The Lynx Formation or Lynx Group is a stratigraphic unit of Late Cambrian ( Dresbachian) age in 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 ...

. It is present in the

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 originally described as the Lynx Formation by Charles Doolittle Walcott in 1913, based on and named for outcrops on the slopes of

Lynx Mountain Lynx Mountain is a mountain peak in the Canadian Rockies. It is located on the Continental Divide of the Americas, Continental Divide between the provinces of Alberta and British Columbia, in the Cushina Ridge of the Continental Ranges. It was nam ...

on the

continental divide A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not ...

east of Mount Robson. It was subdivided into five formations and elevated to group status by J.D. Aitken and R.G. Greggs in 1967.Aitken, J. D and Greggs, R G., 1967. Upper Cambrian formations, southern Rocky Mountains of Alberta, an interim report. Geological Survey of Canada, Paper 66-49. The name Lynx Formation continues to be used in areas where some or all of the subdivisions cannot be distinguished. All of the formations in the Lynx Group include fossil trilobites and some contain the stromatolite ''

Collenia ''Collenia'' is genus of fossil cyanobacteria that form a particular type of stromatolites. Description ''Collenia'' are stromatolites made up of convex layers flattened in the center, forming columnar colonies. The microorganisms involved were ...

''.

Lithology and deposition

The Lynx Group is composed alternating zones of carbonate rocks, most of which are dolomitic, and

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 ...

s. It was deposited in shallow marine environments along the western margin of the North American Craton during Late Cambrian time.Aitken, J.D. 1966. Middle Cambrian to Middle Ordovician cyclic sedimentation, southern Rocky Mountains of Alberta. Bulletin of Canadian Petroleum Geology, vol. 14, no. 6, p. 405-441. In many areas it is subdivided into the five formations listed below.Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. .

Subdivisions

Upper Lynx Group Lower Lynx Group

Distribution

The Lynx Group is present in the Canadian Rockies of Alberta and British Columbia. It is typically between 1068-1220 metres (3500-400 feet) thick in the front and main ranges. It extends as far north as the Monkman Pass area of British Columbia.

Relationship to other units

The Lynx Group overlies the Arctomys Formation and the contact is gradational. It is overlain by the

Survey Peak Formation The Survey Peak Formation is a stratigraphic unit of latest Cambrian to earliest Ordovician age. It is present on the western edge of the Western Canada Sedimentary Basin in the Canadian Rockies of Alberta and British Columbia. It was named for ...

and the contact is concordant but abrupt.

References

{{Western Canadian Sedimentary Basin, Canadian Rockies=yes Cambrian Alberta Stratigraphy of British Columbia Cambrian southern paleotropical deposits Cambrian System of North America Western Canadian Sedimentary Basin Geologic formations of Alberta Geologic formations of Canada