{{Short description|Geologic formation in Saskatchewan}} {{Infobox rockunit | name = Herald Formation | image = | imagesize = | caption = | type = Geological formation | age = {{Fossil range|Late Ordovician|Late Ordovician|Late Ordovician}} | period = Late Ordovician | prilithology = limestone, dolomite, anhydrite | otherlithology = | namedfor = | namedby = Saskatchewan Geological Society, 1958. | region = WCSB | country = Canada | coordinates = {{coord|49.0746|N|104.6521|W|display=inline,title|name= Herald Formation}} | unitof = | subunits = Lake Alma Member<br>Coronach Member<br>Redvers Unit | underlies = Stony Mountain Formation | overlies = Yeoman Formation | thickness = up to {{convert|38|m|ft|-1}}<ref name=lexicon/> | extent = | area = | map = | map_caption = }}
The '''Herald Formation''' is a stratigraphic 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.<ref>Saskatchewan Geological Society, 1958. Report of the Lower Paleozoic Names and Correlation Committee, Regina.</ref>
== Lithology == The Herald Formation is composed of dolomitic limestone and dolomite, which can be microcrystalline, argillaceous or microlaminated. <ref name=lexicon> {{Cite web |url=http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:006479 |archive-url=https://archive.today/20130221102945/http://cgkn1.cgkn.net/weblex/weblex_litho_detail_e.pl?00053:006479 |url-status=dead |archive-date=2013-02-21 |title=Herald Formation |author=Lexicon of Canadian Geologic Units |accessdate=2010-02-01 }} </ref> In the centre of the basin, it is represented by anhydrite.
== Distribution == The Herald Formation reaches a maximum thickness of {{convert|38|m|ft|-1}} in the Lake Alma area.<ref name=lexicon/>
== Relationship to other units == The Herald Formation is disconformably overlain by the Stony Mountain Formation and conformably overlays the Yeoman Formation.<ref name=lexicon/>
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 == {{reflist}}
{{Western Canadian Sedimentary Basin|Saskatchewan=yes}}
Category:Geologic formations of Saskatchewan Category:Ordovician Saskatchewan Category:Western Canadian Sedimentary Basin Category:Limestone formations of Canada Category:Dolomite formations of Canada