Sanidine holocrystalline ejecta from central Sabatini Volcanic District, latium (Italy). I. Introduction and isotropic ejecta

The chemical analysis of main mineralogical constituents of the sanidine holocrystalline ejecta with isotropic texture found in the central area of the Sabatini Volcanic District leads to their petrological characterization. The application of the most advanced graphical geothermometers to coexisting feldspar pairs of various samples provides a temperature of equilibration ofT≤900°C. A chronologically intermediate event of vesiculation is evident in the crystallization sequence. Products of a peculiar late magmatic fluid circulation also occur.