Primary Dolomite Named by A.D. Baillie, 1951 Overlies Stonewall Formation | Underlies Ashern Formation | |
Thickness up to 335 metres (1,100 ft) Regions Western Canadian Sedimentary Basin, Williston Basin | ||
The Interlake Formation is a stratigraphical unit of Silurian age in the Western Canadian Sedimentary Basin.
Contents
It takes the name from the Interlake Region, Manitoba, and was first described in outcrop by A.D. Baillie in 1951.
Lithology
The Interlake Formation is composed of very finely crystalline dolomite. Oolitic, stromatolitic and biohermal interbeds also occur.
Distribution
The Interlake Formation is present throughout the Williston Basin. 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.
In the sub-surface it is given group status and contains, in different regions, the following subdivisions: