Abstract

Sandstone textures provide critical information for reservoir modeling and interpreting depositional processes. While loose sand textures are easy to describe, various authors have developed thin-section and image-analysis techniques to characterize lithified deposits that were assumed impossible to disaggregate successfully. These methods are effective but tedious, and are generally not feasible for processing many samples. We present a new methodology for disaggregating quartz-dominated sandstones cemented by quartz overgrowths, with application to the Permian Coconino Sandstone of northern and central Arizona, USA. Textural parameters of the disaggregated sand were measured using a laser diffraction particle analyzer. Our average grain sizes from laser analysis are coarser than those from thin section (as expected), but trends from the analyzer correlate well with thin-section results. This strong correlation strengthens the validity of both methods and suggests that disaggregation and whole-particle analysis may effectively replace petrographic techniques in many textural studies. We hope that our methods, which increase the efficiency of grain-size analysis, will expand the potential for collecting textural data from quartz-cemented sandstones.