CONFIRMED IMPACT CRATERS/STRUCTURES*

*In my articles I use the term crater to define a circular impact depression and the term structure to define an impact crater that is severely altered by erosion.

Name Diameter (km) Age (million years) Morphological type Date Related Extinction Notes
Barringer, Arizona 1.19 0.049 ± 0.003 Simple1 Jointed
Beaverhead, Montana/Idaho ~100 ~600 Peak ring1
Brent, Ontario 3.8 396 ± 20 Simple1 Late Devonian Overflight of Brent Crater
Carswell, Alberta 39 115 ± 10 Peak ring1
Charlevoix, Quebec 54 342 ± 15 Peak ring1 Late Devonian Elevated Earthquake Zone
Chicxulub, Yucatan, Mexico 150 66.043 ±0.011 Peak ring basin5 CRETACEOUS-PALEOGENE
Clearwater East, Quebec 26 ~460–470 Central peak1 Ordovician Possible Multiple Impact?
Clearwater West, Quebec 32 290 ± 20 Peak ring1 Possible Multiple Impact?
Cloud Creek, Wyoming 7 ~190 +/- 30 Ma Complex2 Triassic-Jurassic Dated chronostratigraphicly
Deep Bay, Saskatchewan 9.5 99 ± 4 Flat floored1 Geological dating
Des Plaines, Illinois 8 <280 Complex2 Geological dating
Eagle Butte, Alberta 10 <65 Central peak2 Geological dating
Elbow, Alberta 8 395 ± 25 Complex2 Late Devonian Geological dating
Glover Bluff, Wisconsin 8 <500 Complex2 Geological dating
Gow, Saskatchewan 5 <250 Complex 2 Permian–Triassic (P–Tr) extinction event
Holleford, Ontario 2.35 550 ±100 Simple1 Overflight of Holleford Crater
Ile Rouleau, Quebec 4 <300 Central peak3 Geological dating
Lac Couture, Quebec 8 425 ± 25 Central peak1 Ordovician
Lac La Moinerie, Quebec 8 400 ± 50 Central peak1 Late Devonian
Manicouagan, Quebec 100 214 ± 1 Peak ring basin5 Late Triassic
Manson, Iowa ~35 73.8 Central peak1
Maple Creek, Saskatchewan 6 <75 Central peak5 Geological dating
Mistastin, Labrador 28 36.6 ± 2 Central peak basin6
Montagnais, off Nova Scotia 45 50.5 ± 0.76 Central peak1
Newporte, North Dakota 3.2 <500 Simple2 Geological biostratigraphic dating
Pilot Lake, North West Territories 6 445 ± 2 Complex2 Ordovician
Pingualuit, Quebec 3.44 1.4 ± 0.1 Simple1 Overflight of Pingualuit Crater
Presqu’ile, Quebec 24 <500 Central peak1 Geological dating
Red Wing, North Dakota 9.1 200 ± 25 Probable Complex8 Late Triassic/Triassic-Jurassic
Rock Elm, Wisconsin 6 420–440 Central peak7 Ordovician
Slate Islands, Lake Superior 32 436 Ma ± 3 Central peak1 Ordovician
St. Martin, Manitoba ~40 227.8 ±0.9 Central peak1 Late Triassic
Sudbury, Ontario 250 1852 +4/-3 Multi ring?1 Sudbury Distal Ejecta
Upheaval Dome, Utah 5.5 <170 Central peak4 Geological dating
Viewfield, Saskatchewan 2.5 190 ± 20 Simple2 Triassic-Jurassic Geological dating
Wanapitei, Ontario 3 to 7.5 37.2 ± 1.2 Flat floored?1
West Hawk, Manitoba 2.44 100 Simple1 Geological dating
Whitecourt, Alberta 0.036 0.00113 Simple1

1 Dence, Michael R. Structural evidence from shock metamorphism in simple and complex impact craters: Linking observations to theory. Meteoritics & Planetary Science 39. Nr 2, 267-286 (2004).

2 Grieve R.A.F., Impact structures in Canada, Geological Association of Canada, 2006.

3 Spray J.G. et al. A marine magnetic study of the Ile Rouleau impact structure, Lake Mistassini, Quebec Canada. Meteoritics, 70th Annual Meeting (2007).

4 Eugene M. Shoemaker, Bryan J. Kriens, Ken E. Herkenhop, GEOLOGY OF THE UPHEAVAL DOME IMPACT STRUCTURE, SOUTHEAST UTAH. Journal of Geophysical Research–Planets, April 16, 1998.

5 Grieve R.A.F. and Head J.W. The Manicouagan impact structure: An analysis of its original dimensions and form. Journal of Geophysical Research 88:A807-A818 (1983).

6 French, B.M. Traces of Catastrophe, Lunar and Planetary Institute, 1998

7 Cordua, W. S., “The Rock Elm Structure, Pierce County, Wisconsin, a possible cryptoexplosion structure”, Geology, vol. 13, p. 372-374. 1985.

8Donofrio, Richard R., IMPACT CRATERS: IMPLICATIONS FOR BASEMENT HYDROCARBON PRODUCTION. Journal of Petroleum Geology, 3, 3, pp. 279-302, 1981.