The use of ArcGIS for determination of quartz optical axis orientation in thin section images

In this paper, a new toolbox for petrographic thin section analysis is presented. It was designed using ArcGIS ModelBuilder to extract quartz grain boundary and determine its optical axis orientation from a set of thin section images. It can perform these analyses with little or no operator intervention and convert the boundary and optical axis data into a digital database with preserved spatial relationship. In order to test the validity of toolbox's outputs, an assessment was performed using three natural quartzite thin sections. The results indicate a close relationship (>0.8) between manual and model‐base extraction of grain boundary and optical axis orientation data. This study demonstrates the feasibility and usefulness of performing thin section image analysis within the GIS framework.