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Elwyn Creek

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Elwyn Creek is a tributary of Mess Creek , which in turn is a tributary of the Stikine River in northwest part of the province of British Columbia , Canada. It flows generally west for about 25 km (16 mi) to join Mess Creek about 10 km (6.2 mi) north of Mess Creek's confluence with Taweh Creek . Elwyn Creek's watershed covers 173 km (67 sq mi) and its mean annual discharge is estimated at 3.34 m/s (118 cu ft/s). The mouth of Elwyn Creek is located about 16 km (9.9 mi) southeast of Telegraph Creek , about 60 km (37 mi) west-southwest of Iskut and about 93 km (58 mi) southwest of Dease Lake . Elwyn Creek's watershed's land cover is classified as 37.9% shrubland , 30.3% conifer forest , 15.2% barren , 7.6% snow/glacier, 7.1% herbaceous , and small amounts of other cover.

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21-625: Elwyn Creek is in Mount Edziza Provincial Park which lies within the traditional territory of the Tahltan people. Elwyn Creek originates in the middle of the Big Raven Plateau . From its source on the northwestern slope of Mount Edziza , Elwyn Creek flows about 4 km (2.5 mi) northwest past Tsekone Ridge and Pillow Ridge to the head of a vegetated canyon. It then continues to flow northwest through

42-704: A Western Union Telegraph expedition in 1866. Mount Edziza Provincial Park Mount Edziza Provincial Park is a provincial park in Cassiar Land District of northern British Columbia , Canada. It was established on 27 July 1972 to showcase the Mount Edziza volcanic complex and the surrounding Tahltan Highland . The park includes the Mount Edziza volcanic complex, a large group of overlapping shield volcanoes , stratovolcanoes , cinder cones , lava domes and calderas oriented in

63-441: A lava flow around the cone's base. When the eruption ends, a symmetrical cone of cinders sits at the center of a surrounding pad of lava. If the crater is fully breached, the remaining walls form an amphitheater or horseshoe shape around the vent. Basaltic cinder cones are the most characteristic type of volcano associated with intraplate volcanism . They are particularly common in association with alkaline magmatism , in which

84-443: A volcanic vent . The pyroclastic fragments are formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as either cinders, clinkers, or scoria around the vent to form a cone that often is symmetrical; with slopes between 30 and 40°; and a nearly circular ground plan. Most cinder cones have

105-486: A bowl-shaped crater at the summit. Cinder cones range in size from tens to hundreds of meters tall. They are composed of loose pyroclastic material ( cinder or scoria ), which distinguishes them from spatter cones , which are composed of agglomerated volcanic bombs . The pyroclastic material making up a cinder cone is usually basaltic to andesitic in composition. It is often glassy and contains numerous gas bubbles "frozen" into place as magma exploded into

126-534: A group of hot springs between elevations of 1,350 and 1,440 m (4,430 and 4,720 ft) called the Elwyn Hot Springs. They occur near the base of the Mount Edziza volcanic complex where basalt of the Nido Formation overlies Tertiary leucogranite . Thick deposits of tufa formed by the precipitation of calcite and aragonite occur at the Elwyn Hot Springs. In 1983, the springs had

147-454: A group of four young cinder cones NW of Las Pilas volcano. Since its initial eruption in 1850, it has erupted more than 20 times, most recently in 1995 and 1999. Satellite images suggest that cinder cones occur on other terrestrial bodies in the solar system. On Mars, they have been reported on the flanks of Pavonis Mons in Tharsis , in the region of Hydraotes Chaos on the bottom of

168-430: A larger area. Therefore, it seems that erupted amount of material is not sufficient on Mars for the flank slopes to attain the angle of repose and Martian cinder cones seem to be ruled mainly by ballistic distribution and not by material redistribution on flanks as typical on Earth. Cinder cones often are highly symmetric, but strong prevailing winds at the time of eruption can cause a greater accumulation of cinder on

189-566: A maximum temperature of 36 °C (97 °F). Their existence may be linked to a shallow hydrothermal system driven by residual magmatic heat from the recently active Desolation Lava Field about 6 km (3.7 mi) to the east. Elwyn Creek is the namesake of the Elwyn Creek Pluton. This is a body of intrusive rock at least 5 km (3.1 mi) wide exposed in Elwyn Creek canyon. The main intrusive rock comprising

210-582: A north−south trending line. It includes Mount Edziza at its northern end and the Spectrum Range at its southern end, both of which are within the boundaries of Mount Edziza Provincial Park. This British Columbia protected areas related article is a stub . You can help Misplaced Pages by expanding it . Cinder cone A cinder cone (or scoria cone ) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around

231-405: Is characterized by slumping and blasts that destroy the original rim, while the fourth stage is characterized by the buildup of talus beyond the zone where cinder falls to the surface (the ballistic zone ). During the waning stage of a cinder cone eruption, the magma has lost most of its gas content. This gas-depleted magma does not fountain but oozes quietly into the crater or beneath the base of

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252-728: The Coprates Chasma , or in the volcanic field Ulysses Colles . It is also suggested that domical structures in Marius Hills (on the Moon) might represent lunar cinder cones. The size and shape of cinder cones depend on environmental properties as different gravity and/or atmospheric pressure might change the dispersion of ejected scoria particles. For example, cinder cones on Mars seem to be more than two times wider than terrestrial analogues as lower atmospheric pressure and gravity enable wider dispersion of ejected particles over

273-648: The Late Miocene . The historic Yukon Telegraph Trail crosses Elwyn Creek in Mess Creek valley. It was built to serve the nearly 3,000 km-long (1,900 mi) Yukon Telegraph Line which was constructed by the Dominion Government Telegraph Service between 1897 and 1901 to send messages from Ashcroft, British Columbia in the south to Dawson City , Yukon in the north. The telegraph trail crosses other tributaries along

294-400: The Elwyn Creek Pluton is fine grained, slightly porphyritic leucogranite containing phenocrysts of sodic plagioclase . It is of Eocene age, having yielded a K–Ar date of 53.1 ± 2.4 million years. This suggests that the Elwyn Creek Pluton was formed by one of the youngest known igneous events in the Elwyn Creek area prior to the onset of volcanism of the Mount Edziza volcanic complex in

315-412: The air and then cooled quickly. Lava fragments larger than 64 mm across, known as volcanic bombs , are also a common product of cinder cone eruptions. The growth of a cinder cone may be divided into four stages. In the first stage, a low-rimmed scoria ring forms around the erupting event. During the second stage, the rim is built up and a talus slope begins to form outside the rim. The third stage

336-435: The canyon for about 5 km (3.1 mi) before flowing west inside the canyon for an additional 12 km (7.5 mi) to empty into Mess Creek. Elwyn Creek's only named tributary, Kadeya Creek , is about 10 km (6.2 mi) east of Elwyn Creek's confluence with Mess Creek. It is about 14 km (8.7 mi) long and flows northwest into Elwyn Creek from near the western side of Mount Edziza. Elwyn Creek contains

357-473: The cone as lava. Lava rarely issues from the top (except as a fountain) because the loose, uncemented cinders are too weak to support the pressure exerted by molten rock as it rises toward the surface through the central vent. Because it contains so few gas bubbles, the molten lava is denser than the bubble-rich cinders. Thus, it often burrows out along the bottom of the cinder cone, lifting the less dense cinders like corks on water, and advances outward, creating

378-823: The downwind side of the vent. Some cinder cones are monogenetic , forming from a single short eruptive episode that produces a very small volume of lava. The eruption typically last just weeks or months, but can occasionally last fifteen years or longer. Parícutin in Mexico, Diamond Head , Koko Head , Punchbowl Crater , Mt Le Brun from the Coalstoun Lakes volcanic field , and some cinder cones on Mauna Kea are monogenetic cinder cones. However, not all cinder cones are monogenetic, with some ancient cinder cones showing intervals of soil formation between flows that indicate that eruptions were separated by thousands to tens of thousands of years. Monogenetic cones likely form when

399-479: The eastern side of Mess Creek, including Crayke Creek about 6 km (3.7 mi) south of Elwyn Creek. Elwyn Creek was formerly called 14 Mile Creek which appeared on a BC Lands map published in 1929. Its current name was suggested by the BC Geographic Division to avoid duplication; it first appeared on maps in 1945. Elwyn Creek is named after Thomas Elwyn , a government agent who accompanied

420-589: The erupted lava is enriched in sodium and potassium oxides . Cinder cones are also commonly found on the flanks of shield volcanoes , stratovolcanoes , and calderas . For example, geologists have identified nearly 100 cinder cones on the flanks of Mauna Kea , a shield volcano located on the island of Hawaii . Such cinder cones likely represent the final stages of activity of a mafic volcano. However, most volcanic cones formed in Hawaiian-type eruptions are spatter cones rather than cinder cones, due to

441-510: The fluid nature of the lava. The most famous cinder cone, Paricutin , grew out of a corn field in Mexico in 1943 from a new vent. Eruptions continued for nine years, built the cone to a height of 424 meters (1,391 ft), and produced lava flows that covered 25 km (9.7 sq mi). The Earth's most historically active cinder cone is Cerro Negro in Nicaragua. It is part of

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