The Debolt Formation is a stratigraphical unit of

Meramecian The Meramecian or Maramec stage is a sequence of Mississippian rocks in the Mississippi River Valley. It is named for the Meramec River in Missouri. Members Included are the St. Louis Limestone, Ste. Genevieve Limestone, Salem Limestone, and t ...

age Age or AGE may refer to: Time and its effects * Age, the amount of time someone or something has been alive or 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 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 takes the name from the hamlet of Debolt, Alberta, and was first described in the Amerada Crown GF23-11 well near Debolt by G. Macauley in 1958.

Lithology

The Debolt Formation is commonly subdivided into a lower and upper unit. Lower Debolt rocks are bioclastic

limestones Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when th ...

deposited on a stable carbonate ramp. These lower Debolt rocks are rarely dolomitized and therefore have little porosity or commercial use. Upper Debolt sedimentation is characterized by a number of shallowing upwards facies. At the base of the Upper Debolt is distal and medial ramp argillaceous limestone facies with limited laminations and thin bedding. These argillaceous facies rarely contain clean carbonate interbeds in the medial ramp setting, predominantly

wackestone Under the Dunham classification (Dunham, 1962Dunham, R.J., 1962. Classification of carbonate rocks according to depositional texture. In: W.E. Ham (Ed.), Classification of Carbonate Rocks. American Association of Petroleum Geologists Memoir. Amer ...

s and

packstone Under the Dunham classification (Dunham, 1962Dunham, R.J. (1962) Classification of carbonate rocks according to depositional texture. In: Classification of Carbonate Rocks (Ed. W.E. Ham), Am. Assoc. Pet. Geol. Mem., 1, 108–121.) system of limesto ...

s. These facies are followed by a capping proximal ramp/shoal facies with abundant skeletal packstones and grainstones.

Distribution

The Debolt Formation is present in the sub-surface in the

Peace River Country The Peace River Country (or Peace Country; french: Région de la Rivière-de-la-paix) is an aspen parkland region centring on the Peace River in Canada. It extends from northwestern Alberta to the Rocky Mountains in northeastern British Columbia, ...

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 cent ...

and north-eastern

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, ...

. The formation is thick close to 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 straight-line distance from the northernmost part of western Canada, to New Mexico in ...

, and thins out northward and eastward. It has a thickness of at its type locality near Debolt, Alberta.

Relationship to other units

The Debolt Formation is the upper most component of the Rundle Group. It rests conformably on the Shunda Formation, resting on

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 ...

and

carbonate A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...

s. It is overlain conformably by the Golata Formation of the

Stoddart Group The Stoddart Group is a stratigraphical unit of Mississippian to Early Pennsylvanian age in the Western Canadian Sedimentary Basin. It takes the name from the Stoddart Creek, a creek that flows into Charlie Lake north of Fort St. John, and w ...

in the west, and the upper contact becomes

unconformable 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 ...

with gradually newer formations to the east and north (

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 Paleoz ...

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), 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 J ...

and

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...

beds).

References

{{Western Canadian Sedimentary Basin, Liard_River=yes, Northwest_Plains=yes Geologic formations of Alberta Stratigraphy of British Columbia Western Canadian Sedimentary Basin Mississippian Series Carboniferous Alberta Carboniferous British Columbia Carboniferous System of North America