Genesis of Roccastrada volcanic rocks (central Italy): inferences from melt inclusions analyses

Melt inclusions analyses were carried out on quaternary rhyolitic rocks from Roccastrada volcano (Tus cany, central Italy). The data confirm the anatectic origin for the magma that gave rise to the Roccastrada volcanism and evidenced no involvement of basic component in the petrogenesis of these melts. Similar compositions of melt incl usions trapped in phenocrysts and of residual glass matrix of Roccastrada rhyolites, suggest that these melts did not undergo to important differentiation processes after their generation. Quartz, sanidine, plagioclase and cordieri te cryst alli zed from peral ominous melts, at temperatures in the range of of 755-820°C, and at pressure of about 150-180 MPa.