The Rundle Group is a

stratigraphic unit A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features ( facies) that characteriz ...

of Mississippian

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone has been alive or something has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older ...

in the

Western Canadian Sedimentary Basin The Western Canada 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 b ...

. It takes the name from Mount Rundle (itself taking the name from Robert Terrill Rundle), and was first described in outcrops at the northern side of the mountain in

Banff National Park Banff National Park is Canada, Canada's first National Parks of Canada, national park, established in 1885 as Rocky Mountains Park. Located in Alberta's Rockies, Alberta's Rocky Mountains, west of Calgary, Banff encompasses of mountainous ter ...

by R.J.W. Douglas in 1953.Douglas, R.J.W., 1953b. Carboniferous stratigraphy in the southern Foothills of Alberta; Alberta Soc. Petrol. Geol., 3rd Ann. Field Conf. Guidebook, p. 66–88.

Lithology

The Rundle Group consists of massive

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

interbedded with dark argillaceous limestone.

Chert Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...

nodules are observed in the shaley beds, and

crinoid Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are ...

s and

brachiopod Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear e ...

s are observed in the clean massive beds. Dolimitization is observed in the Elkton Member of the Turner Valley Formation.

Distribution

The Rundle Group reaches a maximum thickness of at Tunnel Mountain. It thins out toward east and north and is completely

eroded Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is disti ...

or absent in east central and only the lower part occurs in

southern Alberta Southern Alberta is a region located in the Canadian province of Alberta. In 2016, the region's population was approximately 291,112. The primary cities are Lethbridge and Medicine Hat. The region is known mostly for agricultural production, but o ...

Relationship to other units

The Rundle Group is disconformably overlain by the Rocky Mountain Formation in the front ranges of the

Canadian Rockies The Canadian Rockies () 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 the Canadian Cordillera, w ...

and by the Fernie Formation in the foothills and by

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

beds in the prairies. It conformably overlies the Banff Formation. The Rundle Group can be correlated with the Mission Canyon Formation in southern Saskatchewan, northeastern Montana and North Dakota.

Subdivisions

The Rundle Group includes the Mount Head Formation and Livingstone Formation in the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

; by the Turner Valley Formation, Shunda Formation and Pekisko Formation in the foothills and plains. It is equivalent to the Debolt Formation and Prophet Formation in north-eastern British Columbia and west-

northern Alberta Northern Alberta is a geographic region located in the Canadian province of Alberta. An informally defined cultural region, the boundaries of Northern Alberta are not fixed. Under some schemes, the region encompasses everything north of the ce ...

. Debolt, Shunda and Pekisko Formations are staked in the

Fort Nelson A fortification (also called a fort, fortress, fastness, or stronghold) is a military construction designed for the defense of territories in warfare, and is used to establish rule in a region during peacetime. The term is derived from Lati ...

area.

Canadian Rockies The Canadian Rockies () 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 the Canadian Cordillera, w ...

Foothills and plains

Deep basin

References

{{WCSB, Northwest_Plains=yes, South AB=yes, Canadian Rockies=yes Geologic groups of Alberta Geologic groups of British Columbia Carboniferous Alberta Carboniferous British Columbia Limestone groups of Canada Chert groups