Herald Formation

Herald Formation Stratigraphic range: Late Ordovician PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Sub-units	Lake Alma Member Coronach Member Redvers Unit
Underlies	Stony Mountain Formation
Overlies	Yeoman Formation
Thickness	up to 38 metres (120 ft)[1]
Lithology
Primary	Limestone, dolomite, anhydrite
Location
Named by	Saskatchewan Geological Society, 1958.
Coordinates	49°04′29″N 104°39′08″W / 49.0746°N 104.6521°W / 49.0746; -104.6521 (Herald Formation)Coordinates: 49°04′29″N 104°39′08″W / 49.0746°N 104.6521°W / 49.0746; -104.6521 (Herald Formation)
Region	WCSB
Country	Canada

The Herald Formation is a stratigraphical unit of Late Ordovician age in the Western Canadian Sedimentary Basin.

It was defined in well Imperial Herald 1-31-1-20W2M by the Lower Paleozoic Names and Correlations Committee of the Saskatchewan Geological Society in 1958.^[2]

Lithology

The Herald Formation is composed of dolomitic limestone and dolomite, which can be microcrystalline , argillaceous or microlaminated. ^[1] In the centre of the basin, it is represented by anhydrite.

Distribution

The Herald Formation reaches a maximum thickness of 38 metres (120 ft) in the Lake Alma area.^[1]

Relationship to other units

The Herald Formation is disconformably overlain by the Stony Mountain Formation and conformably overlays the Yeoman Formation.^[1]

It can be correlated with the Fort Garry Member of the Red River Formation in Manitoba and in the Williston Basin.

Subdivisions

In south-eastern Saskatchewan, the formation is divided in three units, corresponding to three sedimentation cycles:

• Lake Alma Member
• Coronach Member
• Redvers Unit

References

1. ^ ^{a b c d} Lexicon of Canadian Geologic Units. "Herald Formation". http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:006479. Retrieved 2010-02-01. 
2. ^ Saskatchewan Geological Society, 1958. Report of the Lower Paleozoic Names and Correlation Committee, Regina.