| Gelasian | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Chronology | |||||||||
| |||||||||
| Formerly part of | Tertiary Period/System Pliocene Epoch/Series | ||||||||
| Etymology | |||||||||
| Name formality | Formal | ||||||||
| Usage information | |||||||||
| Celestial body | Earth | ||||||||
| Regional usage | Global (ICS) | ||||||||
| Time scale(s) used | ICS Time Scale | ||||||||
| Definition | |||||||||
| Chronological unit | Age | ||||||||
| Stratigraphic unit | Stage | ||||||||
| Time span formality | Formal | ||||||||
| Lower boundary definition |
| ||||||||
| Lower boundary GSSP | Monte San Nicola Section, Gela, Sicily, Italy 37°08′49″N 14°12′13″E / 37.1469°N 14.2035°E | ||||||||
| Lower GSSP ratified | 1996 (as base of Gelasian)[3] | ||||||||
| Upper boundary definition | Approximately 8 m after the end of magnetic polarity chronozone C2n (Olduvai). | ||||||||
| Upper boundary GSSP | Vrica Section, Calabria, Italy 39°02′19″N 17°08′05″E / 39.0385°N 17.1348°E | ||||||||
| Upper GSSP ratified | 5 December 2011 (as base of Calabrian)[4] | ||||||||
The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary Period/System and Pleistocene Epoch/Series. It spans the time between 2.58 Ma (million years ago) and 1.80 Ma.[5] It follows the Piacenzian Stage (part of the Pliocene) and is followed by the Calabrian Stage.