Vanguard Formation

The Vanguard Formation is a stratigraphical unit of Callovian to Oxfordian age in the Western Canadian Sedimentary Basin.

Vanguard Formation
Stratigraphic range: Callovian to Oxfordian
TypeGeological formation
Sub-unitsMasefield Shale
Roseray Formation
Rush Lake Shale
UnderliesMannville Group
OverliesShaunavon Formation
Thicknessup to 180 metres (590 ft)[1]
Lithology
PrimaryShale, sandstone
Location
Coordinates49.36°N 107.79°W / 49.36; -107.79 (Vanguard Formation)
RegionWCSB, Williston Basin
Country Canada
 United States
Type section
Named forVanguard, Saskatchewan
Named byMilner & Thomas
Year defined1954
Vanguard Formation (Canada)

It takes the name from Vanguard, and was first defined by R.L. Milner and G.E. Thomas in 1954.[2]

Lithology

The Vanguard Formation is composed of calcareous shale with a median quartzose sandstone. [1]

Distribution

The Vanguard Formation Lateral reaches a maximum thickness of 180 metres (590 ft) in the Williston Basin along the Saskatchewan/Montana border.[1]

Relationship to other units

The Vanguard Formation is unconformably overlain by the Mannville Group and disconformably overlays the Shaunavon Formation.[1]

It is equivalent to the Ellis Group in Montana and North Dakota.

Subdivisions

In south-western Saskatchewan, Vanguard has group status, and includes the following subdivisions (of formation rank):

References

  1. Lexicon of Canadian Geologic Units. "Vanguard Formation". Retrieved 2010-01-01.
  2. Milner, R.L. and Thomas, G E., 1954. Jurassic System in Saskatchewan. In: Western Canada Sedimentary Basin. American Association of Petroleum Geologists, p. 250-267
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