The Electron Microscope in Earth Sciences

Abstract

Over the last ten years the electron microscope has become well-established in mineralogical research and what used to be an exotic instrument has found its way into several geology departments. The rapidly growing literature on electron microscopy in mineralogy has recently been summarized (Wenk et al., 1976) and there is not much point in systematically reviewing progress of the last two years. Philosophy and techniques remained largely the same except that there is more emphasis on high resolution, and energy dispersive X-ray detectors have become standard attachments of electron microscopes. Instead I would like to use some examples studied at the Geology Department at Berkeley during the last few months to illustrate a variety of applications in materials which could not be investigated with conventional techniques such as light microscopy, standard chemical analyses and X-ray diffraction. Geology is a broad science which ranges from the study of crystal structures on the atomic scale to processes taking place during mountain building on the scale of the size of continents. The transmission electron microscope has been used in such diverse fields as crystallography, petrology, rock deformation, stratigraphy and environmental geology.