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Images of the Odessa Crater Pictures Courtesy of Professor Glen Evans
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Posted on 06/22/2003 6:50:41 AM PDT by MeekOneGOP
Getting to bottom of crater mystery
06/22/2003
ODESSA – It took two hours for Vance Holliday to travel back thousands of years.
For a time machine, he drilled into the dirt of the meteor crater just west of Odessa. The deeper he went, the closer Dr. Holliday got to his goal – discovering the crater's age.
When the Odessa meteorite hit, some tens of thousands of years ago, it would have been a fearsome sight. An iron rock nearly 50 feet across fell screaming from the sky, hitting with energy roughly equivalent to that of the atomic bomb dropped on Hiroshima. The impact would have kicked up fierce winds and startled the mammoths, camels and giant ground sloths that prowled the landscape.
In late May, Dr. Holliday, a geoarchaeologist at the University of Arizona, dug back into history and 30 feet into the ground. The samples, now at an Arizona lab, act as a geological time capsule that has preserved the environment since impact.
Thirty feet of drilling isn't as much as the scientists would have liked, Dr. Holliday said, "but we're going to give it a whirl."
Two years ago, his team drilled 70 feet into the crater but didn't get many solid dates. Results from the new work are expected within six months.
The research is the first coring foray into the crater since 1960 and comes at a time when the long-maligned crater is beginning to gain scientific and public respect.
Last spring, a $400,000 museum opened at the site to showcase meteorites picked up here and elsewhere. It draws more than 50 visitors a day, most of them following signs from Interstate 20 two miles to the north, said Tom Rodman, a local lawyer whom most Odessans credit for the crater's renaissance.
Odessa isn't the only place in Texas to feature a meteor crater. The Sierra Madera Uplift, in Pecos County, and the Marquez Dome, in Leon County, are also confirmed impact craters, said David Kring of the University of Arizona.
None of these are as dramatic as North America's most famous crater, Barringer or Meteor Crater near Winslow, Ariz. It measures about 4,000 feet across; Odessa's is just 550.
Over time, wind and rain have filled the Odessa crater with sediments so that it resembles a bomb-blasted landscape surrounded by a low and barely distinguishable rim.
Researchers have dated Arizona's crater at nearly 50,000 years old, and that's the only reason why the Odessa crater has been estimated to be the same age, Dr. Holliday said. In the 1920s, scientists thought the two impacts might have been from part of the same giant meteorite. Now the two are considered unrelated.
Meteorite hunters have picked up fragments of the Odessa meteorite for miles around. The biggest chunk found weighed nearly 300 pounds, said Bob Rice, the museum's manager. Nothing bigger remains; the main mass of the meteorite exploded, creating four to five obvious craters and a number of smaller pits.
In the late 1930s, the University of Texas led an expedition to drill into the geology of the main crater. Scientists sunk a shaft 165 feet into the ground, but the wooden ladder used to access it burned in the 1950s, and the shaft is now covered.
For the new project, Dr. Holliday decided to drill relatively close to the old shaft. But he ran into trouble in the uppermost layers of dirt.
After driving the truck-hauled rig into the center of the crater, graduate student James Mayer set up two anchors to hold the drilling setup in place. Swiftly, the three-inch-diameter core barrel plunged into the dirt and began extracting core after core of sediment.
Dr. Holliday crumbled the material in his fingers, pointing out darker clay layers that represented times when Odessa was wetter than today.
"You never know at the surface what you'll find," he said, marking interesting spots in the dirt core.
For the first 20 feet and two hours, all went smoothly. But suddenly, the drilling jolted to a halt. The sharp tip of the core barrel, made to drive through soft sediments, bent against a hard substance – perhaps a layer of gravel or some big chunks of limestone, Dr. Holliday said.
The researchers pulled out the drill and tried again. As they tried to jam through the resistant layer, a piston on their new drill rig bent like a wire. Work halted.
"Now we know what kind of an animal we're wrestling here," Mr. Mayer said in frustration.
No one cursed, but the mood blackened noticeably. Dr. Holliday called the rig manufacturer. Mr. Rodman went into the museum and called a local hydraulics company. Half an hour later, two machinery specialists took away the piston for repair.
By late afternoon, Dr. Holliday was back in business. By the next day, he had drilled to about 30 feet deep before giving up for the year.
The new cores should help the team get better a idea on how old the material is, Dr. Holliday said. The researchers will use luminescence dating to measure how long it's been since the rock grains were exposed to light.
Mr. Rodman can't wait for the results.
"I wish they could go deeper, right to the bottom of the crater," he said.
E-mail awitze@dallasnews.com
When I visited that site, there was no nice museum and the crater was far from impressive.
The Wink Sink--now that's a hole.
I wonder how they made that decision?
With almost 1100 rigs running there may not be a good one left in west Texas. Sounds like they are using a small coring rig or a water well rig.
BTW you may be the only guy from California I know that has seen the Wink Sink! ;-)
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Images of the Odessa Crater Pictures Courtesy of Professor Glen Evans
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Who knows? Coin flip? hehe!
Bad/incomplete reporting I suppose.
Thanks for #8-9.
There. Now everyone can see it.
Sabertooth: Thanks for the ping.
Physicist: The meteorite I sent is from this fall.
And a big ping for the rest of you! :-)
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