Geochemistry is the study of how the Earth chemically changes and the composition of the material.
In the absence of isotopic data, modern CVZ arc dacites (63.5 to 68.5% SiO2) can be discriminated from the APVC flare-up dacites through incompatible trace elements such as Nb and Ta. Here the APVC flare-up related dacites (ignimbrites and post caldera domes) clearly define a high Nb trend broadly parallel with the arc dacite trend. Simple AFC curves for upper crust and lower crust are shown schematically. The 1600 eruption of Huaynpautina is an example of a major explosive arc-related dacite eruption (VEI ~6; de Silva, 2008). Uturuncu data (Sparks et al 2008) clearly shows an affinity with the APVC rather than the arc. Arc data filtered to include only obvious composite cone related compositions. Collaborative Research: Investigating the relationship between the pluton growth and volcanism at two active intrusions in the central Andes)