Burckle Crater
Burckle Crater is an undersea feature hypothesized to be an impact crater by the Holocene Impact Working Group. They considered that it likely was formed by a very large scale and relatively recent (c. 2800-3000 BC) comet or meteorite impact event. It is estimated to be about 30 km (18 mi) in diameter,[1] hence about 25 times larger than Meteor Crater.
Its proposed location is to the east of Madagascar and west of Western Australia in the southern Indian ocean. Its position was determined in 2006 by the same group using evidence of its existence from prehistoric chevron dune formations in Australia and Madagascar that allowed them to triangulate its location. But the theory that these chevron dunes are due to tsunamis has been challenged by geologist Jody Bourgeois; using a computer model to simulate a tsunami, she believes the structures are more consistent with aeolian processes.[2][3]
Burckle Crater lies at 30°51′54″S 61°21′54″E / 30.865°S 61.365°ECoordinates: 30°51′54″S 61°21′54″E / 30.865°S 61.365°E in the Indian Ocean and is 12,500 feet (3,800 m) below the surface.
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[edit] Formation
Burckle Crater has not yet been dated by radiometric analysis of its sediments. The Holocene Impact Working Group think that it was created about 5,000 years ago (c. 2800–3000 BC) during the Holocene epoch when a comet impacted in the ocean, and that enormous megatsunamis created the dune formations which later allowed the crater to be pin-pointed.
- Unusual carbonate (CaCO3) crystals, translucent carbon spherules, fragments of mineral glass and native metals are reported in near the crater and associated with impact ejecta or hot water precipitates form crater ridges and vents.[4]
[edit] See also
[edit] Notes
- ^ "Meteor 'misfits' find proof in sea". http://www.signonsandiego.com/uniontrib/20061114/news_1n14meteors.html. Retrieved 2006-11-14.
- ^ "Past Tsunamis? Contrary To Recent Hypothesis, 'Chevrons' Are Not Evidence Of Megatsunamis". http://www.sciencedaily.com/releases/2009/04/090429091637.htm. Retrieved 2010-02-11.
- ^ Contrary to recent hypothesis, 'chevrons' are not evidence of megatsunamis
- ^ Odd CaCO3 from the Southwest Indian Ocean Near Burckle Crater Candidate: Impact Ejecta or Hydrothermal Precipitate? Abbott, D. H.; Gerard-Little, P.; Costa, S.; Breger, D. 40th Lunar and Planetary Science Conference, (Lunar and Planetary Science XL), held March 23–27, 2009 in The Woodlands, Texas, id.2243 [1]
[edit] External links
- Meteor 'misfits' find proof in sea Impacts more recent and often, researchers say
- Impact Craters as Sources of Megatsunami Generated Chevron Dunes
- Transcript of ABC interview with Ted Bryant
- Chevron-shaped Accumulations Along the Coastlines of Australia as Potential Tsunami Evidences? Science of Tsunami Hazards (2003), Vol. 21, #3, p 174.
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