Oklahoma Impact Crater Dated to 370 Million Years Ago
New analysis recalibrates the age of the Ames crater, aligning its formation with the Late Devonian mass extinction period.
Updated on Oct. 14, 2026 in Geology
Researchers determined that the Ames crater in northern Oklahoma formed 370 million years ago, a significant revision from the previous 467-million-year estimate. This new timeline links the formation of the 10-mile-wide impact site to the Late Devonian period.
Why it matters
The updated dating allows scientists to examine whether this massive impact contributed to the Frasnian-Famennian mass extinction, which began roughly 372 million years ago and eliminated up to half of all marine life.
Researchers dated the crater by analyzing high-pressure fracture patterns within zircon crystals found at the site. The refined estimate shifts the crater's age by nearly 100 million years compared to prior dating models.
The details
The analysis relied on the physical structure of zircon crystals—durable minerals that record signs of extreme shock—to determine the timing of the impact. Oil prospectors first discovered the 10-mile-wide structure in 1991 while drilling, revealing a geological feature buried beneath the surface. This impact event would have occurred with massive energy, as the original object struck at high velocity.
Timeline
1991: Oil prospectors discovered the Ames crater.
370 million years ago: The impact that formed the crater occurred.
372 million years ago: The Frasnian-Famennian mass extinction event began.
467 million years ago: The date previously assigned to the crater's formation.
July 7, 2026: The study was published in Meteoritics and Planetary Science.
The Tech Race
This finding aligns the Ames crater's history with the Frasnian-Famennian mass extinction period. It places the crater's formation as a potential variable in the environmental shifts that occurred during the Late Devonian.
This research provides a more accurate historical record for Oklahoma residents interested in the state's deep geological past. The discovery serves as a scientific benchmark for understanding how space impacts have shaped the regional landscape over millions of years.
The takeaway
The recalibration of the Ames crater age forces a re-evaluation of its role in the Late Devonian period. Researchers will continue to investigate if the impact coincides precisely enough with the Frasnian-Famennian extinction to be considered a trigger.
Further reading
For more information on the geological history of the region, visit Geology.
