Maastrichtian
| Maastrichtian | |||||||||
|---|---|---|---|---|---|---|---|---|---|
Opening of the western Indian Ocean in the Maastrichtian | |||||||||
| 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 | Mean of 12 biostratigraphic criteria | ||||||||
| Lower boundary GSSP | Grande Carrière quarry, Landes, France 43°40′46″N 1°06′48″W / 43.6795°N 1.1133°W | ||||||||
| Lower GSSP ratified | February 2001 | ||||||||
| Upper boundary definition | Iridium enriched layer associated with a major meteorite impact and subsequent K-Pg extinction event. | ||||||||
| Upper boundary GSSP | El Kef Section, El Kef, Tunisia 36°09′13″N 8°38′55″E / 36.1537°N 8.6486°E | ||||||||
| Upper GSSP ratified | 1991 | ||||||||
The Maastrichtian ( /mɑːˈstrɪktiən/ mahss-TRIK-tee-ən) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from 72.2 to 66 million years ago. The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). It is named after the city of Maastricht, the capital and largest city of the Limburg province in the Netherlands.
The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary extinction event) occurred at the end of this age. In this mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-known groups, died out. The cause of the extinction is most commonly linked to an asteroid about 10 to 15 kilometres (6.2 to 9.3 mi) wide colliding with Earth, ending the Cretaceous.