Geologic Timescale

Geologic Timescale

EraPeriodEpoch Approximate duration (millions of years) Approximate number of years ago (millions of years)
Cenozoic 7 Quaternary 2Holocene10,000 years ago to the present 
Tertiary 5Pliocene112
Mesozoic 3Cretaceous 7165
Jurassic 54136
Triassic 35190
Paleozoic 6Permian 55225
Carboniferous 65280
Devonian 60345
Silurian 20405
Ordovician 75425
Cambrian 100500
Precambrian1  >4,000600
1 Not an era but the time preceding the Cambrian.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on Geologic Timescale table from Fact Monster:

  • Permian period - Permian period Permian period [from Perm, Russia], sixth and last period of the Paleozoic era (see ...
  • epoch - epoch epoch, unit of geologic time that is a subdivision of a period. The Pleistocene and Holocene ...
  • Carboniferous period - Carboniferous period Carboniferous period , fifth period of the Paleozoic era of geologic time (see ...
  • Cretaceous period - Cretaceous period Cretaceous period , third and last period of the Mesozoic era of geologic time ...
  • Pleistocene epoch - Pleistocene epoch Pleistocene epoch , 6th epoch of the Cenozoic era of geologic time (see Geologic ...

See more Encyclopedia articles on: Geology and Oceanography

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