Cape York (meteorite)

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Fragments of the Cape York Meteorite: The Main Mass, the Ahnighito Meteorite (in the background), "The Woman" (front) and "The Dog" (on the stand) in the American Museum of Natural History.
Agpalilik

The Cape York Meteorite (also Cape York Meteorite ) is an iron meteorite that was classified as a group III AB mean octahedrite and consists of 91% iron , 7.58% nickel , 19.2  ppm gallium , 36.0 ppm Germanium and 5.0 ppm iridium . It is named after the place of its discovery, Cape York in Greenland in the administrative district of Avanersuaq , and originally weighed probably 200  tons .

The meteorite is around 4.6 billion years old. It was exposed to cosmic rays for about 93 million years . This means that it was separated from its mother body much less time ago than other octahedrites of chemical group III AB, which as a rule have a higher radiation age of around 650 million years.

When entering the earth's atmosphere nearly 10,000 years ago, the Cape York meteorite broke over Melville Bay and produced one of the largest known meteor showers . The elliptical scatter field extends over an area of ​​100 km x 15 km. The scattered ellipse suggests a flight direction of the meteorite from the northwest (where the Thule fragment was found) to the southeast (where the Ahnighito fragment was found). The shape of the Cape York meteorite has not yet been reconstructed. It is possible that there are still large pieces under the ice or in the sea.

So far, parts of the meteorite with a total weight of 58 t have been found. The main mass of the Cape York meteorite is the Ahnighito meteorite with a weight of 31 t. It is on display in the Arthur Ross Hall of Meteorites at the American Museum of Natural History in New York . Robert Peary found the meteorite in Greenland in 1897 and brought it to New York. Besides the Ahnighito are in the American Museum of Natural History two other sections of the Cape York meteorite, "The Woman" (Woman) with a weight of 3 t and "The Dog" (Dog) with 400 kg.

A total of twelve fragments of the Cape York meteorite are known. In 1963 a large fragment of the Cape York meteorite was discovered by the Danish meteorite researcher Vagn Buchwald on the island of Agpalilik. The Agpalilik meteorite ("The Man") weighs around 20 t and is located in the courtyard of the Geological Museum of the University of Copenhagen . Other smaller fragments are z. B. the 3 t heavy Savik-I meteorite, which was found in 1913 by Knud Rasmussen , the 48 kg heavy Thule meteorite, discovered in 1955 by the geologist Mark Meier (1925–2012), the 7.8 kg heavy Savik-II -Meteorite and the 250 kg Tunorput fragment, which was found in the sea in 1984 by the hunter Jeremias Petersen. By comparing the chemical compositions, Vagn Buchwald recognized that a fragment that was found near an old Inuit camp on Ellesmere Island's Knud Peninsula in Canada belonged to the Cape York meteorite. This 1.6 kg fragment, which was given the name Akpohon, appears to have been transported by the Inuit over 600 km from the place where it fell to where it was found in Canada.

literature

  • Monica M. Grady: Catalog of Meteorites. 5th edition. Cambridge University Press, Cambridge 2000, ISBN 978-0-521-66303-8 .

Web links

Commons : Cape York  - Collection of images, videos and audio files

Individual evidence

  1. ↑ a b c Cape York Montréal Planetarium
  2. ^ History of Meteorites, Cape York Astronomical Research Network
  3. ↑ a b c Vagn Fabritius Buchwald : Thermal Migration III: Its Occurrence in Cape York and Other Iron Meteorites Meteoritics, No. 22, p. 343
  4. ^ Mineralienportrait Eisen, Eisen in Grönland mineralienatlas.de
  5. ↑ Discovery of Cape York Iron Meteorite (PDF; 369 kB) Meteoritical Bulletin, No. 28, Moscow 1963
  6. ^ Meteoritical Bulletin Database, Cape York