- D. Rajmon (2009).
8 Dec 01 Abstracts of Annual AGU meeeting: "Ewing structure: a possible abyssal impact crater" by Dallas Abbott -
"about 150km in diameter...about the age of the late/middle Miocene boundary, a prominent mass extinction event"
[see this New Zealand article - an ocean impact might have started off the Antarctic ice sheet due to the water released and the global cooling].
(GSA 2002: MICROFOSSIL MELTING BY THE EWING IMPACT)
Спутниковая фотография района кратера из Google Earth.