The Sulphur Mountain Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

Early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

Middle Triassic In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided in chronostratigraphy. The Middle Triassic spans the time between Ma an ...

age. It is present on the western edge of 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 sedimen ...

in the foothills and

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 straight-line distance from the northernmost part of western Canada, to New Mexico ...

of western

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest T ...

and northeastern

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...

. It includes marine

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s from the time shortly after the Permian-Triassic extinction event.Noad, Jon, 2017. Field trip to examine Montney Formation analogs: Exposures of the Sulphur Mountain Formation around Canmore and Kananaskis, western Alberta, Canada. In: J.C.C. Hseih, ed., Geologic field trips of the Canadian Rockies: 2017 meeting of the GSA Rocky Mountain Section, Geological Society of America, Field Guide 48, p. 137-152; doi: 10.1130/2017.0048(05). The Sulphur Mountain Formation was first described as a

member Member may refer to: * Military jury, referred to as "Members" in military jargon * Element (mathematics), an object that belongs to a mathematical set * In object-oriented programming, a member of a class ** Field (computer science), entries in ...

of the Spray River Formation by P.S. Warren in 1945, who named it for Sulphur Mountain in

Banff National Park Banff National Park is Canada's oldest national park, established in 1885 as Rocky Mountains Park. Located in Alberta's Rocky Mountains, west of Calgary, Banff encompasses of mountainous terrain, with many glaciers and ice fields, dense co ...

. It was later raised to formation status. Its

type section A stratotype or type section in geology is the physical location or outcrop of a particular reference exposure of a stratigraphic sequence or stratigraphic boundary. If the stratigraphic unit is layered, it is called a stratotype, whereas the stan ...

is located in the

Spray River The Spray River is a tributary of the Bow River in western Alberta, Canada. The Spray River originates in the southern area of Banff National Park in the Canadian Rockies and soon enters the Spray Lakes Reservoir formed in 1951 after the const ...

gorge at the southern end of Sulphur Mountain.

Lithology and stratigraphy

The Sulphur Mountain Formation was deposited on the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

along the western margin of the

North American craton North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is ...

,Paull, R.K., Paull, R.A. and Laudon, T.S. 1997. Conodont biostratigraphy of the Lower Triassic Mackenzie Dolomite Lentil, Sulphur Mountain Formation in the Cadomin area, Alberta. Bulletin of Canadian Petroleum Geology, vol. 45, no. 4, p. 708-714. which at that time was part of the

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which leav ...

Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

. It consists primarily of grey to rusty brown

dolomitic Dolomite () is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite. An alternative name sometimes used for the dolomitic ...

and

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an ad ...

quartz Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical f ...

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, ...

, with interbeds of silty

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

, silty

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology.' ...

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, especiall ...

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...

aceous shale, and minor fine-grained

Cross-bedding In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The origina ...

and

ripple marks In geology, ripple marks are sedimentary structures (i.e., bedforms of the lower flow regime) and indicate agitation by water ( current or waves) or wind. Defining ripple cross-laminae and asymmetric ripples * ''Current ripple marks'', ''u ...

are common in its strata. The Sulphur Mountain Formation is subdivided into the following members:

Paleontology

The Sulphur Mountain Formation has yielded fossils that provide a record of Triassic life shortly after the Permian-Triassic extinction event. Remains of

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

marine reptiles Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semiaquatic life in a marine environment. The earliest marine reptile mesosaurus (not to be confused with mosasaurus), arose in the Permian period during th ...

and fish have been found in its strata, as well as

conodont Conodonts ( Greek ''kōnos'', " cone", + ''odont'', "tooth") are an extinct group of agnathan (jawless) vertebrates resembling eels, classified in the class Conodonta. For many years, they were known only from their tooth-like oral elements, whi ...

s; shells of

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan 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 end, w ...

s and

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

s; teeth of '' Hybodus''; shells of

ammonoids Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

; the

ichnofossil A trace fossil, also known as an ichnofossil (; from el, ἴχνος ''ikhnos'' "trace, track"), is a fossil record of biological activity but not the preserved remains of the plant or animal itself. Trace fossils contrast with body fossils, ...

s '' Thalassinoides'', '' Planolites'', and '' Zoophycos''; and traces of microbial mats. Fish found at the formation include: Triassic marine vertebrate apex predators

Triassic marine vertebrate apex predators

Remains of the following marine reptiles have been found in the Sulphur Mountain Formation:

Distribution and thickness

The Sulphur Mountain Formation is present in the foothills and eastern front ranges 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 ...

from the

Canada–United States border The border between Canada and the United States is the longest international border in the world. The terrestrial boundary (including boundaries in the Great Lakes, Atlantic, and Pacific coasts) is long. The land border has two sections: ...

in southwestern Alberta to the Pine River area of northeastern British Columbia. It ranges in thickness from a minimum of south of the

Bow River The Bow River is a river in Alberta, Canada. It begins within the Canadian Rocky Mountains and winds through the Alberta foothills onto the prairies, where it meets the Oldman River, the two then forming the South Saskatchewan River. These w ...

in Alberta to a maximum of in northeastern British Columbia.

Relationship to other units

The Sulphur Mountain Formation is laterally equivalent to Montney, Doig, and Halfway Formations in the subsurface beneath the plains of Alberta and northeastern British Columbia, and to the

Toad Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands. A distinction between frogs and toads is not made in scient ...

, Grayling, and Liard Formations in the foothills of northeastern British Columbia. It

unconformably An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval ...

overlies the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleo ...

Ishbel Group or, in some areas, the Mississippian

Rundle Group The Rundle Group is a stratigraphical unit of Mississippian age in the Western Canadian Sedimentary Basin. It takes the name from Mount Rundle (itself taking the name from Robert Terrill Rundle), and was first described in outcrops at the northe ...

. It is conformably overlain by the Whitehorse Formation in the southern part of its extent and by the laterally equivalent Charlie Lake Formation in the north. In areas where those formations were removed by

erosion 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 d ...

it is unconformably overlain by the

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

Fernie Formation The Fernie Formation is a Stratigraphy, stratigraphic unit of Jurassic Geochronology, age. It is present in the western part of the Western Canadian Sedimentary Basin, Western Canada Sedimentary Basin in western Alberta and northeastern British Col ...

Economic resources

Petroleum and natural gas

Outcrops of the Sulphur Mountain Formation provide an analog for studying the

Montney Formation The Montney Formation is a stratigraphical unit of Lower Triassic age in the Western Canadian Sedimentary Basin in British Columbia and Alberta. It takes the name from the hamlet of Montney and was first described in Texaco's Buick Creek No. 7 ...

, a laterally equivalent formation that is a major producer of

shale oil Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock ( kerogen) into synthetic oil and gas. The resulting ...

and

shale gas Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some ...

in the subsurface to the east.

Building stone

The flaggy siltstones of the Vega Member have been

quarried A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environ ...

building stone Building material is material used for construction. Many naturally occurring substances, such as clay, rocks, sand, wood, and even twigs and leaves, have been used to construct buildings. Apart from naturally occurring materials, many man- ...

in the Canmore area. This rock, which is commonly called "Rundle Rock" or "Rundle Stone", has been used extensively to face buildings and construct floors, patios, and fireplaces in the

Jasper Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases,Kostov, R. I. 2010. Review on the mineralogical systematics of jasper and related rocks. – Archaeometry Workshop, 7, 3, 209-213PDF/ref ...

, Banff, and

Calgary Calgary ( ) is the largest city in the western Canadian province of Alberta and the largest metro area of the three Prairie Provinces. As of 2021, the city proper had a population of 1,306,784 and a metropolitan population of 1,481,806, maki ...

areas.

Phosphate

Although localized deposits of granular

phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosph ...

are present at the base of the Whistler Member, they lie within

Jasper National Park Jasper National Park is a national park in Alberta, Canada. It is the largest national park within Alberta's Rocky Mountains spanning . It was established as a national park in 1930 and declared a UNESCO World Heritage Site in 1984. Its locatio ...

and are protected from development.

References

{{Western Canadian Sedimentary Basin, Canadian Rockies=yes Geologic formations of Canada Western Canadian Sedimentary Basin Stratigraphy of Alberta Stratigraphy of British Columbia Triassic Alberta Triassic British Columbia Triassic System of North America Lower Triassic Series Middle Triassic Series Building stone