The Snake Indian Formation is a stratigraphic unit of Middle Cambrian age that 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 northern

Canadian Rockies The Canadian Rockies (french: Rocheuses canadiennes) or Canadian Rocky Mountains, comprising both the Alberta Rockies and the British Columbian Rockies, is the Canadian segment of the North American Rocky Mountains. It is the easternmost part ...

of Alberta and British Columbia. It was named for Snake Indian River in Jasper National Park by E.W. Montjoy and J.D. Aitken in 1978. The

type locality Type locality may refer to: * Type locality (biology) * Type locality (geology) See also * Local (disambiguation) * Locality (disambiguation) {{disambiguation ...

was established on

Chetamon Mountain Chetamon Mountain is a mountain summit located in Jasper National Park, in the De Smet Range of the Canadian Rockies in Alberta, Canada. The peak is situated north of the municipality of Jasper, in the Athabasca Valley and is visible from Hig ...

Lithology and deposition

The Snake Indian Formation was deposited in shallow marine environments along the western shoreline of the North American Craton during Middle Cambrian time. It is a thick sequence of

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 calcareous shale with interbeds of limestone 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 ...

. Mudcracks in the basal shales indicate that there were periods of subaerial exposure during the early stages of deposition.

Distribution and stratigraphic relationships

The Snake Indian Formation is present in the northern

of Alberta and British Columbia where it reaches thicknesses of up to about 610 metres (2000 ft). It unconformably overlies the Gog Group, and is conformably overlain by the Titkana Formation in the north and the

Eldon Formation The Eldon Formation is a stratigraphic unit that is present on the western edge of the Western Canada Sedimentary Basin in the southern Canadian Rockies of southwestern Alberta and southeastern British Columbia. It is a thick sequence of massi ...

in the south. It is equivalent to the

Mount Whyte Mount Whyte is a mountain in Alberta, Canada located in Banff National Park, near Lake Louise. The mountain can be seen from the Trans-Canada Highway, and offers views of the Valley of the Ten Peaks, including the Chateau Lake Louise. The mounta ...

, Cathedral, and Stephen Formations of the southern Canadian Rockies.

Paleontology

The Snake Indian Formation is fossiliferous and includes the remains of several

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

of Middle Cambrian trilobites, as well echinoderms, other marine invertebrates, and stromatolites.

References

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