An asteroid crater that turned out to be an ore body
One of the oldest and largest impact structures on Earth, and the reason Ontario has a mining industry. An asteroid 10 to 15 kilometres across hit here 1.849 billion years ago, and the melt sheet that formed in the crater floor concentrated nickel, copper, gold, silver, platinum, palladium, rhodium, iridium and ruthenium into the rock around its edge. The basin is about 60 by 30 kilometres, eroded now into a valley that the people who live in it simply call The Valley. Sudbury grew on those ores and the smelters around it were once so hard on the ground that NASA sent Apollo astronauts to train on the blasted rock, a story the city has spent decades undoing with one of the largest regreening programmes anywhere.
Ontario, Canada
See it on the map
Other places on the map within a couple of hours of here.
