The Borsato Formation is a stratigraphic unit of

Late Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, wher ...

(

Frasnian The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage. Major reef-building was under way during th ...

) age. It is present on the western edge of the

Western Canada Sedimentary Basin The Western Canadian Sedimentary Basin (WCSB) underlies of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. This vast sedimentary ...

in the southern Rocky Mountains of Alberta and British Columbia. It consists of

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

and was named for Mount Borsato in the

Flathead Range The Flathead Range is a mountain range of the Northern Rocky Mountains located southeast of Whitefish, Montana in the Great Bear Wilderness, part of the Bob Marshall Wilderness Complex. It is west of the Rocky Mountain Front, east of the Swan Ra ...

near North Kootenay Pass by R.A. Price in 1965. The formation is fossiliferous and includes remains of stromatoporoids and

tabulate corals Tabulata, commonly known as tabulate corals, are an order of extinct forms of coral. They are almost always colonial, forming colonies of individual hexagonal cells known as corallites defined by a skeleton of calcite, similar in appearance to ...

Thickness and lithology

The Borsato Formation is thick. It was deposited in a reefal environment and consists of dark coloured, medium- to thick- bedded, medium- to coarse-crystalline dolomite.

Distribution and relationship to other units

The Borsato Formation is present in the Rocky Mountains of southeastern British Columbia and southwestern Alberta, west of the Lewis Thrust Fault and south of about 49° 45". It overlies the Hollebeke Formation, and is overlain by the Mount Hawk Formation or the Peechee Member of the Southesk Formation, depending on the location.

References

{{Western Canadian Sedimentary Basin, Canadian Rockies=yes Geologic formations of Alberta Geologic formations of British Columbia Devonian Alberta Devonian British Columbia Frasnian Stage Dolomite formations Reef deposits Western Canadian Sedimentary Basin Fossiliferous stratigraphic units of North America Paleontology in Alberta