Geologists seek signs of meteorite strike 300 million years ago

OSCEOLA, Mo. -- The possibility that a meteorite slammed into a sea that covered much of Missouri 300 million years ago brought more than 100 geologists and students to St. Clair and Hickory counties to look for evidence of the collision.

The gathering Friday was a field trip for participants in the Association of Missouri Geologists 50th annual meeting in Springfield.

Geologist Kevin Evans said the research could bolster extinction theories based on meteorite strikes and let astronomers know what a strike from a small meteorite might do.

"We think we've got something kind of interesting here," Evans said of what is called the Weaubleau-Osceola Structure.

The geologists studied rock formations on highways 13 and 82 and at a quarry.

Evans recounted how he and fellow researchers discovered what may be the concentric rings of uplifted rock, signifying what could be one of the largest meteorite strike zones in the United States.

"It will make a good story," Evans said, perhaps good enough to lure outside help.

The next step in the project is to try for a National Science Foundation grant to finance further research.

The story began when Evans used computer software to join four maps together and discovered the ring formations around Weaubleau Creek. The research team theorizes the meteor strike created a crater 12 miles wide and more than 1,000 feet deep at ground zero. It would have dwarfed a nuclear bomb blast, Evans said.

Some of the evidence is just south of the quarry, where researchers point out signs that the area was one of several strike zones running from Kansas to Illinois.

Twisted formations of what should have been horizontal layers of sedimentary rock support the belief that something big hit the Ozarks millions of years before the dinosaurs lived.

While the Missouri Department of Transportation has helped by drilling three test holes in July along Highway 13, a grant would enable the team to do more extensive drilling, Evans said.

Retired geology professor Dick Gentile said he doesn't believe any clues support the Southwest Missouri team's theory.

Unless pieces of meteorite are found, theories such as cryptovolcanic activity -- in effect, the surfacing of superheated gasses and liquid rock without a volcano -- are just as valid, he said.

"You've got evidence for both," he said. "There's not enough evidence for either side to silence the other side."

Missouri Department of Natural Resources chief park naturalist George Kastler said he hasn't made up his mind about the meteorite theory, but he knows that once the team starts publishing scientific articles, the debate will intensify.

"I think there should be some good discussions," he said.