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.[2]
The Tetcho Formation is composed of fine grained limestone with shale partings, silty at the base. [1]
The Tetcho Formation reaches a maximum thickness of 75 metres (250 ft).[1] 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.[1]
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.