The problem of rock assimilation by Somma-Vesuvius magma

摘要: Mineralogical and chemical compositions of ejected carbonate inclusions Vesuvian gaseous phase are compared with those sediments the Somma-Vesuvius area. The basement Vesuvius mainly consists Mesozoic limestones. Most these characterized by extremely low insoluble residues. In this area thick dolomite beds occur in Triassic system only. A calcareous layer approximately 100 to 150 meters thickness high Sr contents (0.19% average) is be found within dolostones. Several ejecta also show (0.1% Sr) but composition some differs somewhat from that Sr. Contact volcanic volatile melt has produced alterations many ejecta. Magnesian calcites abundant periclase, brucite, tremolite, phlogopite magnesite were examined. Silicon, manganese, iron, zinc and, a smaller extent, potassium copper have been most probably transported gas into inclusions. Owing metasomatic actions components, rearrangement alteration Ca Mg occurred minerals several Under influence pressure temperature, magnesium content originally might transformed calcite structure. \(\frac{{{\text{MgO}}}}{{{\text{CaO + MgO}}}}\) molar ratios do not correspond sedimentary limestones It cannot proved whether mixed calcite-dolomite partially introduced volatiles or lost phases.