[meteorite-list] Scientists Could Unveil Age Of Odessa Impact Crater

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:22:33 2004
Message-ID: <200306021955.MAA24432_at_zagami.jpl.nasa.gov>

http://www.oaoa.com/news/nw053003c.htm

Scientists could unveil age of meteor crater
By Julie Breaux
Odessa American
May 30, 2003

A trio of scientists trying to get the Odessa meteor crater to
give up its age were met by stiff resistance at the prehistoric site
Thursday.

The three University of Arizona scientists pulled several core
samples of sediment from beneath the floor of the crater, a
National Natural Landmark located about seven miles west of
Odessa.

Led by Vance Holliday, a professor of anthropology and
geoscience, the group included David Kring, professor of
geoscience and planetary science, and James Mayer, a field
assistant who is studying for his doctorate in geosciences.
The group is taking core samples so Holliday can determine the
exact age of the crater, which has never been done before,
Holliday said.

But at about 20 feet below ground, the doughnut-shaped drill
bit attached to a long hollow tube in which the core samples
were being collected struck something so impenetrable that the
field work came to halt.

The group arrived at the site just after daybreak to begin boring
through infill sediment at the approximate center of the crater,
which is 510 feet in diameter, its deepest depression about 30
feet below the surface of the surrounding, mesquite-choked
plain.

Holliday, Kring and Mayer hope to leave Odessa with 40 feet or
more of core samples, Holliday said.

>From them, Holliday may be able to determine when chunks
from a huge iron asteroid that broke up in the atmosphere
slammed into the ground at an estimated 40,000 miles an hour,
Kring said.

Holliday estimated the cosmic event happened between 50,000
and 100,000 years ago. The core samples will help pin that
timeline down and more, Kring said.

Kring, who specializes in studying the impact of meteor craters,
said he will use analyses of the organic makeup of the soil to
reconstruct what the environment was like thousands of year
ago, what types of plants and animals were living here when the
meteor struck West Texas.

"So this is a time when this part of North American had
mastodons and mammoths and giant ground sloths and things of
that sort," Kring said. "But until we get a precise date, we
won't be able to gather that picture with any detail."

Kring came to Odessa with impressive credentials.
He was a principal investigator at the Chicxulub Scientific
Drilling Project near Merida, Mexico, in the Yucatan
Peninsula. The impact of the Chicxulub meteor is believed to
have led to one of the greatest mass extinctions on Earth,
including that of the dinosaur.

Because relatively few large meteor craters remain intact, the
Odessa meteor crater is a "fantastic and rare educational
opportunity" for area residents and the scientific community.
"Impact cratering is the dominant geological process in the
solar system," he said. "It is the process that shapes planets
moreso than any other process."

Impact cratering alters the environment, moving water around
and creating a new habitat for plants and animals. That has
occurred in Odessa, but to what extent isn't known - yet.

"The Chicxulub crater wiped out the dinosaurs, and it wiped out
more than 75 percent of the species of plants and animals, both
on land and in the sea, from the face of the Earth," Kring said.
"And that cleared the way for mammals to evolve. If that
impact didn't occur, we wouldn't be here. So having a center
like this is an extraordinary opportunity."
Received on Mon 02 Jun 2003 03:55:06 PM PDT