Burckle Crater

Burckle crater is an undersea feature about 29 kilometres (18 mi) in diameter,[2] in the southwestern Indian Ocean.

Burckle crater
Burckle crater
Location of Burckle Crater in the Indian Ocean
Impact crater/structure
ConfidenceProbable[1]
Hypothesized, contested
Diameter~29 km (18 mi)
Depth3,800 m (12,500 ft)
Age~5000 years (Holocene)
ExposedNo
DrilledNo
Bolide typeUnknown, possibly remains of a comet
Location
Coordinates30.865°S 61.365°E / -30.865; 61.365

The Russian Academy of Sciences lists the feature as a potential impact crater.[1] The Holocene Impact Working Group (HIWG)[3] propose that it was formed by a very large-scale and relatively recent (c. 3000–2800 BCE) meteorite impact event, possibly resulting from a comet.

Description

The feature is located east of Madagascar and west of Western Australia in the southern Indian ocean, adjacent to the SW Indian Ocean Ridge.[4] Its position was determined in 2006 by the Holocene Impact Working Group using prehistoric chevron dune formations in Australia and Madagascar. Based on the hypothesis these dunes were formed by a megatsunami resulting from an impact, the researchers were able to triangulate the location of Burckle crater. The hypothesis that these chevron dunes were caused by a megatsunami has been challenged by geologists Jody Bourgeois and R. Weiss in 2009. Using a computer model to simulate a tsunami, they argue that the structures are more consistent with aeolian processes.[5] The tsunami origin of these chevrons is also disputed by other Earth scientists.[6]

Burckle crater is located at 30.865°S 61.365°E / -30.865; 61.365 in the Indian Ocean and is 3,800 metres (12,500 ft) below the surface.

Formation

Burckle crater has not yet been dated by radiometric analysis of its sediments. The Holocene Impact Working Group researchers think that it formed about 5,000 years ago (c. 3000–2800 BCE), during the Holocene epoch. They consider the possibility that a comet, or the remains of one, hit the ocean floor, with subsequent megatsunamis creating the dune formations which allowed the crater to be pin-pointed.

Unusual calcite (CaCO3) crystals, translucent carbon spherules, fragments of basaltic glass and native metals (native iron and nickel) are reported near the crater and associated with impact ejecta or hot water precipitates. Seawater at the depth of the crater is undersaturated with respect to calcite and rapid burial would have been needed to preserve those crystals.[4]

See also

References
  1. Mikheeva, 2017
  2. Abbott et al., 2006
  3. "Holocene Impact Working Group (HIWG)". Retrieved 2020-01-26.
  4. Abbott et al., 2009
  5. Bourgeois & Weiss, 2009
  6. Pinter & Ishman, 2008, p.37

Bibliography
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