Texture Analysis of Quartz in a Granite Mylonite byEBSP-Orientation Imaging Microscopy

Abstract

The crystallographic preferred orientation (texture) of the quartz phase in a mylonitic leucogranite from the Santa Rosa mylonite zone was investigated using automated analysis of electron backscattering patterns (EBSP) in the scanning electron microscope (SEM). The separation of the quartz diffraction patterns from patterns of other constituents (feldspar, mica, etc.) in this polymineralic rock was achieved using an image quality parameter. The quartz phase displays a texture typical for high temperature mylonites (c-axis maximum in the intermediate strain direction). The misorientation distribution between next neighbors is dominated by Dauphine twins.