Instructions
It is recommended that you have completed at least two
of the following stations before working at this station.
-Read It!
-Explore It!
-Watch It!
-Research It!
Answer each of the task card questions on the lab sheet in
complete sentences.
OUTPUT
STATION
Do at least two
input stations
before this.
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Output:
Write
It!
Output:
Write
It!
1 of 3
2 of 3
1. How do geologists use
index fossils to
determine the age of
rock strata?
Geologic Time Scale Station Lab
© Kesler Science, LLC
Output:
Write
It!
2. What is the difference
between relative dating
and absolute dating?
Geologic Time Scale Station Lab
© Kesler Science, LLC
Output:
Write
It!
3 of 3
3. Briefly describe the
geologic time scale.
Geologic Time Scale Station Lab
© Kesler Science, LLC
Geologic Time Scale Station Lab
© Kesler Science, LLC
Challenge It! Station Instructions
All other stations must be completed before you begin
this station.
Using the task cards provided, choose one or more
challenge to complete.
Your completed challenge(s) will be checked by the
teacher and/or attached to your answer sheet.
BONUS
STATION
Do all the input
and output
stations first!
Geologic Time Scale Station Lab
Version 7/21
© Kesler Science, LLC
Output:
Challenge
It!
Output:
Challenge
It!
RESEARCH
1 of 4
Research how radioactive decay
happens. Create a Power Point,
Google Slide, or teacher
approved presentation explaining
how radioactive decay helps
geologists with absolute age
dating of rocks.
Geologic Time Scale Station Lab
Output:
Challenge
It!
© Kesler Science, LLC
ACROSTIC POEM
3 of 4
Create a flipbook that includes at
least 5 separate pages to
demonstrate either absolute or
relative age dating of rocks. Be
sure to include both pictures and
words in your flipbook. You may
use this site as a resource:
https://www.flipbookpdf.net/
Geologic Time Scale Station Lab
Output:
Challenge
It!
© Kesler Science, LLC
CROSSWORD PUZZLE
4 of 4
Create an acrostic poem using
the words “Geologic Time” that
describe how geologists use
absolute and relative age to date
rocks.
Geologic Time Scale Station Lab
FLIPBOOK
2 of 4
© Kesler Science, LLC
Select at least 10 vocabulary words
from this lesson and use them to
create a crossword puzzle. You may
create a paper version or visit
https://puzzlemaker.discoveryeducat
ion.com/criss-cross to make a digital
version. Don’t forget to include an
answer key!
Geologic Time Scale Station Lab
© Kesler Science, LLC
Geologic Time Scale Station Lab
Read It!
1.
2.
3.
4.
______
______
______
relative age
Name ____________________________ Date _______
rule of superposition
absolute age
fossils
half-life
Research It!
Watch It!
Explore It!
1. Hadean___________________________
Archean____________________________
Proterozoic____________________________
Mesozoic____________________________
Cenozoic____________________________
1. ____________________________
____________________________
____________________________
____________________________
____________________________
1. ____________________________
____________________________
____________________________
2. ____________________________
____________________________
____________________________
____________________________
3. ____________________________
____________________________
____________________________
2. ____________________________
____________________________
____________________________
____________________________
____________________________
3. ____________________________
____________________________
____________________________
____________________________
____________________________
(Do when ALL other stations are done)
Geologic Time Scale Station Lab
3. ____________________________
____________________________
____________________________
4. ____________________________
____________________________
____________________________
5. ____________________________
____________________________
____________________________
6. ____________________________
____________________________
____________________________
____________________________
4. ____________________________
____________________________
____________________________
____________________________
Challenge It!
2. ____________________________
____________________________
____________________________
____________________________
❑ Checked by teacher. Initials: _______
❑ Attached
© Kesler Science, LLC
Illustrate It!
Assess It!
1. ______
2. ______
3. ______
(use the Read It! words as
your word bank for 4 - 8.)
4.
5.
6.
7.
8.
________________________
________________________
________________________
________________________
________________________
Organize It!
_____________________
_____________________
___________________
Write It!
1. _______________________________________________________
_______________________________________________________
_______________________________________________________
_______________________________________________________
2. _______________________________________________________
_______________________________________________________
_______________________________________________________
_______________________________________________________
3. _______________________________________________________
_______________________________________________________
_______________________________________________________
_______________________________________________________
Geologic Time Scale Station Lab
© Kesler Science, LLC
Read It!
1.
2.
3.
4.
______
______
______
relative age
Geologic Time Scale Station Lab
Name ___________________________
rule of superposition
absolute age
Watch It!
fossils
Date _______
half-life
Explore It!
1. ____________________________________________
1. ____________________________________________
____________________________________________
____________________________________________
____________________________________________
____________________________________________
2. ____________________________________________
____________________________________________
____________________________________________
____________________________________________
3. ____________________________________________
____________________________________________
____________________________________________
____________________________________________
2. ____________________________________________
____________________________________________
3. ____________________________________________
____________________________________________
4. ____________________________________________
____________________________________________
5. ____________________________________________
____________________________________________
6. ____________________________________________
____________________________________________
____________________________________________
____________________________________________
Geologic Time Scale Station Lab
© Kesler Science, LLC
Illustrate It!
Assess It!
1. ______
2. ______
3. ______
Word Bank for 4 - 8:
• relative age
_____________________
_____________________
_____________________
• rule of superposition
• absolute age
• fossils
• half-life
Organize It!
4. ________________________
5. ________________________
6. ________________________
7. ________________________
8. ________________________
Geologic Time Scale Station Lab
© Kesler Science, LLC