AGE

by: Charles O’Dale

*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 (megayears) Dating method Morphological type Notes
Charity Shoal, Lake Ontario ~1  ? PROPOSED Simple underwater Lake Ontario Negative magnetic anomaly
Charron Lake, Manitoba >4.5  ? PROPOSED Simple Negative magnetic anomaly
Eclipse Lake, Labrador small ~1.5  ? IMPROBABLE Simple – Possible flat-floored Two possible structures
Eclipse Lake, Labrador large ~6  ? IMPROBABLE Complex  Two possible structures
Kakiattukallak Lake, Quebec 3 – 6  ? PROPOSED Simple Possible Multiple Impact?
Lac de Courval, Quebec ~1.6  ? PROPOSED Simple Circular lake
Lac La Moinerie (north), Quebec 1.8  ? IMPROBABLE Simple Circular structure
Merewether, Labrador 0.19812 (largest of three) 0.00087? Sediment depth POSSIBLE Simple Possible methane explosion
Whitecourt, Alberta 0.036 0.00113 14C dating of charcoal CONFIRMED Simple Medium octahedrite (Om) IIIAB
Barringer, Arizona 1.19 0.049 ± 0.003 Radioactive decay CONFIRMED Simple Jointed
Plevna/Tomvale Structure, ONTARIO ~0.01 <.012  Created in glacial remains IMPROBABLE Simple
Bloody Creek, Nova Scotia 0.350 X 0.420 ~0.012 Geological dating PROBABLE Simple  Elliptical basin
Jocko, Ontario >0.2 <0.012 Created in glacial remains IMPROBABLE Simple Ground Exploration Video
Corossol Structure, Gulf of St. Lawrence 4.0 ~0.012 14C age shells in sediments PROPOSED Complex Underwater Gulf St. Lawrence
Carolina Bays, NC Various ~0.0129-0.14 Not firmly quantified PROPOSED Simple Younger Drias black mat
Pingualuit, Quebec 3.44 1.4 ± 0.1 Ar40-Ar39 melt rock CONFIRMED Simple Overflight of Pingualuit Crater
Chesapeake, Virginia ~85 35.5 ± .3 Geological dating CONFIRMED Complex Coesite in suevites
Mistastin, Labrador 28 36.6 ± 2 Ar40-Ar39 melt rock CONFIRMED Central peak basin Maskelynite
Wanapitei, Ontario 3 to 7.5 37.2 ± 1.2 K/Ar, Ar40-Ar39 melt rock CONFIRMED Simple – Possible flat-floored? L or LL chondrite projectile
Victoria Island, California 5.5 37-49 Drilling data PROPOSED Simple Geological dating
Montagnais, off Nova Scotia 45 50.5 ± 0.76 K-Ar, 40Ar/39Ar and Rb-Sr CONFIRMED Complex Submerged south of Nova Scotia, Canada
Parry Peninsula, NWT 160 <65 Post Cretaceous IMPROBABLE Complex
Eagle Butte, Alberta 10 <65 Geological dating CONFIRMED Complex Shatter-coned Cretaceous rocks
Chicxulub, Yucatan, Mexico 150 66.043 ±0.011 40Ar/39Ar CONFIRMED Peak ring basin Cretaceous-Paleogene
Dumas, Saskatchewan 4 <70 Geological dating PROBABLE Simple Seismic and borehole data
Manson, Iowa ~35 73.8 Ar40-Ar39 melt rock CONFIRMED Central peak No surface evidence
Lac du Bonnet, Manitoba ~3.8  75 Sedimentary cover depth PROPOSED Simple Circular magnetic anomaly
Purple Springs, Alberta 6 <75 Geological dating PROBABLE Complex  No surface expression
Bow City, Alberta 6 <75 Geological dating PROBABLE Complex  No surface expression
Maple Creek, Saskatchewan 6 <75 Geological & radioactive decay dating CONFIRMED Complex Disrupts Late Cretaceous rocks
Howell Creek, BC ~10 90-97 Between syenites and Cardium sands IMPROBABLE Simple Circular geologic formation
Kentland, Indiana ~13 >97 Geological dating CONFIRMED Complex Quarry
Deep Bay, Saskatchewan 9.5 99 ± 4 Geological dating CONFIRMED Simple Flat-floored Cretaceous sediments
West Hawk, Manitoba 2.44 100 Geological dating CONFIRMED Simple No reliable age
Carswell, Alberta 39 115 ± 10 40Ar/39Ar Peak ring Multi-ring impact?
Miami Florida Crater/Structure ~1 ~140 After Florida Plateau deposition IMPROBABLE Complex? Underwater off Miami
Upheaval Dome, Utah 5.5 <170 Geological dating CONFIRMED Complex Younger than the Jurassic Navajo Sandstone
Cloud Creek, Wyoming 7 ~190 ± 30 Geological dating CONFIRMED Complex Chronostratigraphic
Viewfield, Saskatchewan 2.5 190 ± 20 Geological dating CONFIRMED Simple Jurassic-Triasic post-impact deposit
Hartney, Manitoba 6 <190 ± 20 Geological dating PROBABLE Complex? Structurally uplifted centre
Red Wing, North Dakota 9.1 200 ± 25 Geological dating CONFIRMED Complex? Stratigraphy
Manicouagan, Quebec 100 214 ± 1 Radioactive decay CONFIRMED Peak ring basin Zircon/melt rock dating
St. Martin, Manitoba ~40 227.8 ±0.9 Ar40-Ar39 melt rock CONFIRMED Complex Dauphin River diversion?
Gow, Saskatchewan 5 <250 Radioactive decay CONFIRMED Complex Smallest currently known complex
Decaturville Structure, Missouri 5.5 260-323 Geological dating CONFIRMED Complex
Des Plaines, Illinois 8 <280 Geological dating CONFIRMED Complex
Clearwater West, Quebec 32 290 ± 20 K-Ar melt rocks CONFIRMED Peak ring
Ile Rouleau, Quebec 4 <300 Geological dating CONFIRMED Complex Age based on stratigraphy
Charlevoix, Quebec 54 342 ± 15 K-Ar CONFIRMED Peak ring Elevated Earthquake Zone
Panther Mountain, New York state 10 ~375 Geological dating PROBABLE Complex Inverted relief
Nicholson Lake, North West Territories 12.5 389 ± 6.7 Pb/U CONFIRMED Complex The large island within the lake is the eroded central peak
Elbow, Alberta 8 395 ± 25 Geological dating CONFIRMED Complex Brecciated Devonian strata
Brent, Ontario 3.8 396 ± 20 K-Ar studies on the coarsely crystalline melt rocks CONFIRMED Simple Overflight of Brent Crater
Lac La Moinerie, Quebec 8 400 ± 50 Ar40-Ar39 melt rock CONFIRMED Complex
Franktown structure, Ontario ~2 >400 Ordovician sediment cover PROPOSED Simple Circular depression
Rock Elm, Wisconsin 6 420–440 Geological dating CONFIRMED Complex Youngest exposed rocks
Lac Couture, Quebec 8 425 ± 25 Ar40-Ar39 melt rock CONFIRMED Complex Submerged central peak
High Rock Lake, Manitoba ~5 435 ± 10 Geological dating PROBABLE Complex
Slate Islands, Lake Superior 32 436 Ma ± 3 Ar40-Ar39 melt rock CONFIRMED Complex Pseudotachylite dating
Bear Swamp, New York 3.5 ~444 Geological dating PROBABLE Simple No surface expression
Pilot Lake, North West Territories 6 445 ± 2 K-Ar, 40Ar/39Ar and Rb-Sr CONFIRMED Complex Dating based on one sample
Calvin, Michigan 7.24 450 ± 10 Geological dating CONFIRMED Complex
Clearwater East, Quebec 26 ~460–470 Rb-Sr melt rocks CONFIRMED Complex Chondrite-type
James River, Alberta 4.8 <480 Geological dating PROBABLE Complex No surface expression
Newporte, North Dakota 3.2 <500 Geological biostratigraphic dating CONFIRMED Simple No surface evidence
Presqu’ile, Quebec 24 <500 Geological dating CONFIRMED Complex High level erosion
Can-Am, Lake Huron 100 ~500 Geological dating PROBABLE Complex Underwater in Lake Huron
Glover Bluff, Wisconsin 8 <500 Geological dating CONFIRMED Complex
Touchwood Hills, Saskatchewan >200 >541 Post Williston Basin deposit IMPROBABLE Multi-ring Basin?
Holleford, Ontario 2.35 550 ±100 Geological dating CONFIRMED Simple Overflight of Holleford Crater
Beaverhead, Montana/Idaho ~100 ~600 K-Ar, 40Ar/39Ar and Rb-Sr CONFIRMED Peak ring Allochthonous
Skeleton Lake, Ontario 3.5 ~800 Geological dating PROBABLE Simple
Sudbury, Ontario 250 1852 +4/-3 U-Pb zircon CONFIRMED Multi ring? Sudbury Distal Ejecta
Hudson Bay Arc >450  ? IMPROBABLE Multi ring basin? No impact metamorphism found</t