The geography of northwestern British Columbia and Yukon, Canada is dominated by volcanoes of the Northern Cordilleran Volcanic Province formed due to continental rifting of the North American Plate. It is the most active volcanic region in Canada. [1] Some of the volcanoes are notable for their eruptions, for instance, Tseax Cone for its catastrophic eruption estimated to have occurred in the 18th century which was responsible for the death of at least 2,000 Nisga'a people from poisonous volcanic gases, [2] the Mount Edziza volcanic complex for at least 20 eruptions throughout the past 10,000 years, and The Volcano (also known as Lava Fork volcano) for the most recent eruption in Canada during 1904. [3] The majority of volcanoes in the Northern Cordilleran Volcanic Province lie in Canada while a very small portion of the volcanic province lies in the U.S. state of Alaska.
Volcanoes of the Northern Cordilleran Volcanic Province are a part of the Pacific Ring of Fire. The largest and most persistent volcanoes are the Mount Edziza volcanic complex and Level Mountain in northwestern British Columbia which have had volcanic activity for millions of years. In the past 7.5 million years, the Mount Edziza volcanic complex has had five phases of volcanic activity while Level Mountain north of Edziza has had three phases of volcanic activity in the past 14.9 million years. [4] The 1,000 km2 (390 sq mi) Mount Edziza volcanic complex has been made into a provincial park since 1972 to protect its volcanic landscape. The 102 Northern Cordilleran volcanoes in the list below are grouped into their political regions in north–south order.
There is no single standard definition for a volcano. It can be defined from individual vents, volcanic edifices or volcanic fields. Interior of ancient volcanoes may have been eroded, creating a new subsurface magma chamber as a separate volcano. Many contemporary volcanoes rise as young parasitic cones from flank vents or at a central crater. Some volcanoes are grouped into one volcano name, for instance, the Mount Edziza volcanic complex, although individual vents are named by local people. The status of a volcano, either active, dormant or extinct, cannot be defined precisely. An indication of a volcano is determined by either its historical records, potassium-argon dating, radiocarbon dating, or geothermal activities.
The primary source of the list below is taken from the Geological Survey of Canada website, compiled by the Earth Sciences Sector of Natural Resources Canada, in which Northern Cordilleran volcanoes in the past 66.4 million years are listed. [5] The Geological Survey of Canada use a catalogue of volcanoes grouped by volcano fields, lava fields and mountain ranges. [5] The Geological Survey of Canada list is the most complete list of volcanoes in the Northern Cordilleran Volcanic Province, but work of understanding the frequency and eruption characteristics at volcanoes in Canada is a slow process. [6] This is because most of Canada's dormant and potentially active volcanoes are located in isolated jagged regions, very few scientists study Canadian volcanoes and the provision of money in the Canadian government is limited. [6] Because of these issues, scientists that study Canada's volcanoes have a basic understanding of Canada's volcanic heritage and how it might impact people in the future. [6] Therefore, instead of using the dates of recorded eruptions, the Geological Survey of Canada mostly uses geological epochs for estimating when a volcano last erupted. Geological epoches include the Cenozoic (66.4 million years ago to present) [7] and its subdivisions Miocene (23.7 to 5.3 million years ago), [8] Pliocene (5.3 to 1.6 million years ago), [9] Quaternary (1.6 million years ago to present), [10] Pleistocene (1.6 to 0.01 million years ago) [11] and Holocene (0.01 million years ago to present). [12]
The northernmost portion of the Northern Cordilleran Volcanic Province extends just across the Alaska-Yukon border into the Southeast Fairbanks Census Area of eastcentral Alaska. Here, a single cinder cone, dated at 177,000 years old occurs within the metamorphic and granitic composed upland of the Yukon–Tanana Terrane. [4] [13] Prindle Volcano is approximately 31 km (19 mi) west of the Alaska-Yukon border. [4]
Volcanoes | |||
---|---|---|---|
Name | Type | Last eruption | Location |
Prindle Volcano | Cinder cone | Pleistocene | 63°43′N141°37′W / 63.72°N 141.62°W |
The central portion of the Northern Cordilleran Volcanic Province extends through Yukon where very few Northern Cordilleran volcanoes exist. Near the junction of the Yukon and Pelly rivers in central Yukon lies the Fort Selkirk Volcanic Field. [14] It is the northernmost Holocene age volcanic field in Canada, consisting of a sequence of valley-filling basalt and basanite lava flows. [14] Further south near the capital city of Whitehorse, a group of volcanoes and lava flows were constructed near Alligator Lake possibly in the past 10,000 years. [15]
Over half of the Northern Cordilleran volcanoes are located in northwestern British Columbia. This portion is where the most recent eruptions in Canada and of the Northern Cordilleran Volcanic Province have occurred, including the catastrophic 18th century eruption of Tseax Cone and the 1904 eruption of The Volcano. [3] [16]
The Northern Cordilleran volcanoes of British Columbia comprises shield volcanoes, stratovolcanoes, subglacial volcanoes, lava domes and a large number of small cinder cones and associated lava plains. [4] The Northern Cordilleran volcanoes of northwestern British Columbia are disposed along short, northerly trending segments which are unmistakably involved with north-trending rift structures including synvolcanic grabens and grabens with one major fault line along only one of the boundaries (half-grabens) similar to those associated with the East African Rift, which extends from the Afar Triple Junction southward across eastern Africa. [4]
The Northern Cordilleran Volcanic Province (NCVP), formerly known as the Stikine Volcanic Belt, is a geologic province defined by the occurrence of Miocene to Holocene volcanoes in the Pacific Northwest of North America. This belt of volcanoes extends roughly north-northwest from northwestern British Columbia and the Alaska Panhandle through Yukon to the Southeast Fairbanks Census Area of far eastern Alaska, in a corridor hundreds of kilometres wide. It is the most recently defined volcanic province in the Western Cordillera. It has formed due to extensional cracking of the North American continent—similar to other on-land extensional volcanic zones, including the Basin and Range Province and the East African Rift. Although taking its name from the Western Cordillera, this term is a geologic grouping rather than a geographic one. The southmost part of the NCVP has more, and larger, volcanoes than does the rest of the NCVP; further north it is less clearly delineated, describing a large arch that sways westward through central Yukon.
Mount Edziza, sometimes called Edziza Mountain or Edziza Peak, is a stratovolcano in Cassiar Land District of northwestern British Columbia, Canada. It is located on the Big Raven Plateau of the Tahltan Highland which extends along the western side of the Stikine Plateau. The mountain has an elevation of 2,786 metres, making it the highest volcano of the Mount Edziza volcanic complex. However, it had an elevation of at least 3,396 metres before its original summit was likely destroyed by a violent, climactic eruption in the geologic past; its current flat summit contains an ice-filled, 2-kilometre (1.2-mile) in diameter crater. Mount Edziza contains several lava domes, cinder cones and lava fields on its flanks, as well as an ice cap that is characterized by several outlet glaciers stretching out to lower altitudes. All sides of the mountain are drained by tributaries of Mess Creek and Kakiddi Creek which are situated within the Stikine River watershed.
Heart Peaks, originally known as the Heart Mountains, is a mountain massif in the Northern Interior of British Columbia, Canada. It is 90 km (56 mi) northwest of the small community of Telegraph Creek and just southwest of Callison Ranch. With a maximum elevation of 2,012 m (6,601 ft), it rises above the surrounding landscape on the Nahlin Plateau, which is part of the western Stikine Plateau. Heart Peaks has been an area of prospecting since the 1980s with the discovery of precious metals.
The Spectrum Range, formerly gazetted as the Spectrum Mountains and the Rainbow Mountains, is a small mountain range in Cassiar Land District of northwestern British Columbia, Canada. Located at the southern end of the Tahltan Highland, it borders the Skeena Mountains in the east and the Boundary Ranges of the Coast Mountains in the west. The Spectrum Range is surrounded by the Arctic Lake Plateau in the southwest and the Kitsu Plateau in the northwest, both of which contain volcanic features such as cinder cones. It lies at the southern end of the Mount Edziza volcanic complex which includes the two neighbouring plateaus as well as Mount Edziza and the Big Raven Plateau to the north. The mountain range is drained on all sides by streams within the Stikine River watershed and, unlike Mount Edziza to the north, contains relatively small separate glaciers. Mount Edziza Provincial Park is the main protected area surrounding the Spectrum Range.
The Atlin Volcanic Field, also called the Llangorse Volcanic Field and the Surprise Lake Volcanic Field, is a group of late-Pleistocene to Holocene cinder cones that lies on the Teslin Plateau east of Atlin Lake, Canada. The largest volcanic feature is the 1880-m-high Ruby Mountain which has been partially dissected by Pleistocene and post-Wisconsin glaciation. Two basaltic cinder cones at the heads of Cracker Creek and Volcanic Creek lie within glacially dissected U-shaped valleys and may be of postglacial age.
Tseax Cone is a small volcano in the Nass Ranges of the Hazelton Mountains in northwestern British Columbia, Canada. It has an elevation of 609 metres and lies within an east–west valley through which a tributary of the Tseax River flows. The volcano consists of two nested structures and was the source of four lava flows that descended into neighbouring valleys. A secondary eruptive centre lies just north of Tseax Cone on the opposite side of a lava-dammed lake. It probably formed simultaneously with Tseax Cone but the timing of volcanism at the two centres is not precisely known; they were both active sometime in the last 800 years. The area has been designated as a provincial park to protect these features.
Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes, and maars, along with less common volcanic forms such as tuyas and subglacial mounds.
The geology of the Pacific Northwest includes the composition, structure, physical properties and the processes that shape the Pacific Northwest region of North America. The region is part of the Ring of Fire: the subduction of the Pacific and Farallon Plates under the North American Plate is responsible for many of the area's scenic features as well as some of its hazards, such as volcanoes, earthquakes, and landslides.
Prindle Volcano is an isolated basaltic cinder cone located in eastern Alaska, United States, in the headwaters of the East Fork of the Fortymile River, approximately 80 kilometers northeast of Tok, Alaska. The cone is fresh-looking and has a base approximately 900 metres wide. It is the northwesternmost expression of the Northern Cordilleran Volcanic Province. The cinder cone, and an approximately 11-kilometre (6.8-mile) long lava flow which breached the margin of the cone, erupted in the Pleistocene approximately 176,000 years ago. The lava flow extends to the southeast, then turns southwest and continues in a river valley.
Maitland Volcano is a heavily eroded shield volcano in the Northern Interior of British Columbia, Canada. It is 83 km (52 mi) 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 landforms created when magma hardened within the vents of the volcano.
The Silverthrone Caldera is a potentially active caldera complex in southwestern British Columbia, Canada, located over 350 kilometres (220 mi) northwest of the city of Vancouver and about 50 kilometres (31 mi) west of Mount Waddington in the Pacific Ranges of the Coast Mountains. The caldera is one of the largest of the few calderas in western Canada, measuring about 30 kilometres (19 mi) long (north-south) and 20 kilometres (12 mi) wide (east-west). Mount Silverthrone, an eroded lava dome on the caldera's northern flank that is 2,864 metres (9,396 ft) high, may be the highest volcano in Canada.
Tennena Cone, alternatively Icebridge Cone, is a small volcanic cone in Cassiar Land District of northwestern British Columbia, Canada. It has an elevation of 2,390 metres and lies on the western flank of Ice Peak, the prominent south peak of Mount Edziza. The cone is almost completely surrounded by glacial ice of Mount Edziza's ice cap which covers an area of around 70 square kilometres. Tennena Cone is 200 metres high, 1,200 metres long and up to 600 metres wide, its symmetrical structure resembling a black pyramid. The cone and the surrounding area are in Mount Edziza Provincial Park which also includes the Spectrum Range to the south.
The Mount Edziza volcanic complex is a group of volcanoes and associated lava flows in northwestern British Columbia, Canada. Located on the Tahltan Highland, it is 40 kilometres southeast of Telegraph Creek and 85 kilometres southwest of Dease Lake. The complex encompasses a broad, steep-sided lava plateau that extends over 1,000 square kilometres. Its highest summit is 2,786 metres in elevation, making the MEVC the highest of four large complexes in an extensive north–south trending volcanic region. It is obscured by an ice cap characterized by several outlet glaciers that stretch out to lower altitudes.
Volcanism in Northern Canada has produced hundreds of volcanic areas and extensive lava formations across Northern Canada. The region's different volcano and lava types originate from different tectonic settings and types of volcanic eruptions, ranging from passive lava eruptions to violent explosive eruptions. Northern Canada has a record of very large volumes of magmatic rock called large igneous provinces. They are represented by deep-level plumbing systems consisting of giant dike swarms, sill provinces and layered intrusions.
Fort Selkirk Vent is a geological name for a cinder cone in central Yukon, Canada, located just east of Fort Selkirk along the Yukon River.
The Volcano, also known as Lava Fork volcano, is a small cinder cone in the Boundary Ranges of the Coast Mountains in northwestern British Columbia, Canada. It is located approximately 60 km (40 mi) northwest of the small community of Stewart near the head of Lava Fork. With a summit elevation of 1,656 m (5,433 ft) and a topographic prominence of 311 m (1,020 ft), it rises above the surrounding rugged landscape on a remote mountain ridge that represents the northern flank of a glaciated U-shaped valley.
The volcanic history of the Northern Cordilleran Volcanic Province presents a record of volcanic activity in northwestern British Columbia, central Yukon and the U.S. state of easternmost Alaska. The volcanic activity lies in the northern part of the Western Cordillera of the Pacific Northwest region of North America. Extensional cracking of the North American Plate in this part of North America has existed for millions of years. Continuation of this continental rifting has fed scores of volcanoes throughout the Northern Cordilleran Volcanic Province over at least the past 20 million years and occasionally continued into geologically recent times.
Jack Gordon Souther was an American-born Canadian geologist, volcanologist, professor and engineer. He contributed significantly to the early understanding of recent volcanic activity in the Canadian Cordillera. Many of his publications continue to be regarded as classics in their field, even now several decades after they were written.
The Canadian Cascade Arc, also called the Canadian Cascades, is the Canadian segment of the North American Cascade Volcanic Arc. Located entirely within the Canadian province of British Columbia, it extends from the Cascade Mountains in the south to the Coast Mountains in the north. Specifically, the southern end of the Canadian Cascades begin at the Canada–United States border. However, the specific boundaries of the northern end are not precisely known and the geology in this part of the volcanic arc is poorly understood. It is widely accepted by geologists that the Canadian Cascade Arc extends through the Pacific Ranges of the Coast Mountains. However, others have expressed concern that the volcanic arc possibly extends further north into the Kitimat Ranges, another subdivision of the Coast Mountains, and even as far north as Haida Gwaii.
The Mount Edziza volcanic complex (MEVC) in British Columbia, Canada, has a long history of volcanism that spans more than 7 million years. It occurred during five cycles of magmatic activity, each producing less volcanic material than the previous one. Volcanism during these cycles has created several types of volcanoes, including cinder cones, stratovolcanoes, subglacial volcanoes, shield volcanoes and lava domes. The approximately 1,000-square-kilometre (400-square-mile) volcanic plateau forming the base of the MEVC owes its origin to successive eruptions of highly mobile lava flows. Volcanic rocks such as basalt, trachybasalt, benmoreite, tristanite, mugearite, trachyte and rhyolite were deposited by multiple eruptions of the MEVC; the latter seven rock types are products of varying degrees of magmatic differentiation in underground magma reservoirs. At least 10 distinct flows of obsidian were produced by volcanism of the MEVC, some of which were exploited by indigenous peoples in prehistoric times to make tools and weaponry. Renewed volcanism could produce explosive eruptions and block local streams with lava flows.