{{short description|Extinct volcano in British Columbia, Canada}} {{Infobox mountain | name = Maitland Volcano | image = | image_caption = | elevation_m = | elevation_ref = | prominence = | country = [[Canada]] | region_type = [[Provinces and territories of Canada|Province]] | region = [[British Columbia]] | range = [[Klappan Range]] | district = [[Cassiar Land District]] | map = Canada British Columbia | map_caption = Location in British Columbia | label_position = below | mapframe = yes | mapframe-zoom = 8 | mapframe-caption = Interactive map of Maitland Volcano | coordinates = | range_coordinates = | type = [[Shield volcano]] | age = 5.2 to 4.7 million years old | volcanic_zone = [[Northern Cordilleran Volcanic Province]] | last_eruption = 4.6 million years ago | first_ascent = | easiest_route = }}
'''Maitland Volcano''' is a heavily eroded [[shield volcano]] in the [[British Columbia Interior|Northern Interior]] of [[British Columbia]], Canada. It is {{nowrap|{{Convert|83|km|mi|abbr=on}}}} southeast of the small community of [[Telegraph Creek]] in what is now the [[Klappan Range]] of the northern [[Skeena Mountains]]. This multi-vent volcano covered a remarkably large area and was topped by a younger volcanic edifice. Little remains of Maitland Volcano today, limited only to eroded lava flows and distinctive upstanding [[landform]]s created when [[magma]] hardened within the vents of the volcano.
The shield is associated with an extensive group of related volcanoes called the [[Northern Cordilleran Volcanic Province]] (NCVP). This forms part of the much larger [[Ring of Fire]], which surrounds most of the [[Pacific Ocean]] basin. Geologic studies have shown that Maitland was a comparatively short-lived volcano. It had volcanic activity for less than a million years, a time span unique from other massive NCVP shields. The volcano is known to have produced at least four types of lava, namely [[alkali basalt]], [[hawaiite]], [[trachyte]] and [[trachybasalt]]. These have been studied by scientists since the 1950s.
==Geology== Maitland Volcano was one of the most voluminous shield volcanoes in the Northern Cordilleran Volcanic Province along with [[Heart Peaks]], [[Level Mountain]] and the [[Mount Edziza volcanic complex]].<ref name="SL"/> Its structure was about {{nowrap|{{Convert|50|km|mi|abbr=on}}}} long and {{nowrap|{{Convert|40|km|mi|abbr=on}}}} wide, covering an area of at least {{nowrap|{{Convert|1000|km2|mi2|abbr=on}}}}.<ref name="QQG"/><ref name="AD"/> This is similar in size to the Mount Edziza complex approximately {{nowrap|{{Convert|40|km|mi|abbr=on}}}} west of Maitland Volcano. Like most shields, Maitland consisted of several [[basalt]]ic lava flows which have low viscosity.<ref name="AD"/> This gave the volcano its massive profile and consequently Maitland might have had a broad [[lava plateau]] like other large NCVP shields.<ref name="SL"/>
Like other [[List of Northern Cordilleran volcanoes|Northern Cordilleran volcanoes]], Maitland Volcano had its origins in [[continent]]al [[rift]]ing—a long rupture in the Earth's [[crust (geology)|crust]] where the [[lithosphere]] is being pulled apart. This incipient rifting formed as a result of the [[Pacific Plate]] sliding northward along the [[Queen Charlotte Fault]], on its way to the [[Aleutian Trench]].<ref name="ZUD">{{cite web|publisher=[[Natural Resources Canada]]|url=http://gsc.nrcan.gc.ca/volcanoes/map/index_e.php|archive-url=https://web.archive.org/web/20080602043532/http://gsc.nrcan.gc.ca/volcanoes/map/index_e.php|archive-date=2008-06-02|title=Map of Canadian volcanoes|work=Volcanoes of Canada|date=2008-02-13|access-date=2014-12-26}}</ref> As the [[continental crust]] stretched, the near surface rocks fractured along steeply dipping cracks parallel to the rift known as [[fault (geology)|faults]]. Basaltic magma rose along these fractures to create [[effusive eruption]]s.<ref name="ZZL">{{cite web|publisher=[[Natural Resources Canada]]|url=http://atlas.nrcan.gc.ca/site/english/maps/environment/naturalhazards/volcanoes/fig_4_volcanoes_continental_rift.jpg/image_view|archive-url=https://web.archive.org/web/20121006015730/http://atlas.nrcan.gc.ca/site/english/maps/environment/naturalhazards/volcanoes/fig_4_volcanoes_continental_rift.jpg/image_view|archive-date=2012-10-06|title=Diagram of the Continental Rift Zone|work=[[The Atlas of Canada]]|date=2007-03-23|access-date=2014-12-26}}</ref> The rift zone has existed for at least 14.9 million years and has created the Northern Cordilleran Volcanic Province. This [[geologic province]] forms part of the Ring of Fire, an area where large numbers of [[earthquake]]s and volcanic eruptions occur along the Pacific Ocean.<ref name="QQG">{{cite book|last=Wood|first=Charles A.|author2=Kienle, Jürgen |pages=114, 121, 126|title=Volcanoes of North America: United States and Canada|year=1990|publisher=[[Cambridge University Press]]|location=[[Cambridge]], [[England]]|isbn=0-521-43811-X}}</ref>
===Volcanic history=== Maitland's volcanic history is poorly known since only isolated remnants of the volcano remain. What is known, however, is that it formed during a pulse of NCVP [[magmatism]] that began with the eruption of Edziza about seven million years ago. The eruption rate of this period was much greater than what is observed for the Northern Cordilleran Volcanic Province today.<ref name="SL">{{cite journal|title=Distribution, nature, and origin of Neogene–Quaternary magmatism in the northern Cordilleran volcanic province, Canada|last=Edwards|first=Benjamin R.|last2=Russell|first2=James K.|journal=[[Geological Society of America Bulletin]]|publisher=[[Geological Society of America]]|pages=1283, 1284, 1292, 1293|volume=112|issue=8|year=2000|issn=0016-7606}}</ref> Following the onset of activity at Edziza, Maitland volcanism commenced 5.2 million years ago with the outpouring of alkali basalt and hawaiite lava on a broad, late [[Tertiary period|Tertiary]], low-relief surface. This resulted in the creation of a broad shield volcano. Subsequent volcanic activity created a complex edifice of trachyte and trachybasalt that formerly overlain the central part of the basaltic shield. Magmatism at Maitland continued until about 4.6 million years ago when the volcano went [[extinct volcano|extinct]].<ref name="AD"/>
Volcanic activity at Maitland Volcano was consistent with extensional stresses across the northern [[Canadian Cordillera]] that began around 10 million years ago as a result of new plate motions between the Pacific and North American plates. This contributed to lithospheric thinning and decompression melting of [[ocean island basalt|OIB]]-like [[mantle (geology)|mantle]] to produce [[alkaline]] [[Neogene]] magmatism.<ref name="SL"/> The time span of 600,000 years for magmatism at Maitland Volcano is relatively small compared to other large NCVP shield volcanoes. This supports field evidence for rapid, relatively uninterrupted growth of the volcanic edifice.<ref name="AD"/> The suspension of Maitland volcanism corresponds with changes in regional [[tectonics]] about four million years ago.<ref name="SL"/>
===Erosion and dissection=== [[File:Maitland Volcanics.png|thumb|right|350px|Diagram of the remains of Maitland Volcano]] After Maitland Volcano became extinct, prolonged [[erosion]] destroyed the volcanic edifice. The reason why Maitland eroded away while its neighbour, Edziza, did not is twofold. With the cessation of volcanic activity, Maitland Volcano was unable to protect itself from erosion by providing a cover of younger lavas on top of the older shield. Another factor is that Maitland's [[basement (geology)|basement]] was built entirely of soft, friable [[sedimentary rock]]s of the [[Bowser Lake Group]]. Such rocks are more vulnerable to erosion than [[igneous rock]]s. The Bowser Lake Group sedimentary rocks are [[shale]], [[sandstone]], [[conglomerate (geology)|conglomerate]] and [[siltstone]], which were deposited in [[marine (ocean)|marine]] and non-marine environments during the [[Jurassic]] and [[Cretaceous]] periods.<ref name="AD"/> Intervening valleys, deeply incised into the Jurassic shale and sandstone, are as much as {{nowrap|{{Convert|600|m|ft|abbr=on}}}} below the base of the now deeply eroded Maitland shield volcano.<ref name="QQG"/> Most of the rugged [[topography]] of the Klappan Range formed after Maitland Volcano was built.<ref name="AD"/>
Erosional remnants of lava flows from Maitland Volcano are present as scattered, cliff-bounded cappings on higher [[mountain]]s of the Klappan Range. These flat-lying lava caps are up to {{nowrap|{{Convert|400|m|ft|abbr=on}}}} thick and contain as much as 20 separate lava flow units, each commonly {{nowrap|{{Convert|2|to|20|m|ft|abbr=on}}}} thick. Aphyric to slightly [[feldspar]]-[[phyric]] basalt is the primary [[volcanic rock]], although greenish-grey trachybasalt and pale green trachyte form the uppermost flows of thick sections.<ref name="AD"/> The highest remnant of Maitland Volcano has an elevation of {{nowrap|{{Convert|2514|m|ft|abbr=on}}}}.<ref name="QQG"/>
A cluster of 14 [[volcanic plug]]s are exposed that were originally under the central part of Maitland Volcano. These form steep-sided, isolated [[monolith]]s that reach heights of {{nowrap|{{Convert|150|m|ft|abbr=on}}}} above the surrounding eroded [[terrain]]. They are circular to elliptical in shape, ranging in diameter from {{nowrap|{{Convert|100|to|250|m|ft|abbr=on}}}}. The plugs represent the principal feeders through which the Maitland lavas reached the surface. Red oxidized [[pyroclastic rock|pyroclastic]] [[volcanic block|blocks]] surround some plugs protruding through the remaining lava flows. These probably formed not far below the surface where eruption was accompanied by vent-clearing explosions.<ref name="AD"/>
==Human history== ===Geological studies=== The remains of Maitland Volcano were first mapped and described by the [[Geological Survey of Canada]] in 1956 as part of Operation Stikine.<ref name="AD"/> They recognized the volcanic rocks capping the Klappan Range as remnants of once-extensive lava flows but noted the remnants may differ in elevation by {{nowrap|{{Convert|305|m|ft|abbr=on}}}} or more. As a result, they speculated that the remnants were not the remains of a continuous blanket of basaltic lava but fragments of individual flows poured out on a surface of considerable relief.<ref>{{cite map|publisher=[[Geological Survey of Canada]]|title=Stikine River area, Cassiar District, British Columbia|scale=1 : 253,440|cartography=Geological Cartography Unit|year=1957}}</ref> These lava flow remnants were subsequently mapped in greater detail by [[Jack Souther]] in 1972 and later by [[Hu Gabrielse]] and Howard Tipper in 1984.<ref name="AD"/>
===Naming=== ''Maitland Volcano'' is the namesake for Maitland Creek, a [[tributary]] of the [[Klappan River]] that flows from the eroded basement of Maitland Volcano.<ref name="FJ">{{cite web|url=http://apps.gov.bc.ca/pub/bcgnws/names/3975.html|title=Maitland Creek|work=[[BC Geographical Names Information System]]|publisher=[[Government of British Columbia]]|access-date=2014-12-25}}</ref><ref name="AD">{{cite book|title=Geology of the Spatsizi River Map Area, North-Central British Columbia|last=Evenchick|first=C.A.|last2=Thorkelson|first2=D.J.|year=2005|publisher=[[Geological Survey of Canada Bulletin]]|pages=15, 16, 65, 137, 138, 140, 142|isbn=0-660-19338-8}}</ref> Maitland Creek was in turn named on May 6, 1975 for William John Maitland of [[Vancouver]] who served as [[flight lieutenant]] in the [[Royal Canadian Air Force]] during [[World War II]]. Maitland was killed in action on December 16, 1943 while serving with 208 squadron on operations over Europe; he was 22 years old.<ref name="FJ"/>
In 1990, Canadian [[volcanologist]] Jack Souther gave the informal name ''Maitland volcanics'' for the remaining lava flows and volcanic plugs of Maitland Volcano. Evenchick ''et al.'' (2005) proposed ''Maitland Volcanics'' as a formal name for these volcanic rocks.<ref name="AD"/>
==See also== *[[List of volcanoes in Canada]] *[[Volcanology of Western Canada]]
==References== {{reflist}}
==External links== *{{cite web|publisher=[[Natural Resources Canada]]|url=http://www.gsc.nrcan.gc.ca/volcanoes/cat/volcano_e.php?id=svb_mvo_072|archive-url=https://web.archive.org/web/20070713224606/http://www.gsc.nrcan.gc.ca/volcanoes/cat/volcano_e.php?id=svb_mvo_072|archive-date=2007-07-13|title=Maitland Volcano|work=Catalogue of Canadian volcanoes|date=2005-08-19|access-date=2015-01-03}}
{{coord|57.4|N|129.7|W|type:mountain_region:CA_scale:100000|format=dms|display=title}} {{Northern Cordilleran volcanoes}} {{Interior Mountains}}
[[Category:Shield volcanoes of Canada]] [[Category:Volcanic plugs of British Columbia]] [[Category:Pliocene shield volcanoes]] [[Category:Polygenetic shield volcanoes]] [[Category:Stikine Country]] [[Category:Skeena Mountains]] [[Category:Two-thousanders of British Columbia]] [[Category:Extinct volcanoes of British Columbia]] [[Category:Northern Cordilleran Volcanic Province]] [[Category:Miocene British Columbia]]