Gog Group
Stratigraphic unit in the Western Canada Sedimentary Basin
From Wikipedia, the free encyclopedia
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][3] It was named by C.F. Deiss in 1940 after Gog Lake near its type locality at Wonder Pass near Mount Assiniboine.[1][4]
| Gog Group | |
|---|---|
| Stratigraphic range: | |
Trace fossils in a slab from the Gog Group. | |
| Type | Group |
| Sub-units | see text |
| Underlies | Mount Whyte Formation, Chancellor Group, Snake Indian Formation |
| Overlies | Miette Group |
| Thickness | up to 2,180 metres (7,150 ft) |
| Lithology | |
| Primary | Quartzose sandstone, quartzite, conglomerate |
| Other | Siltstone, mudstone, limestone, dolomite |
| Location | |
| Region |  Alberta  British Columbia |
| Country |  Canada |
| Type section | |
| Named by | C.F. Deiss, 1940[1] |
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).[2][3][5]
Stratigraphy
Subdivisions
The Gog Group is subdivided into the following formations:
Jasper area (north)
| Formation | Age | Lithology | Maximum Thickness | Reference |
|---|---|---|---|---|
| Hota Formation | late Early Cambrian | arenaceous limestone | 244 m (800 ft) | [2][4][6] |
| Mahato Formation | Early Cambrian | quartzose sandstone | 240 m (790 ft) | [2][4][6] |
| Mural Formation | Early Cambrian | limestone, dolomite, shale, quartzose sandstone | 545 m (1,790 ft) | [2][4][6] |
| McNaughton Formation | Early Cambrian | quartzose sandstone, quartzite, arkosic sandstone, conglomerate | 600 m (1,970 ft) | [2][4][6] |
| Jasper Formation | Early Cambrian | arkosic sandstone, quartzite, conglomerate, argillite | 500 m (1,640 ft) | [2][4][6] |
Kicking Horse Pass area (south)
| Formation | Age | Lithology | Max. Thickness | Reference |
|---|---|---|---|---|
| Peyto Formation | late Early Cambrian | limestone, dolomite | 125 m (410 ft) | [2][4][6] |
| St. Piran Formation | Early Cambrian | quartzose sandstone | 825 m (2,710 ft) | [2][4][6] |
| Lake Louise Formation | Early Cambrian | limestone, dolomite, shale, quartzose sandstone | [2][4][6] | |
| Fort Mountain Formation | Early Cambrian | quartzose sandstone, quartzite, arkosic sandstone, conglomerate | 510 m (1,670 ft) | [2][4][6] |
| Jasper Formation | Early Cambrian | arkosic sandstone, quartzite, conglomerate, argillite | 500 m (1,640 ft) | [2][4][6] |
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.[2][5] 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.[4]
.svg){kind=small}
