Evaluation of the petrogenetic significance of melt inclusions in pegmatitic schorl-dravite from graphic tourmaline-quartz assemblages: application of LA-ICP-QMS analyses and volume ratio calculations

The composition of melt inclusions in tourmaline was studied from graphic quartz-tourmaline intergrowth assemblages of common, muscovite – rare-element class pegmatites belonging to the lithium-caesium-tantalum family. This study applied laser ablation inductively coupled quadrupole mass spectrometry in combination with 2D and 3D microscopic volume calculation to analyse these unhomogenised melt inclusions. The determination of the analytical precision of the method is performed by repeated microscope-scanning and laser ablation analyses of tourmaline mineral inclusions in muscovite hosts for which the compositions have been independently measured by electron microprobe.