| Isachsen Formation | |
|---|---|
| Stratigraphic range: Aptian ~ | |
| Type | Formation |
| Sub-units | Walker Island Member |
| Overlies | Christopher Formation |
| Location | |
| Coordinates | 76°06′N109°00′W / 76.1°N 109.0°W |
| Approximate paleocoordinates | 71°30′N20°30′W / 71.5°N 20.5°W |
| Region | Northwest Territories, Nunavut |
| Country | Canada |
The Isachsen Formation is a geologic formation in the Northwest Territories and Nunavut. It preserves fossils of Polycotylidae indet., dating back to the Aptian stage of the Cretaceous period.