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Hoodoo Mountain is a potentially active flat-topped stratovolcano in the Stikine Country of northwestern British Columbia, Canada, located northeast of Wrangell, Alaska on the north side of the lower Iskut River and east of its junction with the Stikine River. It is situated in the Boundary Ranges of the Coast Mountains and has been in existence since the Late Pleistocene stage of the Pleistocene epoch, which began 130,000 years ago and ended 10,000 years ago. The mountain gets its name from the needle-like lava spines or hoodoos that reach heights of , which give the volcano a strange appearance. This appearance makes Hoodoo Mountain different from other neighbouring mountains in the Boundary Ranges. The volcano boasts an ice cap on its summit, and radar imaging of the rock beneath the ice has shown that the mountain's flat-topped summit is not just attributable to the ice cap, but the top of the mountain is flat as well. Beneath the summit ice cap lies an ice-filled volcanic crater that rises at an elevation of and a topographic prominence of . Except for minor irregularities caused by erosion, any contour line drawn is practically a circle. Hoodoo Mountain consists of a balanced lava dome in diameter and throughout most of its history, it has been influenced by glacial ice, causing several periods of subglacial eruptions and interactions between volcanic activity and ice sheets. This volcanic process has created Hoodoo's structure and stratigraphy similar to subglacial volcanoes. ==Geography and geology== Hoodoo Mountain lies on the southern axis of the Northern Cordilleran Volcanic Province, a large line of volcanoes extending from the Alaska-Yukon border to a point near Prince Rupert, British Columbia. The region in turn is part of the Pacific Ring of Fire, a seismically active region that encircles the Pacific Ocean and contains some of the world's most active volcanoes. The Northern Cordilleran Volcanic Province is produced by continental rifting as the Pacific Plate slides northward along the Queen Charlotte Fault, on its way to the Aleutian Trench, which extends along the southern coastline of Alaska and the adjacent waters of northeastern Siberia off the coast of Kamchatka Peninsula. As the continental crust stretches, hot magma rises and the near-surface rocks fracture along steeply graduated cracks parallel to the rift known as faults. Like many other rift-related volcanoes, Hoodoo Mountain generates passive and occasionally explosive eruptions. Hoodoo Mountain is one of the three large compositionally diverse volcanoes of the Northern Cordilleran Volcanic Province along with the Mount Edziza volcanic complex and Level Mountain. The overall flat-topped topography of Hoodoo Mountain led Canadian volcanologist Jack Souther to refer Hoodoo Mountain as a tuya, which are flat-topped, steep-sided subglacial volcanoes formed when lava erupts through a thick glacier or ice sheet.〔 However, Hoodoo Mountain does not fit the normal tuya model because of its complex layering of rocks, although Hoodoo's unusual structure obviously results from frequent interactions between volcanic activity and Pleistocene ice sheets over the past 100,000 years.〔 Hoodoo Mountain contains at least two sets of prominent cliffs, producing a discontinuous, step-like topographic profile.〔 The base of Hoodoo Mountain is largely delimited by a series of cliffs that range from to high, while Hoodoo's southeastern flank is relatively gentle.〔 Here, lava flows from the most recent volcanic activity cover earlier topography; the southeastern flank is smooth from around the summit to the Iskut River.〔 The top of the lower cliff ring defines a broad bench with an elevation of about that terminates against an upper set of cliffs.〔 The seconed set of vertical cliffs is between and high and surrounds the summit.〔 A prominent dike, known as The Monument, rises more than in elevation on Hoodoo's southwestern flank and is the remnants of a volcanic vent surrounded by thick deposits of lava and breccia formed during subglacial eruptions.〔 Hoodoo Mountain lies in an area of high elevation ecosystems colonizing very erodible substrate.〔(【引用サイトリンク】url=http://www.env.gov.bc.ca/skeena/pas/hoodoo.htm ) 〕 The mountain is generally poorly forested due to its high altitude and remote alpine location. This mountainous terrain has made Hoodoo Mountain a site for alpine tundra. Even though alpine tundra lacks trees, Hoodoo's lower flanks contain mountain hemlock.〔 Because alpine tundra is located in various widely-separated regions on Earth, there is no animal species common to all areas of alpine tundra. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Hoodoo Mountain」の詳細全文を読む スポンサード リンク
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