阳光晒退对泥石流表层物质热释光信号的影响

Influence of Thermoluminescence Signal for Debris Flow Surface Materials by Sunlight Bleaching

应用热释光技术对模拟阳光晒退后的泥石流标样和实际阳光晒退后的泥石流样品进行了热释光信号分层测定。实验结果表明:泥石流发生后经过曝光,样品积存热释光晒退程度随深度增加逐渐减弱,光晒退明显。光晒退随光照强度和时间增大而增强,深度增大,但深度变化总体不大。模拟的阳光晒退实验晒退深度达1mm左右,实际阳光晒退实验晒退深度达6mm左右。根据等效剂量随深度的变化可知,天然泥石流块状样由两次泥石流堆积形成。这一结果可为利用热释光技术开展泥石流测年和发生期次研究提供依据。

Thermoluminescence was utilized for measuring the thermoluminescence signals of the standard debris flow samples which were bleached by simulated sunlight and debris flow samples after real sunlight bleaching. The experiment results demonstrate that light bleaching phenomenon of the debris flow occurs when it experiences a period of exposure. The thermoluminescence signal of the samples weakens gradually with the increase of depth. The optical bleaching phenomenon is obvious. Within a certain depth, light bleaching phenomenon is enhanced with the increase of light intensity. The annealing depth of simulated sunlight bleaching experiment is about 1 ram, and the actual annealing depth of sunlight bleaching is about 6 mm. According to the equivalent dose variation with depth, the mud of natural debris flow can be divided into two stages. It has fundamental significance in the application of thermolurninescence dating techniques to divide the stages of debris flow sediments.