The Pictou Group is a stratigraphical unit of

Late Carboniferous Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

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 ...

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 Cumberland Basin of

Atlantic Canada Atlantic Canada, also called the Atlantic provinces (french: provinces de l'Atlantique), is the region of Eastern Canada comprising the provinces located on the Atlantic coast, excluding Quebec. The four provinces are New Brunswick, Newfoundlan ...

. It takes the name from

Pictou County, Nova Scotia Pictou County is a county in the province of Nova Scotia, Canada. It was established in 1835, and was formerly a part of Halifax County from 1759 to 1835. It had a population of 43,657 people in 2021, a decline of 0.2 percent from 2016. Furtherm ...

, and was first described in outcrop along the

West Branch River John West Branch River John is a community in the Canadian province of Nova Scotia, located in Pictou County Pictou County is a county in the province of Nova Scotia, Canada. It was established in 1835, and was formerly a part of Halifax County ...

by W.A. Bell in 1926.Bell, W.A., 1926. Carboniferous formations of Northumberland Strait, Nova Scotia:

Geological Survey of Canada The Geological Survey of Canada (GSC; french: Commission géologique du Canada (CGC)) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canada's natural resources and protecting the en ...

, Summary Report for 1924, Part C, pp. 142C-180C.

Lithology

The Pictou Group is composed of red beds

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) ...

, mostly sub arkose and sublith

arenite Arenite ( Latin: ''arena'', "sand") is a sedimentary clastic rock with sand grain size between 0.0625 mm (0.00246 in) and 2 mm (0.08 in) and contain less than 15% matrix. The related adjective is ''arenaceous''. The equivalen ...

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, p ...

is also present, also rarely conglomerate and

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

. Fossil remains include bivalves, ostracods, fish, amphibians and reptile fragments, as well as rare plant fragments.

Distribution

The Pictou Group is present throughout the Maritimes Basin, thickness vary from in Pictou County to in

Prince Edward Island Prince Edward Island (PEI; ) is one of the thirteen Provinces and territories of Canada, provinces and territories of Canada. It is the smallest province in terms of land area and population, but the most densely populated. The island has seve ...

Relationship to other units

The Pictou Group contains the Balfron, the Tatamagouche, and the Cape John Formations. The Formation is mostly exposed in

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 superficial ...

s or covered with

glacial till image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

. 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 ...

overlays the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

Cumberland Group or the Mississippian Windsor Group. It is equivalent to the Morien Group of

Cape Breton Island Cape Breton Island (french: link=no, île du Cap-Breton, formerly '; gd, Ceap Breatainn or '; mic, Unamaꞌki) is an island on the Atlantic coast of North America and part of the province of Nova Scotia, Canada. The island accounts for 18. ...

and Stellarton Group on central

Nova Scotia Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native Eng ...

. The Pictou Group is also a synonym to the Prince Edward Island Group (include the Miminegash, Egmont Bay, Kildare Capes, Hillsborough River and Orby Head formations.

References

Stratigraphy of Canada Carboniferous System of North America Permian System of North America Oil shale in Canada Oil shale formations {{Canada-geologic-formation-stub