Maastrichtian Stage
Chicxulub meteorite impact
The Maastrichtian (71–66 Ma) is the sixth and last epoch of the Late Cretaceous, occurring after the Campanian, and before the Paleogene.
Geologic Age
72.1±0.2–66.0 Ma
Eon / Era / Period / Epoch
What happened during this time?
The Maastrichian ends with a 6-mile-wide bolide impact that brings massive global environmental disturbance, causing the extinction of large land and sea vertebrates
This bolide impacted the Yucatán Peninsula
This event, called the Chicxulub impact, killed off most large animals, including all non-avian dinosaurs
It is assumed that the impact ejected dust and dirt into the atmosphere, triggering an "impact winter", which is a period of prolonged cooling during which global temperatures plummeted
Research examining proxies for mean annual air temperature (MAAT) before and after K-PG boundary indicates little prolonged variation in temperatures (O'Connor et al. 2023), therefore no impact winter
Research by Cox and Keller (2023) analyzed all the data from the end-Cretaceous to pinpoint the cause of the mass extinction
While not conclusive, the model suggested that the outpouring of climate-altering gases from the Deccan Traps alone could have been sufficient to trigger the global extinction
The Traps had been erupting for roughly 300,000 years before the Chicxulub asteroid
During their nearly 1 million years of eruptions, the Deccan Traps are estimated to have pumped up to 10.4 trillion tons of carbon dioxide and 9.3 trillion tons of sulfur into the atmosphere
Evidence of global disruption of plant communities at the K–Pg boundary ((Vivi, Raine, and Hollis 2001; Wilf and Johnson 2004; Nichols and Johnson 2008).
Extinctions are seen both in studies of fossil pollen, and fossil leaves.
In North America, the data suggest massive devastation and mass extinction of plants at the K–Pg boundary sections; approximately 57% of plant species became extinct.
In high southern hemisphere latitudes, such as New Zealand and Antarctica the mass die-off of flora caused no significant turnover in species, but dramatic and short-term changes in the relative abundance of plant groups.
A series of large volcanic eruptions, began forming 66.25 Ma.
The remnants of these lava flows are known as the Deccan Traps west-central India
This series of eruptions may have lasted less than 30,000 years in total, covering an area as large as 1.5 million km², approximately half the size of modern India.