The Naiset Formation is a
stratigraphic unit of
Middle Cambrian age. It is present on the western edge of the
Western Canada Sedimentary Basin in the southern
Rocky Mountains of
British Columbia. It consists primarily of
siliciclastic rocks, and was named for
Naiset Point
Naiset Point is a mountain summit located in Mount Assiniboine Provincial Park, in the Canadian Rockies of British Columbia, Canada. The mountain is situated southeast of Lake Magog, and at the end of the ridge extending north from Terrapin Mou ...
near
Mount Assiniboine
Mount Assiniboine, also known as Assiniboine Mountain, is a pyramidal peak mountain located 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 Ro ...
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 minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...
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.Blatt ''et al.'' 1980, p ...
. There are minor beds of
sandstone,
conglomerate
Conglomerate or conglomeration may refer to:
* Conglomerate (company)
* Conglomerate (geology)
* Conglomerate (mathematics)
In popular culture:
* The Conglomerate (American group), a production crew and musical group founded by Busta Rhymes
** Co ...
, and
calcareous 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 (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...
at the base, and minor beds of
oolitic and
oncolitic limestone near the top.
Distribution and relationship to other units
The Naiset Formation is present in Rocky Mountains of southeastern British Columbia. It
unconformably overlies the
Gog Group. 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 w ...
, 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 ...
.
[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
Siltstone formations
Sandstone formations of Canada
Conglomerate formations
Limestone formations of Canada