Thermoluminescence study of recently excavated river sediments from Tamilnadu, India

Thermoluminescence (TL) property of sediments from Vellar river which originates at Kalrayan hills of Salem district and terminates at the Bay of Bengal at Porto-Novo of Cuddalore district in Tamilnadu, has been studied. The samples of twenty seven sites were tested for natural thermoluminescence (NTL) and artificial thermoluminescence (ATL) studies. The NTL glow curve of all the samples shows only one peak at around 330 deg C. The sample irradiated with a gamma dose of 3.3 Gy and recorded with linear heating rate of 10 deg C/s shows additional peaks at around 135, 158 and 270 deg C. The TL intensity is found to decrease from origin to end point. The same trend is observed when the quartz samples are extracted from each site and from various grain sizes sieved samples. The TL intensity is the maximum at 300 and minimum at 53 μm grain size samples. The correlation made through FTIR and TL studies shows that the luminescence effect is found to decrease with decrease in grain sizes. (author)