Introduction

The most important applications of cathodoluminescence imaging to description and interpretation of sedimentary rocks are presented in modest detail in preceding chapters. Additional, less common, uses of CL in study of sedimentary rocks are discussed briefly in this chapter. These miscellaneous applications include CL study of recent and fossils shells (skeletal petrology), evaluation of the CL characteristics and significance of nonskeletal apatite, economic applications such as the use of CL to study petroleum reservoirs and sedimentary ore deposits, application to study of archeological materials, and use of CL to investigate characteristics of very old (Precambrian) sedimentary rocks.

Skeletal petrology

As mentioned in the discussion of carbonate petrology in Chapter 6, numerous workers have used CL imaging to study carbonate fossils because CL images commonly show skeletal outlines and internal details more clearly than do optical images. See, for example, Figure 6.4. cathodoluminescence can be particularly useful in identifying poorly preserved fossils. Barbin (1995, 2000) provides an extensive list of references dealing with application of CL to delineation of skeletal details and identification of fossils. Most CL studies of fossils have been applied to carbonate fossils; however, CL is also useful for studying skeletal material composed of apatite (francolite) and silica (e.g., Richter et al., 2003).

Carbonate skeletons

In addition to its use in skeletal morphology and fossil identification, CL is being used to search for ontogenetic (development stages in growth of individual organisms) and paleoenvironmental records in skeletal organisms, as well as investigation of how CL patterns differ between biochemical and diagenetic CL emissions.