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Pyramid Mountain (volcano)
Encyclopedia
Pyramid Mountain is a subglacial mound
located on the Murtle Plateau
in Wells Gray Provincial Park
, east-central British Columbia
, Canada
.
and is now known to have erupted underneath about 1600 m (5,249 ft) of glacial ice. The volcano erupted vigorously and cooled rapidly when the hot lava contacted the surrounding ice and melted it, creating an envelope of water around the rising volcano. The result was a cement-like surface with smoothed cobbles of granite
, schist
, phyllite
and other non-volcanic pebbles which were carried by the ice from many kilometers distant. As a result of this type of eruption, Pyramid Mountain has no crater and no lava flows stretching away from its base. The secondary cone to the east (best seen from Clearwater Valley Road near Hemp Creek) was not formed by a separate eruption, but was simply a slump when the ice melted away from Pyramid, releasing the pressure against its slopes.
The trail to the top of Pyramid Mountain starts at Pyramid Campground. It is 4 km (2.5 mi) to the summit. The view is mostly southward to Trophy Mountain
, Battle Mountain
and Dunn Peak
. The Murtle River
flows along the east and south sides of Pyramid. In some weather conditions, the plume of spray over Helmcken Falls
can be seen to the west.
Subglacial mound
A subglacial mound is a type of subglacial volcano. This type of volcano forms when lava erupts beneath a thick glacier or ice sheet. The magma forming these volcanoes was not hot enough to melt a vertical pipe right through the overlying glacial ice, instead forming hyaloclastite and pillow lava...
located on the Murtle Plateau
Murtle River
The Murtle River is a river in east-central British Columbia, Canada. It rises from a large unnamed glacier in the Cariboo Mountains at an elevation of and flows southwest for to the head of gigantic Murtle Lake. The river also drains Murtle Lake then flows southwest for into the Clearwater...
in Wells Gray Provincial Park
Wells Gray Provincial Park
Wells Gray Provincial Park is a large wilderness park located in east-central British Columbia, Canada. The park protects most of the southern, and highest, regions of the Cariboo Mountains and covers 5,250 square kilometres...
, east-central British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
.
Formation
Pyramid Mountain erupted about 11,000 years ago. It was once mistaken for a cinder coneCinder cone
According to the , Cinder Cone is the proper name of 1 cinder cone in Canada and 7 cinder cones in the United States:In Canada: Cinder Cone In the United States:...
and is now known to have erupted underneath about 1600 m (5,249 ft) of glacial ice. The volcano erupted vigorously and cooled rapidly when the hot lava contacted the surrounding ice and melted it, creating an envelope of water around the rising volcano. The result was a cement-like surface with smoothed cobbles of granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...
, schist
Schist
The schists constitute a group of medium-grade metamorphic rocks, chiefly notable for the preponderance of lamellar minerals such as micas, chlorite, talc, hornblende, graphite, and others. Quartz often occurs in drawn-out grains to such an extent that a particular form called quartz schist is...
, phyllite
Phyllite
Phyllite is a type of foliated metamorphic rock primarily composed of quartz, sericite mica, and chlorite; the rock represents a gradation in the degree of metamorphism between slate and mica schist. Minute crystals of graphite, sericite, or chlorite impart a silky, sometimes golden sheen to the...
and other non-volcanic pebbles which were carried by the ice from many kilometers distant. As a result of this type of eruption, Pyramid Mountain has no crater and no lava flows stretching away from its base. The secondary cone to the east (best seen from Clearwater Valley Road near Hemp Creek) was not formed by a separate eruption, but was simply a slump when the ice melted away from Pyramid, releasing the pressure against its slopes.
Access
Pyramid Mountain can be viewed from Wells Gray Park roads at three locations:- 1 km south of Hemp Creek on Clearwater Valley Road
- Green Mountain viewing tower (see picture above)
- Majerus Farm trailhead on Clearwater Valley Road
The trail to the top of Pyramid Mountain starts at Pyramid Campground. It is 4 km (2.5 mi) to the summit. The view is mostly southward to Trophy Mountain
Trophy Mountain
Trophy Mountain is a mountain in east-central British Columbia, Canada, located in the south-east region of Wells Gray Provincial Park. The Clearwater River flows to the west, Raft River to the east and Spahats Creek to the south. Trophy Mountain is part of the Shuswap Highland...
, Battle Mountain
Battle Mountain (British Columbia)
Battle Mountain is a mountain in east-central British Columbia, Canada, located in the south-east region of Wells Gray Provincial Park. The Clearwater River flows to the west, Stevens Lakes are to the east, Philip Creek is to the south and Hemp Creek is to the north. Battle Mountain is part of the...
and Dunn Peak
Dunn Peak massif
The Dunn Peak massif is a group of peaks in the central Interior of British Columbia, Canada. Its most prominent summit, Matterhorn Peak, rises to , making it the highest point in the Shuswap Highland....
. The Murtle River
Murtle River
The Murtle River is a river in east-central British Columbia, Canada. It rises from a large unnamed glacier in the Cariboo Mountains at an elevation of and flows southwest for to the head of gigantic Murtle Lake. The river also drains Murtle Lake then flows southwest for into the Clearwater...
flows along the east and south sides of Pyramid. In some weather conditions, the plume of spray over Helmcken Falls
Helmcken Falls
Helmcken Falls is a waterfall on the Murtle River within Wells Gray Provincial Park in British Columbia, Canada. The protection of Helmcken Falls was one of the reasons for the creation of Wells Gray Provincial Park in 1939....
can be seen to the west.
See also
- List of volcanoes in Canada
- Volcanism of Canada
- Volcanism of Western CanadaVolcanism of Western CanadaVolcanism of Western Canada produces lava flows, lava plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calderas, diatremes and maars, along with examples of more less common volcanic forms such as tuyas and subglacial mounds.-Volcanic belts:*Anahim...
- Wells Gray-Clearwater volcanic fieldWells Gray-Clearwater volcanic fieldThe Wells Gray-Clearwater volcanic field, also called the Clearwater Cone Group, is a potentially active monogenetic volcanic field in east-central British Columbia, Canada, located approximately north of Kamloops. It is situated in the Cariboo Mountains of the Columbia Mountains and on the...