Editing Chilcotin Group (section)

{{Short description|Large area of basaltic lava in south-central British Columbia, Canada}}
[[File:Canadian Cascade Arc.png|thumb|right|300px|Map showing geological formations related to the [[Canadian Cascade Arc]]]]
The '''Chilcotin Group''', also called the '''Chilcotin Plateau Basalts''', is a large area of [[basalt]]ic lava that forms a [[volcanic plateau]] running parallel with the [[Garibaldi Volcanic Belt]] in south-central [[British Columbia]], Canada.

Predominantly, during [[Chattian|Miocene]] and [[Pliocene]] times, a medium-sized volcanic field of overlapping vents occurred in British Columbia's [[Interior Plateau]]. The distribution is assumed to engulf up to 50,000&nbsp;km<sup>2</sup> of the [[Pacific Northwest]], forming a medium-sized [[large igneous province]], of volume 3300&nbsp;km<sup>3</sup>.<ref>[http://www.nrcresearchpress.com/doi/abs/10.1139/e83-049?journalCode=cjes Regional stratigraphy and age of Chilcotin Group basalts, south-central British Columbia] Retrieved on 2012-09-22</ref>  Volcanism occurred as late as Oligocene time, but continues sporadically up to present. Eruptions were most vigorous 6-10 million years ago and 2-3 million years ago, when most of the basalt was released. Less extensive eruptions continued 0.01 to 1.6 million years ago.<ref name="SI">[http://gsc.nrcan.gc.ca/volcanoes/cat/belt_chilcotin_e.php National Resources Canada - Catalogue of Canadian volcanoes: Chilcotin Plateau basalts] {{webarchive |url=https://web.archive.org/web/20080315201506/http://gsc.nrcan.gc.ca/volcanoes/cat/belt_chilcotin_e.php |date=March 15, 2008 }} Retrieved on 2008-03-15</ref>

These lava flows have been dominantly exposed by erosion resulting from the great floods that flowed in this region throughout the past ice ages, which laid bare many layers of the basalt flows along the [[Fraser Canyon]] from [[Soda Creek]] south to [[Canoe Creek (British Columbia)|Canoe Creek]] elsewhere along the [[Chilcotin River|Chilcotin]], [[Chilko River|Chilko]], [[Chilanko River|Chilanko]] and [[Taseko River]]s, and also to the east of the Fraser River at [[Chasm Provincial Park]] and along the [[Deadman River|Upper Deadman River]]. Prior to Late Pleistocene glacial erosion these centers formed a series of coalesced, low-profile [[shield volcano]]es of unknown volume and distribution.

The Chilcotin Group were thought to potentially be linked to the partly coeval [[Columbia River Basalt Group]]. However, its morphology and geochemistry have been proven much similar to other volcanic plateaus such as the [[Snake River Plain]] in Idaho and parts of [[Iceland]] (Bevier, 1983).