The Minnes Group, originally named the Minnes Formation, is a geologic unit of latest Jurassic to earliest Cretaceous 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 northern foothills of 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 ...

and the adjacent plains in northeastern British Columbia and west-central Alberta.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. . Its strata include natural gas reservoirs and minor coal deposits. Fossil dinosaur tracks have been described from one of its formations.Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.): The Dinosauria, 2nd ed., "Dinosaur distribution," pp. 517-607. Berkeley: University of California Press. 861 pp. .

Stratigraphy and lithology

The strata of the Minnes Group were originally described as the Minnes FormationZiegler, W.H. and Pocock, S.A.J. 1960. The Minnes Formation. In: Second Annual Field Trip Guidebook, Rock Lake, August 1960. Edmonton Geological Society, p. 43-71. which was revised to group status by D.F. Stott.Stott, D.F. 1998. Fernie Formation and Minnes Group (Jurassic and lowermost Cretaceous), northern Rocky Mountain foothills, Alberta and British Columbia. Geological Survey of Canada, Bulletin 516. Stott subdivided the group into four formations in the north as shown below. South of the Pine River the upper three formations are not readily divisible and those beds are included in the

Gorman Creek Formation The Gorman Creek Formation is a geologic formation of Early Cretaceous ( Valanginian) age in the Western Canada Sedimentary Basin that consists primarily of nonmarine sediments. It is present in the northern foothills of the Canadian Rockies an ...

. North: South:

Environment of deposition

The formations of the Minnes Group were deposited in marine and nonmarine environments within and adjacent to the Western Interior Seaway. Depositional settings ranged from shallow marine to shoreline, coastal plain, deltaic,

river channel In physical geography, a channel is a type of landform consisting of the outline of a path of relatively shallow and narrow body of water or of other fluids (e.g., lava), most commonly the confine of a river, river delta or strait. The word is ...

, floodplain, and

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

environments.

Paleontology and age

The age of the Minnes Group strata has been determined from their fossil fauna, primarily species of the

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

''Buchia''. Ammonites, plant fossils, palynomorphs, and microfossils have also been described from the Minnes Group. Dinosaur trackways are present on bedding surfaces in the Gorman Creek Formation of the Minnes Group near the Narraway River:

"More than 200 fossil footprints are preserved in at least 8 trackways... The majority of the footprints were made by small theropods, but the most dramatic trackway was made by a large biped whose feet were more than a half meter in length."Currie, P.J. 1991. Dinosaur footprints of western Canada. In: ''Dinosaur tracks and traces'', D.D. Gillette and M. Lockley (eds.), p. 294. Cambridge University Press, , 476 p.

Thickness and distribution

The Minnes Group can be seen in outcrops in the northern foothills of the

and is present beneath the adjacent plains from the Prophet River in northeastern British Columbia to the Berland River in west-central Alberta. It reaches a maximum thickness of in the foothills and thins eastward, reaching zero at its erosional edge.

Relationship to other units

The Minnes Group was deposited conformably over the marine

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 of the Fernie Formation, and was eroded prior to the deposition of the Cadomin Formation of the Bullhead Group which unconformably overlies it. The Minnes strata grade into those of the

Nikanassin Formation The Nikanassin Formation is a stratigraphic unit of Late Jurassic (Portlandian) to Early Cretaceous (Barremian) age.Poulton, T.P., Tittemore, J. and Dolby, G. 1990. Jurassic strata of northwestern (and west-central) Alberta and northeastern Britis ...

to the south in Alberta.

Economic Resources

The Minnes Group contains natural gas reservoirs in the subsurface of the Peace River Plains and Deep Basin areas, where it is sometimes reported as "Nikanassin Formation". Coal seams and carbonaceous

s, which may have been the source for much of the gas, are also present in the Minnes Group, but none of the coal deposits have been found to be economically mineable.