There are many observational technologies that can be used to supplement or quantify optical petrographic observations. Some apply directly to light microscopy (staining, for example), some are done with light microscopes but require specialized additional equipment (fluid inclusion geothermometry, some forms of cathodoluminescence and fluorescence microscopy), and others require completely different and typically more expensive instrumentation (SEM/TEM, microprobe/ion probe, X-ray computed tomography and many others). Examples of output from some of the most common and best established of these techniques have already been shown and referenced throughout this book (e.g., staining, fluorescence, SEM and backscattered electron imaging) and so will not be further illustrated here, although useful summary and case-study references are provided at the close of this chapter. One well established technique, cathodoluminescence, has undergone new instrumentation developments, including diversification from light microscopes to scanning electron microscopes, and so it will be featured in this chapter along with two other relatively new and promising imaging and analysis technologies, including X-ray computed tomography, grouped here under the term “digital rock physics”. These technologies are evolving rapidly and the descriptions in this chapter will soon be superceded by new developments. Nonetheless, they should serve to show readers to the potential of such technologies to enhance petrographic investigations.
Figures & Tables
AAPG Memoir 109 is designed as a practical guide for students and professionals to learn the fundamentals of microscopic examination of sandstones, mudrocks, and associated rocks. With more than 1100 color illustrations, it covers the identification of grains, textures, and structures of clastic terrigenous rocks as well as their diagenetic alteration (compaction, cementation, dissolution, and replacement) and porosity reduction or enhancement. It also provides classification diagrams for formal description of those rocks and their porosity. Although the majority of the outcrop and subsurface examples come from the United States (35 states and Puerto Rico), there are representative photographs from 32 other countries, including many from the offshore areas. The foldout birefringence chart and an included DVD with Powerpoint files of all of the petrographic images provide additional aids for instructors and students.