Cape York meteorite

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Cape York
Ahnighito AMNH, 34 tons meteorite.jpg
The "Ahnighito" fragment, weighing 31 t,
in the American Museum of Natural History
TypeIron
Structural classificationOctahedrite, medium
GroupIIIAB
Composition7.58% Ni, 19.2 ppm Ga, 36.0 ppm Ge, 5.0 ppm Ir
CountryGreenland
RegionNordgronland
Coordinates76°08′N 64°56′W / 76.133°N 64.933°W / 76.133; -64.933Coordinates: 76°08′N 64°56′W / 76.133°N 64.933°W / 76.133; -64.933[1]
Fall date10,000 years ago
Found date1894
TKW58200 kg[1]
Commons page Related media on Wikimedia Commons

The Cape York meteorite is named for Cape York, near the location of its discovery in Savissivik, Meteorite Island, Greenland, and is one of the largest iron meteorites in the world.

History[edit]

The meteorite collided with Earth thousands to millions of years ago.[2] The iron masses were known to Inuit as Ahnighito (the Tent), weighing 31 metric tons (31 long tons; 34 short tons); the Woman, weighing 3 metric tons (3.0 long tons; 3.3 short tons); and the Dog, weighing 400 kilograms (880 lb).[3] For centuries, Inuit living near the meteorites used them as a source of metal for tools and harpoons.[4][5] The Inuit would work the metal using cold forging—that is, by stamping and hammering it.

Peary with the Ahnighito fragment

The first stories of its existence reached scientific circles in 1818. Five expeditions between 1818 and 1883 failed to find the source of the iron. It was located in 1894 by Robert E. Peary, the famous American Navy Arctic explorer. Peary enlisted the help of a local Inuit guide, who brought him to Saviksoah Island, just off northern Greenland's Cape York in 1894. It took Peary three years to arrange and carry out the loading of the heavy iron meteorites onto ships. It required the building of small and short railroad. Peary sold the pieces for $40,000 to the American Museum of Natural History in New York City where they are still on display. It is unknown whether the Inuit were compensated for the theft of their resource.

Today the 3.4 by 2.1 by 1.7 metres (11.2 ft × 6.9 ft × 5.6 ft) piece named Ahnighito ("The Tent") is open for viewing at the American Museum of Natural History in the Arthur Ross Hall. It is the second-heaviest meteorite to have been relocated (after El Chaco, at 37 tons). It is so heavy that it was necessary to build its display stand so that the supports reached directly to the bedrock below the museum. [6]

In 1963, a fourth major piece of the Cape York meteorite was discovered by Vagn F. Buchwald on Agpalilik peninsula.[3] The Agpalilik meteorite, also known as the Man, weighs about 20 metric tons (20 long tons; 22 short tons), and it is currently on display in the Geological Museum of the University of Copenhagen, Denmark. Other smaller pieces have also been found, such as the 3 metric tons (3.0 long tons; 3.3 short tons) Savik I meteorite found in 1911 and the 250 kilograms (550 lb) Tunorput fragment found in 1984.

The Cape York asteroid has been suggested to be a part of the asteroid which created the Hiawatha crater which split off prior to impact by the discoverers of the crater.[7]

Specimens[edit]

A lance made from a Narwhal tusk with an iron head made from the Cape York meteorite

Each of the most important fragments of Cape York has its own name (listed in order of discovery date):

  1. Ahnighito (the Tent), 30,900 kilograms (68,100 lb),[8] 1884-1897, Meteorite Island, 76°04'N - 64°58'W
  2. Woman, 3,000 kilograms (6,600 lb),[8] 1897, Saveruluk, 76°09'N - 64°56'W
  3. Dog, 400 kilograms (880 lb), 1897, Saveruluk, 76°09'N - 64°56'W
  4. Savik I, 3,400 kilograms (7,500 lb),[8] 1913, Savequarfik, 76°08'N - 64°36'W
  5. Thule, 48.6 kilograms (107 lb), summer 1955, Thule, 76°32'N - 67°33'W[9]
  6. Savik II, 7.8 kilograms (17 lb), 1961, Savequarfik, 76°08'N - 64°36'W
  7. Agpalilik (the Man), 20,000 kilograms (44,000 lb), 1963, Agpalilik, 76°09'N - 65°10'W[8]
  8. Tunorput, 250 kilograms (550 lb), 1984

Composition and classification[edit]

It is an iron meteorite (medium octahedrite) and belongs to the chemical group IIIAB.[1] There are abundant elongated troilite nodules. The troilite nodules contain inclusions of chromite, sulfides, phosphates, silica and copper. The rare nitride mineral carlsbergite (CrN) occurs within the matrix of the metal phase. Graphite was not observed and the nitrogen isotopes are in disequilibrium.[10]

See also[edit]

References[edit]

  1. ^ a b c Cape York on the Meteoritical Bulletin Database
  2. ^ Pringle, H. (1997). "New Respect for Metal's Role in Ancient Arctic Cultures". Science. 277 (5327): 766–767. doi:10.1126/science.277.5327.766.
  3. ^ a b The Permanent Commission on Meteorites of the International Geological Congress (1963). "Discovery of Cape York (Apalilik) Iron Meteorite, Northwest Greenland" (PDF). Meteoritical Bulletin. 28.
  4. ^ T. A. Rickard (1941). "The Use of Meteoric Iron". Journal of the Royal Anthropological Institute. 71 (1/2): 55–66. doi:10.2307/2844401. JSTOR 2844401.
  5. ^ Buchwald, V F (1992). "On the Use of Iron by the Eskimos in Greenland". Materials Characterization. 29 (2): 139–176. doi:10.1016/1044-5803(92)90112-U.
  6. ^ "Ahnighito". American Museum of Natural History. Retrieved 2016-06-30.
  7. ^ "Greenland ice sheet hides huge 'impact crater'". BBC. Retrieved November 15, 2018.
  8. ^ a b c d J. Kelly Beatty, Carolyn Collins Petersen, Andrew Chaikin. The new solar system. Cambridge University Press, 1999, ISBN 0-521-64587-5
  9. ^ Meteoritical Bulletin Database: Thule
  10. ^ Zipfel, J.; Kim, Y.; Marti, K. Nitrogen Isotopic Disequilibrium in the Cape York III A Iron

Bibliography[edit]

External links[edit]