Cardium Formation

Cardium Formation Stratigraphic range: Turonian to Coniacian PreЄ Є O S D C P T J K Pg N
Photomicrograph of drill cuttings from Cardium Formation sandstone.
Type	Geological formation
Unit of	Alberta Group, Colorado Group, Smoky Group
Sub-units	Sturrock Member, Leyland Member, Cardinal Member, Kiska Member, Moosehound Member, Ram Member.
Underlies	Wapiabi Formation
Overlies	Blackstone Formation, Kaskapau Formation
Thickness	22 metres (70 ft) to 109 metres (360 ft)
Lithology
Primary	Sandstone
Other	Shale
Location
Coordinates	51°08′28″N 114°59′40″W / 51.14101°N 114.99446°W / 51.14101; -114.99446 (Cardium Formation)Coordinates: 51°08′28″N 114°59′40″W / 51.14101°N 114.99446°W / 51.14101; -114.99446 (Cardium Formation)
Region	Western Alberta, and northeastern British Columbia
Country	Canada
Type section
Named for	Cardium shells
Named by	James Hector, 1895

The Cardium Formation is a stratigraphic unit of Late Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the fossilized Cockle (Cardiidae) shells that it contains, and it was first described along the Bow River banks by James Hector in 1895. It is present throughout western Alberta and in northeastern British Columbia, and it is a major source of petroleum and natural gas.

The Cardium Formation is composed primarily of beds of massive, fine-grained to conglomeratic sandstone, which are separated by thick layers of shale. The formation is subdivided into the following members from top to base:

In central Alberta, the formation is divided into the Pembina River Member and Cardium Zone.

The Cardium Formation was deposited during the Turonian and Coniacian stages of the Late Cretaceous along the western edge of the Alberta Foreland Basin. It extends northward from the Canada-United States border to northeastern British Columbia near Dawson Creek, and eastward from the foothills of the Canadian Rockies into the plains of southern and central Alberta. Beyond there, the sandstones grade into shale. Thickness of Cardium sand varies between 5 and 30 meters in Alberta, Canada.