Sinemurian | |||||||||
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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 Ammonites Vermiceras quantoxense and Vermiceras palmeri | ||||||||
Lower boundary GSSP | East Quantoxhead, West Somerset, England, UK 51°11′27″N 3°14′11″W / 51.1909°N 3.2364°W | ||||||||
Lower GSSP ratified | 2000[2] | ||||||||
Upper boundary definition | FAD of the Ammonite species Bifericeras donovani and genus Apoderoceras | ||||||||
Upper boundary GSSP | Robin Hood's Bay, Yorkshire, England, UK 54°24′25″N 0°29′51″W / 54.4069°N 0.4975°W | ||||||||
Upper GSSP ratified | March 2005[3] |
In the geologic timescale, the Sinemurian is an age and stage in the Early or Lower Jurassic Epoch or Series. It spans the time between 199.5 ±0.3 Ma and 192.9 ±0.3 Ma (million years ago).[4] The Sinemurian is preceded by the Hettangian and is followed by the Pliensbachian.[5]
In Europe the Sinemurian age, together with the Hettangian age, saw the deposition of the lower Lias, in Great Britain known as the Blue Lias.