Nazko Cone is a small potentially active

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 ...

cinder cone A cinder cone (or scoria cone) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruption ...

in central

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 ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

, located 75 km west of

Quesnel Quesnel or Quesnell means "little oak" in the Picard language, Picard dialect of French language, French. It is used as a proper name and may refer to: Places * Le Quesnel, a commune the Somme department in France * Quesnel, British Columbia, a c ...

and 150 kilometers southwest of Prince George. It is considered the easternmost volcano in the

Anahim Volcanic Belt The Anahim Volcanic Belt (AVB) is a west–east trending chain of volcanoes and related magmatic features in British Columbia, Canada. It extends from Athlone Island on the Central Coast, running eastward through the strongly uplifted and deeply ...

. The small

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

-covered cone rises 120 m above the Chilcotin- Nechako Plateau and rests on glacial till. It was formed in three episodes of activity, the first of which took place during the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

interglacial stage about 340,000 years ago. The second stage produced a large hyaloclastite scoria mound erupted beneath the Cordilleran Ice Sheet during the Pleistocene. Its last eruption produced two small

lava flow 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 un ...

s that traveled 1 km to the west, along with a blanket of

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer ...

that extends several km to the north and east of the cone.

Geology and history

Origins

Nazko Cone probably began erupting about 340,000 years ago and has grown steadily since then. Like all of the Anahim volcanoes, Nazko Cone has its origins in the

Anahim hotspot The Anahim hotspot is a hypothesized hotspot in the Central Interior of British Columbia, Canada. It has been proposed as the candidate source for volcanism in the Anahim Volcanic Belt, a long chain of volcanoes and other magmatic features th ...

—a plume of magma rising from deep in the Earth's

mantle A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that. Mantle may refer to: *Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear **Mantle (vesture), an Eastern Orthodox ve ...

. The hotspot remains in a fixed position, while the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Paci ...

drifts over it at a rate of 2 to 3.3 centimetres per year. The upwelling of the hot magma creates volcanoes, and each individual volcano erupts for a few million years before the movement of the plate carries it away from the rising magma. The hotspot has existed for at least 13 million years, and the Anahim Volcanic Belt stretches almost 600 kilometres (400 mi) away from the hotspot. Currently, the hotspot lies under Nazko Cone, which is the youngest volcano in the Anahim Volcanic Belt.

7200 BP Eruption of Nazko Cone

The eruptive cycle of Nazko Cone 7200 years ago started with the eruption of two different progressions of fluid

s, an older grey basalt overlain by a younger, darker black basalt. The passive eruptions were followed by a period of

explosive eruption In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma su ...

s.Natural Resources Canada: Nazko Cone
This explosive activity built three overlapping cinder cones near the end of the explosive phase of activity. The last phase of explosive activity spread tephra to the north and east of the cones. The deepest deposits near the cones are over 3 m deep and thin to less than a few centimetres only a few kilometres away, which suggests that the explosive eruptions at Nazko Cone were fairly small. However, the last eruption from Nazko Cone could have started

forest fire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...

s, since there is

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ...

inside the

tephra Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they r ...

layer.

Recent activity

The volcano has been dormant since the 7200 BP eruption. On October 10, 2007, a small swarm of earthquakes appeared 20 kilometres west of Nazko Cone.Chronology of Events in 2007 at Nazko Cone
Most of these earthquakes were magnitude 1.0 or less; some as strong as M 3.1 or 3.2 were centered 25 kilometres below the surface. The cause of this seismic activity is believed to be the upwelling of

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natura ...

because the area is not close to any faults or

tectonic plate Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large te ...

boundaries.

Hazards

Future eruptions from Nazko Cone are unlikely to cause many fatalities, due to the region's remoteness. There is active

logging Logging is the process of cutting, processing, and moving trees to a location for transport. It may include skidding, on-site processing, and loading of trees or logs onto trucks or skeleton cars. Logging is the beginning of a supply cha ...

and

ranch A ranch (from es, rancho/Mexican Spanish) is an area of land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of a farm. These terms are most ofte ...

ing in the region, and people engaged in these activities are at some risk. Lava flows are likely to flow only a few kilometres from the volcano which could possibly start

s in the dry region. Any future eruption is likely to affect low flying air traffic only, since eruptions would likely be in the form of

Hawaiian eruption A Hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle, low level eruption; it is so named because it is characteristic of Hawaiian volcanoes. Typically they are effusive eruptions, with basaltic ...

lava fountain 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 ...

s that create small

s and lava flows rather than voluminous ash clouds.

Monitoring

Nazko Cone has been an intensively monitored volcano by the Geological Survey of Canada since October 10, 2007. One of the most important tools is seismometry. About 5

seismometer A seismometer is an instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The outpu ...

s were set up around Nazko Cone to enable scientists to measure the intensities and locations of hundreds of small earthquakes every day. Since then, there have been more than 1000 small earthquakes recorded. Earthquakes can begin to increase years before an eruption actually starts. Another type of seismic activity occurs in the hours preceding an eruption. So-called harmonic tremor is a continuous "rumble" which contrasts with the normal seismic activity of sudden shocks and is believed to be caused by the rapid movement of magma underground. Volcanic tremor normally indicates an imminent eruption, although it may also be caused by shallow intrusions of magma which do not reach the surface. Another important indicator of what is happening underground is the shape of the volcano. Tiltmeters measure very small changes in the profile of the volcano, and sensitive equipment measures distances between points on the volcano. As magma fills the shallow reservoirs below the summit, the mountain inflates.

Recent history

Nazko Cone was staked for

mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the econom ...

its cinder and scoria in the early 1990s by the Canadian Pumice Corporation, and has since been steadily reduced to produce red industrial aggregate for landscaping. Before mining, the Nazko Cone was also a unique ecosystem. The vegetation included a complex of species. Very large old

Douglas fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three v ...

trees were common, growing in some of the more soil-like ash 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 moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or ...

White spruce White spruce is a common name for several species of spruce (''Picea'') and may refer to: * ''Picea glauca'', native to most of Canada and Alaska with limited populations in the northeastern United States * ''Picea engelmannii ''Picea engelman ...

was surprisingly common, although severely stunted, whereas lodgepole pine was not. There were some shallow

cave A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...

s and hollows below the volcano. To the west, following the lava flow mentioned above, is a unique

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...

which appears to be saturated ash. What makes it unique is the fact that normally wetlands are saturated organic material such as

peat moss ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...

. The wetland at Nazko Cone, however, is mixed organic and lava or ash, and the resultant ecosystem is quite unexpected.

Geothermal Potential

High heat flow in the Nazko Cone area is being evaluated as a potential source of geothermal heating.

References

External links

*
Volcano World description
{{Anahim Volcanic Belt Anahim Volcanic Belt Cinder cones of British Columbia VEI-3 volcanoes Pleistocene volcanoes Holocene volcanoes Polygenetic cinder cones Cariboo Land District One-thousanders of British Columbia