Type Locality:

Wonder Pass, near Mount Assiniboine, on northeast spur of the Towers, southern Banff National Park (Sec. 21, Twp. 22, Rge. 12W5M).

Distribution:

The Gog Group thickens northwestward from 375 m (1,235 ft) at Mount Assiniboine to 490 m (1,620 ft) near Mount Temple Ski Lodge, and to between 1,200 and 1,500 m (4,000 and 5,000 ft) in the Sunwapta Pass and Jasper areas (Mountjoy, 1962; Mountjoy and Aitken, 1963). Northwestward from Jasper the Gog thickens to between 1,500 and 1,820 m (5,000 and 6,000 ft), then thins towards Pine Pass (Slind and Perkins, 1966; Campbell, Mountjoy and Young, 1972). Generally the Gog is thickest in the western main ranges, ranging from 1,350 m (4,430 ft) in the Solitude Range (Meilliez, 1973) to 2,180 m (7,200 ft) near McBride, British Columbia.

Lithology:

Dominated by quartzose sandstone, in places subarkosic near the base, tending to become quartzite in relatively deformed areas; the Fort Mountain Member (south) and McNaughton Formation (north), at the base and the St. Piran Member (south) and Mahto Formation (north) at the top are predominantly quartzite. The Lake Louise Shale and Holmes River Member of the McNaughton are predominantly mudstone with thin interbeds of siltstone and sandstone; the Mural Formation is mainly limestone or dolomite with lesser amounts of shale and sandstone.

Relationship:

The Gog Group is generally absent in thrust sheets of the front ranges and foothills, hence its relationship to the Basal Sandstone unit of the Alberta subsurface is unknown. Westward it is correlative with the upper part of the Hamill Group and the Badshot Formation of the Purcell Mountains, and the upper part of the Caribou Group of the Caribou Mountains. It is conformable above the Miette Group in most western localities, becoming unconformable eastward. Overlain conformably by carbonate rocks of the Mount Whyte (south) and Hota-Adolphus (north) formations, or banded, grey limy shales equivalent to the Chancellor Formation in some western localities.

History:

The name Gog Formation was applied originally to 375 m (1,235 ft) of quartzose sandstone near Mount Assiniboine by Deiss (1940). Mountjoy (1962) raised the unit to group status in the Jasper Park area, where it includes, in ascending order the McNaughton, Mural and Mahto formations. Hughes (1955) proposed new formational names for Lower Cambrian strata in the northern Banff Park area, but these names were found unnecessary during subsequent geological mapping (Price and Mountjoy, 1966). The Gog Formation is now used to include the Fort Mountain, Lake Louise and St. Piran members in the Lake Louise area, established originally by Walcott as formations.

References:

Deiss, Charles Frederich, 1940. Lower and Middle Cambrian stratigraphy of southwestern Alberta and southeastern British Columbia; The Geological Society of America (GSA), GSA Bulletin, vol. 51, no. 5 (May), pp. 731-794.

Hughes, R.D., 1955. Geology of portions of Sunwapta and Southesk map-areas, Jasper National Park, Alberta, Canada. Alberta Soc. Petrol. Geol., Guidebook, 5th Ann. Field Conf., p. 69-116.

Meilliez, E., 1973. Etude geolog gue du secteur meridional de Soltude Range (Rocheuses), Colombie Britannique. Ph.D. thesis, Univ. des Sciences et Techniques de Lille.

Mountjoy, E.W. and Aitken, J.D., 1963. Early Cambrian and late Precambrian paleocurrents, Banff and Jasper National Parks. Bull. Can. Petrol. Geol., vol. 11, pp. 161-168.

Mountjoy, E.W., 1962. Mount Robson map-area (southeast), Rocky Mountains of Alberta and British Columbia; Geological Survey of Canada, Paper 61-31.

Slind, O.L. and Perkins, G.D., 1966. Lower Paleozoic and Proterozoic sediments of the Rocky Mountains between Jasper, Alberta and Pine River, British Columbia; Canadian Society of Petroleum Geologists (CSPG), Bulletin of Canadian Petroleum Geology, vol. 14, no. 4 (December), pp. 442-468.