The Interlake Formation is a

stratigraphical Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostrati ...

unit of

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

age in the Western Canadian Sedimentary Basin. It takes the name from the Interlake Region in Manitoba, and was first described in outcrop by A.D. Baillie in 1951.Ballie, A.D., 1951 Silurian geology of the Interlake area, Manitoba. Manitoba Department of Mines and Natural Resources, Mines Branch, Pub. 50-1.

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 in the subsurface of North Dakota, and is typically up to 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 The Stonewall Formation is a Stratigraphy, stratigraphical unit of Late Ordovician to Early Silurian Geochronology, age in the Western Canadian Sedimentary Basin. It takes the name from Stonewall, Manitoba, and was first described in the Stonewa ...

. 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

{{Western Canadian Sedimentary Basin, Saskatchewan=yes Silurian Alberta Silurian Manitoba Silurian Saskatchewan Western Canadian Sedimentary Basin