Geology and Minerals
El Laco
El Laco is a volcanic complex in the Antofagasta Region of Chile. It is directly south of the Cordón de Puntas Negras volcanic chain. Part of the Central Volcanic Zone of the Andes, it is a group of seven stratovolcanoes and a caldera. It is about two million years old. The main summit of the volcano is a lava dome called Pico Laco, which is variously reported to be 5,325 metres (17,470 ft) or 5,472 metres (17,953 ft) high. The edifice has been affected by glaciation, and some reports indicate that it is still fumarolically active. The volcano is known for its magnetite-containing lava flows of enigmatic origin. In total, there are four lava flows and two dykes, as well as a formation of uncertain nature. In addition to lava flow structures, pyroclastics containing iron oxide are also found within the complex. Whether the iron-rich lavas are native magnetite lavas or were formed by hydrothermal processes acting on regular rock is under debate. After their discovery in 1958, these iron deposits have been mined. The latest mining activity have been carried out by Compañía Minera del Pacífico from 1988 to 1996. Mining ended in 1996 as consequence of low price of iron in addition to the stop of purchases from Altos Hornos Zapla of Fabricaciones Militares in Argentina.< Similar deposits of volcanic iron oxide exist in Australia, Chile, and Iran.
Also on this shelf
Karl Cäsar von Leonhard.
Forest of Dean.
See also
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