| Willamette | |
|---|---|
| Willamette Meteorite at the American Museum of Natural History | |
| Type | Iron |
| Group | IIIAn |
| Structural classification | Medium Octahedrite |
| Composition | 7.62% Ni, 18.6ppm Ga, 37.3ppm Ge, 4.7ppm Ir |
| Country | United States |
| Region | Oregon |
| Coordinates | [1] |
| Observed fall | No |
| Found date | 1902 |
| TKW | 14150 kg[2] |
The Willamette Meteorite, officially named Willamette[3], 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.[4][5] 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).[6] The meteorite is currently on display at the American Museum of Natural History, which acquired the meteorite in 1906.[5] 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.[7][8][9]
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The Willamette Meteorite weighs about 32,000 pounds or 15.5 tons. 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 (3.05 m) tall by 6.5 feet (1.98 m) wide by 4.25 feet (1.3 m) deep. The deep crevasses of the meteorite resulted from both its high-speed atmospheric entry and subsequent terrestrialization, i.e., weathering. Exposed to the elements for thousands of years, rainwater interacted with the mineral troilite, resulting in a form of sulfuric acid which slowly dissolved portions of the meteorite. This resulted (over a very long period) in the development of the hollows that are visible today. 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.[5][10]
The Willamette Meteorite was discovered in the Willamette Valley of Oregon near the modern city of West Linn. Although apparently known to Native Americans, its modern discovery was made by settler Ellis Hughes in 1902. At that time the land was owned by the Oregon Iron and Steel Company. Hughes recognized the meteorite's significance, and in an attempt to claim ownership, secretly moved it to his own land. This involved 90 days of hard work to cover the 3/4 mile (1200 m) distance. The move was discovered, and after a lawsuit, the Oregon Supreme Court held that Oregon Iron and Steel Company was the legal owner. Oregon Iron Co. v. Hughes, 47 Or 313, 82 P 572 (1905).[11]
In 1905 the meteorite was purchased by Mrs. William E. Dodge for $26,000 (around $680,000 in 2011). After being displayed at the Lewis and Clark Centennial Exposition, it was donated to the American Museum of Natural History in New York City where it has since been on display.[12]
The meteorite was apparently venerated by the Clackamas tribe inhabiting the area where it was found. The Confederated Tribes of the Grand Ronde Community of Oregon, a confederation of Native American tribes, used the meteorite, which they call Tomanowos, in ceremonies and demanded that it be returned and filed a NAGPRA action (Native American Graves Protection and Repatriation Act) against the American Museum of Natural History in 1999. In response, the Museum filed a federal lawsuit seeking a declaratory judgment against the Grand Ronde in 2000. An agreement with the Museum was reached later that year in which the meteorite would remain at the museum with tribal members being able to conduct a private ceremony around the meteorite once a year, and that ownership will be transferred to Grand Ronde should the museum cease to have the meteorite on display.[13]
In response to a student's request in 2007, Representative John Lim introduced a resolution that would demand that the museum return the meteorite to Oregon. The tribes said they were not consulted, they did not support the resolution, and were content with the current arrangement with the museum.[14]
The 28-pound (13 kg) crown section of the meteorite that had been traded to the Macovich Collection for a Martian meteorite in 1997, was planned to be auctioned in October 2007, which led to claims of insensitivity by the Grand Ronde.[15][16][17] Bidders dropped out when an editorial in the Portland Oregonian newspaper asserted the Grand Ronde would file a lawsuit against the new owner, but the Grand Ronde disavowed the editorial and said they had no such intent, and that they couldn't stop the sale. While the newspaper printed an apology, the specimen was withdrawn.[18][19][20] A lawsuit was filed against the newspaper in Oregon Circuit Court and failed.[21]
A 4.5-ounce (130 g), 7.5-inch (19 cm) piece of the meteorite, also with a Macovich Collection provenance, was purchased in a 2006 auction and is on display at the Evergreen Aviation & Space Museum in McMinnville, Oregon.[22][23]
There is some confusion about the actual weight of the Willamette meteorite due difference between metric tons and short tons, often both referred simply as tons. The result is that several sources report different weights ranging from 15500 kg (15.5 tonnes)[3] to 12700 kg[24] The official American Museum of Natural History website also reports both "15.5 tons"[25] and "14 tons".[26][27] However 15500 kg are likely 15.5 short tons converted as metric tons and 12700 kg are likely 14 metric tons converted as short tons. Moreover in 1906 the American Museum of Natural History itself stated that the weight of the Willamette meteorite was at least 31200 pounds, or about 15.6 tons.[2] After these considerations it is reasonable to guess that the real weight of the meteorite is about 14150 kg = 15.6 short tons = 14.15 tonnes.
A replica of the meteorite is in Eugene, Oregon, outside the University of Oregon Museum of Natural and Cultural History on the University of Oregon campus.[12] Another replica stands near the Willamette Methodist Church in West Linn, Oregon.[28]