Interlake Formation

Interlake Formation (Group)
Stratigraphic range: Llandovery to Ludlow
Type Geological formation
Underlies Ashern Formation
Overlies Stonewall Formation
Thickness up to 335 metres (1,100 ft)[1]
Lithology
Primary Dolomite
Location
Coordinates 51°27′13″N 98°45′37″W / 51.4535°N 98.7603°WCoordinates: 51°27′13″N 98°45′37″W / 51.4535°N 98.7603°W
Region WCSB
Williston Basin
Country  Canada
 United States
Type section
Named for Interlake Region, Manitoba
Named by A.D. Baillie, 1951

The Interlake Formation is a stratigraphical unit of Silurian age in the Western Canadian Sedimentary Basin.

It takes the name from the Interlake Region, Manitoba, and was first described in outcrop by A.D. Baillie in 1951.[2]

Lithology

The Interlake Formation is composed of very finely crystalline dolomite. [1] Oolitic, stromatolitic and biohermal interbeds also occur.

Distribution

The Interlake Formation is present throughout the Williston Basin.[1] It reaches a maximum thickness of 335 metres (1,100 ft) in the subsurface of North Dakota, and is typically up to 110 metres (360 ft) thick in outcrop in its type locality.

Relationship to other units

The Interlake Formation is overlain with an angular unconformably by the Ashern Formation and sharply overlays the Stonewall Formation.[1]

In the sub-surface it is given group status and contains, in different regions, the following subdivisions:

References

  1. ↑ 1.0 1.1 1.2 1.3 Lexicon of Canadian Geologic Units. "Formation". Retrieved 2010-02-01.
  2. ↑ Ballie, A.D., 1951 Silurian geology of the Interlake area, Manitoba. Manitoba Department of Mines and Natural Resources, Mines Branch, Pub. 50-1.