Historical Geology with Lab
Lab 1: Geologic Time Scale
Name: ______________________________ Date: ___________
How old is the Earth? Well, if the Earth celebrated its birthday every million years, there would be 4,600
candles on its birthday cake! Humans have been around only long enough to light the last candle on the
cake. Because the Earth is 4.6 billion years old, geologists have created a geologic time scale to make
their job of studying Earth’s history easier. The geologic time scale is a standard method used to divide
the Earth’s long history into smaller parts. Just as your life’s history is broken up into sections, the history
of the Earth is broken up into smaller sections called Time. Your life history can be broken up into
sections and labeled as decades, like, the 90’s (1990‐1999), the teens (2010‐2019). Time can be broken
down even further, they call these eras. Just think how decades can be broken down into years, 1991,
1992, 1993, etc. Eras can be further broken down to periods. Just think about how years can be broken
down into months, January, February, March, etc.
In this activity you will construct a scale model of geologic time that will show the relative amount of time
of the events in Earth’s history.
5 meters of adding machine tape, ruler, colored pencils/crayons, computer (for research)
1. Measure out 5 meters of adding‐machine tape and cut.
2. Stretch out the adding‐machine tape on the floor. Tape each end of the adding‐ machine
tape onto the floor or a stable surface.
3. Use a meter stick to draw a continuous horizontal line (i.e., lengthwise) 2 cm from the top
of the 5 m strip of adding‐machine tape. Use a scale of 1 meter equals 1 billion years. Each
millimeter then represents 1 million years.
4. At one end of the tape, draw a vertical line across the entire tape and label it “TODAY” using a
5. Measure off the distance starting from the “TODAY” line that represents 4.6 billion years (b.y.)
ago. Draw a vertical line across the entire tape at that point and label it “Earth’s Beginning” using
a black marker. Then fill out the data table on page 2.
6. Between the top of the paper and the line marked at 2cm, write down the time using a
blue marker that applies. For example, PreCambrian or Phanerozoic (see data table on page
7. Using the Geologic Time Scale chart:
a. Mark with a vertical line each era and period in Phanerozoic Time. Write the name of
each era below the line marking 2cm with a red marker. Write each period at the bottom of
the paper with a purple marker.
1 | P a g e