Name:______________________________ Period: 1 2 3 4 5 6 7 Date:________________
Constructing a Geologic
Time Line
Background Information:
Understanding the true age of the Earth as well as the timing of geological events is difficult to
visualize. Human’s perspective of time is limited to the important events that directly precede
their lifetime and then occur within the course of their lifetime. Geologists study the entire
breadth and depth of the 4.6 billion years that the Earth has existed. For this assignments
students will be constructing a timeline that will show the important geological events that have
occurred throughout the course of history.
Materials Needed:
Meter Stick
4.6 Meters of Adding Machine Tape
iPads (Geology App)
Procedure:
1. For your timeline, the scales is 1mm = 1 million years, 1cm = 10 million years, and 1m = 1
billion years.
2. Stretch out the adding machine tape. Using the meter stick, draw a continuous straight line
down the middle of the tape. This line represents your time line. Draw a straight line across the
tape at one end. Label this line “The Present.”
3. From the line labeled “The Present,” draw four more lines, exactly 1m apart. Label the first
of these lines “1 billion years ago.” Label the second line “2 billion years ago,” and so on. The
very end of your timeline should be labeled “4.6 billion years ago.” Label this side of your time
line “Earth’s beginning.”
4. Plot each event in the table below on the time line. Label both the number of years ago and
the event.
5. Using your paper titled “Interpreting the Geological Time Scale” label the start and end of the
major geological eras and periods.
6. Using the Geology App on your iPad plot out 15-20 other important geological events that
you investigate while using the application.
7. Draw pictures and color them next to important geological events on your timeline. These
pictures should correspond with the events happening at that point in time.
Inferred Ages of Events in Years Before Present
Label
Years Ago Label
First mammals and dinosaurs
200 mya
Oldest Carbon from Plants
First Group of Abundant Fossils 570 mya
Oldest rocks known
Oldest Fungi
1.7 bya
First Birds
Last Ice Age
10,000 ya
First Humanlike Creatures
First Reptiles
290 mya
Humans Begin to Make Tools
Formation of the Moon
4.4 bya
Earth’s Crust Cools to a Solid
Oldest Fossils from Bacteria
3.5 bya
Complex singled celled life
starts
Years Ago
3.6 bya
4.2 bya
160 mya
2 mya
500,000 ya
4 bya
1.8 bya
Multicellular Organisms Evolve 1 bya
Earth’s Largest Extinction
275 mya
Event
Tyrannosaurus Rex Exists
68 mya
First Winged Insects
N. America separates from
Africa
Dinosaur Extinction
359 mya
180 mya
65 mya
Additional Follow-Up Questions:
1. What did you learn from completing this project about the history of the Earth? (2 paragraph
minimum required)
2. If human-like creatures have existed for 2 million years and the Earth is 4.6 billion years old.
What percentage of time have humans existed on the Earth for?
3. Dinosaurs existed from 231 mya to 65 mya. Since the Earth is 4.6 billion years old what
percentage of time did dinosaurs exist on the Earth for?
4. List the additional events that you plotted on your graph from the research you did using the
Geology app on the iPads. List the geological event and how long ago it occurred.
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