The Wabamun Group in the Stettler Area, Alberta
1956; Canadian Society of Petroleum Geologists; Volume: 4; Issue: 5 Linguagem: Inglês
ISSN
2368-0261
AutoresJ. S. Wonfor, John M. Andrichuk,
Tópico(s)Hydrocarbon exploration and reservoir analysis
ResumoABSTRACT The Wabamun group is the uppermost major rock unit of the Upper Devonian throughout central Alberta. This group can be correlated from the Edmonton type section into the Stettler area of central Alberta. In the Edmonton area the Wabamun consists predominantly of carbonates whereas in the Stettler area it is predominantly an evaporitic section. The Graminia formation of the Winterburn underlying the Wabamun in the Edmonton area is not a mappable unit at Stettler, therefore the base of the Wabamun at Stettler is placed at the top of the Calmar. The Wabamun in the Stettler area is divisible into two distinct units, the upper unit, the Big Valley formation and the lower unit, the Stettler formation. The name Big Valley formation is proposed for the thinner upper marine carbonates overlying the Stettler evaporites and underlying the Exshaw shale or Mesozoic beds. The Big Valley formation is relatively uniform in thickness from 40 to 60 feet where not affected by pre-Mesozoic erosion. The characteristic rock types of the Big Valley are grey, dense to finely crystalline, fossiliferous, normal marine limestone and some interbedded green-grey calcareous shales and argillaceous limestones. The name Stettler formation is proposed for the lower unit and predominantly evaporitic unit of the Wabamun group south of the Mississippian erosional limit in the Stettler area. The strata consist of anhydrite, primary dolomite and salt, with associated secondary dolomites. The Stettler formation ranges in thickness from less than 400 feet to 700 feet.
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