Obolon' crater

Template:Short description Template:Infobox terrestrial impact site Obolon' crater (Template:Langx) is a Template:Convert diameter buried meteorite impact crater situated about Template:Convert southeast of Kyiv in Ukraine (Poltava Oblast).<ref name="Masaitis-1976">Template:Cite journal</ref><ref name="Valter-1977">Template:Cite journal</ref> The site has been drilled, which revealed the presence of shocked minerals and impact melt rock; the high chlorine content of the latter suggesting that the area was covered by shallow sea at the time of impact.<ref name="Gurov-1995">Gurov E.P., Gurova E.P. (1995). "Impact melt composition of the Obolon crater: chlorine as a possible indicator of the submarine crater formation". Meteoritics, v. 30, p 515. Abstract</ref> One estimate puts the age at 169 ± 7 million years (Middle Jurassic).<ref name="EIDb">Template:Cite Earth Impact DB</ref>

Hypothetical multiple impact event

Template:Main It has been suggested by Geophysicist David Rowley of the University of Chicago, working with John Spray of the University of New Brunswick and Simon Kelley of the Open University, that Obolon' may have been part of a hypothetical multiple impact event which also formed the Manicouagan impact structure in northern Quebec, Rochechouart impact structure in France, Saint Martin crater in Manitoba, and Red Wing crater in North Dakota.<ref name="Spray-1998">Spray, J.G., Kelley, S.P. and Rowley, D.B. (1998). "Evidence for a late Triassic multiple impact event on Earth". Nature, v. 392, pp. 171–173. Abstract</ref> All of the craters had previously been known and studied, but their paleoalignment had never before been demonstrated. Rowley has said that the likelihood that these craters could be aligned like this due to chance is nearly zero.<ref>Template:Cite news</ref> However, more recent work has found that the craters formed many millions of years apart, with the Saint Martin crater dating to 227.8 ± 1.1 Ma,<ref>Template:Cite journal</ref> while the Rochechouart structure formed 206.92 ± 0.20/0.32 Ma.<ref>Template:Cite journal</ref>

References

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