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Rincón de la Vieja is an active andesitic complex volcano in north-western Costa Rica, about 25 km from Liberia, in the province of Guanacaste. Its name means "The Old Woman's Corner", a reference to a local legend about a girl whose lover was thrown into the crater by her father; she became a recluse living on the mountain, and was credited with powers of healing. Rincón de la Vieja stands above sea level, and its summit is the highest point in Rincón de la Vieja Volcano National Park. It erupted most recently in September 2011. The volcano has a large number of fumaroles and hot springs on its slopes. It is formed by felsic lava. Rincón de la Vieja is one of six active Costa Rican volcanoes: the others are Poás, Irazú, Miravalles, Arenal, and Turrialba. ==Geology== Rincón de la Vieja is a ridge-shaped massif, with several volcanic vents lying along a northwest-southeast axis. Several craters and peaks exist, with Santa María peak being the highest at 1916m above sea level. Von Seebach peak, 1895m above sea level, has been the site of most historical eruptions. Little is known about Rincón de la Vieja's early eruptive history. It lies within a larger caldera, which indicates that a very large eruption probably occurred thousands of years ago. Analysis of nearby pyroclastic flow deposits shows that they were erupted in a moderately large eruption about 3500 years ago, and the first recorded eruption of the volcano took place in 1765. Since then, many minor eruptions have occurred, the most recent in September 2011. They have mostly occurred at a crater near Von Seebach peak, and have been characterised by strombolian and vulcanian activity in which eruptions are confined to the crater, and ash is ejected to moderate heights. The active crater is currently filled with a hot, acidic crater lake.〔 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「Rincón de la Vieja Volcano」の詳細全文を読む スポンサード リンク
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