Willamette Meteorite
| Willamette | |
|---|---|
Willamette Meteorite at the American Museum of Natural History
|
|
| Type | Iron |
| Structural classification | Medium Octahedrite |
| Group | IIIAn |
| Composition | 7.62% Ni, 18.6ppm Ga, 37.3ppm Ge, 4.7ppm Ir |
| Country | United States |
| Region | Oregon |
| Coordinates | 45°22′N 122°35′W / 45.367°N 122.583°WCoordinates: 45°22′N 122°35′W / 45.367°N 122.583°W |
| Observed fall | No |
| Found date | 1902 |
| TKW | 14,150 kilograms (15.60 short tons) |
 |
|
The Willamette Meteorite, officially named Willamette, is an iron-nickel meteorite discovered in the U.S. state of Oregon. It is the largest meteorite found in North America and the sixth largest in the world. There was no impact crater at the discovery site; researchers believe the meteorite landed in what is now Canada or Montana, and was transported as a glacial erratic to the Willamette Valley during the Missoula Floods at the end of the last Ice Age (~13,000 years ago). It was long held sacred by indigenous peoples of the Willamette Valley, including the federally recognized Confederated Tribes of the Grand Ronde Community of Oregon (CTGRC). The indigenous peoples referred to this stone with the name Tomonowos (the visitor from the sky).
The meteorite is currently on display at the American Museum of Natural History in New York City, which acquired it in 1906. Having been seen by an estimated 40 million people over the years, and given its striking appearance, it is among the most famous meteorites known. In 2005, the Confederated Tribes of the Grand Ronde Community of Oregon sued to have the meteorite returned to their control but they were unsuccessful.
The Willamette Meteorite weighs about 32,000 pounds (15,000 kg). It is classified as a type III iron meteorite, being composed of over 91% iron and 7.62% nickel, with traces of cobalt and phosphorus. The approximate dimensions of the meteorite are 10 feet (3 m) tall by 6.5 feet (2 m) wide by 4.25 feet (1.3 m) deep. Most iron meteorites like Willamette have originated from the differentiated core of planetesimals or asteroids that collided with another object. Willamette has a recrystallized structure with only traces of a medium Widmanstätten pattern; it is the result of a significant impact-heating event on the parent body. The Willamette Meteorite contains higher concentrations of various metals that are quite rare in Earth's crust. For example, Iridium, one of the least abundant elements in Earth's crust, is found in the Willamette Meteorite at a concentration of 4.7 ppm, thousands of times more than its crustal abundance.
...
Wikipedia