The Albert Formation is a stratigraphic unit of Early Mississippian (Tournaisian) age in the Moncton Subbasin of southeastern New Brunswick. It was deposited in a lacustrine environment and includes fossils of fish and land plants, as well as trace fossils. It also includes significant deposits of oil shale. The oil shale beds are the source rocks for the petroleum and natural gas that has been produced from Albert Formation reservoirs at the Stoney Creek and McCully fields. In addition, the solid asphalt-like hydrocarbon albertite was mined from the Albert Formation at Albert Mines between 1854 and 1884.
| Albert Formation | |
|---|---|
| Stratigraphic range: Early Mississippian (Tournaisian) ~ | |
| Type | Formation |
| Unit of | Horton Group[1] |
| Sub-units | Gautreau Member[1] Round Hill Member[1] Hiram Brook Member[1] Frederick Brook Member[1] Dawson Settlement Member[1] |
| Underlies | Moncton Formation[1] |
| Overlies | Memramcook Formation[1] |
| Thickness | Up to 1,800 m (5,910 ft)[2] |
| Lithology | |
| Primary | Sandstone, siltstone, oil shale |
| Other | Mudstone, limestone, comglomerate |
| Location | |
| Coordinates | 45°52′40″N 64°40′07″W / 45.8779°N 64.6685°W |
| Region |  New Brunswick |
| Country |  Canada |
| Type section | |
| Named for | Albert County |
Lithology and mineralogy
editThe Albert Formation includes sandstone, siltstone, mudstone, and oil shale, with minor limestone and conglomerate.[2] The oil shale beds are primarily kerogen-rich calcareous to dolomitic marlstones, clay marlstones, and laminated marlstones.[3] The formation also includes local deposits of the evaporite minerals halite (rock salt), gypsum, anhydrite, and glauberite. The solid hydrocarbon albertite occurs as veins filling fissures in some of the beds, and is derived from the hydrocarbons in the oil shales.[2]
Environment of deposition
editThe Albert Formation has been interpreted as a composite alluvial fan, fluvial-deltaic, and lacustrine sequence.[1] The coarser-grained lithologies are nearshore deposits, while the finer-grained rocks, including the oil shale beds, are an offshore, deeper-water assemblage.[1][2] Fossils of whole fish preserved in the laminated oil shales indicate very low energy, anoxic conditions.[4]
Paleontology
editThe Albert Formation is known for its complete, articulated specimens of lower actinopterygian (palaeoniscoid) fishes, including the genera Rhadinichthys, Elonichthys, and Canobius.[5] There are remains of land plants such as Lepidodendrales and Sphenopteris,[6] as well as palynomorphs.[7] Trace fossils include Paleodictyon, Helminthopsis, and Planolites.[8]
Economic resources
editOil and gas
editThe Albert Formation hosts the only two commercial onshore oil and gas fields in Canada's Maritime Provinces. The Stoney Creek field produced from sandstone reservoirs in the Albert Formation between 1909 and 1991, and estimates suggest that significant oil remains in place there. The McCully field, which was discovered in 2000, produces from tight gas sandstones in the upper part of the Albert Formation, above the main organic mudstone (oil shale) source rocks.[4]
Albertite
editVeins of the solid black hydrocarbon that was subsequently named albertite were first noted in the Albert Formation in 1820. In 1846, Abraham Gesner used albertite in developing the first method for distilling kerosene, and between 1854 and 1884 albertite was mined by underground methods at Albert Mines for use in the production of kerosene and illuminating gas.[9]
References
edit- ^ a b c d e f g h i j Carter, D.C. and Pickerill, R.K. 1985. Lithostratigraphy of the Late Devonian – Early Carboniferous Horton Group of the Moncton Subbasin, southern New Brunswick. Atlantic Geology, vol. 21, p. 11-24.
- ^ a b c d Smith, W.D. and Gibling, M.R. 1987. Oil shale composition related to depositional setting: A case study from the Albert Formation, New Brunswick, Canada. Bulletin of Canadian Petroleum Geology, vol. 35, no. 4, p. 469-487.
- ^ Macauley, G., Ball, F.D. and Powell, T.G. 1984. A review of the Carboniferous Albert Formation oil shales of New Brunswick. Bulletin of Canadian Petroleum Geology, vol. 32, no. 1, p. 27-37.
- ^ a b Keighley, D. 2008. A lacustrine shoreface succession in the Albert Formation, Moncton Basin, New Brunswick. Bulletin of Canadian Petroleum Geology, vol. 56, no. 4, p. 235-258.
- ^ Mickle, K.E. 2017. The lower actinopterygian fauna from the Lower Carboniferous Albert shale formation of New Brunswick Canada – A review of previously described taxa and a description of a new genus and species. College of Science, Health and the Liberal Arts Faculty Papers, paper 1. https://jdc.jefferson.edu/jchsfp/1; doi:10.5194/fr-20-47-2017.
- ^ Bell, W.A. 1960. Mississippian Horton Group of type Windsor-Horton District, Nova Scotia. Geological Survey of Canada, Memoir 314, 112 p.
- ^ Utting, J. 1987. Palynostratigraphic investigation of the Albert Formation (Lower Carboniferous) of New Brunswick, Canada. Palynology, vol. 11, no. 1, p. 73-96.
- ^ Pickerill, R.K. 1990. Nonmarine Paleodictyon from the Carboniferous Albert Formation of southern New Brunswick. Atlantic Geology, vol. 26, p. 157-163.
- ^ Albert County Museum. "Albertite Mining". Retrieved 23 April 2020.
- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.