The Naiset Formation is a

stratigraphic unit A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features ( facies) that characteriz ...

Middle Cambrian Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (disambiguation) * Middle Brook (disambiguation) * Middle Creek (di ...

age. It is present on the western edge of the

Western Canada Sedimentary Basin The Western Canada 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 ba ...

in the southern

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

. It consists primarily of

siliciclastic Siliciclastic (or ''siliclastic'') rocks are clastic noncarbonate sedimentary rocks that are composed primarily of silicate minerals, such as quartz or clay minerals. Siliciclastic rock types include mudrock, sandstone Sandstone is a Clastic ...

rocks, and was named for Naiset Point near

Mount Assiniboine Mount Assiniboine, also known as Assiniboine Mountain, is a pyramidal peak mountain on the Great Divide, on the British Columbia/Alberta border in Canada. At , it is the highest peak in the Southern Continental Ranges of the Canadian Rockies. ...

by C.E. Deiss in 1940.

Thickness and lithology

The Naiset Formation ranges in thickness from about 100 to 212 m (328 to 695 ft), and was deposited in a deep-water marine environment. It consists primarily of thin-bedded

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

and

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeabil ...

. There are minor beds of

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

, conglomerate, and

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime (mineral), lime or being chalky. The term is used in a wide variety of Science, scientific disciplines. In zoology ''Calcare ...

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from ''shale'' by its lack of fissility.Blatt, H., and R.J. Tracy, 1996, ''Petrology.'' New York, New York, ...

at the base, and minor beds of oolitic and oncolitic

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

near the top.

Distribution and relationship to other units

The Naiset Formation is present in Rocky Mountains of southeastern British Columbia. It

unconformably An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

overlies the

Gog Group The Gog Group is a stratigraphic unit in the Western Canada Sedimentary Basin. It is present in the eastern and western main ranges of the Canadian Rockies in Alberta and British Columbia.Desjardins, P.R., Buatois, L.A., Pratt, B.E. and Mágano, ...

. It is overlain by the

Cathedral Formation The Cathedral Formation is a stratigraphic unit in the southern Canadian Rockies of Alberta and British Columbia, on the western edge of the Western Canada Sedimentary Basin. It is a thick sequence of carbonate rocks of Middle Cambrian age. It ...

, and the contact is gradational. Equivalent strata to the east of the Kicking Horse area are assigned to the

Mount Whyte Formation The Mount Whyte Formation is a stratigraphic unit that is present on the western edge of the Western Canada Sedimentary Basin in the southern Canadian Rockies and the adjacent southwestern Alberta plains. It was deposited during Middle Cambrian t ...

.Aitken, J.D. 1997. Stratigraphy of the Middle Cambrian platformal succession, southern Rocky Mountains. Geological Survey of Canada, Bulletin 398, 322 p.

References

{{Western Canadian Sedimentary Basin, Canadian Rockies=yes Western Canadian Sedimentary Basin Cambrian System of North America Cambrian British Columbia Geologic formations of British Columbia Shale formations of Canada Siltstone formations of Canada Sandstone formations of Canada Conglomerate formations of Canada Limestone formations of Canada