{{short description|Stratigraphic unit in Canada}} {{for|the UK supergroup|Windermere Supergroup}} {{Infobox Rockunit | name = Windermere Group | image = | caption = | type = Geological group or supergroup | age = {{Long fossil range|1000|600|Neoproterozoic}} | period = Proterozoic | prilithology = Conglomerate, sandstone | otherlithology = Shale, carbonate rocks | namedfor = Windermere map-area, British Columbia | namedby = J.F. Walker<ref name=Walker /> | region = Montana, Idaho, Washington; Alberta, British Columbia, Northwest Territories, Yukon | country = United States, Canada | coordinates = | unitof = | subunits = Many | underlies = Various units | overlies = Purcell Supergroup (Belt Supergroup) | thickness = more than {{convert|8000|m|ft|-1}}<ref name="MF2426" /> | extent = | area = | map = }}
Called the '''Windermere Group''' in the United States and the '''Windermere Supergroup, Windermere Series''', and '''Windermere System''' in Canada,<ref name=Miller>Miller, F.K., McKee, E.H. and Yates, R.G. 1973. Age and correlation of the Windermere Group in northeastern Washington. Geological Society of America Bulletin, vol. 84, no. 11, p. 3723-3730.</ref> the Windermere sequence of North America is an extensive assemblage of sedimentary and volcanic rocks of latest Precambrian (Neoproterozoic) age. It is present in the northern part of the North American Cordillera, stretching from Montana, Idaho, and Washington in the northwestern United States, through Alberta, British Columbia, the Northwest Territories, and the Yukon in western Canada.<ref name="MF2426">{{cite web|last1=Miller, F.K. and Burmester, R.F. 2003|title=U.S. Geological Survey, Miscellaneous Field Investigations, MF-2426|url=https://pubs.usgs.gov/mf/2003/2426/bferry_met.txt|accessdate=12 April 2018}}</ref><ref name=Miller /><ref name=Mossop06>{{cite web|last1=Hein, F.J. and McMechan, M.E. 1994|title=Atlas of the Western Canada Sedimentary Basin (Mossop, G.D. and Shetsen, I., compilers), Chapter 6: Proterozoic and Lower Cambrian strata of the Western Canada Sedimentary Basin|url=http://ags.aer.ca/publications/chapter-6-proterozoic-and-lower-cambrian-strata|accessdate=11 April 2018}}</ref><ref name=Glass>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}}.</ref> It was named for the Windermere map-area in the East Kootenay region of southeastern British Columbia by J.F. Walker in 1926.<ref name=Walker>Walker, J.F. 1926. Geology and mineral deposits of the Windermere map-area, British Columbia. Geological Survey of Canada, Memoir 148, 69 p.</ref>
The Windermere rocks include Ediacaran fossils and stromatolites,<ref name=Mossop06 /> and host deposits of base and precious metals.<ref name=Walker />
==Lithology== The Windermere consists primarily of coarse-grained feldspathic conglomerates and pebbly sandstones, with lesser amounts of pelitic shales, dolomites, and limestones.<ref name=Glass /><ref name=Mossop06 /> Mafic igneous rocks are present in some areas.<ref name="MF2426" /><ref name=Miller /> In most areas the Windermere rocks are highly sheared, faulted, and metamorphosed.<ref name=Miller />
==Environment of deposition== Most of the Windermere rocks were deposited as deep-water turbidite flows along a continental margin or in an active volcanic rift basin.<ref name=Mossop06 /> Glacial events such as the Sturtian and Marinoan glaciations that occurred during Neoproterozoic time strongly influenced sedimentation,<ref name=Mossop06 /> and some of the Windermere conglomerates are believed to be till or diamictite of glacial origin.<ref name=Miller />
==Paleontology== Trace fossils, Ediacaran fossils, and Ediacaran-like fossils have been described from the Windermere Suprgroup in the Mackenzie and Werneke Mountains of the eastern Northwest Territories, the Cariboo Mountains of British Columbia, and the Canadian Rockies near Jasper, Alberta.<ref name=Mossop06 /> Stromatolites are present in some of the carbonate beds.<ref name=Glass />
==Thickness and distribution== The Windermere is both thick and extensive. It reaches thicknesses of more than {{convert|8000|m|ft|-1}},<ref name="MF2426" /> and is present parts of Montana, Idaho, and Washington in the United States, and parts of Alberta, British Columbia, the Northwest Territories, and the Yukon in Canada.
==References== {{reflist}}
Category:Geologic groups of the United States Category:Geologic groups of Washington (state) Category:Western Canadian Sedimentary Basin Category:Geologic groups of British Columbia Category:Ediacaran British Columbia Category:Geologic groups of Alberta Category:Geologic groups of Montana Category:Geologic groups of Idaho Category:Geologic groups of Yukon Category:Geologic groups of the Northwest Territories Category:Conglomerate groups Category:Sandstone groups Category:Shale groups