| Tetcho Formation | |
| Type: | Geological formation |
| Period: | Famennian |
| Prilithology: | Limestone |
| Otherlithology: | Shale |
| Namedfor: | Tetcho Lake |
| Namedby: | H.R. Belyea, D.J. McLaren, 1962 |
| Region: | |
| Country: |  Canada |
| Coordinates: | 60.155°N -121.3044°W |
| Underlies: | Kotcho Formation |
| Overlies: | Trout River Formation Fort Simpson Formation |
| Thickness: | up to 75m (246feet) |
The Tetcho Formation is a stratigraphical unit of Famennian age in the Western Canadian Sedimentary Basin.
It takes the name from Tetcho Lake, and was first described in the Imperial Island River No. 1 well (located south of Trout Lake by H.R. Belyea and D.J. McLaren in 1962.[1]
The Tetcho Formation is composed of fine grained limestone with shale partings, silty at the base.[2]
The Tetcho Formation reaches a maximum thickness of 75m (246feet).[2] it occurs in the sub-surface in north-eastern British Columbia and southern Northwest Territories.
The Tetcho Formation is conformably overlain by the Kotcho Formation and conformably overlays the Trout River Formation and Fort Simpson Formation.[2]
It is equivalent to the lower Wabamun Group in Alberta and to parts of the Besa River Formation in the Liard area of British Columbia.