|
Black Butte is a stratovolcano (not a cinder cone) west of Sisters, Oregon in Deschutes National Forest. Black Butte looks young, as it is barely eroded (except for little gullies a little bit above the base that were carved by long-gone streams). Mount Washington, which is visible from the summit of Black Butte, looks much more eroded, and older, than Black Butte. However, Black Butte is significantly older than Mount Washington which was eroded by glaciers, but Black Butte is east of the Cascade crest and does not receive enough precipitation to support glaciers, so erosion is minimal). It is an extinct volcano composed of basaltic andesite. The cone rises over the surrounding plateau. Black Butte is a striking feature just north of US Highway 20, which descends from the east flank of the Cascades. It is nearly symmetrical,〔 〕 with no marks of glaciation. Even though it is older than the High Cascades mountains visible to the west, which are heavily scoured by ice-age glacier activity, Black Butte receives less snow at its lower elevation and location east of the High Cascades. The headwaters of the Metolius River flow from Metolius Springs near the northern base of Black Butte.〔 The spring flows at a consistent rate of per minute.〔 〕 In the local indigenous tongue, the mountain is called Turututu, but records show settlers calling it Black Butte as early as 1855.〔 Forest Service road 1110 climbs halfway up the mountain and a hiking trail continues to the summit.〔 (【引用サイトリンク】 Black Butte Trail )〕 At the summit, there are two fire lookout towers, one that was built in 1934 and is condemned, and another that was constructed in 1995 to replace the older one. The older is the taller of the two.〔 (【引用サイトリンク】 Black Butte Lookout )〕 ==See also== *Black Butte Ranch, Oregon 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「Black Butte (Oregon)」の詳細全文を読む スポンサード リンク
|