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Coordinates: 27°38′S 61°42′W / 27.633°S 61.700°W / -27.633; -61.700
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[[File:Las Víboras Meteorite.jpg|thumb|left|"Las Víboras" meteorite found in Campo del Cielo and exhibited at the Universidad Nacional del Nordeste (Chaco, Argentina)]]
[[File:Las Víboras Meteorite.jpg|thumb|left|"Las Víboras" meteorite found in Campo del Cielo and exhibited at the Universidad Nacional del Nordeste (Chaco, Argentina)]]


In 1576 the governor of a province in Northern Argentina commissioned military to search a huge mass of iron, which he heard Indians used for their weapons. The Indians claimed the mass had fallen from the sky in a place they called ''Piguem Nonralta'' which the Spanish translated as ''Campo del Cielo'' ("Field of the sky"). The expedition found a large mass of metal protruding out of the soil. They assumed it an iron mine and brought back a few samples, which were described as iron of unusual purity. The governor has documented the expedition and deposited the report in the Archivo General de Indias in [[Seville]]. The discovery was quickly forgotten so that later reports on that area merely repeated the Indian legends. Following the legends, In 1774 don Bartolome Francisco de Maguna had rediscovered the iron mass which he called ''el Meson de Fierro'' ("the table of iron"). Maguna sought of the mass a tip of an iron vein. The next expedition in 1783 led by Rubin de Celis used explosives to clear the ground around the mass and found it was likely a single stone. Celis estimated its mass as 15 tons and abandoned it as worthless. He himself did not believe the stone fell from the sky and assumed it was due to a volcanic eruption. However, he sent the samples to the Royal Society of London and published his report in the [[Philosophical Transactions of the Royal Society]].<ref>{{cite journal|author=M. R. Celis|title=An account of a mass of native iron found in South America|journal=Philosphical Transactions of the Royal Society|volume=78|pages=183-189|year=1788}}</ref> Those samples were later analyzed and found to contain 90% of iron and 10% of nickel and assigned a meteoritic origin.<ref name=history>{{cite book|url=http://books.google.com/books?id=7SvtVoa1W-cC&pg=PA28|pages=28-30|title=The history of meteoritics and key meteorite collections|author=Gerald Joseph Home McCall, A. J. Bowden, Richard John Howarth|publisher=Geological Society|year= 2006}}</ref>
In 1576 the governor of a province in Northern Argentina commissioned the military to search for a huge mass of iron, which he heard Indians used for their weapons. The Indians claimed the mass had fallen from the sky in a place they called ''Piguem Nonralta'' which the Spanish translated as ''Campo del Cielo'' ("Field of the sky"). The expedition found a large mass of metal protruding out of the soil. They assumed it an iron mine and brought back a few samples, which were described as iron of unusual purity. The governor has documented the expedition and deposited the report in the Archivo General de Indias in [[Seville]]. The discovery was quickly forgotten so that later reports on that area merely repeated the Indian legends. Following the legends, In 1774 don Bartolome Francisco de Maguna had rediscovered the iron mass which he called ''el Meson de Fierro'' ("the table of iron"). Maguna sought of the mass a tip of an iron vein. The next expedition in 1783 led by Rubin de Celis used explosives to clear the ground around the mass and found it was likely a single stone. Celis estimated its mass as 15 tons and abandoned it as worthless. He himself did not believe the stone fell from the sky and assumed it was due to a volcanic eruption. However, he sent the samples to the Royal Society of London and published his report in the [[Philosophical Transactions of the Royal Society]].<ref>{{cite journal|author=M. R. Celis|title=An account of a mass of native iron found in South America|journal=Philosphical Transactions of the Royal Society|volume=78|pages=183-189|year=1788}}</ref> Those samples were later analyzed and found to contain 90% of iron and 10% of nickel and assigned a meteoritic origin.<ref name=history>{{cite book|url=http://books.google.com/books?id=7SvtVoa1W-cC&pg=PA28|pages=28-30|title=The history of meteoritics and key meteorite collections|author=Gerald Joseph Home McCall, A. J. Bowden, Richard John Howarth|publisher=Geological Society|year= 2006}}</ref>


Later, many iron pieces were found in the area weighing from few milligrams to 34 tons. A mass of about 1000&nbsp;kg known as ''Otumpa'' was located in 1803. Its larger part of about 634&nbsp;kg was brought in 1813 to Buenos Aires and later donated to the British Museum. Other large fragments are summarized in the table above. The mass called ''el Taco'' was originally 3070&nbsp;kg, but the largest remaining fragment weighs 1998&nbsp;kg.<ref>{{cite news|url=http://www.fcaglp.unlp.edu.ar/~sixto/arqueo/meteoritos.htm|title=Meteoritos de Campo del Cielo: Impactos en la cultura aborigen|author=S. R. Giménez Benítez ''et al.''}}</ref>
Later, many iron pieces were found in the area weighing from few milligrams to 34 tons. A mass of about 1000&nbsp;kg known as ''Otumpa'' was located in 1803. Its larger part of about 634&nbsp;kg was brought in 1813 to Buenos Aires and later donated to the British Museum. Other large fragments are summarized in the table above. The mass called ''el Taco'' was originally 3070&nbsp;kg, but the largest remaining fragment weighs 1998&nbsp;kg.<ref>{{cite news|url=http://www.fcaglp.unlp.edu.ar/~sixto/arqueo/meteoritos.htm|title=Meteoritos de Campo del Cielo: Impactos en la cultura aborigen|author=S. R. Giménez Benítez ''et al.''}}</ref>

Revision as of 19:26, 23 July 2009

Campo del Cielo
Campo del Cielo iron meteorite with natural hole, 576 grams
TypeIron
Structural classificationOctahedrite
GroupIAB
Composition92.9% Fe, 6.7% Ni, 0.4% Co
CountryArgentina
RegionChaco Province and Santiago del Estero Province
Coordinates27°38′S 61°42′W / 27.633°S 61.700°W / -27.633; -61.700
Observed fallNo
Fall date4,000-5,000 years ago
Found date<1576
TKW>100 tonnes
Related media on Wikimedia Commons

The Campo del Cielo refers to a group of iron meteorites or to the area where they had been found situated on the border between the provinces of Chaco and Santiago del Estero, 1,000 kilometers (620 mi) northwest of Buenos Aires, Argentina. The crater field covers the area of 3x20 km, it contains at least 26 craters, the largest being 115x91 m. The craters' age is estimated as 4,000-5,000 years. The craters containing iron masses were reported in 1576, but were well known before by the original inhabitants. The craters and the area around contain numerous fragments of an iron meteorite. The total weight of the thus recovered pieces exceeds 100 tonnes making the meteorite the heaviest ever recovered on Earth. The mass of 37 tonnes is the second heaviest single-piece meteorite recovered on Earth, after Hoba.

History

Campo del Cielo is located in Argentina
Campo del Cielo
Campo del Cielo
Location of Campo del Cielo craters
Major fragments of the Campo del Cielo meteorite[1][2][3][4]
Mass (tonnes) Name Year of discovery
>15 el Meson de Fierro 1576
1 Otumpa 1803
1.5 1913
4.21 el Toba 1923
2.5 el Hacha 1924
0.732 el Mocovi 1925
0.85 el Tonocote 1931
0.46 el Abipon 1936
1 el Mataco 1937
0.9 1937
3.09 el Taco 1962
5 la Peridida 1965
37 el Chaco 1969
10 1997
15 la Sopressa 2005
1 Runa Posito ?
3.12 Las Viboras ?
"Las Víboras" meteorite found in Campo del Cielo and exhibited at the Universidad Nacional del Nordeste (Chaco, Argentina)

In 1576 the governor of a province in Northern Argentina commissioned the military to search for a huge mass of iron, which he heard Indians used for their weapons. The Indians claimed the mass had fallen from the sky in a place they called Piguem Nonralta which the Spanish translated as Campo del Cielo ("Field of the sky"). The expedition found a large mass of metal protruding out of the soil. They assumed it an iron mine and brought back a few samples, which were described as iron of unusual purity. The governor has documented the expedition and deposited the report in the Archivo General de Indias in Seville. The discovery was quickly forgotten so that later reports on that area merely repeated the Indian legends. Following the legends, In 1774 don Bartolome Francisco de Maguna had rediscovered the iron mass which he called el Meson de Fierro ("the table of iron"). Maguna sought of the mass a tip of an iron vein. The next expedition in 1783 led by Rubin de Celis used explosives to clear the ground around the mass and found it was likely a single stone. Celis estimated its mass as 15 tons and abandoned it as worthless. He himself did not believe the stone fell from the sky and assumed it was due to a volcanic eruption. However, he sent the samples to the Royal Society of London and published his report in the Philosophical Transactions of the Royal Society.[5] Those samples were later analyzed and found to contain 90% of iron and 10% of nickel and assigned a meteoritic origin.[6]

Later, many iron pieces were found in the area weighing from few milligrams to 34 tons. A mass of about 1000 kg known as Otumpa was located in 1803. Its larger part of about 634 kg was brought in 1813 to Buenos Aires and later donated to the British Museum. Other large fragments are summarized in the table above. The mass called el Taco was originally 3070 kg, but the largest remaining fragment weighs 1998 kg.[7]

The largest mass of 37000 kg was located in 1969 at a depth of 5 m using a metal detector.[6] This stone named El Chaco is the second heaviest single-piece meteorite after Hoba (Namibia) which weighs 60 tons. However, the total mass of the Campo del Cielo fragments found so far exceeds 60 tons making it the heaviest meteorite recovered on Earth.[8]

In 1990 a local Argentinean highway police officer foiled a plot by Robert Haag to steal El Chaco. The stone had already been moved out of the country, but was returned to Campo del Cielo and is now protected by a provincial law.[9]

The meteorite impact, age and composition

A crater field of at least 26 craters was found in the area, the largest being 115x91 m. The field covered the area 3x19 km with an associated strewn area of smaller meteorites extending further by about 60 km. At least two of the craters contained thousands of small iron pieces. Such unusual distribution suggested that a large body entered the Earth atmosphere and broke to pieces which fell to the ground. The size of the main body is estimated as larger than 4 meters. The fragments contain unusually high for an iron meteorite amount of inclusions, which might have facilitated the breaking of the original meteorite. Samples of the charred wood were taken from underneath the meteorite fragments and analyzed for carbon-14 composition. The results indicated the date of the fall around 4,200-4,700 years ago, or 2,200-2,700 years BC.[6][10]

The average composition of the Campo Del Cielo meteorites is 6.67% Ni, 0.43% Co, 0.25% P, 87 ppm Ga, 407 ppm Ge, 3.6 ppm Ir, the rest being iron.[1][6]

References

  1. ^ a b Vagn F. Buchwald (1975). The Handbook of Iron Meteorites, Their History, Distribution, Composition and Structure. Vol. 2. Berkeley: University of California Press. ISBN 0520029348.
  2. ^ Monica M. Grady, A. L. Graham, Natural History Museum (London, England) (2000). Catalogue of meteorites. Cambridge University Press. p. 126. ISBN 0521663032.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. ^ S.P. Wright; et al. (2006). "Revisiting the Campo del Cielo, Argentina crater field: A new data point from a natural laboratory of multiple low velocity, oblique impacts" (PDF). Lunar and Planetary Science. XXXVII: 1102. {{cite journal}}: Explicit use of et al. in: |author= (help)
  4. ^ M. C. L. Rocca; et al. (2006). "A catalogue of large meteorite specimens from Campo del Cielo meteorite shower, Chaco province, Argentina" (PDF). 69th Annual Meteoritical Society Meeting: 5501. {{cite journal}}: Explicit use of et al. in: |author= (help); line feed character in |title= at position 41 (help)
  5. ^ M. R. Celis (1788). "An account of a mass of native iron found in South America". Philosphical Transactions of the Royal Society. 78: 183–189.
  6. ^ a b c d Gerald Joseph Home McCall, A. J. Bowden, Richard John Howarth (2006). The history of meteoritics and key meteorite collections. Geological Society. pp. 28–30.{{cite book}}: CS1 maint: multiple names: authors list (link)
  7. ^ S. R. Giménez Benítez; et al. "Meteoritos de Campo del Cielo: Impactos en la cultura aborigen". {{cite news}}: Explicit use of et al. in: |author= (help)
  8. ^ "Campo Del Cielo". Planetarium de Montreal. Retrieved 2009-07-07.
  9. ^ Danny Aeberhard, Andrew Benson, Rough Guides, Lucy Phillips (2000). The Rough Guide to Argentina. Rough Guides. p. 370. ISBN 1858285690.{{cite book}}: CS1 maint: multiple names: authors list (link)
  10. ^ Peter T. Bobrowsky, Hans Rickman (2007). Comet/asteroid impacts and human society: an interdisciplinary approach. Springer. pp. 30–31. ISBN 3540327096.