miércoles, 16 de mayo de 2007

Lanín volcano

Argentina (on the border with Chile actually) also has a volcano and has the typical symmetric volcano shape as well

"Lanín is a large conical late-Pleistocene to Holocene stratovolcano along the Chile-Argentina border. The dominantly effusive basaltic-to-trachydacitic volcano lies at the eastern end of a NW-SE-trending volcanic group beginning with Villarrica that is transverse to the Andean chain. The beautifully symmetrical, 3737-m-high Lanín rises 2500 m above its base; shoulder areas on the upper flanks hint at a buried caldera. The volcano was formed in four eruptive stages dating back to the early Pleistocene or late Pliocene. The last two stages occurred during the late-Pleistocene and Holocene. A small lava dome at the summit fed blocky lava flows to the north about 2200 years ago. Lanín was reported active after an earthquake in 1906, but Sapper (1917) stated that newspaper accounts are strongly disputed, and no historical eruptions are known. A postglacial tuff ring (Volcán Arenal) is located below the SW flank of Lanín in Argentina. A younger lava flow from Lanín covers deposits of Volcán Arenal and extends south into Lago Paimún."

Source