New dating shows Oklahoma impact crater formed 370 million years ago

A team from the University of Texas at Austin analyzed zircon crystals extracted from the Ames impact structure beneath Ames, Oklahoma, and concluded the meteor strike happened about 370 million years ago in the Late Devonian. The new age overturns prior assumptions that the crater belonged to the Ordovician meteor event, which had been inferred from older fossil material mixed into the rocks. By using U-Pb dating and imaging techniques, the scientists confirmed the zircons recorded the impact itself.

This timing places the crater close to the Frasnian-Famennian extinction event that devastated marine life. The Ames structure remains an important source of oil and gas, and the revised chronology may affect interpretations of other North American impact sites.