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Poker Chip Shale

Fernie Formation (Group)
Stratigraphic range: Jurassic
Fernie downtown.jpg
Fernie shales are exposed in the mountains near Fernie
Type Geological formation
Sub-units Nordegg Member, Red Deer Member, Poker Chip Shale, Lille Member, Rock Creek Member, Highwood Member, Pigeon Creek Member, Ribbon Creek Member
Underlies Morrissey Formation, Nikanassin Formation, Monteith Formation
Overlies Schooler Creek Group, Montney Formation, Rundle Group
Thickness up to 400 metres (1,310 ft)
Lithology
Primary Shale
Other Sandstone, siltstone, limestone
Location
Coordinates 49°33′N 115°10′W / 49.55°N 115.16°W / 49.55; -115.16 (Fernie Formation)Coordinates: 49°33′N 115°10′W / 49.55°N 115.16°W / 49.55; -115.16 (Fernie Formation)
Region  Alberta
 British Columbia
Country  Canada
Type section
Named for Fernie, British Columbia
Named by Leach, 1914.

The Fernie Formation is a stratigraphic unit of Jurassic age. It is present in the western part of the Western Canada Sedimentary Basin in western Alberta and northeastern British Columbia. In some interpretations it has Group status. It takes its name from the town of Fernie, British Columbia, and was first defined by Leach in 1914.

The Fernie Formation consists of marine sediments that were deposited in the Western Interior Seaway. Deposition took place throughout most of the Jurassic period, starting during the Hettangian stage in some parts of northeastern British Columbia and continuing until the mid-Tithonian, as determined from its fossil assemblages, including ammonites, molluscs and microfossils.

The sediments were sourced from the east during the deposition of the lower and middle units of the Fernie, where the coarser facies occur in the eastern part of the formation. In the uppermost Fernie, the coarsest material is found in the west, however, indicating a shift to sources in the west and south.

The Fernie Formation is composed primarily of brown and dark gray to black shales that range from massive with conchoidal fracture to laminated and highly fractured or papery. Phosphatic sandstone and limestone, including cherty limestone, occur locally in the lower parts of the formation; siltstone, sandstone, coquinas and oolitic limestone interbeds can occur in the center; glauconitic sandstone and siltstone can be present in the upper parts.


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