Canyon Diablo (meteorite)

Canyon Diablo
Canyon Diablo iron meteorite fragment (IAB) 2,641 grams. Note colorful natural desert patina.
Type	Iron
Structural classification	Coarse Octahedrite
Group	IAB-MG
Composition	7.1% Ni; 0.46% Co; 0.26% P; 1% C; 1% S; 80ppm Ga; 320ppm Ge; 1,9ppm Ir
Country	United States
Region	Coconino County, Arizona
Coordinates	35°03′N 111°02′W / 35.050°N 111.033°WCoordinates: 35°03′N 111°02′W / 35.050°N 111.033°W[1]
Observed fall	No
Fall date	49000 years ago[2]
Found date	1891
TKW	30 tonnes
Strewn field	Yes
etched slice

The Canyon Diablo meteorites include the many fragments of the asteroid that created the Barringer Crater (Meteor Crater), Arizona, USA. Meteorites have been found around the crater rim, and are named for nearby Canyon Diablo, which lies about three to four miles west of the crater.

History

The asteroid fell about 50,000 years ago.^[3] The meteorites have been known and collected since the mid-19th century and were known and used by pre-historic Native Americans. The Barringer Crater, from the late 19th to the mid-20th century, was the center of a long dispute over the origin of craters that showed little evidence of volcanism. That debate was settled in the 1950s thanks to Eugene Shoemaker's study of the crater.

In 1953, Clair Cameron Patterson measured ratios of the lead isotopes in samples of the meteorite. The result permitted a refinement of the estimate of the age of the Earth to 4.550 billion years (± 70 million years).^[4]

Composition and classification

This meteorite is an iron octahedrite. Minerals reported from the meteorite include:

• Cohenite - iron carbide
• Chromite - iron magnesium chromium oxide
• Daubréelite - iron(II) chromium sulfide
• Diamond and lonsdaleite - carbon
• Graphite - carbon
• Haxonite - iron nickel carbide
• Kamacite iron nickel alloy - the most common component.
• base metal sulfides
• Schreibersite - iron nickel phosphide
• Taenite iron nickel alloy
• Troilite a variety of the iron sulfide mineral pyrrhotite. The troilite in this sample is used as the standard reference for sulfur isotope ratios.
• Moissanite - a variety of silicon carbide, the second hardest natural mineral.

Samples may contain troilite-graphite nodules with metal veins and small diamonds.

Fragments

"Holsinger Meteorite", the biggest recovered fragment of the Canyon Diablo meteorite

Example of a small (90mm) fragment of the meteorite

The biggest fragment ever found is the Holsinger Meteorite, weighing 639 kilograms (1,409 lb), now on display in the Meteor Crater Visitor Center on the rim of the crater. Other famous fragments:

• 485 kilograms (1,069 lb), Canterbury Museum, Christchurch, New Zealand. The largest fragment outside the United States.^[5]
• 360 kilograms (790 lb), Muséum national d'Histoire naturelle (MNHN), Paris
• 242.6 kilograms (535 lb), Lowell Observatory in Flagstaff, Arizona^[6]
• 225.9 kilograms (498 lb), Academy of Natural Sciences of Drexel University, Philadelphia, Pennsylvania.
• 194 kilograms (427 lb), Beloit College, Beloit, Wisconsin.
• 162 kilograms (357 lb), Meteorite Museum, University of California, Los Angeles ^[7]
• 136 kilograms (300 lb), Franklin Institute, Philadelphia.^[8]
• 122 kilograms (269 lb), Griffith Observatory, Los Angeles, California. Fragment loaned by the Geology Department of Pomona College.
• 179 kilograms (395 lb), Griffith Observatory, Los Angeles, California.
• 100 kilograms (220 lb), California Academy of Sciences, San Francisco.
• 54 kilograms (119 lb), Newark Museum, Newark, New Jersey.
• Basket Meteorite (22 kilograms (49 lb)), Meteor Crater Museum, Arizona.^[9][10]

See also

• Glossary of meteoritics

References

1. Meteoritical Bulletin Database: Canyon Diablo
2. Spaceguard Foundation UK
3. Roddy, D. J.; E. M. Shoemaker (1995). "Meteor Crater (Barringer Meteorite Crater), Arizona: summary of impact conditions". Meteoritics 30 (5): 567.
4. Patterson, C. (1956). "Age of Meteorites and the Earth". Geochimica et Cosmochimica Acta 10: 230–237. Bibcode:1956GeCoA..10..230P. doi:10.1016/0016-7037(56)90036-9.
5. Canyon Diablo Meteorite; MET16, Canterbury Museum collection on eHive
6. Meteorite moves to Flag
7. UCLA's new Meteorite Museum rocks
8. Canyon Diablo meteorite at The Franklin Institute
9. Rummager's galactic find turns out to be stolen meteorite
10. Long-lost meteorite comes home to Arizona

External links

• Mindat.org
• NASA research note