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.
- Proposed: some structural, geological and/or geophysical evidence
exists but the impact origin is still highly uncertain for the lack of data.
| Name | Diameter (km) | Age (million years) | Dating method | Morphological type | Notes |
|---|---|---|---|---|---|
| Carolina Bays, NC | Various | ~0.0129-0.14 | Not firmly quantified | Simple | Younger Drias black mat |
| Charity Shoal, Lake Ontario | ~1 | ? | Simple underwater Lake Ontario | Negative magnetic anomaly | |
| Charron Lake, Manitoba | >4.5 | ? | Simple | Negative magnetic anomaly | |
| Corossol Structure, Gulf of St. Lawrence | 4.0 | ~0.012 | 14C age shells in sediments | Complex | Underwater Gulf St. Lawrence |
| Dumas, Saskatchewan | 4.0 | <70 | Geological dating | Simple | Seismic and borehole data |
| Franktown Structure, Ontario | ~2 | >400 | Ordovician sediment cover | Simple | Circular depression |
| Harris Beach Structure, Oregon | 0.137 | >10,000 years | Not firmly quantified | Simple | Underwater research |
| Hotchkiss Structure, Alberta | 3.9 | 120-330 | Dated unconformity | Complex | Seismic research |
| Kakiattukallak Lake, Quebec | 3 – 6 | ? | Simple | Possible Multiple Impact? | |
| Lac de Courval, Quebec | ~1.6 | ? | Simple | Circular lake | |
| Lac du Bonnet, Manitoba | ~3.8 | 75 | Sedimentary cover depth | Simple | Circular magnetic anomaly |
| Stac Fada, Scotland | 40 | 1177 ± 5 | 40Ar/39Ar dating of authigenic K-feldspars | Complex | Buried beneath the Moine Thrust complex |
| Upheaval Dome, Utah | 2.57 | <170 | Geological dating | Complex | Younger than the Jurassic Navajo Sandstone |
| Victoria Island, California | 5.5 | 37-49 | Drilling data | Simple | Geological dating |
