[meteorite-list] Rocks From Heavan - Finding Meteorites In Nevada May Be Easier Than You Think

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:15 2004
Message-ID: <200211141659.IAA19886_at_zagami.jpl.nasa.gov>

http://www.rgj.com/news/stories/html/2002/11/13/28014.php?sp1=&sp2=&sp3=

Rocks from heaven
Finding meteorites in Nevada may be easier than you think
Mark Vanderhoff
RENO GAZETTE-JOURNAL
November 13, 2002

It's been five months since a retired Reno couple found two rocks experts
believe might be meteorites. If the rocks pass a test this week at the Lunar
and Planetary Laboratory in Tucson, Ariz., their find will mark the fifth
recovery of space rocks in Nevada.

That's not many finds, considering a meteor probably hits the ground here
about once every two years, said Keith Johnson, director of the Fleischmann
Planetarium in Reno. But meteorites kind of look like every other rock in
Nevada, so outdoors enthusiasts may have walked by quite a few while
exploring the state.

"There's probably a lot remaining to be found out there," he said.

The four Nevada meteorites on display at the Fleischmann Planetarium on the
University of Nevada, Reno campus may resemble dark chunks of basalt or some
other volcanic rock to the layman. Those with some geologic knowledge might
suspect something unusual, however, if they pick one up for closer
inspection.

Many of the meteorites found weigh more than the average rock found on the
earth's surface because they are made of nickel-iron, a heavy metal.
Thumb-like impressions in the rock caused when weaknesses burn off during
descent might also arouse suspicion.

Gordon and Patricia Cave, the couple who found the potential meteorites,
thought something was unusual when they uncovered one June day two heavy
rocks with a "stainless steel" color.

Stumbling upon meteorites

The Caves consider themselves desert rats, fans of the rugged, dry mountains
and valleys in Nevada. They also consider themselves amateur gold
prospectors, a hobby that has yielded them "about enough gold to fill a
tooth," Gordon said.

Earlier this year, their friend David Davis, a UNR geologist, suggested they
try searching for meteorites. First, they searched with metal detectors
around Fallon, to no avail. Then they tried a spot northeast of Sulphur.
First, Patricia found one. Less than an hour later, Gordon found another.

"It looked like a good-sized gold nugget, all beat up from being in the
water," Gordon said.

They knew it wasn't gold, though, because it was too metallic and shiny.
Maybe it was slag, metal waste from welding, they thought. Or maybe shrapnel
from one of the World War II bombing exercises conducting in the region.

The Caves brought the rocks to Davis, who examined them and ran some tests.
Davis, thinking the rocks could be meteorites, brought them to Johnson at
the planetarium.

People bring rocks to the planetarium several times each year, Johnson said.

"Usually people have been in the desert, hiking or looking for gold," he
said. "They're always apologetic. They say they feel foolish for bringing
them in, and I have to tell them 'No, you're not.'"

In May 1999, for example, Harold McCormick of Carson City discovered a
meteorite while rock hunting near the Majuba Mountains east of Winnemucca.
McCormick brought the Majuba Meteorite, as it has come to be known, to the
planetarium, which sent to it to the Arizona lab. That meteorite is now on
display at the planetarium, a gift from McCormick.

Rocks from the sky

Meteorites come from planetary bodies such as asteroids, moons or other
planets.

While most come from asteroids, some have come from Mars and the Earth's
moon, said David Kring, an associate professor at the University of Arizona
in Tucson and researcher at the Lunar and Planetary Laboratory.

By learning about the gradual evolution of the solar system from these
samples, scientists obtain clues about the gradual evolution of earth, he
said. Asteroids may have brought the ingredients for life on earth with
them, Kring said.

"We actually find out about the earth's history at a time when there's no
record of that history on earth," he said.

Most of the meteorites scientists study come from Antarctica. Since figuring
out 20 years ago that meteorites are easier to find and better preserved
among the ice and snow, more than 15,000 specimens have been recovered from
Antarctica.

More than 150 meteorites have been found in New Mexico and almost 300 have
been found in Arizona, both nearby desert states where, as in Nevada, plain
old earth rocks could potentially be confused with meteorites. So why have
only four confirmed meteorites been found in Nevada? The state's rugged
topography and sparse population mean fewer people are looking in fewer
accessible places, Kring said.

"Meteorites fall randomly over the surface of the Earth," he said. "You have
as many fall over Nevada as do here in Arizona."

That means people who spend spare time gallivanting around the Nevada have a
chance at finding those galactic chunks.

"Most meteorites are found by people while hiking, riding horses or while
digging in their back yard," Kring said.

How to find a meteorite

Here are some features to help identify a potential meteorite:

o A black or brown surface, often marked by thumb-like impressions, but
  without pores or hollow vesicles.
o The rock is heavy for its size. This may be a nickel-iron meteorite.
o A metallic silver interior.
o The rock is unlike other rocks in the area.
o The rock attracts a magnet or deflects a compass needle, showing
  magnetism. This may be a nickel-iron meteorite.

Sources: Keith Johnson (Fleischmann Planetarium) and David Kring
(Lunar and Planetary Laboratory)
Received on Thu 14 Nov 2002 11:59:17 AM PST