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Earth and Environmental Science 11–12 · Year 12

A scale model of geological time from the International Chronostratigraphic Chart

Module 5: Earth’s Processes

PracticalLow risk

The idea

Almost all of Earth history passed before complex life; a scaled timeline built from the chart’s numerical ages makes the proportions of the eons and the brevity of human time visible.

What you need

  • 46 m of string or a 45.7 m corridor, tape measure, pegs or tape, labels
  • the ICS International Chronostratigraphic Chart (v2023/09) for the boundary ages
  • calculator

How to do it

  1. Choose the scale 1 cm = 1 million years; the chart’s age for the base of the Hadean, 4567 Ma, sets the line at 45.67 m.
  2. Calculate the position of each boundary: base of the Cambrian 538.8 Ma, base of the Ediacaran about 635 Ma, Cretaceous–Paleogene boundary 66.0 Ma, base of the Chibanian 0.774 Ma, base of the Holocene 0.0117 Ma.
  3. Peg the labels at the computed distances from the present end.
  4. Mark the earliest fossil evidence discussed in class (stromatolites) and the Cambrian fauna at their chart positions.
  5. Measure how much of the line the Phanerozoic occupies and how much the Holocene does.

What you should see

At 1 cm per million years the Cambrian base lies 5.39 m from the present end, the Ediacaran base about 6.35 m, the K–Pg boundary 0.66 m, the Chibanian base 7.7 mm and the Holocene 0.117 mm, thinner than the label pin. The Phanerozoic is 11.8 % of the line and the Precambrian the remaining 88.2 %.

What changes

This activity lists no variables to change, measure and keep the same.

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

  • Dinosaurs lived near the beginning of Earth history.
  • Humans and dinosaurs overlapped.

Safety card

Low riskLearners carry it out

Hazards

  • trip hazard from string

Controls

  • lay the line clear of doorways

Note

No hazardous chemicals or heat sources: record the activity in the school's RiskAssess risk assessment, following the NSW Department of Education Science safety and compliance page; the Chemical Safety in Schools package is not triggered.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

  • Earth and Environmental Science Stage 6 Syllabus (2017), NESA; current, replaced by the 11–12 Syllabus (2025) from 2028EES12-12EES11/12-5EES11/12-6EES11/12-7
  • Earth and Environmental Science 11–12 Syllabus (2025), NESA; to be implemented from 2028, not yet taughtEES-12-01
  • Australian Curriculum v9No Australian Curriculum v9 code is listed.

Sources

The pages the author read to write this activity.

  1. www.nsw.gov.au/education-and-training/nesa/curriculum/science/earth-and-environmental-science-stage-6-2017
  2. stratigraphy.org/ICSchart/ChronostratChart2023-09.pdf
  3. www.ga.gov.au/education/classroom-resources/create-your-own-geological-timewalk
  4. www.ga.gov.au/education/classroom-resources/geological-timescale

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