Interlake Formation

(Redirected from Interlake Group)

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

Interlake Formation (Group)
Stratigraphic range: Llandovery to Ludlow
TypeGeological formation
UnderliesAshern Formation
OverliesStonewall Formation
Thicknessup to 335 metres (1,100 ft)[1]
Lithology
Primarydolomite
Location
Coordinates51°27′13″N 98°45′37″W / 51.4535°N 98.7603°W / 51.4535; -98.7603 (Interlake Formation)
RegionWCSB
Williston Basin
Country Canada
 United States
Type section
Named forInterlake Region, Manitoba
Named byA.D. Baillie, 1951
Interlake Formation within Williston Basin stratigraphy

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

Lithology

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

Distribution

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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

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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:

  • Strathclair, Brandon and Cedar Lake Formations
  • Lower, Middle and Upper Interlake
  • Rupert, Hansen and Risser Formations
  • Strathclair, Fife Lake, Guernsey, Cedar Lake and Taylorton Formations

References

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  1. ^ a b c d Lexicon of Canadian Geologic Units. "Formation". Archived from the original on 2009-04-16. 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.