(Adapted from the Minerals of Wisconsin database)
Wisconsin has been hit by at least 13 meteorites since the 1860s. The meteorites ranged in size from less than 1 pound to around 530 pounds.
Meteorites are called “falls” when the meteorite was observed falling to the ground; those recovered later are called “finds.”
Algoma: A meteorite massing nearly 9 pounds was found during plowing about 4 miles west of Algoma (Kewaunee County). It contained 88.6% iron and 10.6% nickel. This meteorite is now on display at the Geology Museum at UW–Madison.
Angelica: Approximately 3 miles north of Angelica (Shawano County), a 33-pound iron meteorite was found in 1916 during plowing.
Belmont: A stony meteorite weighing 58.28 pounds was found in 1958 near Belmont (Lafayette County). It contained mostly bronzite and olivine, but also about 23% iron-nickel alloys. The Belmont meteorite is currently in the Geology Museum at UW–Madison.
Colby: Two stony meteorites with a combined weight of over 200 pounds fell at 6:15 P.M. on July 4, 1917 near Colby (Clark County). Samples are in the Geology Museum at UW–Madison.
Hammond: An iron meteorite massing almost 53 pounds was recovered from a plowed field near Hammond (St. Croix County) in 1884. Troilite was present in nodules and as fracture fillings. Chemical analysis gave 89.78% iron and 7.6% nickel with trace amounts of cobalt, phosphorous, silicon, carbon, copper and tin.
Kilbourn: A 772-gram stony meteorite fell through a barn roof near Kilbourn (Columbia County) at 5:00 P.M. June 16, 1911. Samples and a replica are in the Geology Museum at UW–Madison.
Mifflin: Named after Mifflin Township in southwest Wisconsin, this stony meteorite fell on April 14, 2010. Several pieces, the largest of which weighs 142 grams, are on display in the Geology Museum at UW–Madison.
Oshkosh: A 4-ounce fragment of stony meteorite was found on gravel approximately 2 miles NW of Oshkosh (Winnebago County).
Trenton: A number of large pieces from an iron meteorite have been found in Trenton township, east of West Bend (Washington County). Fragments were first found in 1858, with more turning up in 1873. A detailed search of the area with a metal detector revealed more fragments in 1952 and 1964. At least 13 fragments had been found so far. The largest chunks weighed 527 pounds and 413 pounds. Sawn and treated fragments show troilite nodules and lenses. Specimens from this meteorite are on display at the Geology Museum at UW–Madison.
Vernon County: The Claywater Meteorite was observed to fall at 9 A.M. on March 25, 1865. It came in as a rotating fireball and exploded near ground level. Two fragments with a combined mass of 3.3 pounds were recovered. The meteorite was mostly stony, containing olivine and enstatite. It also contained about 17% iron-nickel alloys.
Waushara County: An iron meteorite with stony inclusions, nicknamed the Pine River Meteorite, was found in 1894 near Saxeville. Its mass is nearly 8 pounds. This proved to be an unusual meteorite for the octahedrite with many silicate inclusions and an “anomalous member of chemical group IA.” The silicate inclusions consist of granular crystalline intergrowths of orthpyroxene, olivine, plagioclase feldspar, troilite and iron nickel metal with accessory chromite, diopside and schreibersite.
Waushara County: A stony meteorite massing 1.5 pounds was found near Mt. Morris. The Mt. Morris Stone is a coarsely crystalline sulfide rich stone with forsterite, enstatite, kamacite, schreibersite, troilite, graphite, chromite, daubreelite and chalcopyrite. Later detailed geochemical analysis suggests that the Mt. Morris meteorite is a fragment from the Pine River Meteorite.
Zenda: The Zenda Meteorite was found in 1955, about a half-mile west of Zenda (Walworth County). It massed 8.16 pounds and was deeply oxidized. It was an iron meteorite containing kamacite, schreibersite patches, troilite, taenite, and lawrencite. It also contained minor graphite, olivine and pyroxene.