ABSTRACT

Quartz cement content is often difficult to quantify using conventional petrography. Developments in equipment and technique reported here show how excellent, high-contrast images of quartz cements can be produced using combined scanning electron microscopy and cathodoluminescence (SEM/CL). In most cases quartz cement can be differentiated readily from detrital quartz. Image analysis allows the percentage of authigenic quartz to be quantified. Advantages of this method are: (1) it can be readily automated; (2) backscatter electron (BSE) and CL images can be compared directly; and (3) images can be improved through acquiring and integrating multiple images.

Comparison of results from conventional optical petrography with those from SEM/CL suggests that the percentages of quartz cement determined by conventional methods are overestimated where quartz cement is present in high proportions and are underestimated where quartz cement is less abundant. By adopting a statistically rigorous approach to image collection, the abundance of quartz cement can be determined by SEM/CL with a known accuracy.