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Crevasse Crag
Crevasse Crag is a jagged steep-sided prominence on the summit of a glaciated mountain ridge in the Lillooet Ranges of southwestern British Columbia, Canada. It is located about southeast of the village of Pemberton. Situated on the boundary between New Westminster Land District and Kamloops Division Yale Land District, the peak has a maximum elevation of and a topographic prominence of . The name of the peak was adopted on March 31, 1969 as submitted by climber Christian Adam. It is named after the large crevasse directly below its north ridge. Prior to its adoption in 1969, Crevasse Crag was climbed by Adam et al. on August 16, 1967. Technically, Crevasse Crag is the remains of an extinct volcano that formed during the onset of Pemberton Belt volcanism 16 million years ago. This activity produced breccias, tuffs and plagioclase- phyric flows, all of which form the present day edifice of Crevasse Crag. Analyses of major, trace and rare-earth elements indicate that dacite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, forests, lakes, mountains, inland deserts and grassy plains, and borders the province of Alberta to the east and the Yukon and Northwest Territories to the north. With an estimated population of 5.3million as of 2022, it is Canada's third-most populous province. The capital of British Columbia is Victoria and its largest city is Vancouver. Vancouver is the third-largest metropolitan area in Canada; the 2021 census recorded 2.6million people in Metro Vancouver. The first known human inhabitants of the area settled in British Columbia at least 10,000 years ago. Such groups include the Coast Salish, Tsilhqotʼin, and Haida peoples, among many others. One of the earliest British settlements in the area was Fort Victoria, established ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rare-earth Element
The rare-earth elements (REE), also called the rare-earth metals or (in context) rare-earth oxides or sometimes the lanthanides (yttrium and scandium are usually included as rare earths), are a set of 17 nearly-indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare earths have diverse applications in electrical and electronic components, lasers, glass, magnetic materials, and industrial processes. Scandium and yttrium are considered rare-earth elements because they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties, but have different electronic and magnetic properties. These metals tarnish slowly in air at room temperature and react slowly with cold water to form hydroxides, liberating hydrogen. They react with steam to form oxides, and at elevated temperature (400°C) ignite spontaneously. These elements and their compounds have no biological function other than in several specialized enzymes, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct 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, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene Volcanoes
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subduction Volcanoes
Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with the average rate of convergence being approximately two to eight centimeters per year along most plate boundaries. Subduction is possible because the cold oceanic lithosphere is slightly denser than the underlying asthenosphere, the hot, ductile layer in the upper mantle underlying the cold, rigid lithosphere. Once initiated, stable subduction is driven mostly by the negative buoyancy of the de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-thousanders Of British Columbia
Two-thousanders are mountains that have a height of at least 2,000 metres above sea level, but less than 3,000 metres. The term is used in Alpine circles, especially in Europe (e.g. German: ''Zweitausender''). The two photographs show two typical two-thousanders in the Alps that illustrate different types of mountain. The Säuling (top) is a prominent, individual peak, whereas the Schneeberg (bottom) is an elongated limestone massif. In ranges like the Allgäu Alps, the Gesäuse or the Styrian-Lower Austrian Limestone Alps the mountain tour descriptions for mountaineers or hikers commonly include the two-thousanders, especially in areas where only a few summits exceed this level. Examples from these regions of the Eastern Alps are: * the striking Nebelhorn (2,224 m) near Oberstdorf or the Säuling (2,047 m) near Neuschwanstein, * the Admonter Reichenstein (2,251 m), Eisenerzer Reichenstein (2,165 m), Großer Pyhrgas (2,244 m) or Hochtor (2,369&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of British Columbia
British Columbia is the westernmost province of Canada, bordered by the Pacific Ocean. With an area of it is Canada's third-largest province. The province is almost four times the size of the United Kingdom and larger than every United States state except Alaska. It is bounded on the northwest by the U.S. state of Alaska, directly north by Yukon and the Northwest Territories, on the east by Alberta, and on the south by the U.S. states of Washington, Idaho, and Montana. Formerly part of the British Empire, the southern border of British Columbia was established by the 1846 Oregon Treaty. The province is dominated by mountain ranges, among them the Canadian Rockies but dominantly the Coast Mountains, Cassiar Mountains, and the Columbia Mountains. Most of the population is concentrated on the Pacific coast, notably in the area of Vancouver, located on the southwestern tip of the mainland, which is known as the Lower Mainland. It is the most mountainous province of Canada. Statist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Survey Of Canada
The Geological Survey of Canada (GSC; french: Commission géologique du Canada (CGC)) is a Canadian federal government agency responsible for performing geological surveys of the country, developing Canada's natural resources and protecting the environment. A branch of the Earth Sciences Sector of Natural Resources Canada, the GSC is the country's oldest scientific agency and was one of its first government organizations. History In September 1841, the Province of Canada legislature passed a resolution that authorized the sum of £1,500 sterling be granted to the government for the estimated expense of performing a geological survey of the province. In 1842, the Geological Survey of Canada was formed to fulfill this request.Christy Vodden (1992)No Stone Unturned: The First 150 years of the Geological Survey of Canada Geological Survey of Canada Web site William Edmond Logan was in Montreal at the time and made it known that he was interested in participating in this survey. G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intrusive Rock
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form ''Igneous intrusion, intrusions'', such as batholiths, dike (geology), dikes, Sill (geology), sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March 27, 2017.Igneous intrusive rocks, accessdate: March 27, 2017.Britannica.comintrusive rock , geology , Britannica.com accessdate: March 27, 2017. Intrusion is one of the two ways igneous rock can form. The other is extrusive rock, extrusion, such as a Types of volcanic eruptions, volcanic eruption or similar event. An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet. In contrast, an ''extrusion'' consists of extrusive rock, formed above the surface of the crust. Some geologists use the term plutonic rock synonymously with intrusive rock, but other geologists subdivide intrusive rock, by crystal size, into coarse-grai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basaltic Andesite
Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central America and the Andes of South America. Description Basaltic andesite is a fine-grained (aphanitic) igneous rock that is moderately low in silica and low in alkali metal oxides. It is not separately defined in the QAPF classification, which is based on the relative percentages of quartz, alkali feldspar, plagioclase feldspar, and feldspathoids, but would fall in the basalt-andesite field. This corresponds to rock in which feldspathoid makes up less than 10% and quartz less than 20% of the total QAPF fraction, and in which at least 65% of the feldspar is plagioclase. Basaltic andesite would be further distinguished from basalt and andesite by a silica content between 52% and 57%. Although classification by mineral content is preferred by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andesite
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende. Andesite is the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic. Along with basalts, andesites are a component of the Martian crust. The name ''andesite'' is derived from the Andes mountain range, where this rock type is found in abundance. It was first applied by Christian Leopold von Buch in 1826. Description Andesite is an aphanitic (fine-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
