• Source: Fort St. John Group

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


The Fort St. John Group is mostly composed of dark shale deposited in a marine environment. Bentonite is present in the shale, and it is interbedded with sandstone, siltstone and conglomerates.




Distribution


The Fort St. John Group occurs in the subsurface in the Peace River Country of northeastern British Columbia and north-western Alberta, in southern Yukon and southern Northwest Territories. It has a thickness of 700 metres (2,300 ft) to 2,000 metres (6,560 ft).




Relationship to other units


The Fort St. John Group is conformably overlain by the Dunvegan Formation and conformably underlain by the Bullhead Group or may rest disconformably on older units.




= Subdivisions

=
The Fort St. John Group is subdivided into the following formations:



Canadian Rockies foothills of British Columbia




Peace River Country




Liard River and Fort Liard Area


*Buckinghorse Formation is equivalent to the sum of Lepine Formation, Scatter Formation and Garbutt Formation. It occurs north-east of the Canadian Rockies foothills in British Columbia, between the Halfway River and Muskwa River. It is composed of silty marine mudstone with fine grained marine sandstone interbeds.




References

Kata Kunci Pencarian:

• Benteng St. Angelo
• John F. Kennedy
• Pembunuhan John F. Kennedy
• Amerika Serikat
• Perang Dunia I
• American Airlines
• Brightline
• Aman Resorts
• Cape Canaveral
• Nelson Mandela
• Fort St. John Group
• Fort St. John
• Fort St. John, British Columbia
• Fort St. John Airport
• Fort St. George (Chennai)
• Fort St. Angelo
• Schooler Creek Group
• Maunsell Forts
• Fort Caroline
• Hulcross Formation