Piccaninny crater

Piccaninny "crater" refers to an impact structure (or astrobleme), the eroded remnant of a former impact crater, situated in northern Western Australia. It was named after Piccaninny Creek and lies within the Purnululu (Bungle Bungle) National Park.

The site is marked by a circular topographic feature on top of the flat-topped sandstone and conglomerate Bungle Bungle Range, clearly visible on remotely sensed images ( [http://maps.google.com/maps?q=Australia&ie=UTF8&om=1&z=12&ll=-17.421408,128.444939&spn=0.128409,0.342636&t=k Google Maps image] ). When first reported in 1983 after aerial observation, it was interpreted as either an impact structure or a cryptovolcanic featurecite journal | author=Beere GM | title=The Piccaninny structure – a cryptoexplosive feature in the Ord Basin, East Kimberly | journal=Geological Survey of Western Australia Record | volume=1983/6 | issue= | year=1983 | pages= | [http://geodocs.doir.wa.gov.au/document/documentSearchCriteria.do?from=topNav&cabinetId=1101 GSWA download search] ] . Later ground examination by E.M. and C.S. Shoemaker confirmed the presence of types of deformation indicative of an impact origincite journal | author=Shoemaker EM, Shoemaker CS | title=Impact structures of Western Australia | journal=Meteoritics | volume=20 | issue= | year=1985 | pages=754–756 [http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1985Metic..20R.754S&db_key=AST&data_type=HTML&format=&high=457bf7462f06111 PDF] ] .

The circular topographic feature is 7 km in diameter, although due to the amount of erosion the original crater may have been larger. It has been estimated that the present land surface is 1–2 km below the original crater floor ] . The impact event has not been dated, but must be younger than the Devonian age of the rocks in the area, but is clearly not recent because of the amount of erosion.

Cited references

External links

* [http://www.unb.ca/passc/ImpactDatabase/images/piccaninny.htm Piccaninny at Earth Impact Database]