Light Microscopy and X-Ray Microanalysis of Inclusion Phases in Magmatic Minerals

摘要

Various inclusion phases of selected magmatic minerals (zircon, K-feidspar) were subjected to a comprehensive microscopical and microchemical analysis. As shown by the typical case of accessory zircon, magmatic minerals contain a wide spectrum of inclusion phases with different size and chemical composition. Whilst fluid inclusions are commonly composed of the two fluid phases H_2O and CO_2, melt inclusions are mainly represented by the amorphous forms of ZrSiO_4 enriched with high amounts of incompatible elements (Hf, U, Th, REE). Mineral inclusions embrace apatite, titanate, rutile, ilmenite and older inherited zircon grains. The analysis of inclusion phases essentially contributes to a better understanding of crystallisation sequences of mineral constituents in magmatic rocks. Furthermore, this investigation provides important information for geochronological studies.