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Cape York meteorite

Coordinates:76°08′N64°56′W/ 76.133°N 64.933°W/76.133; -64.933
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Cape York
The "Ahnighito" fragment in theAmerican Museum of Natural History
TypeIron
Structural classificationMedium octahedrite
GroupIIIAB
Composition7.84%Ni,0.50%Co,0.15%P,0.02%C,1.3%S,19ppmGa,36 ppmGe,5 ppmIr[1]
CountryGreenland
RegionAvannaata
Coordinates76°08′N64°56′W/ 76.133°N 64.933°W/76.133; -64.933[2]
Fall dateA few thousand years ago[3]
Found dateAbout 1000 years ago[4]
TKW58,200 kg[2]
Strewn fieldYes
Related media on Wikimedia Commons

TheCape York meteorite,also known as theInnaanganeq meteorite,is one of the largest knowniron meteorites,classified as a mediumoctahedritein chemical groupIIIAB.[5]In addition to many small fragments, at least eight large fragments with a total mass of 58 tonnes have been recovered, the largest weighing 31 tonnes (31 long tons; 34 short tons). The meteorite was named afterCape York,a prominent geographic feature located approximately 30 miles (48 km) west of the east coast ofMeteorite islandand the nearby peninsulas in northernMelville Bay,Greenland,where the first meteorite fragments were discovered.

The date of the meteorite fall is debated, but was likely within the last few thousand years.[3]It was known to theInughuit(the localInuit) for centuries, who used it as a source ofmeteoritic ironfor tools. The first foreigner to reach the meteorite wasRobert Pearyin 1894, with the assistance of Inuit guides. Large pieces are on display at theAmerican Museum of Natural Historyand theNatural History Museum of Denmark.

History

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Presumably the meteorite fell to Earth a few thousand years ago. Some estimates have put the date of the fall as 10,000 years ago.[6] All fragments recovered were found at the surface, partly buried, some on unstable terrain. The largest fragment was recovered in an area where the landscape consists of "flowing" gravel or clay-like sediments on permafrost.[7]There are mainly two hypotheses being discussed: the meteorites fell in an unknown place in Greenland, but were carried byglaciersto their current locations,[8]or they fell directly to where they were found after the glaciers had retreated.[1][9]

Presumably, none of the people saw the fall. Although, based on legends told by locals toWesterntravelers, there are some dubious grounds to assume that the fall happened after the first people, known as theDorset people,arrived in these places in the 7th and 8th century AD.[10][4]LaterInuitpeople referred to the known meteorite fragments under the general nameSaviksue(Great Irons). The three most important fragments, according to the legend told to Robert Peary, were Inuit sewing woman (the Woman) with her tent (the Tent) and curled up dog (the Dog) who had been all hurled from heaven by the evil spiritTornarsuk.[11][10]For centuries, Inuit living near the meteorites used them as a source of metal for tools and harpoons.[12][13]The Inuit would work the metal usingcold forging,that is, by hammering the metal with stones. Excavations of a medievalNorsefarm in the modern dayNuukarea in 1976 revealed an arrowhead made ofiron from the meteorite.Its presence is evidence of the connections between Greenland Norse and northern Greenland.[14]Other pieces of Cape York meteoritic iron dating prior to 1450 (i.e. before theLittle Ice Age) have been found throughout theArctic Archipelagoand on the North American mainland, and are evidence of an extensiveThule culturetrade network[15]which supplied iron toFirst Nationspeoples prior to European contact.[16]

Alancemade from anarwhaltusk with an iron head made from the Cape York meteorite

In 1818, the BritishFirst Ross Expedition(led by CaptainJohn Ross) made contact with Inuit on the northern shore ofMelville Bay,who stated they had settled in the area to exploit a nearby source of iron. The Inuit loosely described the location of this iron as Sowallick (probably this refers to Savilik which in Greenlandic means ‘with knife’), but poor weather andsea iceprevented Ross from investigating further. Ross correctly surmised that the large iron rocks described by the Inuit were meteorites, and purchased several tools with blades made of the meteoritic iron.[17]

Peary with theAhnighitofragment

Between 1818 and 1883, several further expeditions to the area were mounted by Britain, Sweden, and Denmark, which all failed to find the source of the meteoritic iron. Gradually, more and more iron objects were found on the west coast of Greenland. In 1870,Nordenskiöldlocated the main source of this iron at Ovifak (Uivfaq) on the south coast ofDisko Island.But it soon became clear that this iron mass was of terrestrial origin. As a result at the end of the century the Sowallick irons were discredited as meteorites.[18]Only in 1894 did a Western explorer reach the meteorite:Robert E. Peary,of theUS Navy.Peary enlisted the help of a local Inuit guide, who brought him to the vicinity of the island now known asMeteorite island.Peary dedicated three years to planning and executing the removal of the meteorite, a process which required, among other things, the construction of a short "railroad" of heavy timbers. In 1895 he managed to transport two smaller fragments (the Womanandthe Dog). In 1897, after great effort, he managed to obtain the third and the largest fragment (the Tent). The curious name“Ahnighito”was given to the meteorite by Peary’s daughter during a “baptizing” ceremony. Her middle name was Ahnighito, which is likely an anglophile version of the Inuit name Arnakitsoq (the name of the daughter’s nanny).[19]Peary sold this specimen for $40,000 (equivalent to $1.47 million in 2023[20]) to theAmerican Museum of Natural HistoryinNew York,where all three of the first discovered Cape York fragments are still on display. 3.4-by-2.1-by-1.7-metre (11.2 ft × 6.9 ft × 5.6 ft)Ahnighitois the second heaviest meteorite known to date (after theHoba meteoriteinNamibia) and the heaviest meteorite to have been relocated. 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.[21]

During his expedition to retrieve the meteorite, Peary convinced sixInughuit Greenlandic Inuitpeople ( "three men, one woman, a boy, and a girl" ), includingMinik Wallace,to travel with him in theUnited Statesfor study at theAmerican Museum of Natural History,where four died within a few months.[22]Later Peary has receivedsignificant criticismfor his treatment of the Inuit. The removal of meteorites from Greenland did not have a great impact on the lives of local residents because by that time they were getting iron for their needs fromwhalers,Peary and later fromThule trading post.[23]

A fourth large piece of the meteorite, 3.4 tonne Savik I, was discovered in 1913 on the promontory Saveqarfik, 10 km east of Woman-Dog location, but had evidently also been known to previous generations ofEskimos,since basaltic hammer stones were located around it. Due toWorld War Iit was left at the scene of its discovery until 1923-24 when the mass was brought down from the top of the cliff to the seashore and transported across 25 km of sea ice to theBushnan Island.Here, open water allowed the ship Sokongen to pick it up and sail with it toCopenhagenwhere it was unloaded in 1925 and thoroughly described.[24]

Thule meteorite[a]was found relatively close toThule townandThule Air Basein 1955 by a group of American glaciologists who surveyed the glacier flowing from Blue Ice Valley into theMoltke Glacier.The meteorite was resting as a boulder betweengneissicboulders on anunatakprotruding through the glaciers which are heading forWolstenholme Fjord.The meteorite has the shape and size of a resting goose, measuring 35 x 30 x 20 cm in the greatest dimensions and weighing 48.6 kg. Its distinctive feature is the "neck and head," a narrow extension of the massive meteorite, measuring about 10 x 3 x 10 cm. It appears that it was formed by fragmentation andsculpturingduring the atmospheric flight.[26]

After the local people had been encouraged to report any unusual boulder in the Cape York area, in 1961 a small, complete mass of 7.8 kg, Savik II, was discovered at the coast 1 km east of the site of Savik I. It was found between gneissic boulders at the foot of a cliff by the Eskimo Augo Suerssaq while on a hunting trip.[27]

In 1963, a fifth major piece of the Cape York meteorite was discovered byVagn Buchwald[da;de]on Agpalilik peninsula. TheAgpalilik meteorite[da],also known asthe Man,weighs about 20 metric tons (20 long tons; 22 short tons), and it is currently on display in theGeological Museumof theUniversity of Copenhagen,Denmark.

Tunorput mass was found in September 1984 by Jeremias Petersen, a hunter from the settlementSavigsivik,on the east coast of theMeteorite islandnear the Ahnighito mass original location[b].It is probably the first meteorite ever to be found in the ocean. It was lying very close to the shore, and was exposed at low tide.[29]Surveys of the area with amagnetometerin 2012 andgeoradarin 2014 found no evidence of further large iron fragments on Meteorite island, either buried or on the surface.[30]

Numerous other small meteorite fragments have been found over the past century, as well as a variety of meteoritic iron artifacts. Most of the finds are not precisely coordinated and are not particularly useful for determining the expected meteoritestrewn field,but they do reflect the important role that the Cape York meteorite once played as a major source of iron for local people.[31][32]

Specimens

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Hall in theAmerican Museum of Natural Historywith the first three fragments of the Cape York meteorite
Agpalilik outside theGeological MuseuminCopenhagen
Known confirmed masses of Cape York meteorite[33][34]
Mass name Year of discovery Latitude (N) Longitude (W) Location Mass, kg
Ahnighito
(the Tent) 		1894[c] 76°03′35″ 64°55′20″ 76°03′35″N64°55′20″W/ 76.05972°N 64.92222°W/76.05972; -64.92222[7] 30,880
Woman 1894[c] 76°08′16″ 64°56′15″ 76°08′16″N64°56′15″W/ 76.13778°N 64.93750°W/76.13778; -64.93750[35] 3,000
Dog 1894[c] 76°08′15″ 64°56′14″ 76°08′15″N64°56′14″W/ 76.13750°N 64.93722°W/76.13750; -64.93722[36] 407
Savik I 1913 76°08′ 64°36′ 76°08′N64°36′W/ 76.133°N 64.600°W/76.133; -64.600 3,402
Thule[37][a] 1955 76°32′ 67°33′ 76°32′N67°33′W/ 76.533°N 67.550°W/76.533; -67.550 48.6
Savik II 1961 76°08′ 64°35′ 76°08′N64°35′W/ 76.133°N 64.583°W/76.133; -64.583 7.8
Agpalilik
(the Man) 		1963 76°09′ 65°10′ 76°09′N65°10′W/ 76.150°N 65.167°W/76.150; -65.167 20,140
Tunorput[29] 1984 76°04′ 64°57′ 76°04′N64°57′W/ 76.067°N 64.950°W/76.067; -64.950[d] 250
Total: 58,135.4

Composition and classification

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Widmanstätten patternof a fragment of the Cape York meteorite

It is aniron meteorite(mediumoctahedrite) and belongs to the chemical group IIIAB.[2]The main distinguishing feature ofmeteoric ironis the highnickelcontent in its composition.[38]There are abundant elongatedtroilitenodules. The troilite nodules contain inclusions ofchromite,sulfides,phosphates,silicaandcopper.The rarenitridemineralcarlsbergite(CrN) occurs within the matrix of the metal phase.Graphitewas not observed and the nitrogen isotopes are in disequilibrium.[39]

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See also

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Notes

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  1. ^abOriginally considered as an individual meteorite, it began to be recognized as a fragment of the Cape York meteorite in the 1980s.[25]
  2. ^Information about the location of the find was taken from the map in Appelt's 2015 report.[28]
  3. ^abcIt is common to see erroneous values for the discovery year of the first three fragments. In particular, the typo in the discovery year has not yet been corrected in theMeteoritical BulletinDatabase.[2]
  4. ^Since there are no publicly available coordinates for the original location of the Turnoprit meteorite, the coordinates of the corresponding point marked on the map in Appelt's 2015 report were calculated.[28]

References

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  1. ^abBuchwald 1975a,p. 410.
  2. ^abcd"Cape York".Meteoritical BulletinDatabase.Lunar and Planetary Institute.5 September 2024.Retrieved2024-09-12.
  3. ^abAppelt et al. 2015,p. 62.
  4. ^abAppelt et al. 2015,p. 16.
  5. ^Buchwald 1975a,p. 424.
  6. ^Pringle, Heather (1997). "New Respect for Metal's Role in Ancient Arctic Cultures".Science.277(5327):766–767.doi:10.1126/science.277.5327.766.S2CID129339473.
  7. ^abAppelt et al. 2015,p. 61.
  8. ^Appelt et al. 2015,p. 63.
  9. ^Peary 1898,p. 611.
  10. ^abBuchwald 1975a,p. 420.
  11. ^Peary 1898,p. 559.
  12. ^Rickard, T. A. (1941)."The Use of Meteoric Iron".The Journal of the Royal Anthropological Institute of Great Britain and Ireland.71(1/2):55–66.doi:10.2307/2844401.JSTOR2844401.
  13. ^Buchwald, Vagn F.(September 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.
  14. ^Appelt et al. 2015,p. 23.
  15. ^Dick 2001,p. 52.
  16. ^Dick 2001,p. 105.
  17. ^Appelt et al. 2015,pp. 10–11.
  18. ^Buchwald 1975a,p. 413.
  19. ^Appelt et al. 2015,p. 13.
  20. ^1634–1699:McCusker, J. J.(1997).How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States: Addenda et Corrigenda(PDF).American Antiquarian Society.1700–1799:McCusker, J. J.(1992).How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States(PDF).American Antiquarian Society.1800–present:Federal Reserve Bank of Minneapolis."Consumer Price Index (estimate) 1800–".RetrievedFebruary 29,2024.
  21. ^"Ahnighito".American Museum of Natural History.Retrieved2024-09-12.
  22. ^Harper, Kenn(2000).Give Me My Father's Body: The Life of Minik, the New York Eskimo.South Royalton,Vermont:Steerforth Press.pp.26–27.ISBN978-1-883642-53-2.Retrieved2024-09-12.
  23. ^Buchwald 1975a,p. 418.
  24. ^Buchwald 1975a,p. 414.
  25. ^Esbensen, Kim H.; et al. (October 1982)."Systematic compositional variations in the Cape York iron meteorite".Geochimica et Cosmochimica Acta.46(10):1913–1920.Bibcode:1982GeCoA..46.1913E.doi:10.1016/0016-7037(82)90129-6.
  26. ^Buchwald 1975b,p. 1191-1192.
  27. ^Buchwald 1975a,pp. 414–415.
  28. ^abAppelt et al. 2015,p. 5.
  29. ^abBuchwald, Vagn F.(December 1987)."Thermal Migration III: Its Occurrence in Cape York and Other Iron Meteorites".Meteoritics.22(4): 343.Bibcode:1987Metic..22..343B.
  30. ^Appelt et al. 2015,p. 71.
  31. ^Buchwald, Vagn F.;Mosdal, Gert (1985)."Meteoritic Iron, Telluric Iron and Wrought Iron in Greenland".Meddelelser om Grønland.Man & Society (9): 11.ISBN978-87-635-1173-5.ISSN0106-1062.Retrieved2024-09-12.
  32. ^Buchwald, Vagn F.(2012)."Meteoritter og inuitter i Nordvestgrønland"[Meteorites and Inuit in Northwest Greenland](PDF).In Nielsen, Marita A. (ed.).Grønlands fascinationskraft. Fortællinger om polarforskningen[Greenland's Power of Fascination. Stories about Polar Research](PDF)(in Danish).Det Kongelige Danske Videnskabernes Selskab.p. 34.ISBN978-87-7304-366-0.Retrieved2024-09-12.
  33. ^"List of Strewnfield Members of Cape York".Meteoritical BulletinDatabase.Lunar and Planetary Institute.2018-12-27.Retrieved2024-09-11.
  34. ^Buchwald 1975a,p. 416.
  35. ^Appelt et al. 2015,p. 26.
  36. ^Appelt et al. 2015,p. 32.
  37. ^"Thule".Meteoritical BulletinDatabase.Lunar and Planetary Institute.5 September 2024.Retrieved2024-09-12.
  38. ^Schledermann, Peter (May 1981)."Eskimo and Viking Finds in the High Arctic"(PDF).National Geographic.159(5): 600.
  39. ^Zipfel, J.; Kim, Y.; Marti, K. (September 1995)."Nitrogen Isotopic Disequilibrium in the Cape York III A Iron".Meteoritics.30(5): 606.Bibcode:1995Metic..30R.606Z.
  40. ^"Bow and Arrow".

Bibliography

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