April 30, 2008

Utah Meteorites

It is the size of a bowling ball but heavier, tumbled from space, and is believed to be about 4.5 billion years old. Now, the Gunlock Meteorite is on display at the Natural Resources Map & Bookstore, 1594 West North Temple, in Salt Lake City.

The Gunlock Meteorite originated from the asteroid belt between Mars and Jupiter.

Geologist Don Adair found the Gunlock Meteorite, so named because it was found near the town of Gunlock in southern Utah, on June 22, 1982. “The black meteorite stood out like a big bandage on a sore thumb.” He found the rock on a slope of contrasting light-gray-colored limestone. He also found a smaller piece about 50 yards away that fit together with the first, indicating that the space rock broke probably on impact.

Mr. Adair, a semi-retired consulting geologist from Boise, Idaho, sawed the large meteorite in half. One half has been residing at the American Museum of Natural History in New York, and the other half with Mr. Adair. Recently, Mr. Adair decided that his half should be displayed in Utah and he donated the 18-pound specimen to the Utah Geological Survey.

The Gunlock Meteorite is only one of 18 known meteorite finds in Utah and one of 1,512 officially named meteorites in the U.S., making it an extremely rare and valuable find. Meteorites are valuable because they are among the only specimens we have on Earth from asteroids, comets, and other planets in the solar system.

The Gunlock Meteorite, which originated from the asteroid belt between Mars and Jupiter, is a chondrite - a particular group of stony meteorites that derives its name from the Greek word for “seeds.” The name alludes to the meteorite’s distinctive texture characterized by small spherical grains called chondrules.

Current theories concerning the origin of chrondrites suggest they are related to the birth of the solar system. Chrondritic meteorites are 4.5 billion years old - older than any other known rocks on Earth. Although Earth probably formed about the same time, no rocks on the surface are that old because geologic processes constantly recycle them.