Gladstone Formation
{{Infobox Rockunit
| name =Gladstone Formation
| image =
| caption =
| type = Geological formation
| age = {{Fossil range|110|125|Early Cretaceous (Aptian)}}
| period = Aptian
| prilithology = Sandstone, siltstone, mudstone
| otherlithology = Limestone, coal
| namedfor = Gladstone Creek
| namedby = J.R. McLeanMcLean, J.R. 1980. Lithostratigraphy of the Lower Cretaceous coal-bearing sequence, foothills of Alberta. Geological Survey of Canada, Paper 80-29.
| region = Alberta
| country = Canada
| coordinates =
| unitof = Blairmore Group, Luscar Group
| subunits =
| underlies = Beaver Mines Formation, Moosebar Formation
| overlies = Cadomin Formation
| thickness = up to about {{convert|180|m|ft|-1}}
| extent =
| area =
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The Gladstone Formation is a stratigraphic unit of Early Cretaceous (Aptian) age in the Western Canada Sedimentary Basin.{{Cite web |url=http://www.ags.gov.ab.ca/publications/wcsb_atlas/a_ch19/ch_19.html |title=The Geological Atlas of the Western Canada Sedimentary Basin, Chapter 19: Cretaceous Mannville Group of the Western Canada Sedimentary Basin |author=Mossop, G.D. and Shetsen, I. (compilers), Canadian Society of Petroleum Geologists and Alberta Geological Survey |year=1994 |accessdate=2013-08-01 |url-status=dead |archiveurl=https://web.archive.org/web/20130814133127/http://www.ags.gov.ab.ca/publications/wcsb_atlas/a_ch19/ch_19.html |archivedate=2013-08-14 }} It is present in the foothills of southwestern Alberta and is named for outcrops along Gladstone Creek, a tributary of the Castle River south of the Crowsnest Pass.Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. {{ISBN|0-920230-23-7}}.
Stratigraphy and lithology
The Gladstone Formation is a unit of the Blairmore and Luscar Groups. The lower portion of the formation consists of fine-grained sandstone interbedded with siltstone, mudstone and claystone. The upper portion consists of limestone beds and coquinas of fresh water shells, interbedded with calcareous mudstone, siltstone and fine-grained sandstone. Thin coal beds are present in northern areas.
Thickness and distribution
The Gladstone Formation is present in the foothills of southwestern Alberta from the Gladstone Creek area south of the Crowsnest Pass, northward to the Kakwa River area. It has a maximum reported thickness of about {{convert|180|m|ft|-1}} north of the North Saskatchewan River.
Environment of deposition and paleontology
The Gladstone sediments were derived from erosion of mountain ranges to the west, transported eastward by river systems, and deposited in a variety of floodplain environments.Taylor, D.R. and Walker, R.G. 1984. Depositional environments and paleogeography in the Albian Moosebar Formation and adjacent fluvial Gladstone and Beaver Mines formations, Alberta. Canadian Journal of Earth Sciences, vol. 21, p. 698-714. They contain a fossil fauna of mainly fresh water bivalves, gastropods, ostracods, and charophytes.
Relationship to other units
The Gladstone Formation rests conformably on the Cadomin Formation. It is overlain by the Beaver Mines Formation in the south, and by the Moosebar Formation in the north. It is equivalent to the Gething Formation of northeastern British Columbia. The upper calcareous portion is equivalent to the Ostracod Beds of the Alberta plains.{{Cite web|url=http://www.aer.ca/documents/catalog/TOF.pdf|title=Alberta Table of Formations; Alberta Energy Regulator|author=Alberta Geological Survey, 2013.|accessdate=2016-10-07|archive-url=https://web.archive.org/web/20150925212120/http://www.aer.ca/documents/catalog/TOF.pdf|archive-date=2015-09-25|url-status=dead}}