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Geology & Earth Sciences vocabulary · Geologic Time & Fossils

Geologic time scale

Meaning in geology & earth sciences, with examples

nounCore term

In geology & earth sciences, geologic time scale means: The system that divides the Earth's roughly 4.6-billion-year history into named units such as eons, eras, periods and epochs, based on rocks and fossils.

In Turkish: jeolojik zaman çizelgesi, jeolojik zaman cetveli

How it is used

Called the geological time scale in the UK. The official chart is published by the International Commission on Stratigraphy. Students learn names such as Palaeozoic, Mesozoic, Cenozoic, Jurassic and Cretaceous, and place events on the scale.

Example sentences

  1. On the geologic time scale, the Jurassic is a period within the Mesozoic era.

  2. Learn the main units of the geologic time scale before the exam.

Common collocations

  • the geologic time scale
  • units of the geologic time scale
  • on the geologic time scale
  • fossilThe remains or traces of a plant or animal that lived long ago, preserved in rock, such as shells, bones, leaf impressions or footprints.
  • radiometric datingA method of finding the age of rocks and minerals by measuring how much of a radioactive element has decayed into its products, using the known rate of decay.
  • stratumA single layer of sedimentary rock or sediment with similar features throughout, separated from the layers above and below it. The plural is strata.
  • index fossilA fossil of a species that lived for only a short time but was widespread and easy to identify, so it is used to date rock layers and match them between areas.

More terms: Geologic Time & Fossils

Practise with graded reading

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