The rush of water through Drake Passage isolated Antarctica's climate from the rest of the globe, and fostered the growth of a large ice sheet which today still acts as a ‘thermostat' for Earth's climate, Glikson explained.
But the cooling caused by the impacts may have gotten things started, chilling the planet down enough to get ice formation started. The study is featured in the new issue of the Australian Journal of Earth Sciences.
While the dome, named Mount Ashmore, is around 50 kilometers in diameter, the entire impact crater could be much larger, said Dr. Glikson. Determining the actual size of the impact crater - and thus the event itself - will go a long way toward pinning down how dramatic and widespread the effects of the impact were.
Impact structures come in all shapes and sizes. The Australian impact is a big one. Smaller impacts only create an impact crater. Meteor crater in Arizona is a good example.
But during larger impacts, something different may happen: an impact dome or central peak rises up in the middle of the crater.