An integrated petrochemical and geophysical view into the processes creating the Central Andes Cº Galán Caldera System.

MAHLBURG KAY, S.; COIRA, B.; CALIXTO, F.; HEIT, B.; YUAN, X.

Selfoss

Conferencia; Chapman Conference on: Large-Scale volcanism in the Arctic: The role of the Mantle and Tectonics.; 2019

American Geophysical Union

The 6-2 Ma Cerro Galán caldera system erupted one of the world´s classic giant monotonous intermediate dactitic/rhyolitic ignimbrite sequences. Chronological, geochemical and seismic studies provide an integrated view into the processes that produced this system whose ultimate origin is tied to steepening of the subducting Nazca slab and lithospheric delamination.The eruptions reflect a 6 my magma buildup in the crust that is punctuated by increasingly larger eruptions of pumice-rich, cristal-poor ignimbrites (Toconquis Group: 8 to 35 km3 at 6.4 to 5.5 Ma; 190 km3 at 4.8 Ma; 390 km3 at 4.7 Ma) that precede the climatic 630 km3 eruption of the cristal-rich, pumice-poor Galán ignimbrite at 2.126-2.056 Ma (see Folkes et al., 2011; Kay et al. 2011).