Kotcho Formation

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Kotcho Formation
Stratigraphic range: Middle Famennian
Type Geological formation
Underlies Exshaw Formation
Overlies Tetcho Formation
Thicknessup to 210.9 metres (690 ft) [1]
Lithology
Primary Shale
Other Limestone
Location
Coordinates 60°09′18″N121°18′16″W / 60.15500°N 121.30444°W / 60.15500; -121.30444 (Kotcho Formation)
Region British Columbia, Northwest Territories
Country Canada
Type section
Named for Kotcho Lake
Named byH.R. Belyea, D.J. McLaren, 1962

The Kotcho Formation is a stratigraphic unit of middle Famennian age in the Western Canadian Sedimentary Basin.

Contents

It takes the name from Kotcho Lake and was first described in the Imperial Island River No. 1 by H.R. Belyea and D.J. McLaren in 1962. [2]

Lithology

The Kotcho Formation is composed of green-grey shale, locally bituminous, with thin argillaceous limestone beds or lenses. [1]

Distribution

The Kotcho Formation reaches a maximum thickness of 210.9 metres (690 ft). [1] It is up to 30 metres (100 ft) thick in the Fort Nelson area, and thins down southwards, disappearing completely on the northern flank of the Peace River Arch.

Relationship to other units

The Kotcho Formation is overlain by the Exshaw Formation and conformably overlays the Tetcho Formation. [1]

To the east, it grades into the upper Wabamun Group carbonate, and to the south-west into the Palliser Formation. To the east it is replaced by the Besa River Formation shale.

References

  1. 1 2 3 4 Lexicon of Canadian Geologic Units. "Kotcho Formation" . Retrieved 2009-03-01.
  2. Belyea, H.R. and McLaren, D.J., 1962. Upper Devonian formations, southern pan of Northwest Territories, northeastern British Columbia and northwestern Alberta. Geological Survey of Canada, Paper 61-29.