Английская Википедия:Guaichane-Mamuta
Шаблон:Short description Шаблон:Coord missingGuaichane-Mamuta is a volcano in Chile. It is formed by a caldera and lava flows which form two separate systems. The volcano is of Miocene age.
Guaichane-Mamuta lies Шаблон:Convert northeast of Pisagua. One half is formed by the Шаблон:Convert wide and Шаблон:Convert deep erosion caldera of Mamuta, which rises to an altitude of Шаблон:Convert. The other half,Шаблон:Sfn southeast of Mamuta,Шаблон:Sfn is the Guaichane half and is constructed by four different units of andesite-basaltic andesite lava flows; these include Cerro Churicoyo (Шаблон:Convert), Cerro Colorado (Шаблон:Convert), Cerro Guaichane (Шаблон:Convert) and Cerro Limpire.(Шаблон:Convert)Шаблон:Sfn
Guaichane-Mamuta is constructed on the mid-Miocene Altos de Nama formation, which is formed by ignimbrites. Mamuta itself was also the origin of ignimbrites. Older pyroclastics from the same centre contain phenocrysts of clinopyroxene, olivine, orthopyroxene and plagioclase.Шаблон:Sfn
Mamuta is a volcano among a group of Miocene age stratovolcanoes on the western slope of the Andes. These are usually only partially eroded, although preferential erosion of the volcanos' central parts can cause the appearance of erosion calderas.[1]
Three ages have been obtained on Mamuta, 8.8±0.5, 9.1±0.6 and 14.5 million years ago. The younger ages are considered more reliable.[1] The older date was obtained on the Mamuta caldera. Ages obtained on Guaichane are 11.3±0.5 and 10.2±0.8 million years ago.Шаблон:Sfn
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