ESR and cathodoluminescence studies of radiation defects in clays and quartz from some U deposits

Clozel, B.*; Komuro, Kosei; Nakashima, Satoru*; Nagano, Tetsushi*; Masaki, Nobuyuki*; Hayashi, Hisato*

Rock samples from different world U deposits mainly in sedimentary rocks have been studied by Electron Spin Resonancc (ESR) spectroscopy and Cathodoluminescence (CL) measurement in order to characterize radiation damage centers in clays and quartz. The presence of kaolinite-like radiation centers ill ESR spectra in some of the samples containing kaolin group minerals suggests that this type of radiation damages can be used as an indicator of U behavior during supergene and hydrothermal alteration of U ores. Other clay minerals such as smectite and illite were not found to exhibit radiation damage centers by ESR. CL measurement on quartz grains iadicated the presence of radiation damage rims for the samples containing high U content. These rims can also be recognized for older samples with low U cocentration because of the longer contact of quartz with U. Although much more systematic studies are need for the reconstruction of the U behavior, these two methods have been proven useful for the characterization of radiation damage histories recorded in minerals.