Schooler Creek Group

Schooler Creek Group
Stratigraphic range: Ladinian to Norian
TypeGeological group
Sub-unitsBocock Formation, Pardonet Formation, Baldonnel Formation, Ludington Formation, Charlie Lake Formation, Halfway Formation
UnderliesFernie, Bullhead, Fort St. John Group
OverliesToad Formation, Doig Formation
Thicknessup to 730 feet (220 m)[1]
Lithology
PrimaryLimestone, dolomite
OtherSiltstone, shale, evaporite minerals
Location
Coordinates56°16′37″N 120°59′01″W / 56.2769°N 120.9836°W / 56.2769; -120.9836 (Pacific Fort St. John No. 16)
Region British Columbia
Country Canada
Type section
Named byF.H. McLearn, 1921

The Schooler Creek Group is a stratigraphic unit of Middle to Late Triassic (Ladinian to Norian) age in the Western Canadian Sedimentary Basin. It is present in northeastern British Columbia. It was named for Schooler Creek, a left tributary of Williston Lake, and was first described in two oil wells (Pacific Fort St. John No. 16 and Southern Production No. B-14-1) northwest of Fort St. John, by F.H. McLearn in 1921.[2] Exposures along Williston Lake serve as a type locality in outcrop.

Lithology

The Schooler Creek Group is composed of limestone and dolomite, with subordinate siltstone, shale, sandstone, and evaporite minerals such as gypsum and anhydrite.

Distribution

The Schooler Creek Group outcrops in the foothills of the northern Canadian Rockies in northeastern British Columbia, where it reaches its maximum thickness of 730 feet (220 m). In the subsurface, it extends throughout the plains of the Peace River Country. The Pardonet Formation has its type locality at Pardonet Hill, on the south shore of the Williston Lake at 56°03′12″N 123°01′08″W / 56.05328°N 123.01889°W / 56.05328; -123.01889 (Pardonel Hill).

Relationship to other units

The Schooler Creek Group is unconformably overlain by the Fernie shale, or by the Bullhead or Fort St. John Group. It conformably overlies the Toad Formation or the Doig Formation.

Subdivisions

The Schooler Creek Group has the following sub-divisions from top to base:

Sub-unit Age Lithology Thickness Reference
Bocock Formation late Norian aphanitic crystalline and bioclastic limestone 63 metres (210 ft) [3]
Pardonet Formation Norian limestone, silty limestone, siltstone, rare shale 137 metres (450 ft) [4]
Baldonnel Formation Carnian limestone, dolomite, with interbeds of siltstone and very fine grained sandstone 146 metres (480 ft) [5]
Ludington Formation Carnian dolomitic and calcareous siltstone, sandstone, bioclastic limestone 500 metres (1,640 ft) [6]
Charlie Lake Formation Carnian aeolian sandstones, limestone, dolomite and evaporite minerals such as anhydrite. Deposited in a series of sand dunes and sabkah environments similar to the modern Coastal Ergs of Namibia. 550 metres (1,800 ft) [7][8][9][10]
Halfway Formation early Ladinian to Carnian sandstone, with interbeds of siltstone, dolomite and limestone 416 metres (1,360 ft) [11]

References

  1. ^ Lexicon of Canadian Geologic Units. "Schooler Creek Group". Retrieved 2009-02-10.
  2. ^ McLearn, F.H., 1921. Mesozoic of upper Peace River, British Columbia Geological Survey of Canada, Summary Report 1920, Part B, p. 1-6.
  3. ^ Lexicon of Canadian Geologic Units. "Bocock Formation". Retrieved 2009-02-11.
  4. ^ Lexicon of Canadian Geologic Units. "Pardonet Formation". Retrieved 2009-02-11.
  5. ^ Lexicon of Canadian Geologic Units. "Baldonnel Formation". Retrieved 2009-02-11.
  6. ^ Lexicon of Canadian Geologic Units. "Ludington Formation". Retrieved 2009-02-11.
  7. ^ Lexicon of Canadian Geologic Units. "Charlie Lake Formation". Retrieved 2009-02-11.
  8. ^ Higgs, R. "Sedimentology and Petroleum Geology of the Artex Member (Charlie Lake Formation), Northeast British Columbia [Abstract]." Bulletin of Canadian Petroleum Geology 38.1 (1990): 166-166.
  9. ^ Arnold, K.J. Origin and distribution of aeolian sandstones in the Triassic Charlie Lake Formation, northeastern British Columbia. 1996.
  10. ^ Fefchak, Chelsea (Oct 2, 2011). "Sedimentology of the Charlie Lake Formation". MSC. Thesis, University of Alberta. hdl:10402/era.27704.
  11. ^ Lexicon of Canadian Geologic Units. "Halfway Formation". Retrieved 2009-02-11.