Figure 5. Compositional variation diagrams for whole-rock samples of Eocene ash-flow tuffs of northeastern Nevada. Data are from this study (Table 2) and Mueller (1992), Brooks et al. (1995a, 1995b), and Wallace (2003a). Major elements normalized to 100% volatile-free. (A) SiO2/Na2O+K2O. (B) SiO2/TiO2. (C) SiO2/P2O5. (D) Zr/Nb. (E) Zr/TiO2.