[Calvin Locke]

Well, not when they "first" encountered it, but after a mining attempt for iron failed, the volcanic activity theory prevailed for scores of years until astronomer Carolyn Shoemaker prodded her geologist husband, Eugene, to take a look at it.

I believe Canada's largest nickel mine is the remains of cosmic collision.

[SuziQ]

One of the most interesting finds of an impact site was by Shoemaker realizing that a German church they saw on a trip once, was built from stone that included Shocked Quartz, which could only have been created as a result of a meteorite impact. Turns out, the entire valley was the crater, now called the Ries Crater, and the mountains ringing it were the sides of the crater. No one had ever even considered that, simply because it was just so large, and no one had ever gone looking for evidence of a meteorite impact.

[gleeaikin]

The Canadian nickel mine may be in an area called the Sudbury. My family and I were driving from New York state into Canada and then across to enter into western Michigan. The look of the entire Sudbury area was very strange. I was told it had been struck by a meteor, but the ground for miles was spoiled by mining and chemical exploitation and pollution.