The Iskut volcanic field is a group of

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

es and

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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

flows on and adjacent to the

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

–

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

border in the

Boundary Ranges The Boundary Ranges, also known in the singular and as the Alaska Boundary Range, are the largest and most northerly subrange of the Coast Mountains. They begin at the Nass River, near the southern end of the Alaska Panhandle in the Canadian pro ...

of the

Coast Mountains The Coast Mountains () 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 British Columbia Coast, Coast of British Columbia sout ...

. All the volcanoes in this

volcanic field A volcanic field is an area of Earth's Earth's crust, crust that is prone to localized volcano, volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters ...

are situated in British Columbia along the

Iskut Iskut is a small, mostly Indigenous community in the Stikine Country of northwestern British Columbia. It is located on Highway 37, at the north end of Eddontenajon Lake just south of Dease Lake and the crossing of the Stikine River. Communi ...

and Unuk rivers and their

tributaries A tributary, or an ''affluent'', is a stream or river that flows into a larger stream ('' main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which the ...

, with lava flows having reached Alaska. The oldest volcanoes in the Iskut volcanic field are Little Bear Mountain and Hoodoo Mountain, which are 146,000 and 85,000 years old, respectively. Younger volcanic centres include Second Canyon, King Creek, Tom MacKay Creek, Snippaker Creek, Iskut Canyon, Cone Glacier, Cinder Mountain and Lava Fork, all of which formed in the last 70,000 years. All of the volcanoes are

mafic A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include ...

in composition except for Hoodoo Mountain which consists of

peralkaline rock Peralkaline rocks include those igneous rocks which have a deficiency of aluminium such that sodium and potassium are in excess of that needed for feldspar. The presence of aegerine (sodium pyroxene) and riebeckite (sodium amphibole) are indica ...

s. The latest volcanic eruption took place from the Lava Fork volcano in 1800, although an uncertain 1904 eruption is also attributed to this volcano. The name Iskut-Unuk River Cones is a nearly synonymous term for this volcanic field but it omits Hoodoo Mountain and Little Bear Mountain, the oldest volcanoes comprising the Iskut volcanic field. The name for this area in the Tlingit language is Séxkhulé, referring to the time of Aan Galakhú (the World Flood) when people took refuge here from the rising flood waters.

References

External links

Catalogue of Canadian volcanoes: Iskut River

Alaska Volcano Observatory: Iskut-Unuk River Cones
Volcanic fields of Canada Boundary Ranges Stikine Country Northern Cordilleran Volcanic Province Quaternary British Columbia {{BritishColumbiaInterior-geo-stub

See also

References

External links