Observations on the micro-texture and ESR spectra of quartz from fault gouge

Abstract

We have investigated fault gouge samples from a variety of sites in eastern China with ESR, optical and scanning electron microscopy (SEM), X-ray diffraction and carthodoluminescence. The results reveal two different types of quartz, a microcrystalline and a microcyrstalline variety. The microcrystalline samples show increasing ESR intensities of the E' centre with increasing grain size whilst the microcrystalline samples show the opposite trend. We also found that the dissolution of quartz grains and secondary quartz precipitaiton on the surface of the grains is significant in some samples, indicating active chemical weathering in these fault zones. The occurrence of secondary quartz has serious implications for the reliability of any dating attempt. Show more