Caribou Tuya is a
basalt
Basalt (; ) is an aphanite, 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 planetary surface, surface of a terrestrial ...
ic
subglacial mound
A subglacial mound (SUGM) 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 ...
in far northwestern
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, ...
that began eruptive activity under glacial ice during the Fraser glaciation (25 to 10
ka). Like
Ash Mountain and
South Tuya
South Tuya, also called Southern Tuya, is a tuya clustered around Tuya Lake in the Northern Cordilleran Volcanic Province in British Columbia, Canada. The base of South Tuya comprises hyaloclastite and pillow lava indicating that the volcano forme ...
, sections of the subglacial mound reveal a consistent stratigraphic progression from
pillow lava
Pillow lavas are lavas that contain characteristic pillow-shaped structures that are attributed to the extrusion of the lava underwater, or ''subaqueous extrusion''. Pillow lavas in volcanic rock are characterized by thick sequences of disconti ...
s to
hyaloclastite
Hyaloclastite is a volcanoclastic accumulation or breccia consisting of glass (from the Greek ''hyalus'') fragments (clasts) formed by quench fragmentation of lava flow surfaces during submarine or subglacial extrusion. It occurs as thin margin ...
deposits from the base upward. Locally the sections are capped by subaerial basaltic
lava flows
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 ...
. Samples of the glassy
pillow 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% of a ...
s and hyaloclastites along with
crystalline
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macrosc ...
basalt flows were collected at Caribou Tuya. The volcano is believed to have formed and last erupted 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 ...
Epoch.
See also
*
List of volcanoes in Canada
List of volcanoes in Canada is an incomplete list of volcanoes found in Mainland Canada, in the Canadian islands and in Canadian waters. All but one province, Prince Edward Island, have at least one volcano.
Alberta
British Columbia
Ne ...
*
List of Northern Cordilleran volcanoes
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 Canad ...
*
Volcanism of Canada
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, calder ...
*
Volcanism of Western Canada
Volcanism of Western Canada has produced lava flows, lava plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, greenstone belts, submarine volcanoes, calderas, diatremes and maars, along with examples of more less common volcanic ...
*
Volcanic history of the Northern Cordilleran Volcanic Province
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 ...
References
Cassiar Country
One-thousanders of British Columbia
Volcanoes of British Columbia
Subglacial mounds of Canada
Northern Cordilleran Volcanic Province
Stikine Ranges
Pleistocene volcanoes
Monogenetic volcanoes
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