Category:Geological timescale

See Geological timescale in Wikipedia, the free encyclopedia.

The Geological timescale is the mainstream description of the Earth's history, divided into eons, eras, periods, and epochs. The divisions are usually made based on index fossils discovered in the fossil record. Relative dating techniques have existed for the better part of two centuries and can be used to organize the timescale independently. Absolute dating (generally in the form of radiometric dating) is used to assign actual numeric ages.