Dalgaranga crater


Dalgaranga crater

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][2] Though reputedly discovered much earlier, it was first reported in the scientific literature in 1938.[3] 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,[4] 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.[5] The age is not accurately constrained but 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. [6]

References

  1. ^ "Dalgaranga". Earth Impact Database. University of New Brunswick. http://www.passc.net/EarthImpactDatabase/dalgaranga.html. Retrieved 2009-08-19. 
  2. ^ Bevan A.W.R. 1996. Australian crater-forming meteorites. AGSO Journal of Australian Geology & Geophysics 16, 421–429.
  3. ^ Simpson E.S. 1938. Some new and little known meteorites found in Western Australia. Mineralogical Magazine 25, 157–171.
  4. ^ Nininger H.H. & Huss G.I. 1960. The unique meteorite crater at Dalgaranga, Western Australia. Mineralogical Magazine 32, 619–639.
  5. ^ 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
  6. ^ Shoemaker E.M. & Shoemaker C.S. 1988. Impact structures of Australia (1987). Lunar and Planetary Science Conference XIX, 1079–1080. Abstract

Coordinates: 27°38′6″S 117°17′20″E / 27.635°S 117.28889°E / -27.635; 117.28889