Aliso (volcano)

Aliso, also known as Pan de Azúcar, is a 3,482-metre-high (11,424 ft) volcano in the Ecuadorian Andes to the east of Antisana volcano. The complex contains a semicircular western ridge and lava domes. The volcano has erupted rhyolites and dacites and some andesitic lava flows on a ridge above Baeza. It is covered with tundra and cloud forests. At least two eruptions of Pumayacu occurred during the Holocene; one dated 4400 years ago and another's lapilli deposits overlie a cultural horizon 2000 years old.[1] Older eruptions have been dated at 1.15 ± 0.07 Ma and are of high-potassium types. They compromise typical arc-derived lavas with fractional crystallization and other differentiation processes.[2]

References

1. "Aliso". Global Volcanism Program. Smithsonian Institution.
2. Le Voyer, Marion; Rose-Koga, Estelle F.; Laubier, Muriel; Schiano, Pierre (2008). "Petrogenesis of arc lavas from the Rucu Pichincha and Pan de Azucar volcanoes (Ecuadorian arc): Major, trace element, and boron isotope evidences from olivine-hosted melt inclusions". Geochemistry, Geophysics, Geosystems. 9 (12): n/a–n/a. doi:10.1029/2008GC002173. ISSN 1525-2027.