Research Article

Evidence of Tectonic Control on the Geochemical Features of the Volatiles Vented along the Nebrodi-Peloritani Mts (Southern Apennine Chain, Italy)

Figure 6

CO2-3He relationships. CO2/3He vs. CO2 content (ml/l STP) (a) and (b) CO2/3He vs. [He]. The sample distribution on (a) shows trends of CO2 dissolution at variable extents (arrows) with almost constant 3He content. (b) Combines (a) with the information that helium isotopes do not denote simple crust/mantle mixes (see text); however, variable CO2/3He ratios at constant 3He/4He ratios are possible results of subsequent elemental fractionation. All error bars are within the symbol size. CO2/3He end members are in the range of (mantle-type volatiles) and crustal volatiles (vertical dashed lines). Symbols are as in Figure 2; labels not reported for a readable figure.