by: Charles O’Dale
CIRCULAR FORMATION
| Name | Diameter KM | Notes |
|---|---|---|
| Alsever Lake, Ontario | ~4 | Brent analog |
| Brackett Lake, NWT | 8.67 | |
| Canoe Lake area, Ontario | 0.150 | |
| Colter, Oklahoma, USA | 0.150 | |
| Hanson Lake, Saskatchewan | 0.550 | |
| La Loche, Saskatchewan | 0.150 | |
| North of Lake Superior, Ontario | <0.050 | |
| Otter Lake, Quebec | <0.050 | |
| Prince Edward Point, Ontario | 0.400 | |
| Quorn Lake, Ontario | 1.73 | |
| Riding Mountains, Manitoba | 1.73 | |
| South of Great Bear Lake, NWT | 0.240 |
MAN MADE STRUCTURE
| Name | Diameter Metres | Notes |
|---|---|---|
| Lac De Gras, NWT | 825 X 720 | Diamonds |
| Marmora, Ontario | 850 X 415 | Iron |
| Tatlock, Ontario | 350 X 300 | Calcium carbonate |
| Timmins, Ontario | 875 X 800 | Gold |
STRATIFIED CIRCULAR FEATURE
| Name | Diameter KM |
|---|---|
| McGruther & Dell Lakes, Ontario | ~2.3 |
| Mecatina Lake, Quebec | ~6.4 |
SYENITE/PLUTON
| Name | Diameter KM | Notes |
|---|---|---|
| Callander Bay – Ontaro | 4 | ~577 ma geological |
| Croker Island Complex, Ontario | 10 | 1510 ±50 ma – Rb-Sr |
| Lake Skootamatta, Ontario | ~5.5 | Presqu’ile analog |
| Manitou Islands Complex, Ontario | 4 | ~577 ma geological |
| Mount Moriah Structure – Ontaro | ~5.5 | |
| Sainte-Véronique Structure – Quebec | 9 |
VOLCANIC CRATER
| Name | Diameter KM | Erupted | Notes |
|---|---|---|---|
| Crater Lake, Oregon | 9.6 | 7,700 (± 150) years | |
| Diamond Head, Hawaii | 1.17 | ~300,000 years | Fort Rae analog |
| Etna, Italy | area of 1,190 km2 | Currently | |
| Fort Rae, NWT | 2.8 | 541 to 252 ma | Diamond Head analog |
| Hicks Dome, Illinois | 5.5 | 270 (± 2) Ma – Cryptovolcanic | |
| Kilauea, Hawai’i | 1.16 | ~280,000 years | |
| Mount St. Helens, Washington | 2.23 | 1980 eruption | |
| Pacaya Crater, Guatemala | 0.21 | 0-23,000 years | |
| Panum Crater, California | 0.776 | <700 years – Mono Lake | |
| Santorini, Greece | 12 to 18 | ~3,600 years ago | Possible shatter cone |




