Objective:
Create a visual analogy to show the geologic time scale of the Earth along with its’ 4 major eras and events.

Background:

One way geologic time is divided up is with eras, which are the second longest periods of time (eons being the longest, and periods being the shortest and sometimes epochs). The first and oldest era is the Precambrian Era. This era started when the Earth was formed, up until about 541 million years ago. The other three eras, the Cenozoic, Mesozoic, and Paleozoic all end in ‘-zoic’ which is a suffix that comes from the root “zoo” which means animal. “Cen- means recent, “Meso-“ means middle, and “Paleo-“ means ancient. These three eras happened during the Phanerozoic Eon. These three divisions in geologic time reflect major changes in extinctions and/or appearances of particular groups of animals.

Directions:

  1. Tape together the two 50-yard regions of the field to make a 100-year football field.
  2. The end zone marked “Earth Formed” is on the left and the end zone marked “Today” is on the right
  3. With a MARKER, OUTLINE each region of the football field that represents each of the four major geologic time periods. Use the colors in the chart below!
  4. Start on the end that says ‘Earth Formed.’
  5. When you are finished, it should be very easy to tell where each time period is!

Note:1 yard= approximately 146,000,000 years

Geologic Time Period / Color / Approximate Length (yrs) / Distance on the Football Field (yds)
Precambrian / Red / 4,059,000,000 billion years / ~ 88.2 yds.
Paleozoic / Yellow / 289,000,000 years / ~6.5 yds
Mesozoic / Green / 186,000,000 years / ~ 4 yds
Cenozoic / Blue / 66,000,000 years / ~ 1.4 yds
  1. Label the TOP of each section of football field the era that it represents.
  1. Place and label each geological event on your football field using the distances (in yards) you have found for each event.
    MAKE SURE YOU BEGIN AT THE END OF THE FIELD LABELED ‘TODAY’!

(Remember: a football field is 100 yards from end zone to end zone)

1 yard= approximately 46,000,000 years

Geologic Event / Approximate Age / Distance on Football Field (in yards)
Rocky Mountains formed / 80 mya / 1.7 (this is 1.7 yards FROM TODAY)
First known fish / 510 mya / 11.1
Earliest humans / 2 mya / .04
Formation of the Earth / 4600 mya / 100 (This is already labeled for you )
First known mammal / 200 mya / 4.5
First single-celled organism / 1200 mya / 26.1
Columbus discovers America / .0005 mya / 0
Oldest rock / 3800 mya / 82.6
Extinction of dinosaurs / 65 mya / 1.4
First known plant / 498 mya / 10.8
First known reptile / 325 mya / 7.1
First multi-celled organism / 700 mya / 15.2
First known amphibian / 375 mya / 8.2
First known bird / 160 mya / 3.5

When completed, go back to your PREDICTION SHEET from the beginning of class. Your predictions should be in pencil.

Using a different color, correct your predictions (only for the ones you did originally, not for the entire list).

Then, label each Time Period just like you did on your large timeline.

Finally, CHECK WITH YOUR TEACHERto receive the analysis questions.

(These will also go on page 82, but you may need to start a new page.)

Analysis Questions:

  1. What is the oldest event on your geologic time scale? How about the most recent event?
  1. Find on the geologic time scale where your birthday would be represented. Why is it almost impossible to show a human’s life on this scale? Would it be easier to show if we changed the amount of years each yard represents?
  1. Every 10 yards on your geologic time scale is equal to how many years?
  1. In what eras did fish, mammals, amphibians, reptiles, and plants appear on Earth?
  1. The first living organism was found how long ago? During what era did this happen?
  1. The Earth’s geologic time divided into sections of time like eras. What separates on era from another?
  1. What era is the shortest? Will it always be the shortest? Why?
  1. How close were you to your prediction from the beginning of class? What surprised you the most?

Analysis Questions:

  1. What is the oldest event on your geologic time scale? How about the most recent event?
  1. Find on the geologic time scale where your birthday would be represented. Why is it almost impossible to show a human’s life on this scale? Would it be easier to show if we changed the amount of years each yard represents?
  1. Every 10 yards on your geologic time scale is equal to how many years?
  1. In what eras did fish, mammals, amphibians, reptiles, and plants appear on Earth?
  1. The first living organism was found how long ago? During what era did this happen?
  1. The Earth’s geologic time divided into sections of time like eras. What separates on era from another?
  1. What era is the shortest? Will it always be the shortest? Why?
  1. How close were you to your prediction from the beginning of class? What surprised you the most?