Dalgaranga crater

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Dalgaranga crater is a small meteorite impact crater located on Dalgaranga pastoral station 75 km west of Mount Magnet (or north of Yalgoo) in Western Australia. It is only 24 m in diameter and 3 m deep, making it Australia's smallest impact crater (with exception of the smallest members of the Henbury crater field).^[1] Though reputedly discovered much earlier, it was first reported in the scientific literature in 1938.^[2] The bedrock at the site is weathered Archaean granite of the Yilgarn Craton. The discovery of fragments of mesosiderite stony-iron meteorite around the crater confirms an impact origin,^[3] making this crater unique as the only one known to have been produced by a mesosiderite projectile. Asymmetries in the crater structure and the ejecta blanket imply that the projectile impacted at low angle from the south-southeast.^[4] The age is not accurately constrained by must be young because it is so well preserved for its small size, and the meteorite fragments have not weathered away; some authors suggest an age of as young as 3000 years. ^[5]

[edit] References

1. ^ Bevan A.W.R. 1996. Australian crater-forming meteorites. AGSO Journal of Australian Geology & Geophysics 16, 421–429.
2. ^ Simpson E.S. 1938. Some new and little known meteorites found in Western Australia. Mineralogical Magazine 25, 157–171.
3. ^ Nininger H.H. & Huss G.I. 1960. The unique meteorite crater at Dalgaranga, Western Australia. Mineralogical Magazine 32, 619–639.
4. ^ Shoemaker E.M., Macdonald F. A. & Shoemaker C.S. 2005. Geology of five small Australian impact craters. Australian Journal of Earth Sciences 52, 529–544. Abstract
5. ^ Shoemaker E.M. & Shoemaker C.S. 1988. Impact structures of Australia (1987). Lunar and Planetary Science Conference XIX, 1079–1080. Abstract

[edit] External links

[1] Dalgaranga at Earth Impact Database, retrieved 23 March 2007.

Coordinates: 27°38′S, 117°17′E