Monteith Formation

{{Infobox rockunit

| name = Monteith Formation

| image =

| caption =

| type = Formation

| age = Valanginian

| period = Valanginian

| prilithology = Sandstone

| otherlithology = Siltstone, mudstone, coal

| namedfor = Mount Monteith

| namedby = W.H. Mathews, 1947Mathews, W.H. 1947. Geology and coal resources of the Carbon Creek, Mount Bickford map area. British Columbia Department of Mines, Bulletin 24, 27 p.

| region = British Columbia
Alberta

| country = Canada

| coordinates = {{coord|55.7833|-122.5833|name=Monteith Formation|display=inline,title}}

| unitof = Minnes Group

| subunits =

| underlies = Beattie Peaks Formation

| overlies = Fernie Formation

| thickness = maximum {{convert|600|m|ft|-1|abbr=on}}

| extent = Western Canadian Sedimentary Basin

| area =

| map = {{Location map+ | Canada

| relief = 1

| width = 250

| float = center

| places =

{{Location map~ | Canada

| lat_deg = 55.8

| lon_deg = -122.5

| mark = Green pog.svg

| marksize = 12

}}

| map_caption =

}}

The Monteith Formation is a geologic formation of Early Cretaceous (Valanginian) age in the Western Canada Sedimentary Basin that consists primarily of sandstone. It is present in the northern foothills of the Canadian Rockies and the adjacent plains in northeastern British Columbia and west-central Alberta.Stott, D.F. 1998. Fernie Formation and Minnes Group (Jurassic and lowermost Cretaceous), northern Rocky Mountain foothills, Alberta and British Columbia. Geological Survey of Canada, Bulletin 516.{{Cite web|url=http://www.ags.gov.ab.ca/publications/wcsb_atlas/a_ch18/ch_18.html|title=The Geological Atlas of the Western Canada Sedimentary Basin, Chapter 18: Jurassic and Lowermost Cretaceous strata 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}}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}}.

Lithology

The Monteith Formation consists primarily of fine-grained argillaceous sandstone with interbeds of siltstone, dark grey mudstone, shale, and minor coal beds. Coarser-grained quartzose sandstones and minor quartz-pebble and chert conglomerates are present in some areas.

Environment of deposition

The Monteith Formation was deposited in marine and nonmarine environments within and adjacent to the Western Interior Seaway. Depositional settings ranged from marine to shoreline, deltaic, river channel, floodplain, and swamp environments.

Paleontology and age

The age of the Monach Formation formations has been determined from its fossil fauna, primarily species of the bivalve Buchia.

Thickness and distribution

The Monteith Formation is present in the foothills of the Canadian Rockies and the adjacent plains from the Prophet River in northeastern British Columbia to the Berland River in west-central Alberta. It attains a maximum thickness of {{convert|600|m|ft|-1|abbr=on}} in the foothills of British Columbia and thins eastward.

Relationship to other units

The Monteith Formation is the basal formation of the Minnes Group. It was deposited conformably over the marine shales of the Fernie Formation and is conformably overlain by the Beattie Peaks Formation. To the south it grades into the Nikanassin Formation.