closest to the surface (5–7 km depth) beneath the resurgent domes. Pie
diagrams compare the relative abundances of volatiles emitted from the
Yellowstone hydrothermal system (top) with the abundances of volatiles
dissolved in Yellowstone rhyolites (middle) and hotspot basalts (bottom).
The CO2-rich hydrothermal system appears to reflect the basaltdominated
crust below. The diagrams are constructed with data from
TABLE 1.