The research of TL background radiation for modern debris flow materials in white river basin Beijing

The TL background radiation of the modern debris flow materials of KeTai and XiBaiLianYu Gully, which in White River Basin of Beijing, was studied using the thermo luminescence technology. The research indicates that the thermo luminescence signal of debris flow materials reduced obviously in the process of flow. The average equivalent doses of the provenance, circulation area and the accumulation area are respectively 63.19, 52.42 and 49.54 Gy. Because of the light fading, the surface sample's background radiation is less than that of the samples 5∼10 cm from the surface. The residual background radiation of the surface debris flow material in White River Basin is between 11.2 to 28.5 ka and the result provides a foundation for using thermo luminescence technology to date old debris flow. (authors)