Turonian | |||||||||
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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 Ammonite Watinoceras devonense | ||||||||
Lower boundary GSSP | Rock Canyon, Colorado, USA 38°16′56″N 104°43′39″W / 38.2822°N 104.7275°W | ||||||||
Lower GSSP ratified | September 2003[2] | ||||||||
Upper boundary definition | Not formally defined | ||||||||
Upper boundary definition candidates | FAD of the Inoceramid Bivalve Cremnoceramus rotundatus | ||||||||
Upper boundary GSSP candidate section(s) |
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The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by the Cenomanian Stage and underlies the Coniacian Stage.[3]
At the beginning of the Turonian an oceanic anoxic event (OAE 2) took place, also referred to as the Cenomanian-Turonian boundary event or the "Bonarelli Event".[4] Sea level fall took place in the latter part of the Turonian from the highstand at the beginning of the Turonian.[5]