Gog Group Explained

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.^[2] It was named by C.F. Deiss in 1940 after Gog Lake near its type locality at Wonder Pass near Mount Assiniboine.^[3]

Lithology and environment of deposition

The Gog Group consists primarily of thick deposits of cross-bedded quartzose sandstone and quartzite, with minor quartzitic conglomerate and sub-arkosic sandstone. It also includes mudstone, siltstone, limestone and dolomite formations. The Gog sediments are thought to have been deposited in shallow marine environments on the subsiding margin of the North American craton (Laurentia).^{[4] [5]}

Stratigraphy

Subdivisions

The Gog Group is subdivided into the following formations:

Jasper area (north)

		Lithology	Maximum Thickness	Reference
Hota Formation			244-1NaN-1	[6]
Mahato Formation			240-1NaN-1
Mural Formation			545-1NaN-1
McNaughton Formation			600-1NaN-1
Jasper Formation			500-1NaN-1

Kicking Horse Pass area (south)

		Lithology	Max. Thickness	Reference
Peyto Formation			125-1NaN-1
St. Piran Formation			825-1NaN-1
Lake Louise Formation
Fort Mountain Formation			510-1NaN-1
Jasper Formation			500-1NaN-1

Paleontology

Trace fossils such as Skolithos, Cruziana, Diplocraterion, Chondrites, Planolites, Rusophycus and others are abundant in the Gog Group sediments, and Early Cambrian trilobites of the genus Olenellus are found in the Peyto Formation limestones at the top of the Group. Small archaeocyathid bioherms have been reported from the base of the Mahato Formation, and archaeocyathids, salterellids, primitive brachiopods and echinoderms have been reported from the Mural Formation.

See also

• List of fossiliferous stratigraphic units in Alberta
• Big Rock (glacial erratic)
• Foothills Erratics Train

Notes and References

1. Deiss, C.F. 1940. Lower and Middle Cambrian stratigraphy of southwestern Alberta and southeastern British Columbia. Geological Society of America Bulletin, vol. 57, p. 731-794.
2. Desjardins, P.R., Buatois, L.A., Pratt, B.E. and Mágano, M.G. 2010. Stratigraphy and sedimentary environments of the Lower Cambrian Gog Group in the southern Rocky Mountains of western Canada. Bulletin of Canadian Petroleum Geology, vol. 58, p. 403-439.
3. 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. .
4. Hein, H. J., and M. E. McMechan (1994). Chapter 6 Proterozoic and Lower Cambrian Strata of the Western Canada Sedimentary Basin ; in Geological Atlas of the Western Canada Sedimentary Basin, G.D. Mossop and I. Shetsen (comp.). Alberta, Canada: Canadian Society of Petroleum Geologists and Alberta Research Council.[Last accessed 28 June 2016].
5. Hein, F.J. and Arnott, R.W. 1983. Precambrian Miette conglomerates, Lower Cambrian Gog quartzites and modern braided outwash deposits, Kicking Horse Pass area. Canadian Society of Petroleum Geologists Field Trip Guidebook, 1983, 46 p.
6. Web site: Alberta Table of Formations; Alberta Energy Regulator. Alberta Geological Survey, 2013.. 2016-06-20.