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Ancient Impact Crater Is Found in Canada

Scientists from Alberta Geological Survey and the University of Alberta have revealed an 8 km wide bowl-shaped impact crater near Bow City in southern Alberta.


This map shows the location (orange point) of the newly discovered impact crater near Bow City, southern Alberta. Image credit: Shaund / CC BY-SA 3.0.

The researchers from the University of Alberta and Alberta Geological Survey have discovered an impact crater near Bow City in southern Alberta, which looked like a bowl with width of eight kilometers. This new finding was released in the journal Meteoritics & Planetary Science.

According to Dr Douglas Schmitt of the University of Alberta and co-author of the study, the impact took place within the last 70 million years, and nearly 1.5 km of sediment had been eroded at that period. Therefore, it is quite difficult to confirm the actual date of the impact now.

As time and glaciers have buried and eroded much of the evidence, so it seems impossible at present to make sure whether this ring-like structure was caused by a meteorite impact. However, the seismic and geological evidence does demonstrate that it really occurred before.

Wearing away all but the roots of the crater, erosion has left a semicircular depression with a central peak. At the time when the impact crater was formed, it probably was 1.6 to 2.4 km deep.

Outcrop photographs

Outcrop photographs from the Bow City crater: top – panoramic view; bottom – a close-up showing thrust faults, outlined in red; geologist kneeling on outcrop, black arrow, for scale. Image credit: Paul Glombick et al.

As Wei Xie, a graduate student at the University of Alberta and a co-author on the study said, such magnificent impact could destroy everything for quite a distance. If it occurred today, Calgary (200 km to the northwest) would be totally fried and in every window would have been completely broken in Edmonton (500 km northwest).

Something of such magnitude could throw much debris in the air and thus had left with the world-wide consequences, which could have ramifications for decades.

Journal Reference: Paul Glombick et al. The Bow City structure, southern Alberta, Canada: The deep roots of a complex impact structure? Meteoritics & Planetary Science, published online April 29, 2014; doi: 10.1111/maps.12296