Oklahoma Crater's Revised Age Aligns with Mass Extinction Event
New dating places the Ames crater during the Late Devonian extinction, reshaping geological theories.
1Crater discovery and initial dating
Discovered in 1991 by an oil company, the Ames crater was initially thought to be part of the Ordovician meteor event 470 million years ago. New research using zircon crystal dating reveals it actually formed 370 million years ago during the Late Devonian period. This 100-million-year discrepancy challenges previous geological assumptions and connects the crater to a different significant era in Earth's history.
2Dating methodology breakthrough
Researchers employed uranium-lead dating on zircon samples, collaborating with NASA to confirm meteor impact evidence. Multiple techniques consistently returned Devonian-era dates across different samples, providing strong statistical evidence. The crater's isolation from Oklahoma's fault lines further supports these findings, ruling out later tectonic events as the source of younger zircon dates.
3Connection to mass extinction
The revised dating places the Ames crater's formation during the Frasnian-Famennian extinction event, which devastated marine ecosystems. While the 9-mile-wide crater alone couldn't cause global extinction, its timing suggests it may have contributed to environmental stresses. This finding reshapes understanding of extinction triggers, adding meteor impacts to existing volcanic eruption theories.
4Scientific implications
The study removes a major piece from Ordovician meteor event theories while adding to Devonian extinction research. Lead author Elizabeth Catlos emphasizes how precise dating of extinction events helps distinguish between volcanic and extraterrestrial causes. The Ames crater's new chronology provides crucial data for modeling Earth's catastrophic events and their environmental impacts.
5Crater characteristics
At 15 kilometers in diameter, the Ames crater ranks among the largest impact structures from the Ordovician period - now revealed to be misclassified. Its size made it significant in previous theories about Ordovician meteors' geological effects. The new dating shows researchers had lacked high-precision geochronologic data until this study's advanced techniques.
6Historical context
The Late Devonian period saw Earth's 'most devastating biotic crisis' according to scientists, with massive marine life extinction. Meteor impacts like Ames may have compounded environmental stresses from volcanism. This research demonstrates how single geological revisions can reshape understanding of entire extinction mechanisms and timelines.
7Comparative impact studies
The Ordovician meteor event, previously associated with Ames, is known to have contributed to biodiversification through chondrite influx. A separate study linked it to global cooling from atmospheric dust. The Ames crater's reclassification shows how impact events can have varied effects depending on their timing in Earth's geological cycles.
8Future research directions
The findings open new questions about the Frasnian-Famennian extinction's exact triggers and the cumulative effects of multiple stressors. Researchers highlight the need to re-examine other impact craters' dating, as similar discrepancies could exist. This case demonstrates how advanced dating techniques can revise fundamental geological narratives.
Original article: Gizmodo — Oklahoma Crater's Revised Age Aligns with Mass Extinction Event