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Pylon Assemblage
The Pylon Assemblage is an accreted terrane of igneous rocks in southwestern British Columbia, Canada, located about north of Vancouver. It is named after Pylon Peak, a summit of the Mount Meager massif. Two units make up the Pylon Assemblage, although the youngest unit comprises nearly 100% of the assemblage. On the southern flank of Pylon Peak, the oldest unit consists of andesitic lava flows. It locally overlies The Devastator Assemblage and older basal breccia. Porphyritic plagioclase andesite of the youngest unit underlies much of the southern and western portions of Meager. Devastator Peak, a volcanic plug at the southern end of the Meager massif, was the source for these lava flows between 1,000,000 and 500,000 years ago. The Pylon Assemblage represents the largest geological formation comprising Meager. See also *Mosaic Assemblage *Job Assemblage * Capricorn Assemblage *Plinth Assemblage *Volcanism of Western Canada *List of Cascade volcanoes *List of volcanoes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terrane
In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own distinctive geologic history, which is different from that of the surrounding areas—hence the term "exotic" terrane. The suture zone between a terrane and the crust it attaches to is usually identifiable as a fault. A sedimentary deposit that buries the contact of the terrane with adjacent rock is called an overlap formation. An igneous intrusion that has intruded and obscured the contact of a terrane with adjacent rock is called a stitching pluton. Older usage of ''terrane'' simply described a series of related rock formations or an area having a preponderance of a particular rock or rock groups. Overview A tectonostratigraphic terrane is not necessarily an independent microplate in origin, since it may not contain the full thickness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devastator Peak
Devastator Peak, also known as The Devastator, is the lowest and southernmost of the six subsidiary peaks that form the Mount Meager massif in southwestern British Columbia, Canada. It is located west of Bralorne. Geology Devastator Peak is a dissected andesitic volcanic plug, which was part of a larger structure of Mount Meager, but parts eroded away, leaving Devastator Peak. Like the rest of the Mount Meager massif, it is part of the Garibaldi Volcanic Belt which is a segment of the Cascade Volcanic Arc, but it is not within the geographic boundary of the Cascade Range. Devastator Peak was the source for a thick sequence of andesite lava flows that occurred 0.5-1.0 million years ago. Erosional remnants of these flows form the stratified crags of Pylon Peak. The slopes of the peak are highly unstable, consisting of weak, hydrothermally altered felsic rocks. There have been many recent debris flows which have flowed down into the Meager Creek drainage. See also * List of vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism Of British Columbia
Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called a vent. It includes all phenomena resulting from and causing magma within the crust or mantle of the body, to rise through the crust and form volcanic rocks on the surface. Magmas, that reach the surface and solidify, form extrusive landforms. Volcanic processes Magma from the mantle or lower crust rises through the crust towards the surface. If magma reaches the surface, its behavior depends on the viscosity of the molten constituent rock. Viscous (thick) magma produces volcanoes characterised by explosive eruptions, while non-viscous (runny) magma produce volcanoes characterised by effusive eruptions pouring large amounts of lava onto the surface. In some cases, rising magma can cool and solidify without reaching the surface. Instead, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 New Brunswick Newfoundland and Labrador Northwest Territories Nova Scotia Nunavut Ontario Quebec Saskatchewan Yukon See also * Outline of Canada * Bibliography of Canada * Index of Canada-related articles * Volcanism of Canada ** Volcanism of Northern Canada ** Volcanism of Western Canada ** Volcanism of Eastern Canada ** List of Northern Cordilleran volcanoes * List of mountains in Canada * List of Cascade volcanoes External links Catalogue of Canadian Volcanoes {{Canadian volcanism Canada Volcanoes Volcanoes Volcanoes A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Cascade Volcanoes
This is a list of Cascade volcanoes, i.e. volcanoes formed as a result of subduction along the Cascadia subduction zone in the Pacific Northwest of North America. The volcanoes are listed from north to south, by province or state: British Columbia, Washington, Oregon, and California. British Columbia Washington Oregon California See also *List of volcanoes in the United States *List_of_volcanoes_in_Canada.html" ;"title="/[Https://www.sci.news/geology/puhahonu-shield-volcano-08435.html Puhahonu ... *List of volcanoes in Canada">/[Https://www.sci.news/geology/puhahonu-shield-volcano-08435.html Puhahonu ... *List of volcanoes in Canada *Volcanology of Canada *Volcanology of Western Canada *List of Northern Cordilleran volcanoes *Lists of volcanoes Notes References {{Reflist * Cascades Volcanoes Geography of the Pacific Northwest *Cascade Volcanoes Cascade Volcanoes *Cascade Volcanoes Cascade Vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 forms such as tuyas and 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 ...s. Volcanic belts * * * * * * * * * External links Erica A. Massey: A Comparative Study of Glaciovolcanic Palagonitization of Tholeitic and Alkaline Sideromelane in Helgafell, Icland, and Wells Gray-Clearwater Volcanic Filed, BC, Canada. B.Sc., The University of British Columbia, 2014 Volcanic fields * * * See also * * * * ReferencesVolcanoes of Canada . . . . {{Manitoba-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plinth Assemblage
The Plinth Assemblage, also known as the Plinth Formation, is an accreted terrane of igneous rocks in southwestern British Columbia, Canada, located just north of the Lillooet River and on the northern flank of the Mount Meager massif. It is named after Plinth Peak, a peak made of Plinth Assemblage rocks. This geological formation is one of the largest comprising the Mount Meager massif. Formed during an onset of volcanic activity about 100,000 years ago, the Plinth Assemblage consists of light grey porphyritic rhyodacite with phenocrysts of plagioclase, quartz, minor biotite and rare hornblende. The of Mount Meager itself is made of Plinth Assemblage rocks and was the southern source of Plinth Assemblage lava flows and breccias. The Plinth Assemblage represents a minor portion of the Pacific Ranges of the southern Coast Mountains. See also *Job Assemblage *Mosaic Assemblage * Capricorn Assemblage *The Devastator Assemblage *Pylon Assemblage *Volcanism of Western Canada *Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capricorn Assemblage
The Capricorn Assemblage, also known as the Capricorn Formation, is a geological formation comprising the central portion of the Mount Meager massif in southwestern British Columbia, Canada. It is named after Capricorn Mountain, the third highest subsidiary peak of Meager. The assemblage was formed during a period of volcanic activity about or less than 90,000 years ago. Weathered rhyodacite is the main volcanic rock comprising the Capricorn Assemblage. It forms the final of Capricorn Mountain and Mount Job. The rhyodacite is characterized by phenocrysts of plagioclase, quartz and biotite. Capricorn Assemblage rhyodacite underlies Plinth Assemblage rhyodacite on the south flank of Plinth Peak. See also *Mosaic Assemblage *Job Assemblage *The Devastator Assemblage *Pylon Assemblage *Volcanism of Western Canada *List of Cascade volcanoes *List of volcanoes in Canada List of volcanoes in Canada is an incomplete list of volcanoes found in Mainland Canada, in the Canadian isla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Job Assemblage
The Job Assemblage is a geological formation comprising a portion of the Mount Meager massif in southwestern British Columbia, Canada. It is named after Mount Job, a subsidiary peak of Meager. The rock unit was formed during a period of rhyodacite volcanism during the Pleistocene epoch. Around Mount Job, rhyodacite contains hornblende, biotite and quartz. On the east side of the Affliction Glacier, rhyodacite of the Job Assemblage overlies porphyritic andesite of the older Pylon Assemblage. The more recently formed Capricorn Assemblage overlies the Job Assemblage at the head of Affiction Glacier and Capricorn Glacier. See also *List of Cascade volcanoes *List of volcanoes in Canada *Mosaic Assemblage *Plinth Assemblage *The Devastator Assemblage *Volcanology of Western Canada Volcanism of Western Canada has produced lava flows, lava plateaus Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaic Assemblage
The Mosaic Assemblage is a rock unit of the Pacific Ranges of the Coast Mountains in southwestern British Columbia, Canada. It is the namesake of Mosaic Glacier, which is drained by Mosaic Creek. This geological formation formed 140,000 to less than 90,000 years ago when porphyritic plagioclase-augite-olivine basalt and trachybasalt was erupted in valleys and on mountain ridges. These volcanic rocks form scoriaceous lava flows, breccias, volcanic bombs and pillow lavas. The location of the Mosaic Assemblage is sparse, being present just north of the Lillooet River, south of and in upper Meager Creek and between Job Creek and Mosaic Creek. Because these four areas are well apart, each area probably has its own volcanic vents. Small patches of the Mosaic Assemblage overlie The Devastator Assemblage and form minor portions of the Mount Meager massif. See also *Job Assemblage *Plinth Assemblage * Capricorn Assemblage *Pylon Assemblage *Volcanism of Western Canada *List of Cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Plug
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption. In a plinian eruption the plug is destroyed and ash is ejected. Glacial erosion can lead to exposure of the plug on one side, while a long slope of material remains on the opposite side. Such landforms are called crag and tail. If a plug is preserved, erosion may remove the surrounding rock while the erosion-resistant plug remains, producing a distinctive upstanding landform. Examples of volcanic plugs Africa Near the village of Rhumsiki in the Far North Province of Cameroon, Kapsiki Peak is an example of a volcanic plug and is one of the most photographed parts of the Mandara Mountains. Spectacular volcanic plugs are present in the center of La Gomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
