Microanalytical Characterization and Application in Magmatic Rocks

Abstract

Chemical characterization of magmatic rocks is a primary requirement in interpreting their evolutionary history. Magmatic rocks are nearly always heterogeneous and thus require micro-scale chemical characterization. Two of the main micro-characterization techniques are Scanning Electron Microscopy (SEM) and Electron Probe Micro Analysis (EPMA). Both are near surface characterization techniques and utilize the effects of interaction of an electron beam with the targeted sample. Back Scattered Electrons (BSE) represent an atomic number dependent elastic scattering effect which provides high resolution petrographic information of heterogeneities while generation of characteristic X-rays from inner shell energy-level transitions of different atoms, a type of inelastic scattering effect, provides quantitative chemical characterization at micron scale. Both are highly useful for describing magmatic rocks as well as inferring the operative magmatic processes.