Stop 24: Purico Complex (Overview)

 

The 1.3 My Purico complex is a ~circular apron of ignimbrites and summit domes overlying older ignimbrites from the La Pacana caldera (4.5-4.1 My). The summit domes overly the ignimbrites and can be characterized as flat "torta" domes (Dome D) or conical Pelean domes (Cerros Purico, Negro, Putas, Chascon, Aspero, and El Cerrillo). The ages of the domes are not available. However, Chascon, Aspero, and El Cerrillo are all post-glacial and therefor less than 0.5 M.

Figures from Schmitt et al. (2001).

Dome D is compositionally similar to the Purico ignimbrite and probably represents the same magma degassed, whereas, post-glacial domes commonly contain mafic enclaves and show signs of magma mixing. These post-glacial domes are of particular interest because the magmatic components (i.e. mafic enclaves) within the domes may be the components responsible for the formation of the APVC. See following stops for more information on the individual domes.

Purico Dome

Image is the Cerro Purico dome