Roadian | |||||||||||||
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Chronology | |||||||||||||
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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 | FAD of the Conodont Jinogondolella nanginkensis | ||||||||||||
Lower boundary GSSP | Stratotype Canyon, Guadalupe Mountains, Texas, USA 31°52′36″N 104°52′36″W / 31.8767°N 104.8768°W | ||||||||||||
Lower GSSP ratified | 2001[2] | ||||||||||||
Upper boundary definition | FAD of the Conodont Jinogondolella aserrata | ||||||||||||
Upper boundary GSSP | Guadalupe Pass, Guadalupe Mountains, Texas, USA 31°51′57″N 104°49′58″W / 31.8658°N 104.8328°W | ||||||||||||
Upper GSSP ratified | 2001[2] |
In the geologic timescale, the Roadian is an age or stage of the Permian. It is the earliest or lower of three subdivisions of the Guadalupian Epoch or Series. The Roadian lasted between 273.01 and 266.9 million years ago (Ma). It was preceded by the Kungurian and followed by the Wordian.[3]