Multiple Electron Beam Analyses Applied to Eclogite from the Western Alps

 The occurrence of compositional and microtextural relics within metamorphic rocks can provide useful information on the pressure-temperature history of the host rock. The grain-size of these microstructures, such as coronitic reaction microtextures, is mostly too fine to be detected by optical microscopy. Therefore, a more detailed analytical approach is needed. In this paper multiple electron beam techniques including the acquisition of X-ray multi-element maps, micro and nano-analysis performed by SEM/EDS and TEM/STEM-EDX systems were applied to a specific petrological problem related to metamorphism. Fine-grained decompressional reaction microtextures of an eclogitic sample (Mt. Rosa Nappe, Western Alps) are described and discussed.