Nahanni Formation

The Nahanni Formation is a Middle Devonian, Givetian-age stratigraphic unit in the Western Canadian Sedimentary Basin, named for Nahanni Butte, where C.O. Hage first described it in 1945. Composed of dolomitic limestone, it extends from the Franklin Mountains into northeastern British Columbia. It is about 137 metres thick at Nahanni Butte, though around 60 metres is more typical. The formation preserves marine fossils such as corals, brachiopods, and trilobites, and in the Mackenzie River Valley it also serves as a producing gas reservoir. In the regional sequence, it rests transitionally above the Headless Formation and is overlain by the Fort Simpson Formation in the west and the Horn River Formation in the east.

Northwest Territories · Canada