Type Geological formation Primary Slate | Country Canada Named for Fort Simpson | |
Underlies Jean Marie Member of the Redknife Formation Overlies Muskwa Member of the Horn River Formation Thickness up to 1,000 metres (3,280 ft) Region Alberta
British Columbia
Northwest Territories | ||
The Fort Simpson Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.
Contents
It takes the name from the settlement of Fort Simpson, and was first described in well Briggs Turkey Lake No. 1 (located south-east of Fort Simpson) by A.E. Cameron in 1918.
LithologyEdit
The Fort Simpson Formation is composed of grey shale and mudstone. The shale can be calcareous, silty or sandy.
DistributionEdit
The Fort Simpson Formation reaches a thickness of over 1,000 metres (3,280 ft) in the sub-surface of the Mackenzie River plain. It extends from northern Alberta to south-western northwest Territories and in north-eastern British Columbia (north of Peace River Arch).
Relationship to other unitsEdit
The Fort Simpson Formation is overlain by the Jean Marie Member of the Redknife Formation in its eastern reaches, and progressively by the Kakisa Formation, Trout River Formation or Tetcho Formation towards the west. It is conformably underlain by the Muskwa Member of the Horn River Formation.
It is replaced by the Besa River Formation in the Liard River area. It is equivalent to the Imperial Formation to the north, the Tathlina Formation, Twin Falls Formation and Hay River Formation to the east, and the Woodbend Group in Alberta.