Along-arc Compositional Variations

Different roles for fluids and silicate melts were suggested by Francalanci et al. (1993b) on the basis of trace element data. These authors argued that an increased fluid/melt ratio in the metasomatic modifications 

Sr-Nd-Pb isotope variation along the Aeolian arc represents a part of a larger hyperbolic array connecting the Na-alkaline rocks of Etna-Iblei-Ustica and Tuscany (Figs. 7.6, 7.17). Most of the western and central Aeolian islands plot near to the low-Sr, high-Nd-Pb end-member, whereas the Stromboli volcanics plot away from Etna together with Campanian volcanoes and Emici-Roccamonfina KS rocks. However, the isotopically most primitive rocks from Alicudi have low Sr-isotopic ratios that fall outside the trend (Fig. 7.17). 

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