The Chilcotin Plateau is part of the

Fraser Plateau The Fraser Plateau is an intermontane plateau. It is one of the main subdivisions of the Interior Plateau located in the Central Interior of British Columbia. Geography The region includes the Cariboo Plateau and Chilcotin Plateau, and the adjoi ...

, a major subdivision of the

Interior Plateau The Interior Plateau comprises a large region of the Interior of British Columbia, and lies between the Cariboo and Monashee Mountains on the east, and the Hazelton Mountains, Coast Mountains and Cascade Range on the west.''Landforms of British C ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...

. The Chilcotin Plateau is physically near-identical with the region of the same name, i.e. "the Chilcotin", which lies between the

Fraser River The Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of Vancouver. The river's annual ...

and the southern

Coast Mountains The Coast Mountains (french: La chaîne Côtière) are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbi ...

and is defined by the basin of the

Chilcotin River The Chilcotin River /tʃɪlˈkoʊtɪn/ located in Southern British Columbia, Canada is a long tributary of the Fraser River. The name Chilcotin comes from Tŝilhqot’in, meaning "ochre river people," where ochre refers to the mineral used by ...

and so includes montane areas beyond the plateau. East of the Chilcotin Plateau, across the

, is the Cariboo Plateau, while to the north beyond the West Road (Blackwater) River is the Nechako Plateau. West and south of the Chilcotin Plateau are various subdivisions of the

, including the

Chilcotin Ranges The Chilcotin Ranges are a subdivision of the Pacific Ranges of the Coast Mountains (in some classifications they are a separate subdivision). They lie on the inland lea of the Pacific Ranges, abutting the Interior Plateau of British Columbia. T ...

which lie along the plateau's southwest. Included within the definition of the Chilcotin Plateau are the Rainbow Range, near Bella Coola and the similarly volcanic

Ilgachuz Range The Ilgachuz Range is a name given to an extinct shield volcano in British Columbia, Canada. It is not a mountain range in the normal sense, because it was formed as a single volcano that has been eroded for the past 5 million years. It lies on t ...

and

Itcha Range The Itcha Range, also known as the Itchas, is a small isolated mountain range in the West-Central Interior of British Columbia, Canada. It is located northeast of the community of Anahim Lake. With a maximum elevation of , it is the lowest of ...

both of which are major

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more vi ...

es. The

Camelsfoot Range The Camelsfoot Range is a sub-range of the Chilcotin Ranges subdivision of the Pacific Ranges of the Coast Mountains in British Columbia. The Fraser River forms its eastern boundary. The range is approximately 90 km at its maximum length and ...

, north of

Lillooet Lillooet () is a district municipality in the Squamish-Lillooet region of southwestern British Columbia. The town is on the west shore of the Fraser River immediately north of the Seton River mouth. On BC Highway 99, the locality is by road abo ...

, is included in the Chilcotin Plateau by some systems of classification. The plateau is nearly entirely drained by the

and its tributaries, the largest of which are the Chilanko and Chilko Rivers. Also draining the plateau on its eastern edge is

Churn Creek Churn Creek is a tributary of the Fraser River in the Canadian province of British Columbia. Course Churn Creek flows generally north before turning northeast on its final leg through grasslands, joining the Fraser River just south of the headquar ...

, which forms the east flank of the

and enters the Fraser directly. On the west side of the plateau, the basins of the Dean, Homathko and Atnarko Rivers penetrate the massifs of the

and have their beginnings, or the early part of their courses, on the Chilcotin Plateau. The Chilcotin Plateau consists of

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or ...

of the

Chilcotin Group The Chilcotin Group, also called the Chilcotin Plateau Basalts, is a large area of basaltic lava that forms a volcanic plateau running parallel with the Garibaldi Volcanic Belt in south-central British Columbia, Canada. Predominantly, during Mio ...

, a group of related

volcanic rock Volcanic rock (often shortened to volcanics in scientific contexts) is a rock formed from lava erupted from a volcano. In other words, it differs from other igneous rock by being of volcanic origin. Like all rock types, the concept of volcanic ...

s that is nearly parallel with the

.Chasm and Dog Creek lithofacies, Chilcotin Group basalt, Bonaparte Lake map area, British Columbia
/ref> It extends along the adjacent

Garibaldi Volcanic Belt The Garibaldi Volcanic Belt is a northwest–southeast trending volcanic chain in the Pacific Ranges of the Coast Mountains that extends from Watts Point in the south to the Ha-Iltzuk Icefield in the north. This chain of volcanoes is located in ...

in the

. Volcanism of the Chilcotin Plateau is considered to be related to

back-arc basin A back-arc basin is a type of geologic basin, found at some convergent plate boundaries. Presently all back-arc basins are submarine features associated with island arcs and subduction zones, with many found in the western Pacific Ocean. Most o ...

crustal extension behind the coastal

Cascadia subduction zone The Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is a very long, sloping subduction zone where the Explorer, Juan de Fuc ...

References

{{Authority control Interior Plateau Landforms of the Chilcotin Volcanism of British Columbia Lava plateaus Back-arc volcanism Plateaus of British Columbia

See also

References