Sudbury Basin - Largest meteor crater in Canada
The Sudbury Basin, also known as Sudbury Structure, is the second largest known impact crater or astrobleme on Earth, and a major geologic structure in Ontario, Canada.
The basin is located on the Canadian Shield in the city of Greater Sudbury, Ontario. The former municipalities of Rayside-Balfour and Valley East lie within the Sudbury Basin, which is referred to locally as "The Valley". The urban core of the former city of Sudbury lies on the southern outskirts of the Basin.
Formation and structure
The Sudbury Basin is 60 km long, 30 km wide and 15 km deep. It was created as the result of a 10 km cometary impact that occurred 1.85 billion years ago in the Paleoproterozoic era. Its present size is believed to be a smaller portion of a 250 km round crater that the bolide originally created. Subsequent geological processes have deformed the crater into the current smaller oval shape. Sudbury Basin would then be the second largest crater on earth, after the 300 km Vredefort crater in South Africa, and larger than the 170 km Chicxulub crater in Yucatán, Mexico which is linked to the extinction of the dinosaurs.Source: http://www.thelivingmoon.com/43ancients/02files/Earth_Images