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 the United States and the sixth largest in the world. No impact crater was preserved at the discovery site; it is possible that the meteorite landed in what is now Canada and was transported to where it was found by moving ice sheets.

Physical characteristics

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 about 8% 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 distinctive pitting on the surface of the meteorite is believed to have resulted from both its high-speed atmospheric entry and subsequent weathering. In the case of weathering, 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 many of the pits 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.

Modern history

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).

SOURCE: Wikipedia