Oct. 25, 2006 — Lessons being learned from massive impact craters on Earth and beyond could help settle the question of whether such a crater exists in the eastern Hudson Bay.
Any map of Hudson Bay shows a suspicious, semi-circular coastline in northwestern Quebec. The Belcher Islands, just to the west of that curved coast, might be the remnants of a central peak — a common feature of impact craters on the moon and elsewhere.
What's more, past work has suggested that when recent rifting of the land near the crater site is accounted for, even more of the circle — about two-thirds — would be visible.
But while the idea of a 280-mile-round (450-km diameter) Hudson Bay crater has been around for 40 years, there has been no conclusive evidence of its existence.
If such a crater exists, it would be the largest known on Earth. The current record-holder is the 112-mile-wide Chicxulub Crater on Mexico's Yucatan Peninsula.
Until recently, no one has been quite sure what evidence would point to the existence of a crater so big, or so old, in this case at least half a billion years.
Any telltale minerals for such a big, old crater would be scarce or at least hard to find, explained geologist Michael Brookfield of Guelph University. What's more, the region's remote location and harsh climate make it a difficult research site.
But recent studies of impact craters on Earth and other planets are helping zero in on what to look for in Hudson Bay — so much so that he visited the area on a recent "on the cheap" research excursion.
Brookfield summarized the trip and his ideas for further exploration in a poster presented this week at the Geological Society of America meeting in Philadelphia.
