Leduc Formation

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Leduc Formation
Stratigraphic range: Frasnian
Type Geological formation
Underlies Duvernay Formation, Ireton Formation
Overlies Beaverhill Lake Formation
Thickness up to 300 metres (980 ft)[1]
Lithology
Primary Limestone, dolomite
Location
Coordinates 53°20′42″N 113°41′42″W / 53.3451°N 113.6949°W / 53.3451; -113.6949 (B.A. Pyrz No. 1 well/Leduc Formation)Coordinates: 53°20′42″N 113°41′42″W / 53.3451°N 113.6949°W / 53.3451; -113.6949 (B.A. Pyrz No. 1 well/Leduc Formation)
Region  Alberta
Country  Canada
Type section
Named for City of Leduc
Named by Imperial Oil Limited, 1950

Leduc Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.

It takes the name from the city of Leduc, and was first described in B.A. Pyrz No. 1 well in central Alberta (between 1,623.7 and 1,807.5m) by Imperial Oil Limited in 1950.[1] A complete section was cored in Imperial Oil's Leduc No. 530 well from 1,633 meters (5,358 ft) to 1,863 meters (6,112 ft).

Lithology[edit]

The Leduc Formation was deposited in a shallow water reef environment, and the limestone consists of stromatolite reefs with skeletal mudstone and floatstone to finer grained muddy packstone and wackestone. Dolomitisation is a common diagenesis throughout the formation.

Oil and gas production[edit]

Oil and gas is produced from the Leduc Formation in central Alberta. The Leduc No. 1 well produced 50 million cubic metres (more than 300 million barrels) of oil[2] and marked the beginning of the post-war Albertan oil boom. The Strachan and Ricinus West gas fields, discovered in 1967 and 1969, produce from the Late Devonian reefs of Leduc age.[3]

Distribution[edit]

Leduc Formation occurs as discrete reef buildups in a line following the Woodbend shelf margin from Drumheller in central Alberta to Peace River Arch area in northern Alberta. The formation is absent in inter-reef areas, and build-ups reach from 180 meters (590 ft) to 300 meters (980 ft).

Relationship to other units[edit]

Leduc Formation conformably overlays the Cooking Lake Formation and the Beaverhill Lake Formation platform carbonates in central Alberta. In northern Alberta, it rests directly on precambrian red beds or on Granite Wash. The Leduc reefs are surrounded by younger sediments, such as the Duvernay and Ireton Formations carbonates or Woodbend Group shale.

References[edit]

  1. ^ a b Lexicon of Canadian Geological Units. "Leduc Formation". Retrieved 2009-02-09. 
  2. ^ Heritage Community Foundation. Alberta's Petroleum Heritage
  3. ^ Hriskevich, M.E., Faber, J.M., and Langton, J.R., 1980, Strachan and Ricinus West Gas Fields, Alberta, Canada, in Giant Oil and Gas Fields of the Decade: 1968-1978, AAPG Memoir 30, Halbouty, M.T., Tulsa: American Association of Petroleum Geologists, ISBN 0891813063, p. 315