Initial Publication Date: May 8, 2012

Geologic Time Learning Goals

This web page is based on a document produced by Francis Jones, Brett Dooley, Kevin Mullins, and Mark Schmitz at the 2012 workshop on Teaching about Time.


Articulating learning goals with an emphasis on what students should be able to do is the first step to creating a targeted and effective curriculum, whether at the program or course level. The Earth Science Literacy Initiative (ESLI) provides a framework of ten "Big Ideas" essential to understanding Earth Science, including geologic time and the rates of geological processes. Using that framework, we have developed lists of possible learning objectives related to temporal concepts embedded in four of these "Big Ideas." The explicit connection to these big ideas or principles is emphasized below by using statements from the Earth Science Literacy Principles to organize our example learning goals. These examples are focused on the development of knowledge, skills, and attitudes, and are formulated with Bloom's Taxonomy of Learning in mind. While this is in no way intended to be a comprehensive list of possible learning goals, it may help you to articulate your own list.

Learning Goals

ESLI 2: Earth is 4.6 billion years old.

  • Attitude: Students will recognize that Earth's history spans many time orders of magnitude longer than the human or historical time scales.

ESLI 2.1 Earth Scientists use the structure, sequence and properties of rocks, sediments and fossils to reconstruct events in Earth's history.

  • Attitude: Students will habitually make use of logic and critical reasoning to interpret and draw inferences from observations, data sets and references.
  • Attitude: Students can recognize that Earth's history is recorded and observable by anyone, in rocks, minerals and fossils.
  • Attitude: Students will seek to transfer basic thinking skills that they use in every day life (such as organizing piles of information on a desk) to situations encountered in Earth science (such as ordering a sedimentary sequence).
  • Attitude: Students will expect to employ basic principals from chemistry, physics and arithmetic (or mathematics) as foundational knowledge and skills necessary for thinking about Earth science topics.
  • Knowledge: Students can identify the different "clocks" that are used to reconstruct Earth's history; i.e. to build the geological time scale. including sidereal variations (annual layer counting), orbital cycles, radioactive decay products, and biological evolution (fossil succession).
  • Knowledge: Students can describe how results of absolute dating measurements are used with other information to calibrate, correlate or determine process rates.
  • Skill: Students can apply the logic of sequences (Steno's laws or relative dating principles) to the observable record of Earth's history
  • Skill: Students will be able to choose appropriate dating techniques to recreate a geologic history, for a given timeframe and available materials.
  • Skill: Students will be able to characterize the importance of correlation between geological sections, and the role fossils play in this regard, in order to document the change in Earth systems in a meaningful global context.

From ESLI 2.1: Decay rates of radioactive elements are the primary means of obtaining numerical ages of rocks and organic remains.

  • Attitude: Students exhibit awareness that scientists use numerical measurements as estimates of the age of geological phenomena, to which are assigned varying degrees of confidence.
  • Knowledge: Students can articulate that Earth materials are made of atoms, some of which are unstable and undergo reactions in their nucleus, and that the rates of those reactions are constant and can be used as clocks. Scientists apply those clocks by measuring the amounts of the components of those reactions (parent and daughter atoms).
  • Skill: Students can choose geochronometers that are appropriate to date Earth processes and products in a chosen area of study.
  • Skill: Students can apply one or more geochronometers together and as necessary, to address a given task using materials (i.e. data) available.
  • Skill: Students will incorporate the need for consistency and reproducibility in discussions involving chronological inference.

From ESLI 2.1: Understanding geologic processes active in the modern world is crucial to interpreting Earth's past.

  • Knowledge: Students will be able to relate various active geologic processes to the products (substitute "rocks", "landforms", "fossils", etc.) they create in the geologic record.
  • Knowledge: Students will be able to identify the geologic and/or tectonic setting in which different rock types are created.

ESLI 3.6 Components of the Earth's systems may appear stable, change slowly over long periods of time, or change abruptly with significant consequences for living organisms.

  • Attitude: Students will exhibit awareness that the Earth system is characterized by change over a variety of time scales.
  • Knowledge: Students should be able to characterize geologic processes in terms of their rates and the span of time over which they operate.

ESLI 6.2 Evolution, including the origination and extinction of species, is a natural and ongoing process.

  • Attitude: Students will be aware that biological evolution throughout Earth history is recorded in fossils preserved in rocks.
  • Attitude: Students can express how geological and biological evolution are coupled.
  • Attitude: Students will exhibit an awareness that evolution, originatination and extinction are happening now, and have happened throughout most of Earth's history, and that evidence for this is preserved in the fossil record.
  • Knowledge: Students will associate groups of fossil organisms with specific depositional environments.
  • Skill: Students will assess the value of individual or groups of fossil organisms for specifying geologic time.

Other Earth Science Literacy key ideas related to teaching about time

  • ESLI 1.5: Earth scientists use their understanding of the past to forecast Earth's future.
  • ESLI 2.6: Life on Earth began more than 3.5 billion years ago.
  • ESLI 2.7: Over Earth's vast history, both gradual and catastrophic processes have produced enormous changes.
  • ESLI 3.4: Earth's systems interact over a wide range of temporal and spatial scales.
  • ESLI 4: Earth is continuously changing.
  • ESLI 6.1: Fossils are the preserved evidence of ancient life.
  • ESLI 6.6: Mass extinctions occur when global conditions change faster than species in large numbers can adapt.
  • ESLI 9.2: Earth scientists use the geologic record to distinguish between natural and human influences on Earth's systems.

Additional Resources