Slag Hill
Encyclopedia
Slag Hill is a subglacial volcano
associated with the Mount Cayley volcanic field
in British Columbia
, Canada
. It consists of glassy, augite
-phyric basaltic andesite
in steep-sided, glassy, finely jointed domes and one small, flat-topped bluff
. The finely jointed domes are similar to those of Ember Ridge
. There are quench features at Slag Hill, which is suggesting that the volcanic activity was subglacial
. Slag Hill was formed throughout the Pleistocene
period, but its most recent volcanic activity produced a lava flow on its western lobe that shows no evidence of ice-contact volcanism. This indicates the lava flow was erupted less than 10,000 years ago after the last glacial period.
Subglacial volcano
A subglacial volcano, also known as a glaciovolcano, is a volcanic form produced by subglacial eruptions or eruptions beneath the surface of a glacier or ice sheet which is then melted into a lake by the rising lava...
associated with the Mount Cayley volcanic field
Mount Cayley volcanic field
The Mount Cayley volcanic field is a remote volcanic zone on the South Coast of British Columbia, Canada, stretching from the Pemberton Icefield to the Squamish River. It forms a segment of the Garibaldi Volcanic Belt, the Canadian portion of the Cascade Volcanic Arc, which extends from Northern...
in 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...
. It consists of glassy, augite
Augite
Augite is a single chain inosilicate mineral, 2O6. The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees.-Characteristics:Augite is a solid solution in the pyroxene group...
-phyric basaltic andesite
Basaltic andesite
Basaltic andesite is a black volcanic rock containing about 55% silica. Minerals in basaltic andesite include olivine, augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central America and the Andes of South America. Basaltic andesite is common in...
in steep-sided, glassy, finely jointed domes and one small, flat-topped bluff
Hill
A hill is a landform that extends above the surrounding terrain. Hills often have a distinct summit, although in areas with scarp/dip topography a hill may refer to a particular section of flat terrain without a massive summit A hill is a landform that extends above the surrounding terrain. Hills...
. The finely jointed domes are similar to those of Ember Ridge
Ember Ridge
Ember Ridge is a volcanic mountain ridge associated with the Mount Cayley volcanic field in British Columbia, Canada. Ember Ridge is made of a series of steep-sided domes of glassy, complexly jointed, hornblende-phyric basalt with the most recent eruptions during the Holocene...
. There are quench features at Slag Hill, which is suggesting that the volcanic activity was subglacial
Subglacial eruption
A subglacial eruption is a volcanic eruption that has occurred under ice, or under a glacier. Subglacial eruptions can cause dangerous floods, lahars and create hyaloclastite and pillow lava. Subglacial eruptions sometimes form a subglacial volcano called a tuya. Tuyas in Iceland are called table...
. Slag Hill was formed throughout the Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
period, but its most recent volcanic activity produced a lava flow on its western lobe that shows no evidence of ice-contact volcanism. This indicates the lava flow was erupted less than 10,000 years ago after the last glacial period.
See also
- Mount CayleyMount CayleyMount Cayley is a potentially active stratovolcano in Squamish-Lillooet Regional District of southwestern British Columbia, Canada. Located north of Squamish and west of Whistler in the Pacific Ranges of the Coast Mountains, it rises above the Squamish River to the west and above the Cheakamus...
- Cascade VolcanoesCascade VolcanoesThe Cascade Volcanoes are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 mi ...
- Garibaldi Volcanic BeltGaribaldi Volcanic BeltThe Garibaldi Volcanic Belt, also called the Canadian Cascade Arc, is a northwest-southeast trending volcanic chain in the Pacific Ranges of the Coast Mountains that extends from Watts Point in the south to the Ha-Iltzuk Icefield in the north. This chain of volcanoes is located in southwestern...
- 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...