The Boulder Creek 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 exp ...

in northeastern

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

. It was named for a tributary to Commotion Creek in the

Pine Pass The Pine Pass, in the Hart Ranges of the Northern Rockies of British Columbia, connects the Peace Country of the province's Northeastern Interior. Highway 97 and the Canadian National Railway (CNR) (formerly BC Rail network) traverse this mount ...

area by E.M. Spieker in 1921. At one time considered to be a member of the

Commotion Formation The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithology T ...

, it was elevated to formation status by D.F. Stott in 1982.Stott, D.F. 1982. Lower Cretaceous Fort St. John Group and Upper Cretaceous Dunvegan Formation in the foothills and plains of Alberta, British Columbia, District of Mackenzie and Yukon Territory. Geological Survey of Canada, Bulletin 328, 124 p. The formation was deposited in shallow marine to shoreline environments during the

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/ Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± ...

stage of the

Early Cretaceous The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pr ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

. It preserves

ammonite 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 cuttle ...

s, plant remains, and other

fossils 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 ...

.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. .

Lithology and Environment of Deposition

The Boulder Creek Formation records the transition from

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

conditions, represented by the

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, especia ...

s of the underlying Hulcross Formation, to continental environments, with a return to marine conditions marked by the shales of the overlying Hasler Formation. Near shore and shoreface deposits consist of massive, fine grained, well sorted

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 silicates ...

s, and massive,

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is o ...

-cemented conglomerates of

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 ...

and

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 ...

pebbles in a matrix of coarse sand.

Delta plain Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D (NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may also r ...

and floodplain deposits consist of interbedded

argillaceous Clay minerals are hydrous aluminium phyllosilicates (e.g. kaolin, Al2 Si2 O5( OH)4), sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations found on or near some planetary surfaces. Clay mineral ...

sandstones, carbonaceous shales and thin

coal Coal is a combustible black or brownish-black sedimentary rock, formed as stratum, rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen ...

beds.Stott, D.F. 1963. Stratigraphy of the Lower Cretaceous Fort St. John Group and Gething and Cadomin Formations, foothills of Alberta and British Columbia. Geological Survey of Canada, Paper 62-39, 48 p.

Thickness and Distribution

Outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficia ...

s of the Boulder Creek Formation can be seen along the

Peace River The Peace River (french: links=no, rivière de la Paix) is a river in Canada that originates in the Rocky Mountains of northern British Columbia and flows to the northeast through northern Alberta. The Peace River joins the Athabasca River ...

eastward from

Hudson's Hope Hudson's Hope is a district municipality in northeastern British Columbia, Canada, in the Peace River Regional District. Having been first settled along the Peace River in 1805, it is the third-oldest European-Canadian community in the province, a ...

, and it is present in the subsurface in the Peace River plains to the east. It is well exposed in the 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 par ...

between the Peace and

Wapiti River The Wapiti River is a river in eastern British Columbia and western Alberta, Canada. It is a major tributary of the Smoky River, located in the southern area of the Peace River Basin. Wapiti is named after the Cree word for elk (''waapiti''). ...

s, where it reaches thicknesses of up to . It can be traced southward through the foothills almost as far the

Kakwa River The Kakwa River is a tributary of the Smoky River in western Alberta, Canada. The river is named for ''Kakwa'', the Cree word for porcupine. Porcupines are abundant in Kakwa Provincial Park and Protected Area. Tourism along the river revolves ar ...

near the British Columbia-Alberta boundary.

Relationship to Other Units

The Boulder Creek Formation is part of the Fort St. John Group. Originally described as a member of the

, the Boulder Creek was elevated to formational status along with the other members of the Commotion by D.F. Stott in 1982, who proposed that the term 'Commotion Formation' be abandoned. The Boulder Creek Formation conformably overlies the marine shales of the Hulcross Formation, and is conformably overlain by the marine shales of the Hasler Formation. It is equivalent to the

Cadotte Member The Peace River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Peace River, and was first described on the banks of the river, downstream from the Smoky River confluen ...

, and possibly the

Paddy Member The Peace River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Peace River, and was first described on the banks of the river, downstream from the Smoky River conflu ...

, of the

Peace River Formation The Peace River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Peace River, and was first described on the banks of the river, downstream from the Smoky River confluen ...

of the Peace River plains. It correlates with the middle part of the

Buckinghorse Formation The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithol ...

in the Muskwa River area, and with the Tussock Member of the

Scatter Formation The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881. Lithology ...

in the

Liard River The Liard River of the North American boreal forest flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows southeast through British C ...

area. Equivalent beds may be present above the coal-bearing strata near

Grande Cache Grande Cache is a hamlet in west-central Alberta, Canada within and administered by the Municipal District of Greenview No. 16. It is located on Highway 40 approximately northwest of Hinton and west of Edmonton. Grande Cache overlooks the Sm ...

References

* {{Authority control Cretaceous System of North America Geologic formations of British Columbia Western Canadian Sedimentary Basin Albian Stage Cretaceous British Columbia Sandstone formations of Canada Geology of the Rocky Mountains Conglomerate formations Shale formations Siltstone formations

Lithology and Environment of Deposition

Thickness and Distribution

Relationship to Other Units

See also

References