A team of researchers from The University of Texas at Austin has fundamentally rewritten a chapter of Oklahoma\u2019s geologic history, providing new insights that could reshape how scientists interpret the catastrophic events that have punctuated the history of life on Earth. The subject of this re-examination is the Ames impact structure, a massive, hidden crater buried deep beneath the surface of Ames, Oklahoma. While the crater has long been a subject of intense scientific study and economic interest\u2014serving as a prolific producer of oil and natural gas\u2014its true age has remained a point of confusion for decades.<\/p>\n
For years, the scientific consensus placed the Ames crater within a cluster of significant meteor impacts across North America, all thought to have occurred approximately 467.5 million years ago. This era, known as the Ordovician Meteor Event, is characterized by a high frequency of impact structures across the continent. Because so many of these craters appear to share the same temporal origin, some planetary scientists have even proposed the dramatic theory that Earth may have once been surrounded by a Saturn-like ring of asteroid debris during the Middle Ordovician period. <\/p>\n
However, new research from the UT Jackson School of Geosciences indicates that the Ames impact does not belong to this crowded Ordovician timeline. By applying advanced dating techniques to zircon crystals extracted from granite altered by the colossal force of the collision, the research team determined that the meteorite actually struck the Earth about 370 million years ago. This discovery shifts the age of the crater forward by nearly 100 million years, placing it squarely in the Late Devonian period rather than the Middle Ordovician.<\/p>\n
The Ames impact structure is a hidden giant. Though it lies concealed beneath layers of sediment, it remains a focal point for both geologists and the energy industry. For generations, the geologic record associated the crater with the Ordovician Meteor Event, a period in Earth\u2019s history marked by a perceived spike in asteroid bombardments.<\/p>\n
The previous age estimation was based primarily on biological evidence rather than isotopic dating. Researchers had discovered the teeth of conodonts\u2014an extinct, eel-like marine organism\u2014within the crater\u2019s rock layers. Because these organisms lived and died during the Ordovician period, it was assumed that the impact occurred at that time. <\/p>\n
Lead author Elizabeth Catlos, an associate professor in UT\u2019s Department of Earth and Planetary Sciences, explained that the reliance on these fossils led to a significant misinterpretation. The conodont teeth were likely already millions of years old by the time the asteroid struck the region. During the impact, the massive energy of the collision likely churned up the surrounding rock, mixing older, pre-existing fossil material into the debris created by the cratering event. The fossils were preserved in the rock, but they acted as a "red herring," trapping scientists into an incorrect timeline.<\/p>\n
"No matter what technique we used, it was coming back to this younger signal," Catlos said, noting that the persistence of the 370-million-year-old data finally forced the team to look past the misleading fossil evidence. The study, which highlights the critical importance of utilizing high-precision geochemical dating over reliance on secondary biological indicators, was published in the journal Meteoritics & Planetary Science<\/em> this past July.<\/p>\n The precision of the new study is owed largely to the analysis of zircon crystals. Danny Stockli, dean of the Jackson School of Geosciences and a co-author of the study, emphasized that zircon U-Pb (uranium-lead) dating represents the gold standard for determining the age of geologic events that occurred deep in Earth\u2019s past. Zircons are incredibly durable, and they serve as microscopic time capsules that can be unlocked with the right technology.<\/p>\n Beyond providing an accurate date, these crystals can preserve the physical record of the cataclysm itself. The extreme heat and pressure generated during a meteor impact cause the crystal lattice of a zircon to undergo structural changes. By studying these microscopic deformations, scientists can confirm that the crystals were indeed subjected to the violent conditions of a celestial collision.<\/p>\n "These small crystals allow us to go back in time and learn about the major changes to Earth\u2019s ancient landscapes," Stockli said. "It would be great to do this for more of the meteor impact sites across the continent so we could get a more accurate timeline for these major events."<\/p>\n To ensure the accuracy of their findings, the UT team collaborated with NASA to image the zircons using advanced techniques such as cathodoluminescence and electron backscatter diffraction. These methods allow researchers to visualize the recrystallization patterns that occur only under the extreme shock of an impact. The distinctive ways in which the zircons reacted to the pressure provided the team with the necessary proof to confirm the 370-million-year-old date, effectively decoupling the Ames crater from the Ordovician period.<\/p>\n The corrected date for the Ames impact has profound implications for our understanding of the Late Devonian period. The new timeline places the asteroid strike in close proximity to the Frasnian-Famennian mass extinction event, which occurred roughly 372 million years ago. This extinction event was one of the most severe in Earth\u2019s history, resulting in a dramatic loss of marine biodiversity.<\/p>\n Establishing precise dates for these major evolutionary bottlenecks is essential for researchers attempting to determine the drivers of extinction. A central debate in geology and evolutionary biology involves whether these mass extinctions were triggered by extraterrestrial forces\u2014such as massive meteor impacts\u2014or by terrestrial processes, such as long-term volcanic activity or shifts in ocean chemistry.<\/p>\n "With this research, we\u2019re basically taking a major pawn out of the Ordovician Meteor Event and dumping it into the Frasnian-Famennian event, and saying, ‘This is where this impact belongs,’" Catlos said. By correctly identifying the age of the Ames crater, scientists can now better evaluate its potential role in the environmental shifts that led to the Late Devonian extinctions.<\/p>\n The study serves as a testament to the collaborative nature of geological research, even as it reflects the personal losses often felt within the scientific community. The project was initiated by Andrew Parisi, a dedicated graduate student at the Jackson School of Geosciences who graduated in 2018 and has since passed away. Parisi\u2019s commitment to the project was instrumental; he traveled to Oklahoma to obtain the original rock core samples from the Oklahoma Geological Survey, performed the tedious work of extracting the zircon crystals, and was deeply involved in the initial age determinations. <\/p>\n The research was also supported by the contributions of co-author Michael Brookfield, an affiliated researcher at the school who also passed away before the paper was finalized for publication. Further contributions were made by Research Professor Sean Gulick and Professor Emeritus Mark Cloos, both of the Jackson School of Geosciences. Through their combined efforts, the team has not only corrected a significant error in the geologic record but has also provided a clearer, more accurate map of the forces that have shaped the history of life on our planet.<\/p>\n","protected":false},"excerpt":{"rendered":" A team of researchers from The University of Texas at Austin has fundamentally rewritten a chapter of Oklahoma\u2019s geologic history, providing new insights that could reshape how scientists interpret the catastrophic events that have punctuated the history of life on Earth. The subject of this re-examination is the Ames impact structure, a massive, hidden crater […]<\/p>\n","protected":false},"author":1,"featured_media":2238,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[370],"tags":[4121,1437,4122,4125,4123,4119,257,3029,61,1415,4124,4120,371,372],"class_list":["post-2239","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-science-and-nature","tag-ames","tag-ancient","tag-crater","tag-event","tag-extinction","tag-geologic","tag-linked","tag-mass","tag-nature","tag-oklahoma","tag-ordovician","tag-revision","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/2239","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2239"}],"version-history":[{"count":0,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/posts\/2239\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=\/wp\/v2\/media\/2238"}],"wp:attachment":[{"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2239"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2239"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/xesi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2239"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Tiny Zircon Crystals Preserve the Impact<\/h3>\n
A New Piece of a Mass Extinction Puzzle<\/h3>\n