ABSTRACT

Some quartzose beach sands, collected from the northern part of Niigata district, were examined by thermoluminescence color image (TLCI) analyses. Analyses were performed after purification of the quartz fraction by magnetic separation. Purified samples underwent chemical etching followed by gamma-ray irradiation. The proportion of red TL-emitting grains to blue ones seems to be related to the origin of the respective beach sands. Red TL grains are tentatively attributable to a volcanic dominated source, whereas the blue ones are mainly weathering products of plutonic rocks such as granite. TL-spectrophotometric analyses have been attempted to obtain more quantitative information on the TL-emission of the two different colors for these beach sands. The intensity ratios of red to blue TL were evaluated from analyses of respective glow-curves, corresponding to different wavelength regions. The ratios were concordant with the TLCI parterns. The applications of TLCI and TL-spectrophotometry to geological and archaeological samples are also suggested.